The Appeal CommissionThe Workers Compensation Act of Manitoba

Preamble

A non-oral file review was held on April 26, 2001, at the request of a worker advisor, acting on behalf of the claimant's widow. The Panel discussed this appeal on several occasions, the last one being September 13, 2001.

Issue

Whether or not the claim is acceptable.

Decision

That the claim is not acceptable.

Background

On November 3, 1999, a representative with the accident employer contacted a Workers Compensation Board (WCB) adjudicator to report that the claimant suffered a fatal heart attack at work at approximately 5:00 p.m. on November 2, 1999. He stated that he was not sure of all the details leading up to the death but that the claimant was operating a surface equipment truck that hauled ore from the pit to the stock pile. He stated that when the claimant didn't respond when signaled to back his truck into the pit, the pit personnel found him slumped over the steering wheel. The employer's representative noted that the claimant was a casual employee and that his general work duties involved laying pipe, helping surveyors and driving a truck.

On November 15, 1999, the claimant's widow filed a Surviving Spouse's Application for Compensation Benefits form.

On November 25, 1999 a WCB adjudicator spoke with the claimant's wife by phone. She stated that her husband previously had two heart attacks. One occurred in approximately 1989 or 1990 while at work. The claimant was working for a mine at the time and had been shoveling when he developed his chest pain. She believed that her husband's present heart attack was caused by the stress of the mine closing down as her husband was worried about losing his job. Apparently, he had just finished tightening the tire bolts of his truck and then went into his truck. He did not respond when he was contacted by his co-worker and was found slumped over the steering wheel. The widow indicated that an autopsy had not been performed as the cause of her husband's death had been deemed to be a massive heart attack.

In addition to the above commentary, a signed statement was taken from the widow on January 4, 2000. She stated that prior to November 2, 1999, her husband felt good. He did not have any chest pains nor did he take Nitro pills for the past 9 years. Her husband smoked approximately 20 cigarettes per day or less depending on how busy his day was. He rarely drank alcohol and if he did it would be one drink. He was a diabetic and he ate very healthy foods and especially liked fruit. He had been diagnosed with diabetes about 2 years ago. The diabetes was controlled by diet and he was not required to take insulin. She believed that the stress at work with the mine closing down in combination with tightening bolts on the truck had caused the claimant's heart attack.

In a memo dated January 10, 2000, a WCB adjudicator spoke with an employer representative and the following information was obtained:

• the claimant's duties involved driving the truck to and from the pit. The only physical activity with this task involved climbing up the step ladder into the truck.
• on November 5, 1999 the claimant began his shift at his normal time of 8:00 a.m. He drove his truck until his lunch at noon and seemed to be fine according to all statements. At 12:30 the claimant resumed driving the truck until his second lunch break at 4:00 p.m. He then had a 15 minute conversation with the pit superintendent whereby the claimant voiced his concerns about the pit closing and discussed the possibility of his future employment.
• after speaking with the pit superintendent the claimant went to the shop to tighten the lug nuts on his truck. This would have been the only unusual thing about the claimant's activities this particular day as normally the mechanics would do this job. The employer indicated that the tightening of the lug nuts would take some physical exertion, however, it would not be overly strenuous. No one knew why the claimant choose to do it this day, but speculation was that he didn't want to wait for the mechanic. The mechanic then arrived after the claimant was already finished. The claimant had a brief general conversation with the mechanic and then left the shop at approximately 4:40 p.m. to return to his duties of driving the truck. He would have driven approximately 2 kms to the pit. When the whistle sounded for the claimant to back his truck into the pit, there was no response. It was then noticed that the claimant was slumped over in the cab of the truck.
• when the claimant had been hired he indicated that he could do anything except shoveling. When asked why, the claimant indicated that he was unable to do so because of a prior heart attack. The employer representative stated that this restriction limited the employment opportunities for the claimant within the mine and that is why he was limited to driving.

