LARRY LAFOON,
                                                 File No. 830047
                                               A R B I T R A T I O N
                                               D E C I S I 0 N
              Insurance Carrier,
                              STATEMENT OF THE CASE
              This is a proceeding in arbitration brought by claimant 
         Larry Lafoon against defendant employer Amhof Trucking, Inc., and 
         defendant insurance carrier Aetna Casualty & Surety Company to 
         recover benefits under the Iowa Workers' Compensation Act as the 
         result of an alleged injury sustained on August 8, 1986.  This 
         matter came on for hearing before the undersigned deputy 
         industrial commissioner in Davenport, Iowa, on May 31, 1989.  The 
         matter was considered fully submitted upon submission of two 
         depositions on June 5, 1989.
              The record in this proceeding consists of joint exhibits A 
         through D, defendants' exhibit 1, and the testimony at hearing 
         and by deposition of claimant.  The depositions of Peter S. 
         Jerome, M.D., and Phillip A. Habak, M.D., each taken May 26, 
         1989, have been identified as exhibits C and D.
              Pursuant to the prehearing report submitted by the parties 
         and approved at hearing, the following issues have been 
         stipulated:  that an employment relationship existed between 
         claimant and employer at the time of the alleged injury; that if 
         claimant has sustained compensable permanent disability, he has 
         suffered an industrial disability to the body as a whole; that 
         the appropriate rate of compensation is $244.18 per week; that 
         affirmative defenses are waived;
         Page 2
         that the fees charged for medical services and supplies are fair 
         and reasonable and incurred for reasonable and necessary medical 
              Issues presented for determination  include:  whether 
         claimant sustained an injury on August 8, 1986, arising out of 
         and in the course of his employment; whether the injury caused 
         temporary or permanent disability and the extent thereof; the 
         extent of claimant's entitlement to medical benefits; taxation of 
                              REVIEW OF THE EVIDENCE
              Claimant testified to being an over-the-road truck driver 
         employed by defendant for approximately six  months prior to 
         August 6, 1986.  He described that day as hot and humid, well 
         over 90 degrees Fahrenheit.  He left Iowa for the state of 
         Georgia with a full load of aluminum coils.
              Claimant indicated his first stop was in Smyrna, Tennessee, 
         and his second stop in Chattanooga, Tennessee.  At each stop 
         claimant broke down the sides, tarp (approximately 300 pounds), 
         and steel bows from his trailer for unloading, then reinstalled 
         the equipment.  His third stop was in Atlanta, Georgia, which he 
         reached approximately 5:00 p.m., about 24 hours after leaving 
         Davenport, Iowa.  He again broke down and reinstalled his 
         equipment in temperatures of approximately 100 degrees 
         Fahrenheit.  He thereafter went to a truck stop, called and 
         reported his status to defendant, and slept.
              On the following morning claimant was to find a return load 
         in Chattanooga.  Amhof Trucking's dispatcher told him to hold off 
         and wait for a more profitable load, and even specifically 
         instructed claimant not to take a particular load. claimant 
         indicated that he took that load anyway because only a few were 
         available and he desired to return home for the weekend.  
         However, on cross-examination, claimant testified that the 
         dispatcher eventually gave him permission to take that load.  In 
         his deposition taken April 3, 1987, claimant testified:
              Q.  How did you go about finding a return load the 
              next morning?
              A.  On the return load board a load came up going 
              to Waterloo, Iowa from Chattanooga.
              Q.  So that morning did you drive up to
         Page 3
              A.  No. I didn't drive up to Chattanooga till in
              the afternoon because Amhof did not want me to
              take the load until it was an absolute last ditch
              Q.  What do you mean?  I didn't understand that.
              A.  They didn't think I should jump right on that
              load.  They wanted me to wait and see if something
              better came up.
              Q.  So are you in contact with the local terminal
              trying to make a decision as to which load to
              bring back?
              A.  Yes.
              Q.  Why do they care about that?
              A.  Their truck, equipment.  They want to make the
              best money they can.
              Q.  I see.  Did Amhof caution you to wait till
              after noon then?
              A.  Yes.
              Q.  Did you get a better offer or did you end up
              taking that particular load?
              A.  I took that particular load.
         (Lafoon deposition, page 24, line 19 through page 25, line 21)
              At hearing, claimant testified that when he left Atlanta on 
         August 7 to pick up his load in Chattanooga he felt "drug out," 
         sick to his stomach, and suffered from what he identified as 
              Claimant loaded two cranes in Chattanooga.  He broke down 
         one side of his truck to help load and helped chain the load down 
         in 102 degree temperatures.
              Claimant indicated that he thereafter drove north but 
         stopped in Franklin, Kentucky, to recuperate for a few hours.  He 
         continued to Hamburg, Indiana, where he  felt quite ill with 
         indigestion and heartburn.  After calling in to report his 
         position claimant slept in his cab the night of August 7.
         Page 4
              Claimant further testified on direct examination that he 
         intended to drive to the Davenport terminal on the morning of 
         August 8.  He awoke that morning feeling a little better, but 
         after taking a break while driving through the state of Illinois, 
         again felt ill.  He arrived at Davenport at approximately 5:00 
         p.m. and was off duty.
              Claimant indicated that he went to his wife's  parents 
         house to visit on the evening of August 8, played a dice game, 
         but left approximately 9:00 p.m. At that time he felt very hot 
         and had increased chest pains.  At home, he watched television 
         until approximately 10:00 p.m. before retiring.  His chest pain 
         worsened while he was in bed and began radiating to his arms at 
         approximately 11:00 p.m. to midnight.  Claimant called his 
         physician, Phillip Habak, M.D., and met the doctor at St. Luke's 
         Hospital where he  was taken by ambulance.  Claimant suffered a 
         myocardial infarction and underwent angioplasty at the hospital.
              Claimant agreed on direct examination that he first 
         suffered heart problems in 1978 when he was hospitalized for 
         tests for approximately five days.  Thereafter, he suffered no 
         chest or heart problems until March, 1986, when he visited the 
         emergency room at a local hospital due to chest pains.
              Claimant agreed that he has a family history of heart 
         disease.  His mother died at age 70 and his brother at age 47 of 
         heart problems.  Claimant denied that his father suffered from 
         heart disease.
