BEFORE THE IOWA INDUSTRIAL COMMISSIONER LARRY LAFOON, Claimant, VS. File No. 830047 AMHOF TRUCKING, INC., A R B I T R A T I O N Employer, D E C I S I 0 N and AETNA CASUALTY & SURETY CO., Insurance Carrier, Defendants. 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. ISSUES 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; LAFOON v. AMHOF TRUCKING, INC. Page 2 that the fees charged for medical services and supplies are fair and reasonable and incurred for reasonable and necessary medical expense. 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 costs. 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 Chattanooga? LAFOON v. AMHOF TRUCKING, INC. 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 effort. 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 heartburn. 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. LAFOON v. AMHOF TRUCKING, INC. 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. LAFOON v. AMHOF TRUCKING, INC. 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 conditioned. 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. LAFOON v. AMHOF TRUCKING, INC. 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 stated: 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. LAFOON v. AMHOF TRUCKING, INC. 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. LAFOON v. AMHOF TRUCKING, INC. 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 18) And: 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 LAFOON V. AMHOF TRUCKING, INC. 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. LAFOON v. AMHOF TRUCKING, INC. 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 attack. LAFOON v. AMHOF TRUCKING, INC. 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 LAFOON v. AMHOF TRUCKING, INC. 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, Illinois. 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. LAFOON v. AMHOF TRUCKING, INC. Page 13 Dr. Habak testified in response to questioning by defense counsel: [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, Doctor? 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 LAFOON v. AMHOF TRUCKING, INC. 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 stressful. (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 LAFOON v. AMHOF TRUCKING, INC. 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) And: 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 problem? 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 4) Peter S. Jerome, M.D., testified by deposition taken May 26, 1989. Dr. Jerome specializes in internal medicine, LAFOON v. AMHOF TRUCKING, INC. 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 Iowa. 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 LAFOON v. AMHOF TRUCKING, INC. 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 infarction? 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 condition? 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 causes. (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; there.is usually escalation of symptoms. Dr. Jerome was asked: Q. Doctor, in terms of medical probability, based upon your review of the records, including your LAFOON v. AMHOF TRUCKING, INC. 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 21) 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 LAFOON v. AMHOF TRUCKING, INC. Page 19 prime candidate, Doctor, to have a myocardial infarction? 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 artery? 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 disease? 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 LAFOON v. AMHOF TRUCKING, INC. 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 (1967). 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 LAFOON v. AMHOF TRUCKING, INC. 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 LAFOON v. AMHOF TRUCKING, INC. 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 LAFOON v. AMHOF TRUCKING, INC. 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 infarction. 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 infarction. LAFOON v. AMHOF TRUCKING, INC. 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 LAFOON v. AMHOF TRUCKING, INC. 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 dispatcher. 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. LAFOON v. AMHOF TRUCKING, INC. Page 26 ORDER 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 COMMISSIONER 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 BEFORE THE IOWA INDUSTRIAL COMMISSIONER LARRY LAFOON, Claimant, VS. File No. 830047 AMHOF TRUCKING, INC., A R B I T R A T I 0 N Employer, D E C I S I 0 N and AETNA CASUALTY & SURETY CO., Insurance Carrier, Defendants. 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 employment.