On February 7, 2000, a WCB adjudicator spoke with the mechanic who would have normally tightened the nuts on the claimant's tires. He stated that by the time he made it back from lunch, the claimant had already tightened the lugs on his tires. This would have involved using an air gun weighing between 75 - 100 pounds. The gun vibrates and was very strenuous to operate. He stated that the claimant normally would not operate the air gun but it was likely that he did it this occasion as the mechanic was not available. The mechanic stated that he and the claimant spoke for maybe 5 to 10 minutes. They did not speak about anything in particular, but joked around about different things. The claimant did not seem sick and he was acting totally normal. He stated that he watched as the claimant climbed into the truck and that this action did not seem to affect him. He did not notice any hesitation from the time the claimant climbed into his truck and when he drove away.

On February 7, 2000, a WCB internal medicine consultant was asked by primary adjudication to review the file evidence and to provide his opinion as to the probable cause of death and whether the action of tightening bolts on a truck may have been a significant trigger factor. In response, the internal medicine consultant provided the following comments in a memo dated February 23, 2000:

• the death in this situation would be classified as sudden, unexpected death. The majority of such deaths were cardiac in origin and with the claimant's previous history of myocardial infarctions and angioplasty, it would seem reasonable to assume that the cause of death was cardiac. As there were no symptoms recorded prior to the event, the claimant likely had some form of ventricular arrhythmia resulting in ventricular fibrillation and death.
• the physical exertion required to tighten the bolts on the wheels did not produce any symptoms at that time. The claimant was seen alive around 3:30 p.m. therefore, it would appear that the proceeding event did not produce any symptoms. Patients with an unstable coronary lesion which may lead to acute events usually have some symptoms prior to the event. The symptoms may be present for a few minutes to several hours prior to the fatal event. In this situation, we have no knowledge of this being the case. The physical exertion did not produce an acute event.

Following a review of all file information and the comments expressed by the WCB's internal medicine consultant, the WCB denied the claim as it could not be established that the claimant had developed symptoms following his activities on November 2, 1999 while working. On April 4, 2000, a worker advisor, acting on behalf of the widow, appealed this decision to Review Office. The worker advisor contended that the work related incident had in fact occurred when the claimant used the impact gun to tighten the bolts on the wheels of his truck. He believed that this exertion was the trigger factor that caused the myocardial infarction on November 2, 1999. A medical report dated March 13, 2000 from the claimant's treating cardiologist was submitted for consideration. The worker advisor indicated that the report confirmed that the claimant had a severely impaired left ventricular function and that his cardiac prognosis would have been fairly guarded because of the severe impairment of function.

The claimant's widow also submitted a letter to the WCB on April 11, 2000 with respect to her appeal. She stated that it was common medical knowledge worldwide that it was possible to suffer a heart attack up to 10-15 minutes after the actual physical exertion. She noted that her husband went to lunch from 4 p.m. to 4:30 p.m. and that he finished his lunch early and had gone to the garage to wait for the mechanic. As the mechanic did not show up right away, her husband started and completed the job of tightening the lug nuts on his truck. After a brief conversation with the mechanic he got into his truck and drove off, minutes later he was found dead in his truck. He therefore only had a 30 minute break and was found dead at 4:30.

She indicated that her husband was never one to mention his fatigue or sickness and that he always kept on working. There was no cardiac monitor on him at the time to confirm any exact diagnosis of death and he must have had some idea of complications moments before his death because he removed his own dentures which was something he was rarely known to do. She stated that if it had been a ventricular arrhythmia resulting in ventricular fibrillation there would have been no indication of any complications, there must have been some indication from him to have had the time to remove his dentures.

The widow noted that the co-worker in question had been known in the past to be very passive, never took note of other things around him and had some confusion about judging time. She stated that the airgun in question weighed about 30 lbs. and when in use is required to be held upright, vibrating continuously while in the use. The air gun had the potential of producing 1250 lbs. of torque. This caused a lot of stress on a person during the process and would last for an extended period of time after the physical activity was complete.

Prior to considering the case, Review Office requested medical information concerning the claimant's previous cardiac difficulties along with information from the Department of Labour, Workplace Safety and Health Division.

A copy of the mine superintendent's statement which had been provided to the mine's inspection branch was obtained. The mine superintendent indicated that between 4:15 p.m. and 4:30 p.m. he was in the lunch room talking to the crew about working on November 6th along with other things, when he noticed that the claimant had left the room. Someone mentioned that the claimant had gone to the shop. He and a co-worker went over to the shop to retorque the front wheels on #2 truck and when they arrived the claimant indicated that he had already done it. The parties talked briefly and then the claimant left at about 4:40 p.m. At 4:55 p.m. the mine superintendent indicated that he was summoned to the radio and a call had come in requesting an ambulance. It appeared the claimant had blacked out. One minute later another call came through indicating that the claimant had more than just blacked out. When the parties reached the bottom of the pit, several of the operators had taken the claimant out of his seat and transferred him to a stretcher and then on to the ambulance.