              On cross-examination, claimant agreed that he suffered 
         chest pains in 1976.  He also agreed that he had been a cigarette 
         smoker for approximately 25 years at 2-3 packs per day until 
         1978.  He discontinued smoking then, but began again in 1979, 
         approximately eight months after quitting.  He at first smoked 
         less than one pack per day, but  gradually increased consumption 
         to two packs per day by 1984 or 1985 and continued smoking two 
         packs a day at the time of  the March, 1986 incident.  He again 
         briefly quit, but had resumed smoking at a two-pack per day level 
         by August,.1986.
              With respect to the sequence of events preceding 
         hospitalization, claimant indicating that he first felt ill after 
         leaving Atlanta on August 6.  In his deposition, claimant 
         testified that he was first ill on August 8.  He further 
         testified that his deposition testimony was due  to "bad 
         recollection," and that his recollection at time of hearing was 
         superior to his recollection on April 3, 1987.
         Page 5
              Claimant also testified that part of his reason for 
         stopping in Kentucky was due to a huge rainstorm that lasted over 
         two hours.
              Claimant also agreed that he had trouble sleeping and was 
         belching in Hamburg, Indiana, although this was inconsistent with 
         his deposition testimony.
              Claimant further testified that he felt better driving 
         between Illinois and Davenport.  He was specific in stating there 
         was no chance whatsoever that chest pain developed in the morning 
         of August 7 as opposed to the afternoon.
              In his deposition of April 3, 1987, claimant indicated that 
         after leaving Chattanooga with his return load, he stopped at a 
         truck stop on top of Mount Eagle, Tennessee for a couple of hours 
         due to rain and later waited approximately three more hours 
         because of rain in Franklin, Kentucky.
              When asked at deposition where he first began to experience 
         any kind of chest discomfort or any kind of feeling sick, 
         claimant answered Hamburg, Indiana on August 8 at 8:30 a.m. 
         shortly after breakfast.  Asked further how soon after eating 
         breakfast he began to feel symptoms of stomach illness, heartburn 
         and difficulty in swallowing, claimant responded that he felt 
         that way when he woke up.  He had not felt at all sick when going 
         to bed the night before, but was just extremely tired.  Claimant 
         indicated that while driving from Hamburg, Indiana, to Oakwood, 
         Illinois, he felt symptoms rather like influenza; those symptoms 
         persisted between Oakwood and Davenport, although they eased up 
         during that leg of the trip.
              Claimant further testified at deposition that he visited 
         his wife's parents after supper, staying until approximately 
         midnight.  After supper, he felt very ill and very hot with 
         sickness to the stomach, heartburn and headache.  He had felt 
         perhaps 50 percent better by the time he reached the Davenport 
         terminal earlier, and  deteriorated approximately 8:00 p.m.
              Claimant agreed that he had had a relatively light day 
         driving before his infarction because of the two lengthy layovers 
         due to weather, but further indicated that traffic and road 
         conditions were stressful.  The cab of his tractor was air 
              Claimant also described his last trip in an undated letter 
         to Dr. Habak.  In that letter he stated that defendant really did 
         not want him to take the particular load but finally agreed.
         Page 6
              Mr. Lafoon's letter further stated:
              After loading I drove to Franklin Ky. through a
              bad thunderstorm.  I stayed there till the storm
              let up & drove on to Hamburg Ind. & slept for
              about 7 hrs.  I left Hamburg Ind. at 8:30 am on
              the 8th.  I drove for around 3 1/2 hours & stopped
              in Oakwood Ill. where I started feeling sick.
              After a 1/2 hr. break I continued home to Dav.  I
              got in to the company yard at 5:00  pm.  Went home
              & ate a little supper.  My wife wanted to go next
              door to her mothers so we walked over there.
              Their house is air cond.  We stayed there & played
              a dice game until around 11:00 pm   I was hot &
              sick so we walked home.  I was getting ready for
              bed when my chest pain got worse & my arms began
              getting numb.  My wife then called you.
              Emergency room records of St. Luke's Hospital show that 
         claimant appeared at 2:10 a.m. on August 9, 1986.  Initial 
         history was obtained of pain starting one hour before:  a heavy 
         squeezing sensation.  Chart notes indicated that claimant had 
         suffered severe crushing chest discomfort radiating to both arms 
         starting around 1:30 a.m., but had otherwise had no recent chest 
         discomfort.  A family history was that both parents died of 
         myocardial infarctions, as did a brother.  Dr. Habak's impression 
         was of severe coronary artery disease with diffuse disease of the 
         proximal segment of the right coronary artery culminating in near 
         total occlusion and complete occlusion of the circumflex coronary 
         artery; also, proximal lesions left anterior descending coronary 
         artery estimated at 40-50 percent and 50-60 percent respectively.
              Dr. Habak wrote claimant's attorney on September 25, 1986 
         in response to a letter of August 26.  Claimant's history was of 
         experiencing intermittent chest discomfort throughout the day 
         before admission and that he may have done heavy work loading and 
         unloading his truck that morning.  Noting that claimant had 
         suffered from a previous myocardial infarction in 1978, Dr. Habak 
              To answer your question I do not believe that the
              patient's employment as a truck drivel lead (sic)
              to the coronary artery disease which in turn is
              responsible for the patient's heart attack.  It is
              possible, however, that the stress involved and
              continued heavy work after the onset of symptoms
              could have aggravated the patient's heart attack
              by imposing additional stress and strain on the
              heart and delaying prompt treatment.
         Page 7
              Dr. Habak's depositions of September 22, 1981 and May 26, 
         1989 are in evidence.  Dr. Habak is a board-certified physician 
         in internal medicine and cardiovascular disease.
              Dr. Habak testified in 1987 that claimant was first seen in 
         1978 for chest pain and that laboratory studies were consistent 
         with heart damage due to heart attack.  Claimant was in good 
         health on subsequent visits until his infarction of August 1986.  
         Dr. Habak had not seen claimant when he visited the emergency 
         room in March 1986.  In August, claimant's electrocardiogram at 
         the time of his emergency hospitalization showed changes of a 
         heart attack just then developing.  Claimant was treated in the 
         emergency room with a clot-disolving medication and then 
         underwent angioplasty.
              Dr. Habak was asked a hypothetical question by claimant's 
         attorney as to whether the heart attack  was casually related to 
         work.  The hypothetical question originally included the 
         assumption that claimant did heavy lifting and unloading the 
         morning or the morning before the infarction.  The record shows:
              Q.  (BY MR. McCARTHY) Well, let's assume that he
              traveled to Smyrna, Tennessee, on the 6th of
              August.  'Let's say this began on the 6th of
              August, the trip down South.  And that between
              on about the 6th of August he was involved in
              heavy exertion and continued -- let me also ask
              you to assume that the weather in the South at
              that time was approximately 100 degrees.  He
              continued to Atlanta, came back sometime in the
              morning of the 8th, which is 8th of August.  He
              woke up, became sick, continued to experience
              nausea and cotton mouth, indigestion.
              Do you have an opinion, then, to a reasonable
              degree of medical certainty as to whether the
              physical exertion caused his heart attack?
              A.  If a patient comes in with chest pain and the
              heart attack which developed as he was doing
              physical exertion, one may be able to implicate a
              casual relationship between the exercise and the
              heart attack.  In my opinion,,the heart attack
              precipitated that particular patient.  He may be
              prone to having the heart attack and may have had
              it at some other time, but it so happened that at
              that particular moment, the stress or strain of
              the exercise on top of the underlying coronary
              disease would have caused it.
         Page 8
              I understand that Larry's chest pain developed
              several hours after the exertion, not during.  I
              think the exertion may have had something to do
              with the other pains he has had; for example, the
              indigestion. It may have been that he was having
              angina.  I don't know.  People with coronary
              disease do get angina when  they exert.  Sometimes
              the pain may feel like indigestion.  But it sounds
              to me that the heart attack started shortly before
              he came to the hospital, because of the changes we
              had on the cardiogram.
              Q.  How shortly are you talking about?
              A.   The pain started at 1:30, he told us, in the
              morning.  Or did he come at 1:30?  It started
              around 1:30 in the morning.
              Q.  Well, are you saying that the exertion could
              have caused the heart attack, then, given the
              underlying coronary disease here?
              A.  It would be difficult to implicate it, at
              least for me, to blame an exercise that was done
              12 hours or 24 hours earlier, with a heart attack
              developing later.
              Q.  What about the -- assume that he was driving,
              that he finished driving and got into Davenport at
              4:30 that afternoon of August the 8th, you saw him
              at 1:30 in the morning on August the 9th, and he
              got into Davenport just, oh, eight, nine hours
              before that, but the nausea, sickness had been
              with him for approximately 16 hours before that
              time. Does that assist you at all in determining
              whether or not the driving and the physical
              exertion could have caused the heart attack?
              A.  Well, I wish it was easy to answer that.  I
              think it would be a little surprising that he
              would have that many symptoms for so long and the
              heart attack would have just started out.  That
              would be the only thing.
         (Dr. Habak 1987 deposition, page 24, line 5 through page 26, line 
              Q.  Are you saying that you really can't tell,
              then?  Is that what you are telling me?  That you
              really can't say what the cause is, then?  The
         Page 9
              cause might have been something other than the
              physical, exertion?
              A.  I would have to say that it is something
              unrelated to the exertion.  I think the underlying
              disease, the coronary disease, was the main
              factor.  Why did he develop pain at that
              particular time and not, say, a week later or a
              week before?  We don't know.  But it is possible
              [sic] that if he had flu-like symptoms, that this
              may have played a factor somehow.
              Q.  Could the preexisting condition, the
              underlying disease, have accelerated the process
              which led to this heart attack at 1:30 in the
              morning on the 9th?
              A.  Yes, I think so.
              Q.  In other words, in some way, the underlying
              disease aggravated his condition which, in your
              opinion, could have then caused the heart attack?
              A.  Well, I think the underlying disease is the
              main cause of the heart attack.  If you have
              normal coronary arteries, he would not have had a
              heart attack.  It is unlikely that -- it is
              reported, but --
              Q.  But could the physical exertion and the
              underlying -- could the physical exertion, then,
              have accelerated the heart attack because of the
              underlying condition?
              A.  I cannot tell you for sure that it has not.
              It is possible.  If he was perspiring a lot with
              the exertion, if he became dehydrated -- the one
              thing that I am trying to associate with that is
              that something has affected the chemistry of the
              blood, the viscosity of the blood, that could have
              led to a clot because of the disease he had.  The
              artery must have been slightly narrowed but was
              not occluded.  It occluded around the time he
              started having the pain in the early morning.
         (Dr. Habak 1987 deposition, page 27, line 13 through page 29, 
         line 3)
              Dr. Habak also pointed out that the exertion may have made 
         conditions more favorable for the development of a heart attack 
         by affecting the viscosity of claimant's blood.
         Page 10
              Dr. Habak described how claimant's occlusion may have been 
         caused by an embolism which was successfully dissolved prior to 
         the angioplasty.  He did not believe that claimant had sustained 
         a total or nearly total occlusion of the right coronary artery 
         long before his admission, since occlusion should produce 
         immediate and severe symptoms.
              On cross-examination, Dr. Habak noted that family history 
         of coronary artery disease increased the likelihood that an 
         individual will similarly suffer coronary artery disease.
              Dr. Habak also commented on internist George River's 
         evaluation of claimant's EKG in March, 1986 to the effect that 
         comparison with a 1982 EKG strongly suggested that there had been 
         an intervening inferior infarction with major myocardial damage; 
         Dr. Habak noted that George River was qualified to interpret 
         EKG'S, but himself did not find the EKG that much different from 
         the 1978 EKG.
              Dr. Habak testified generally that the longer the interval 
         between an exertion and the development of symptoms, the less 
         likely there is that a casual relationship exists:
              Q.  Doctor, if the specific acts of exertion
              described by Mr. Lafoon where he breaks down his
              trailer occur, hypothetically, on day one, and
              then he rests all night, gets up the next morning
              and has some complaints of discomfort in his
              stomach, but basically does no specific exertion
              for the balance of that day other than simply
              driving his truck, and then symptoms develop early
              in the morning, 1:30 a.m., on what is essentially,
              then, the third day, is that lapse of time such
              that it makes it doubtful that the original
              exertion caused the heart attack?