At the request of Review Office, a WCB internal medicine consultant reviewed the case on January 9, 2001. This review included additional medical information concerning the claimant's past medical history. The consultant concluded that the cause of the claimant's death "was a ventricular arrhythmia. The exertion, which he undertook 15-20 minutes earlier, was coincidental and in my opinion did not contribute to the genesis of the arrhythmia." The Review Officer wrote on the memo that he had spoken with the internal medicine consultant regarding "exertion causing an arrhythmia. He said if the exertion was the proximate cause the deceased would have experienced immediate symptoms while doing the work or at least immediately afterward. This is not the case here."

In a decision dated January 19, 2001, Review Office determined that the worker's death did not arise out of his employment and that the claim for compensation was not acceptable. Review Office indicated that there was no question that the claimant died while in the course of his employment as he was found slumped over the steering wheel of his truck while parked at the mine pit. The Workers Compensation Act (the Act) contained a presumption under Section 4(5). It was the opinion of Review Office that the cardiac event experienced by this worker leading to his unfortunate death did not arise out of his employment. Review Office was of the view that the evidence did not support a conclusion that the claimant's work as a truck driver or the tightening of the lug nuts had caused his demise. The presumption had been rebutted and the claim was not acceptable.

On February 1, 2001, the worker advisor appealed Review Office's January 19, 2001 decision and a non-oral file review was requested. On April 26, 2001, a non-oral file review took place and the Appeal Panel considered all file information including the following submissions that were received from:

• a worker advisor dated February 14, 2001 and April 9, 2001;
• the claimant's daughter which was received on April 17, 2001 by facsimile;
• the claimant's family physician dated April 18, 2001;
• a letter from the claimant's wife dated April 18, 2001;
• a letter from the employer dated April 18, 2001.

Following the review, the Panel determined that additional information was required prior to discussing the case further. The Panel requested that an independent cardiologist attend the Appeal Commission to meet with the Panel to discuss the medical aspects surrounding the claimant's demise on November 2, 1999 and the medical relationship to his work activities. The independent cardiologist attended the Appeal Commission on June 25, 2001 and a copy of the transcript was distributed to the interested parties for comment.

In a letter dated July 19, 2001, a solicitor for the employer requested that the Appeal Panel meeting scheduled for August 2, 2001 be postponed to a later date in order to allow him additional time to prepare a submission to the Panel. The solicitor's request was granted. On September 13, 2001, the Panel met to render its final decision and took into consideration submissions received from both the worker advisor dated July 19, 2001 and September 5, 2001 and from the solicitor dated August 28, 2001.

Reasons

Chairperson MacNeil and Commissioner Finkel:

Section 4(1) of the Act provides for the payment of compensation benefits to a worker where he or she sustains personal injury by accident arising out of and in the course of employment.

“Where, in any industry within the scope of this Part, personal injury by accident arising out of and in the course of the employment is caused to a worker, compensation as provided by this part shall be paid by the board out of the accident fund, subject to the following subsections.”

In keeping with this section, the Panel must, initially, be satisfied that there has been an accident within the meaning of Section 1(1) of the Act. That is, “a chance event occasioned by a physical or natural cause; and includes

(a) A wilful and intentional act that is not the act of the worker,

(b) any

(i) event arising out of, and in the course of, employment, or

(ii) thing that is done and the doing of which arises out of, and in the course of, employment, and

(c) an occupational disease and as a result of which a worker is injured.”

With respect to the present case, the worker advisor acting on behalf of the deceased worker’s widow advanced the argument that the worker’s sudden death was causally related to his employment duties. In other words, the worker’s sudden death was the accident itself. According to section 1(1)(b)(i) of the Act, it is necessary to establish that the accident both arose out of and in the course of employment. The phrase “arising out of” generally refers to a causal connection between the work being carried on by the worker and the injury sustained. The phrase “in the course of” has been interpreted to mean that the incident occurred at work, or while discharging one’s employment duties.