              A.  I think it should.
         (Dr. Habak 1987 deposition, page 45, line 22 through page 46, 
         line 9)
              On redirect examination, Dr. Habak noted again that heart 
         pain and indigestion can simulate one another and that it is 
         possible for a person to have angina with indigestion which goes 
         away and then comes back subsequently as a heart attack.  He also 
         noted that the stress of driving a truck ("Maybe ignoring body 
         needs and keeping going and feeling tired and still driving and 
         missing meals") could possibly be sufficient to cause a heart 
         Page 11
              Subsequently, Dr. Habak wrote claimant's attorney on March 
         18, 1988.  This apparently closely followed receipt of claimant's 
         undated letter. In pertinent part  he  wrote:
              Mr. Lafoon left Davenport on August 5th, driving
              his truck as far as Atlanta, Georgia.  Between
              that time and until August 7th, the patient was
              involved in various strenuous activities, at times
              under extreme heat with temperatures as high as
              100 [degrees].  The patient's activities included
              loading his truck, untarping the trailer, taking
              the sides off, removing blocking, loading and
              unloading the truck, etc.
              On October 7th [sic], the patient was under
              pressure to return to Davenport before the weekend
              on account of his birthday.  He spent several
              hours looking for a load back towards Iowa and
              when he eventually located one the Company
              initially refused allowing him to take this load.
              He became very upset and pleaded with them until
              they eventually agreed to allow him to return to
              Davenport with this particular load.  He then
              drove to Hamburg, Indiana, to pick up the load and
              left that town on the 8th at 8:30 AM.  Three hours
              later, he stopped in Oakwood, Illinois, with
              general malaise, being sick at the stomach and
              having symptoms of indigestion. He took a half
              hour break and was quickly on his way towards
              Davenport.  That evening, he had a little supper
              and went next door, to his wife's mother, where
              they stayed until around 11:00 PM.  At that time,
              he was not feeling well and noted that he was hot
              and sick. He then went back home and noted the
              discomfort in the chest to be progressive as he
              was getting ready to go to bed.  Eventually he was
              brought to the emergency room at St. Luke's
              Hospital with findings of a heart attack or
              myocardial infarction.
              * * *
              I also in Mr. Lafoon's account that the 2
              weeks prior to his heart attack he has worked long
              hours and had driven hundreds of miles.  He had to
              maintain a tight schedule in order to be in
              various locations for loading and unloading.
              * * *
              Although we know that the patient has underlying
              coronary artery disease, we also know that he was
         Page 12
              feeling well and not [sic] experiencing any
              symptoms when he left Davenport on August 5th, on
              that last trip reaching as far as Atlanta,
              Georgia.  Mr. Lafoon also developed symptoms at
              1:00 PM, the afternoon of August 8th.  The
              symptoms are mainly described as indigestion,
              nausea, general malaise and feeling sick.  These
              were not quite relieved and he apparently did not
              feel well throughout the remainder of the day.  At
              11:00 PM, further symptoms occurred, eventually
              culminating with the onset of pain in the chest
              and the left arm.
              It is well known that a certain number of patients
              suffering from angina pectoris or myocardial
              infarctions present with symptoms of indigestion
              rather than clear cut chest pain.  In fact, many
              patients go around treating themselves with
              antacids and other digestive products prior to
              seeking medical attention for what is eventually
              discovered to be a cardiac or coronary event.
              It is safe to assume that there is a significant
              possibility that the patient's symptoms at 1:00,
              that afternoon, of August 8th could have
              represented angina pectoris or a warning symptom
              of what was yet to come.  Mr. Lafoon ignored these
              symptoms and pursued his intended goal to reach
              Davenport that day.  Accordingly, it is likely
              that, although the heart attack started in the
              early hours of August 9th, the patient's symptoms
              may well have started in the afternoon of the day
              before, about the time.he reached Oakwood,
              Although the patient was not particularl exerting
              himself on August 8th, I note that during this
              particular trip there was a significant amount of
              physical exertion, long hours, exposure to high
              temperatures, insufficient sleep as well as
              excessive mental stress and frustrations.  Thus,
              these factors may have worked synergistically to
              significantly contribute to the patient's heart
              attack, (sic)  These events, although hot directly
              causing the heart attack, must have.played a
              significant role in contributing.or precipitating
              the patient's illness.
              Dr. Habak testified further by deposition on May 26, 1989.
         Page 13
              Dr. Habak testified in response to questioning by defense 
              [Q.] I want you to assume that Mr. Lafoon was off
              duty in Atlanta, Georgia, from 1:30 p.m. on August
              6, 1986, stayed overnight there, and was off duty
              through 10:30 a.m. on August 7th.  That is a total
              of 21 hours off duty.
              I want you to further assume that starting at
              10:30 in the morning he drove two hours and 15
              minutes to Chattanooga, at that point picked up a
              load, and then drove one hour and 15 minutes to a
              place called Monteagle, Tennessee, where he
              stopped for two hours due to weather I believe.
              I want you to further assume he then drove for
              another two hours and 30 minutes to a place called
              Franklin, Tennessee, where he again stopped either
              due to weather or road conditions, this time
              stopping for a total of three hours.
              Then I want you to assume that he drove two hours
              and 15 minutes to a place called Hamburg, Indiana,
              in other words, his driving, Doctor, that day was
              broken up far more than usual by these large rests
              or layovers due to weather or road conditions.
              Have you understood my basic hypothetical facts,
              A.  Okay, yeah.
              Q.  My question is this: From what I have
              described to you, that is a pattern of driving
              then resting or being off the road for a period of
              time then driving again, does that sound to you in
              your experience like an activity that would be
              generating either very much stress or very much
              exertion for one's heart?
              A.  Generally not I think.
              Q.  I want to carry through this hypothetical just
              a moment, Doctor.  I want you to assume that when
              he got in Hamburg, Indiana, it was around  midnight
              on August 8, 1986.  He then slept for eight hours
              in his sleeper cab until 8:30 in the morning.
              I want you to assume at that point he got up, he
              had a breakfast, and during the course of that
              breakfast, during the breakfast remembers feeling
              sick to my stomach, heartburn, and difficulty in
         Page 14
              swallowing, in other words, he felt that way while
              eating breakfast.
              I want you to assume he then drove for three and a
              half hours, took a coffee break for 30 minutes at
              a place called Oakwood, Illinois, at that point he
              said he felt like he had the flu.
              He then drove the rest of the way home to
              Davenport which was approximately four hours
              arriving at 4:30 p.m. and that by his recollection
              during the leg from Oakwood to Davenport he felt
              about 50 percent or half better.  Have you
              understood these additional hypothetical facts?
              A.  Yeah.
              Q.  Doctor, does the type of driving pattern that
              I have just described to you which added in an
              eight-hour sleep pattern, breakfast, some more
              driving broken up at least once by a 30 minute
              stop, does that in your experience sound like the
              type of activity that would be very stressful or
              very exertional to one's heart?
              A.  The activity by itself would probably not be
         (Dr. Habak 1989 deposition, page 61, line 22 through page 64, 
         line 11)
              Dr. Habak further testified that if he assumed that 
         symptoms developed at 1:00 p.m. rather than 8:30 p.m. on August 
         8, he could not be specific as to the most probable cause of 
         symptoms, although they could have been indigestion or an 
         ischemic episode.
              Dr. Habak testified:
              Q.  Is there any way, Doctor, as you testify today
              that with a reasonable degree of medical
              probability you could rule out the final deposits
              of sufficient plaque to cause an occlusion to this
              artery during the night or at least to begin
              producing angina or angina pectoris during the
              night of August 7th to August 8th?.
              A.  That could have been initiated during the
              night, but they could also have occurred earlier.
              Q.  So in the spectrum of possibilities, I take it
              the deposits or the vasospasms could theoretically
         Page 15
                   occur on August 7th, they could occur during the
                   night of August 7th, or those events could occur
                   on August 8th itself, is that correct?
                   A.  One can say so, yes.
                   Q.  Is there any way, Doctor, with any kind of
                   reasonable medical probability that you can
                   pinpoint which of those three scenarios?
                   A.  I don't think we can answer that with
                   certainty; however, the kind of activities that
                   Mr. Lafoon related to in this letter on August
                   7th, including working hard in a temperature
                   reaching as much as 100 degrees, that could be a
                   factor that possibly may initiate the process that
                   would eventually lead to a heart attack.
         (Dr. Habak 1989 deposition, page 69, line 23 through page 70, 
         line 24)
                   A.  Well, most of the time -- well, in a
                   significant number of patients, maybe about half
                   the patients who come with a heart attack, one can
                   obtain a history of symptoms that have occurred
                   earlier, past two or three days that could have
                   represented ischemic episodes but were ignored by
                   the patient and even though the timing of complete
                   and irreversible occlusion occurred when he came
                   to the emergency room that morning, it is likely
                   that he may have had either intermittent occlusion
                   with either spasm or a clot forming and through a
                   process we call lysis, regressing and then
                   reforming and that may have caused the initial
                   symptoms he described that morning or the morning
                   before.  Now, whether that is the case, I don't
                   know, but I think these are possibilities.
                 Q.  How do you rule out the fact he simply had
                 indigestion or a legitimate stomach or bowel
                 A.  I don't know.  I don't think we can answer
                 that for sure.
         (Dr. Habak 1989 deposition, page 72, line 9 through page 73, line 
              Peter S. Jerome, M.D., testified by deposition taken
         May 26, 1989.  Dr. Jerome specializes in internal medicine,
         Page 16
         pulmonary medicine and critical care medicine.  He saw claimant 
         once for evaluation on May 5, 1989.  In response to a 
         hypothetical question, Dr. Jerome testified:
              Q.  I want you to assume, Doctor, by way of
              hypothetical that Mr. Lafoon was off duty as a
              trucker in Atlanta, Georgia, from 1:30 p.m. on
              August 6, 1986, through 10:30 a.m. on August 7,
              1986, that is a total of 21 hours of off duty.  He
              then started to drive that morning and drove two
              hours and 15 minutes to Chattanooga, Tennessee,
              where he picked up a load to be brought back to
              When the load was connected to his truck, he then
              drove an hour and 15 minutes to a place in
              Tennessee called Monteagle, he stopped for two
              hours we believe because of bad weather.  He then
              drove for another two hours and 30 minutes to
              Franklin, Tennessee, he then stopped for about
              three hours either due to bad weather or road
              conditions at that time.
              He then resumed driving and drove two hours and 15
              minutes to a place called Hamburg, Indiana.  At
              that point because of ICC rules he had to rest.
              He arrived at Hamburg around midnight, he slept
              for eight hours until 8:30 in the morning.
              He then upon awakening had breakfast and during
              the breakfast can recall feeling sick to his
              stomach, a sensation of heartburn, some difficulty
              in swallowing, the point being he felt that way
              while he was eating the breakfast.  He then
              proceeded to drive three and a half hours to a
              rest stop in Oakwood, Illinois.  He took a brief
              rest of about 30 minutes.
              He remembers feeling somewhat like he had the flu
              or symptoms comparable to the flu.  He then
              completed the trip home to Davenport which took an
              additional four hours arriving at about 4:30 in
              the afternoon.  Have you understood those basic
              hypothetical facts?
              A.  That's correct.  That's similar to the story
              that was described to me.
              Q.  All right.  Doctor, I want to first of all
              concentrate on August 7th when he is down in
              Atlanta, Georgia.  From my hypothetical question
              did it sound like the periods of driving followed
         Page 17
              by forced layovers because of weather or bad roads
              would be the kind of exertion that within a
              reasonable degree of medical probability might
              either trigger or cause ultimately a myocardial
              A.  I believe this not to be likely.
         (Dr. Jerome deposition page 6, line 12 through page 8, line 10)
              Dr. Jerome explained that there are three basic mechanisms 
         for myocardial infarction:  coronary artery thrombosis, coronary 
         artery vasospasm, and coronary artery plaque rupture.  With 
         respect to a coronary vasospasm, he indicated that there is 
         ordinarily a close temporal relationship between suspected 
         exertional activity and an infarct.  However, there are 
         exceptions, for example if a patient has underlying angina or 
         coronary artery disease. Dr. Jerome further indicated that there 
         is a statistical correlation between heart attacks and 
         individuals with prior history of warning signs of angina.  He 
         further testified:
              Q.  How can either yourself today or better yet
              Dr. Habak when he actually works on Mr. Lafoon on
              August 9th, how can you say with any degree of
              certainty whether those symptoms were indicative
              of something going on in his intestines or his
              stomach as opposed to being early signs of a heart
              A.  In retrospect, looking at the sequence of
              events, the symptoms could correlate with an early
              myocardial infarction and one could not exclude
              that out as well as exclude gastrointestinal
         (Dr. Jerome deposition, page 15, line 15 through page 16, line 1)
              Dr. Jerome also noted that claimant's morning infarction 
         could have been produced by any of the three possible heart 
         events he had described, although thrombosis and vasospasm would 
         be the most common types.  However, in either case, it would be 
         unusual for sickness to occur for a period of time and then 
         subside; usually escalation of symptoms.