In cases, which involve sudden death, it often happens that one component of an accident can readily be determined, but not the other. When this situation occurs, section 4(5) of the Act then comes into play. The section reads as follows:

“Where the accident arises out of the employment, unless the contrary is proven, it shall be presumed that it occurred in the course of the employment: and, where the accident occurs in the course of the employment, unless the contrary is proven, it shall be presumed that it arose out of the employment.”

Section 4(5) creates a rebuttable presumption of law that where the accident occurred in the course of employment it is presumed that it arose out of the employment and vice versa, unless the contrary is proven. Proof of the contrary is generally a question of appropriate medical evidence and fact.

As the background notes indicate, the deceased began his shift at the usual time of 8:00 a.m. on the day of his demise. His duties largely involved the operation of a surface equipment truck, which hauled ore from the pit of the mine to a stockpile. The only physical aspect of the deceased’s job involved his climbing up a stepladder approximately 4 to 5 feet in order to reach the cab of the truck. According to witnesses who came into contact with the worker throughout the day, he did not appear to manifest any physical symptoms or difficulties.

Sometime after 4 p.m. the worker engaged in a brief conversation with the pit supervisor. Following this meeting, the worker proceeded to the shop where he tightened the lug nuts on his truck. The evidence confirmed that the tightening of these lug nuts was not part of the deceased’s job description as the mine mechanic normally performed this function.

The mechanic indicated that the tightening of the lug nuts involved the use of an air gun weighing somewhere between 75 and 100 pounds. In addition, the operation of this equipment was very strenuous not only because of the weight, but also, because the tool produced a great deal of vibration. The mechanic stated that he had engaged in 5 to 10 minute conversation with the deceased prior to his climbing up into the truck and that the deceased did not appear to be ill. The deceased resumed his regular duties of driving the truck and a short time following his conversation with the mechanic he expired. He was discovered slumped over the steering wheel of his truck while parked at the mine pit.

The worker was taken by ambulance to the emergency department of a local hospital where he was pronounced dead on arrival. The presumed diagnosis ascribed by the hospital authorities as to the cause of death was that of a massive myocardial infarction. However, this diagnosis is a matter of medical conjecture, as it has never been conclusively established that the deceased suffered a myocardial infarction.

It is a well-documented fact that the deceased had a long history of heart problems as well as several associated major risk factors:

• First myocardial infarction 1988;
• Second myocardial infarction April 1990;
• Angiogram in September 1990 reveals dominant right coronary artery with diffuse disease and narrowing up to 60-70% in the mid portion. The left coronary artery showed moderate stenotic lesion up to 70% narrowing in the distal third of the left anterior branch.
• Angioplasty on September 18^th, 1990 resulting in a dissection in the right coronary artery;
• September 19^th, 1990 repeat angiogram showing residual stenosis and diffuse disease of the left anterior descending branch;
• A persantine infusion and myocardial perfusion studies in June 1994 showed fixed defects in both infralateral and anterior wall. The inferior and basal wall defects were noted to be severe.
• September 1994 worker admitted in emergency department of hospital for heart failure;
• Echocardiogram of September 1994 confirmed two chamber involvement, depression of systolic and diastolic function of the left ventricle. An estimated ejection fraction of 15 and 20% and mitral and perhaps tricuspid valve insufficiency;
• September 1994 chest x-ray showed severe cardiomegaly and heart failure;
• Echocardiogram of June 8^th, 1995 revealed dilated left ventricle and left atrium. There was also severe reduction of the left ventricular function. The overall ejection fraction was estimated at 23%;
• November 1997 repeat congestive heart failure precipitated by salt infusion;
• Echocardiogram of November 4^th, 1997 revealed left sided cardiac chamber enlargement with severe reduction in left ventricle systolic function and regional wall motion abnormalities, mild mitral valve sclerosis with at least mild to moderate mitral regurgitation and mild aortic sclerosis. The left ventricle was enlarged and there was a severe reduction in left ventricle systolic function with an estimated ejection fraction of approximately 13%;
• The worker was a diagnosed diabetic. Diabetes can cause impairment of the left ventricle function;
• The worker smoked for many years;
• The worker had a cholesterol problem;
• The worker was prone to have hypertension. His medications included Digoxin, Enalapril, Furosamide and enteric-coated aspirin.