              Dr. Jerome was asked:
              Q.  Doctor, in terms of medical probability, based
              upon your review of the records, including your
         Page 18
              review of Dr. Habak's earlier deposition, do you
              have any opinion within a reasonable degree of
              medical certainty as to what was the most likely
              cause of Mr. Lafoon's myocardial infarction?
              A.  His underlying coronary artery disease.
              Q.  Why do you say that?
              A.  And natural progression of that disease.
              Q.   Why do you say that, Doctor?
              A.  He's had well established severe coronary
              artery disease since his late thirties and this
              would be a fairly natural progression of events.
              Q.  Would it be a natural progression, Doctor,
              irrespective of any particular exertional event or
              any particular amount of work?
              A.  Yes, it could be.
              Q.  Let's digress for just a second, Doctor.  If a
              person has underlying coronary artery disease and
              engages in strenuous labor in a hot environment,
              would you normally expect the onset of cardiac
              symptoms that were caused by the exertion to be
              fairly immediate, and by that I mean within a
              matter of perhaps three to four hours?
              A.  Yes.
              Q.  Is the suspected relationship between exertion
              at any one point in time and a subsequent
              myocardial infarction weakened, is that temporal
              relationship weakened as the time span gets bigger
              and bigger?
              A.  Yes.
         (Dr. Jerome deposition, page 21, line 14 through page 22, line 
              Dr. Jerome testified further:
              Q.  If Mr. Lafoon had a risk factor of family
              history of heart problems as I have described as
              well as a history of smoking and then as a third
              factor had a known or demonstrable prior history
              of some ischemic events, does that make him a
         Page 19
              prime candidate, Doctor, to have a myocardial
              A.  Yes.
              Q.  Is there any relative weighting or relative
              ranking in terms of seriousness between the family
              history, the smoking, or the prior history of
              ischemic events as to what is the most serious
              risk factor?
              A.  You are talking about two factors that cause
              coronary disease, coronary artery disease that has
              been established; but persistent smoking on top of
              an established diagnosis tends to advance this
              risk for further events.
              Q.  Just a couple more questions, Doctor.  If a
              patient has known or demonstrable atherosclerotic
              conditions, particularly if they involve the
              coronary artery, can those conditions progress on
              their own to the point where there is a serious
              blockage or partial occlusion of the coronary
              A.  Yes.
              Q.  Can they progress on their own in the absence
              of any specific trauma or exertion and lead to a
              partial or total occlusion?
              A.  Yes.
              Q.  Would there be anything at all unusual or out
              of the ordinary for that kind of progression to
              occur in an individual like Mr. Lafoon?   By that I
              mean if he already has the condition, if he has
              the hereditary risk factor, and if he has a
              history of smoking, would there be anything at all
              out of the ordinary about an individual like that
              developing a heart attack that was related to
              natural progression of the atherosclerotic
              A.  That would be an expected event.
              Q.  Doctor, would you have an opinion based upon a
              reasonable degree of medical probability as to
              whether an individual who exhibits Mr. Lafoon's
              history and exhibits his cardiac makeup would be
              likely to develop a myocardial infarction in the
         Page 20
              absence of any specific exertion or any specific
              work or any specific overload?
              A.  He would run a fairly high risk of development
              of myocardial infarction despite, you know, heavy
              exertion factors.
              Q.  From the history we have described, Doctor,
              from the hypothetical history I have described to
              you do you have an opinion within a reasonable
              degree of medical probability as to whether Mr.
              Lafoon's heart attack was related to any specific
              work event?
              A.  Historically that is not clear at all.
              Q.  Given his risk factors is it just as likely or
              probable that his heart attack could be a
              developmental or a progressive result of his
              atherosclerotic condition?
              A.  Yes.
         (Dr. Jerome deposition, page 28, line 2 through page 30, line 14)
                           APPLICABLE LAW AND ANALYSIS
              An employee is entitled to compensation for any and all 
         personal injuries which arise out of and in the course of the 
         employment.  Section 85.3(l).
              Claimant has the burden of proving by a preponderance of 
         the evidence that he received an injury on or about August 8, 
         1986 which arose out of and in the course of his employment.  
         McDowell v. Town of Clarksville, 241  N.W.2d  904 (Iowa 1976); 
         Musselman v. Central Telephone Co., 261 Iowa 352, 154 N.W.2d 128 
              The injury must both arise out of and be in the course of 
         the employment.  Crowe v. DeSoto Consol. Sch. Dist., 246 Iowa 
         402, 68 N.W.2d 63 (1955) and cases cited at pp. 405-406 of the 
         Iowa Report.  See also Sister Mary Benedict v. St. Mary's Corp., 
         255 Iowa 8417, 124 N.W.2d 548 (1963) and Hansen v. State of Iowa, 
         249 Iowa 1147, 91 N.W.2d 555 (1958).
              The words "out of" refer to the cause or source  of  the 
         injury.  Crowe v. DeSoto Consol. Sch. Dist., 246 Iowa 402, 68 
         N.W.2d 63 (1955).
              The words "in the course of" refer to the time and place 
         and circumstances of the injury.  McClure v. Union
         Page 21
         et al. Counties, 188 N.W.2d 283 (Iowa 1971); Crowe v. DeSoto 
         Consol. Sch. Dist., 246 Iowa 402, 68 N.W.2d 63 (1955).