In summary, the evidence confirms that the deceased had very severe myocardial damage resulting in an extremely low ejection fraction as well as significant injury to his left ventricle.

We consulted the services of an independent cardiologist to help us gain a better understanding of the deceased’s coronary artery disease. The consultant furnished the following information in response to various questions posed by the Panel.

“Well after reading the information that I had, I think the basic information that maybe the Panel would like to know is that the long-term prognosis of a cardiac patient is determined by the power of the pump or the ejection fraction.

A short-term prognosis occurs every time there’s an ischemic event. So if you were to look at an individual and say what’s their long term-term prognosis, look at their ejection fraction.

An ejection fraction is the power of the pump, how it squeezes. And a normal heart will squeeze to 70, 65 to 70 percent of its dimensions at rest, and when it contracts it reduces the volume by 60 to 65 percent. An ejection fraction of less than 40 percent is considered significantly impaired. An ejection fraction of less than 20 percent is severely impaired and carries with it a very poor long-term prognosis. His was 15 percent in 1997. We don’t know what his ejection fraction was in 2000, but it certainly wasn’t better than 15 percent.”

“Most people with impaired LV [left ventricle] function have two methods of death. One is sudden, as in Mr. [the deceased’s] case, or progressive heart failure and then they get progressively more short of breath and die.

"60 percent of people with an ischemic cardiomyopathy, which is the medical terminology of his heart condition, die suddenly, irrespective of a heart attack, an arrhythmic death. So 60 percent of people die suddenly, an arrhythmic death based on potential several mechanisms which we could get into. 40 percent of people just get progressively more short of breath and die. So he fits into that category of the 60 percent who die suddenly.”

“And then you go into what are the mechanisms of sudden death. One of them is just the underlying pathophysiology of an ischemic cardiomyopathy. They are prone to serious arrhythmias, incompatible with life. A chaotic rhythm of the heart, so it no longer functions as a pump. [This arrhythmia] can be spontaneous, with virtually no warning. I mean you’re talking somebody could keel over and drop dead.

Another potential mechanism is an ischemic event, i.e. a plaque ruptures in a coronary artery, blood vessel becomes occluded and that’s the setting of an ischemic arrhythmia, a malignant arrhythmia and that’s how many people die presenting to hospital with a heart attack. They die very quickly. So that’s the second potential mechanism.

The third mechanism may well be just a sudden change in hemodynamics. A change in the filling pressures of the heart by doing strenuous work or doing some heavy lifting could predispose him to change in the hemodynamics of the pump, such that he may, in fact, elicit a malignant arrhythmia.”

“So in his case, was it the basic pathophysiology of his underlying condition, did he have a sudden plaque rupture and have an ischemic event, or was it related to strenuous activity that changed the hemodynamics of his filling pressures acutely and predisposed him to sudden death?

You know statistically it’s likely the underlying pathophysiology of having an ischemic cardiomyopathy. Certainly nobody can say that he didn’t have an ischemic event, although I see in the emergency sheet when he arrived, they said he had a massive heart attack. And I don’t think anyone could say that, based on the story that I saw, with certainty. He may have had a heart attack, can’t say yes or no.

The other compounding factor in this case is that he did do some strenuous work lifting a heavy airgun, which I would have to admit for somebody with his heart shouldn’t have been doing. But whether that was his volition to do that or not, that’s – but that is another potential mechanism.”

Q. If someone was to have done strenuous activity, would they have become symptomatic immediately or can they have a delay? “Yes he could have – you know, most people that do strenuous work, he did have a leaking valve as well, in addition to having a heart that lost a lot of power and the two are often related. As the heart dilates, the valves become incompetent and leak.

One of the mechanisms is if they do heavy work, that valve suddenly leaks more because of the extra work that the heart has to do and the change in the hemodynamics in the heart in that situation usually are associated with the patient saying, ‘I’m short of breath’. I didn’t get that history from what I read.

But it is possible that he could have raised his filling pressures, the pressures inside the heart just by doing that strenuous work without becoming short of breath or admitting, or obvious shortness of breath (sic) that potentially could have provoked an arrhythmia. But there certainly is no history that I could read from the information I was provided that he complained of any dyspnea or shortness of breath.”