              "An injury occurs in the course of the employment when it 
         is within the period of employment at a place the employee may 
         reasonably be, and while he is doing his work or something 
         incidental to it."  Cedar Rapids Comm. Sch. Dist. v. 
         Cady, 278 N.W.2d 298 (Iowa 1979), McClure v. Union et al. 
         Counties, 188 N.W.2d 283 (Iowa 1971); Musselman v. Central 
         Telephone Co., 261 Iowa 352, 154 N.W.2d 128 (1967).
              The supreme court of Iowa in Almquist v. Shenandoah 
         Nurseries, 218 Iowa 724, 731-32, 254 N.W. 35, 38 (1934) discussed 
         the definition of personal injury in workers, compensation cases 
         as follows:
              While a personal injury does not include an
              occupational disease under the Workmen's
              Compensation Act, yet an injury to the health may
              be a personal injury.  [Citations omitted.]
              Likewise a personal injury includes a disease
              resulting from an injury....The result of changes
              in the human body incident to the general
              processes of nature do not amount to a personal
              injury.  This must follow, even though such
              natural change may come about because the life has
              been devoted to labor and hard work.  Such result
              of those natural changes does not constitute a
              personal injury even though the same brings about
              impairment of health or the total or partial
              incapacity of the functions of the human body.
              A personal injury, contemplated by the Workmen's
              Compensation Law, obviously means an injury to the
              body, the impairment of health, or a disease, not
              excluded by the act, which comes about, not through the
              natural building up and tearing down of the human body,
              but because of a traumatic or other hurt or damage to
              the health or body of an employee.  [Citations
              omitted.]  The injury to the human body here
              contemplated must be something, whether an accident or
              not, that acts extraneously to the natural processes of
              nature, and thereby impairs the health, overcomes,
              injures, interrupts, or destroys some function of the
              body, or otherwise damages or injures a part or all of
              the body.
              The claimant has the burden of,proving by a preponderance 
         of the evidence that the injury on or about August 8, 1986 is 
         casually related to.the disability on
         Page 22
         which he now bases his claim.  Bodish v. Fischer, Inc., 257 Iowa 
         516, 133 N.W.2d 867 (1965). Lindahl v. L. 0. Boggs, 236 Iowa 296, 
         18 N.W.2d 607 (1945).  A possibility is insufficient; a 
         probability is necessary.  Burt v. John Deere Waterloo Tractor 
         Works, 247 Iowa 691, 73 N.W.2d 732 (1955).  The question of 
         casual connection is essentially within the domain of expert 
         testimony.  Bradshaw v. Iowa Methodist Hospital, 251 Iowa 375, 
         101 N.W.2d 167 (1960).
              However, expert medical evidence must be considered with 
         all other evidence introduced bearing on the casual connection.  
         Burt, 247 Iowa 691, 73 N.W.2d 732.  The opinion of experts need 
         not be couched in definite, positive or unequivocal language.  
         Sondag v. Ferris Hardware, 220 N.W.2d 903 (Iowa 1974).  However, 
         the expert opinion may be accepted or rejected, in whole or in 
         part, by the trier  of fact. Id. at 907.  Further, the weight to 
         be given to such an opinion is for the finder of fact, and that 
         may be affected by the completeness of the premise given the 
         expert and other surrounding circumstances.  Bodish, 257 Iowa 
         516, 133 N.W.2d 867.  See also Musselman v. Central Telephone Co.
         , 261 Iowa 352 , 154 N.W.2d 128 (1967).
              While a claimant is not entitled to compensation for the 
         results of a preexisting injury or disease, the mere existence at 
         the time of a subsequent injury is not a defense.  Rose v. John 
         Deere Ottumwa Works, 247 Iowa 900, 908, 76 N.W.2d 756, 760-61 
         (1956).  If the claimant had a preexisting condition or 
         disability that is aggravated, accelerated, worsened or lighted 
         up so that it results in disability, claimant is entitled to 
         recover.  Nicks v. Davenport Produce Co., 254 Iowa 130, 115 
         N.W.2d 812, 815 (1962).
              Claimant originally testified that he took a load 
         apparently in contravention of dispatcher's orders in order to 
         return to Iowa to be home for the weekend.  However, on 
         cross-examination, he appeared to indicate that he did have 
         permission to take the load he actually did after noon.  No 
         contrary evidence was produced by defendants.  It is held that 
         claimant has established that he was in the course of his 
         employment where symptoms occurred while driving on his last trip 
         before the myocardial infarction.
              But, was the eventual myocardial infarction an injury 
         arising out of claimant's employment?. As has been seen, the 
         question of casual relationship is largely in the sphere of 
         expert testimony.  The evidence shows that claimant had 
         preexisting coronary artery disease.  Quoting 1A [sic] Larson 
         Workmen's Compensation Law, section 38.83, the Iowa court in 
         Briarcliff College v. Campolo, 360 N.W.2d 91 (Iowa 1984) noted 
         that a compensable injury may result when heavy
         Page 23
         exertions ordinarily required by work are superimposed upon a 
         defective heart, aggravating or accelerating the preexisting 
         condition or "when the medical testimony shows an instance of 
         unusually strenuous employment exertion, imposed upon a 
         preexisting diseased condition."  Claimant must prove by a 
         probability, not a possibility, that some employment incident or 
         activity caused his coronary event.  Because he had a preexisting 
         heart condition, he must prove that he suffered an aggravation to 
         his already impaired physical condition.  Id.
              The medical opinions are in conflict, as are claimant's 
         various recitations of his history preceding the myocardial 
              At hearing, claimant indicated that when he left Atlanta on 
         August 7 on his way to Chattanooga, he suffered from flu-like 
         symptoms and heartburn.  He loaded and chained in Chattanooga and 
         felt ill in Franklin, Kentucky and Hamburg, Indiana.  After 
         sleeping in his cab, he felt a little better on the morning of 
         August 8, but felt ill again while driving through Illinois.
              In his deposition, claimant testified that his first 
         manifestations of illness were on August 8, one day later than 
         the version of events testified to at hearing.  He specified at 
         deposition that he first experienced any kind of discomfort or 
         sickness in Hamburg, Indiana on August 8 at 8:30 a.m., shortly 
         after breakfast.  He had felt approximately 50 percent better by 
         the time he reached Davenport later that day.