“Ventricular arrhythmia generally refers to an arrhythmia originating in the ventricle from a variety of potential etiologies, but that in most cases is originally, initially ventricular tachycardia. It’s a regular rhythm, but it’s very rapid. Normal heartbeat being 70 to 85, this may be a heartbeat of 180. A normal heart could probably tolerate that for several hours. A sick heart cannot tolerate that rapid rate and then breaks down into a chaotic rhythm called ventricular fibrillation.

But some people can go right into ventricular fibrillation without first going into V tach, although that’s not the usual case. I would think the vast majority of people initially go into V tach and they may get enough time to say, “I feel dizzy, light headed.’ And they may be able to talk at that point and give some warning, but it may quickly break down into ventricular fibrillation, which is sudden unconsciousness within a second or two. Or they may go primarily into ventricular fibrillation. You can be sitting there and then just suddenly fall over, no warning. So, and in this case, it’s not clear which of those two likely occurred.”

In conjunction with the foregoing evidence, we also attached considerable weight to the opinion provided by the WCB’s internal medicine consultant. After his review of the literature, he ascertained the following facts:

• Sudden cardiac death is instantaneous and most individuals become unconscious within a few seconds to minutes as a result of insufficient cerebral blood flow. There is usually no pre-monetary (sic) symptoms.
• The exact mechanism of collapse is impossible to establish. From observation in people who had been monitored, 80% of cases are due to sustained ventricular arrhythmia, which is preceded by an increased number of premature ventricular contractions. “I should like to point out here that halter monitor done by Dr. [name of physician] in 1977 did show that Mr. [the deceased] had a tendency towards ventricular arrhythmia, including short ventricular tachycardia.”
• Most people experiencing sudden cardiac death have chronic coronary artery disease. The incidence is higher in men and increases with age. If one looks at acute myocardial infarction, only 15% of such cases suffer from sudden cardiac death in the first 24-48 hours. The incidence falls to 3% in the next several days. Thus acute myocardial ischemia or infarction is not the cause in the majority of the cases.
• Presence of congestive heart failure increases the overall mortality and incidence of sudden cardiac death. Left ventricle hypertrophy increases risk of sudden cardiac death.

The WCB’s internal medicine consultant outlined his opinion, in a memorandum dated February 23^rd, 2000, as to why he believed the physical exertion with the airgun did not result in the deceased’s sudden death, but rather, it was caused by an arrhythmia.

“The death in this situation would be classified as sudden, unexpected death. The majority of such deaths are cardiac in origin and with the claimant’s previous history of myocardial infarctions and angioplasty, it would seem reasonable to assume that the cause of death was cardiac. When one considers the cardiac event leading to sudden death, the most frequent cause is cardiac arrest due to ventricular fibrillation. In only 15% or less cases the triggering mechanism for ventricular arrhythmia is recent ischemic changes. In the majority of cases, the ventricular fibrillation occurs as a result of ventricular arrhythmia, which progresses to rapid ventricular rate and finally ventricular fibrillation.

Since there were no symptoms recorded prior to the event, I suspect Mr. [the claimant] had some form of ventricular arrhythmia resulting in ventricular fibrillation and death.

The physical exertion required to tighten the bolts on the wheels did not produce any symptoms at that time. He was seen alive around 3:30 (sic) p.m. Therefore, it would appear that the proceeding event did not produce any symptoms. Patients with unstable coronary lesion, which may lead to acute events, usually have some symptoms prior to the event. These symptoms may be present from a few minutes to several hours prior to the fatal event. We have no knowledge of this being the case in this situation.

I therefore think that the physical exertion did not produce an acute event.”

Prior to reaching our final conclusions, we also took into consideration and attached weight to certain comments made by the deceased’s former treating cardiologist. His remarks are recorded in a letter dated May 15^th, 2000 to the Worker Advisor acting on behalf of the deceased’s widow.