              In his letter to Dr. Habak, claimant indicated that he 
         began feeling ill in Oakwood, Illinois, about three and one-half 
         hours after leaving Hamburg, Indiana.  Given these three 
         conflicting versions, two of which were given under oath, it is 
         difficult to a high degree to accurately determine where and when 
         claimant first developed symptoms of flu-like malaise or 
         heartburn.  Admission notes of the hospital show that claimant 
         did not have chest discomfort until shortly before admission.
              Dr. Habak wrote on September 25, 1986 to note that 
         claimant's employment did not lead to the coronary artery 
         disease, but that it was "possible" that stress and continued 
         heavy work after the onset of symptoms could have aggravated a 
         heart attack by imposing additional stress and strain and by 
         delaying prompt treatment.  In his 1987 deposition, Dr. Habak 
         found it difficult to implicate an exercise that was done 12 or 
         24 hours earlier with a heart attack developing later.  In 
         essence, he found no casual connection between the work and the 
         Page 24
              Dr. Habak's letter to claimant's attorney of March  18, 
         1988 (apparently following claimant's undated letter) was based 
         on claimant developing symptoms on the afternoon of August 8.  He 
         felt there was a "significant possibility" that claimant's 
         symptoms of that afternoon could have represented angina pectoris 
         or a warning symptom of what was yet to come.  It was "likely" 
         that although the heart attack started in the early hours of 
         August 9, the symptoms may well have started in the afternoon of 
         the day before when claimant reached Oakwood, Illinois.  Dr. 
         Habak wrote that claimant's significant amount of physical 
         exertion, long hours, exposure to high temperatures, insufficient 
         sleep and excessive mental stress and frustrations may have 
         worked synergistically to significantly contribute to the heart 
         attack. "These events, although not directly causing the heart 
         attack, must have played a significant role in contributing or 
         precipitating the patient's illness."
              In his 1989 deposition, Dr. Habak, given a different 
         hypothetical scenario closer to claimant's testimony at trial, 
         conceded that claimant's activity "would probably not be 
         stressful."  In essence, he was able to discuss casual 
         relationship only in terms of possibility, not  probability. 
         Asked how he could rule out the fact that claimant had simply 
         suffered indigestion or legitimate stomach or bowel problems 
         while on the road, Dr. Habak responded:  "I  don't know.  I don't 
         think we can answer that for sure."
              Dr. Jerome testified after evaluating claimant that it was 
         unlikely that periods of driving followed by forced layovers 
         because of weather or bad roads would be the kind of exertion 
         that within a reasonable degree of medical probability might 
         trigger or ultimately cause a myocardial infarction.  He noted 
         that claimant's early symptoms could correlate with an early 
         myocardial infarction, but that one could not exclude 
         gastrointestinal causes.  He specifically pointed out that one 
         would normally expect the onset of cardiac symptoms caused by 
         exertion to be fairly immediate, perhaps within a matter of 3-4 
         hours.  He opined (in response to leading questions) that the 
         relationship between exertion and infarction weakens as the 
         intervening time span increases.  In general, he opined that it 
         is unclear that claimant's heart attack was related to any 
         specific work event and that it was just as likely or probable 
         that the infarction was a developmental or progressive result of 
         his atherosclerotic condition.  He further noted claimant's 
         family history of heart disease and history of smoking.
              As has been seen, claimant's history of the events 
         preceding his infarction has varied from time to time.  Dr. 
         Habak's opinion has varied with the history he was given.  At his 
         latest deposition, Dr. Habak did not testify to a
         Page 25
         reasonable degree of medical certainty that any work incident was 
         casually related to the infarction.  Dr. Jerome was of the view 
         that no such casual relationship existed.  On balance, the 
         undersigned concludes that claimant has failed to meet his burden 
         of proof in establishing that his myocardial infarction of August 
         9, 1986 was casually related to his work or that this incident 
         arose out of the employment.
              Therefore, other issues are moot.
                                 FINDINGS OF FACT
              THEREFORE, based on the evidence presented, the following 
         ultimate facts are found:
              1. When returning with a load to the state of Iowa in 
         August, 1986, claimant was driving with permission of his 
              2. On August 7 and 8, 1986, while driving truck, claimant 
         developed symptoms such as indigestion and heartburn.
              3. Claimant has given contradictory versions of when his 
         symptomatology arose.
              4. Claimant suffered a myocardial infarction on the early 
         morning of August 9, 1986.
              5. Claimant's driving activities on the three days prior to 
         his infarction included periods of strenuous work and extended 
         periods of rest, although temperatures were high.
              6. Claimant has failed to establish that his myocardial 
         infarction is casually related to any work incident or exertion.
                                CONCLUSIONS OF LAW
              WHEREFORE,.based on the principles of law previously cited, 
         the following conclusions of law are made:,
              1. Claimant was in the course of.his employment when he 
         developed symptoms on August 7 and/or 8, 1986, which may or may 
         not have been indicative of his subsequent myocardial infarction.
              2. Claimant has failed to establish that his myocardial 
         infarction arose out of his employment or is casually related to 
         the same.
         Page 26
              THEREFORE, IT IS  ORDERED:
              Claimant shall take nothing from this proceeding.
              Costs of this action are taxed to defendants pursuant to 
         Division of Industrial Services Rule 343-4.33.
               Signed and filed this 25th day of April, 1990.
                                               DAVID RASEY
                                               DEPUTY INDUSTRIAL 
         Copies To:
         Mr. Michael J. McCarthy
         Mr. Lawrence J. Lammers
         Attorneys at Law
         701 Kahl Building
         Davenport, Iowa  52801
         Mr. Thomas N. Kamp
         Attorney at Law
         600 Davenport Bank Building
         Davenport, Iowa  52801
                                            1108.10, 1402.30
                                            Filed April 25, 1990
                                            DAVID RASEY
         LARRY LAFOON,
                                                 File No. 830047
                                              A R B I T R A T I 0 N
                                                 D E C I S I 0 N
              Insurance Carrier,
         1108.10, 1402.30
              Claimant developed flu-like symptoms for one or two days 
         (his.versions varied) while driving truck, later suffered a 
         myocardial infarction at home.  Medical evidence was in conflict.  
         It was found that claimant failed to prove
         the infarction arose out of or was casually related to