“The circumstances undoubtedly support a connection between this strenuous exercise and the subsequent cardiac event. The late Mr. [the deceased] could have developed chest pain due to the work of a substantial portion of his heart far exceeding the capability of its blood supply to provide it with oxygen. The development of an electrical disturbance of heart rhythm is equally plausible. (Emphasis ours)

Clearly it is of great importance to consider the likely course of events if Mr. [the deceased] had not performed this strenuous work. He was well documented as having severe heart disease resulting from his previous heart attacks. Individuals in this situation have, perhaps, a 50/50 chance of surviving over a five year period. When it occurs, death is sudden in up to 60% of cases. In North America each year there are 350,000 sudden cardiac deaths and at least 100,000 of these will be patients with severe coronary disease and impaired heart function like the late Mr. [the deceased].”

It is well established that the standard of proof applicable to the workers’ compensation scheme is the ordinary standard of proof practiced in civil litigation and that is proof on a balance of probabilities. In addition, the proper standard of proof to be applied in determining whether the statutory presumption contained in section 4(5) of the Act has been rebutted is also on a balance of probabilities.

After having reviewed all of the materials contained on file, as well as the arguments submitted by the parties having a direct interest, we find the evidence clearly establishes, on a balance of probabilities, that the deceased’s sudden death was not caused by any physical exertion, which he had undertaken on the day of his demise. We further find based on the preponderance of evidence that the deceased’s sudden death was, on a balance of probabilities, caused as a result of his ventricular arrhythmia. Accordingly, the presumption created by section 4(5) of the Act that the deceased’s death arose out of his employment has been rebutted by the weight of evidence in our view. There has been no accident and therefore the claim is not acceptable.

Panel Members

R. W. MacNeil, Presiding Officer
A. Finkel, Commissioner
M. Day, Commissioner

Recording Secretary, B. Miller
R. W. MacNeil,

R. W. MacNeil - Presiding Officer
(on behalf of the panel)

Signed at Winnipeg this 11th day of October, 2001

Commissioner's Dissent

The worker advisor, in his submission on this appeal, advised that there are 12 - 1 ¾ inch nuts on each wheel of the vehicle that the claimant operated. The elapsed time from when the claimant tightened the lugs and when he died was between 15 – 30 minutes.

Because there was no autopsy on this gentleman, the cause of death is unknown and therefore is classified as sudden, unexpected death. We can assume the cause of death was cardiac related but cannot use WCB policy 44.10.10.60 on myocardial infarctions as it deals with claims that specifically involve a myocardial infarction. The claim therefore needs to be dealt with as an accident arising out of and in the course of employment.

Section 4(5) of the Act provides that where the accident arises out of the employment, it shall be presumed the accident occurred in the course of employment unless the contrary is proven; and where the accident occurs in the course of employment, it shall be presumed that the accident arose out of the employment unless the contrary is proven.

The majority has determined the presumption has been rebutted in that there is evidence to support the accident did not arise out of the claimant’s employment. There is no dispute that the worker died while in the course of his employment. I am satisfied that his death did arise out of his employment in light of the fact that he used an air impact gun that generated extra force and pressure to his upper body and in all likelihood placed a strain on his heart. This was unaccustomed work that was highly strenuous and translated into exertion that was out of the ordinary for the claimant.

Review Office, in their decision, references the remarks from the internal medicine consultant to the board who indicates “that the exertion which the worker undertook some 15 to 20 minutes earlier was coincidental and did not contribute to the genesis of the arrhythmia.”

The Appeal Commission consulted with an independent cardiologist on this file. The cardiologist indicated that the claimant was in a medical category of 60% of people who die suddenly as a result of their heart condition. He indicated that death can be sudden, can be a result of an ischemic event, and also that one of the potential causes of arrhythmic death may be a sudden change in hemodynamics which is a change in the filling pressures of the heart by doing strenuous work or doing some heavy lifting. This could predispose him to a change in the hemodynamics of the pump, such that he may in fact, illicit a malignant arrhythmia.

The claimant’s treating cardiologist indicated in a May 2000 report that the event may well have its origin in the usage of the torque wrench which weighs around 75 pounds and generates 1450 pounds of torque pressure.

Based on the medical remarks of the independent cardiologist to the Appeal Commission and the cardiologist’s report dated May 15, 2000, I am satisfied that on a balance of probabilities the strenuous activity performed by the worker was a major contributing factor in his demise. I am, therefore, satisfied that the worker sustained an accident that arose out of and in the course of his employment. I would consider the claim to be acceptable and therefore disagree with the majority on their decision.

M. Day, Commissioner