The opinion
PALLADINO, Judge,
dissenting.
I respectfully dissent.
I believe the majority has not only overlooked the equivocal nature of the medical testimony, but has ignored the statutory requirements that must be met before the presumption of compensability for occupational diseases can be applied. The following factual background is helpful.
On May 14, 1985, John C. Edwards (Decedent), a volunteer fireman, was called to assist in fighting a brush fire, and was asked to drive a 1967 tanker truck to the scene. Decedent performed this activity in the past. Upon arriving at the scene, Decedent was told to return to the firehouse because the brush fire had been extinguished. Shortly after returning to the fire station, Decedent was stricken by *79 a condition which ultimately lead to his death. Decedent’s personal physician, Dr. Donald J. Stone, without reviewing the emergency room records or personally examining the Decedent, listed the cause of death as acute myocardial infarction.
Claimant filed a fatal claim petition alleging that Decedent’s heart attack occurred in the course and scope of his employment as a volunteer fireman with Hunlock Township (Employer). Employer filed an answer to the petition denying that Decedent’s death was work-related, and alleging that any heart attack was related to a pre-existing condition and not affected or caused by his employment.
Following a hearing, the referee issued a decision in which he found that Decedent’s death was directly caused by his employment and granted the fatal claim petition. The following pertinent parts of the findings of fact are relevant:
3. ... [T]he Fire Chief of Hunlock Township Fire Company was called and he testified that the Decedent had been within the volunteer corps for 21 years and that he served as a Treasurer, drove a truck and was also a dispatcher____ The witness further indicated that the vehicle driven by the Decedent was a 1967 truck, had a manual shift, was a difficult vehicle to drive, and that although the decedent had driven the vehicle in the past, he had not driven the particular vehicle for a number of months prior to this incident....
4. The medical evidence presented established unequivocally that although no autopsy was performed, the Decedent had in fact died from a coronary incident, episode or infarct, and the only disagreement between the two Doctors, was whether the events of the day, the driving of the truck, the stress of a fire or other precipitating factors in fact caused death. Dr. Grow, on behalf of the Defendant, opined that it did not, while Dr. Stone, on behalf of the Decedent, opined that it had.
5. The Referee is satisfied, however, from this record that the Claimant has sustained her burden of proof in *80 establishing a relationship between the incidence of the day and the ensuing death. As the Chief of the Fire Department indicated, the vehicle in question, was a difficult vehicle to drive, that it had a manual shift which created part of th [sic] difficulty and that although the Decedent was experienced in driving it, he had not driven it for a number of months, and as a result, and because of the stress of responding to fires, the Referee feels that these are key factors in buttressing the medical testimony of Dr. Stone____
Employer appealed to the Board which reversed, finding that there was no proof of stress in the record to support the hypothetical question posed to Decedent’s treating physician, Dr. Donald Stone, and that Dr. Stone’s testimony was not legally sufficient to show a causal relationship between Decedent’s employment and his death.
Because the death certificate listed the cause of death as acute myocardial infarction, and because Decedent had been a volunteer fireman for more than four years, the majority concludes Decedent had an occupational disease as defined by section 108(o) of the Act. However, these two facts, in and of themselves are legally insufficient to establish an occupational disease under section 108(o).
Under this section of the Act, the Claimant must establish that he actually had the occupational disease in question, Harrigan v. Workmen’s Compensation Appeal Board, 40 Pa.Commonwealth Ct. 390, 397 A.2d 490 (1979), and that the disease of the heart and/or lungs was caused by “extreme overexertion in times of stress or danger or by exposure to heat, smoke, fumes or gases, arising directly out of the employment ...” as a fireman. These two factors are the basis of the dispute in this case.
Addressing the cause of death issue first, Claimant had the burden of proving that Decedent’s death was a result of an occupational disease, i.e. a disease of the heart, Purex v. Workmen’s Compensation Appeal Board (Oden), 70 Pa.Commonwealth Ct. 548, 454 A.2d 203 (1982), which burden of proof requires substantial competent medical evidence *81 that Decedent died as a result of a heart condition. When there is a dispute 1 as to the existence of an occupational disease, unequivocal medical testimony is necessary. See Werner v. Workmen’s Compensation Appeal Board (Bernardi Bros., Inc.), 102 Pa.Commonwealth Ct. 463, 518 A.2d 892 (1986).
Where medical testimony is necessary to establish a causal connection, the medical witness must testify, not that the injury or condition might have or possibly came from the assigned cause, but that in his professional opinion the result in question did come from the assigned cause.
Lewis v. Workmen’s Compensation Appeal Board (Pittsburgh Board of Education), 508 Pa. 360, 365 , 498 A.2d 800, 802 (1985). The determination of whether medical testimony is unequivocal or not is a question of law, determined by reviewing the entire testimony of the medical witness. Id.
Claimant introduced the death certificate to show that the cause of death was an acute myocardial infarction. While a death certificate is prima facie evidence of the cause of death Hauck v. Workmen’s Compensation Appeal Board, 47 Pa.Commonwealth Ct. 554, 408 A.2d 585 (1979), it is not *82 conclusive evidence of the cause of death. Id. In the present case, Decedent’s personal physician, Dr. Stone, demonstrated in his testimony, that he was not reasonably sure of the cause of death, even though he had listed the cause of death on the death certificate as an acute myocardial infarction.
Q. Doctor, am I correct in stating that without an autopsy we can’t say within a reasonable degree of medical certainty what the cause of Mr. Edwards’ death was?
A. I can say with a reasonable medical background yes. I think, in my opinion, he suffered from an acute coronary event.
Q. Doctor, this patient you said had coronary artery disease or you suspected he had coronary artery disease?
A. I suspected.
Q. Would you be able to state that within a reasonable degree of medical certainty, doctor?
A. Yes.
Q. Do you suspect that he died of a heart attack or of a coronary event — strike that — or is it your opinion that he did?
A. I’ll say, in my opinion, I have a high indicis [sic] suspicion that Mr. Edwards’ demise was a direct result from a coronary event.
Q. You again agree then and it’s your opinion that he had coronary artery disease, is that correct, prior to his demise?
A. In my opinion, I state I had a high indicis suspicion that Mr. Edwards had coronary disease.
Deposition of Dr. Stone at 10-12. Viewing Dr. Stone’s testimony as a whole, there is no degree of certainty as to the cause of Decedent’s death. A “high indicis suspicion” and a feeling that the death was due to a coronary event, is not unequivocal testimony.
*83 The majority relies upon a single response of Dr. Stone to conclude that the evidence supports the referee’s decision in favor of the Claimant. However, the testimony must be reviewed in its entirety. As the above excerpt shows, when Dr. Stone was asked directly whether Decedent had coronary artery disease, he did not reply in a definite manner, but could only state within a reasonable degree of medical certainty that he “suspected” Decedent had the disease and a “high indicis suspicion” that the disease was present. Accordingly, I believe that the medical testimony in support of Claimant’s claim that Decedent had a heart condition, is equivocal and insufficient as a matter of law.
On the issue of the existence of stress, even if it were assumed that Decedent suffered from a disease of the heart, section 108(o) requires that the death be a result of “extreme over-exertion in times of stress or danger.” On this issue Dr. Stone testified as follows:
Q. Do you know the circumstances immediately proceeding — strike that — do you know the cause of his death?
A. I can state my opinion. In my opinion, his cause of death was an acute coronary event and so stated on his death certificate. Again, there was no autopsy done, however; I’ve been suspicious throughout his care and felt that at the time of death it was due to an acute coronary event.
Q. Based on your knowledge of your treatment of Mr. Edwards and in light of the — are you familiar with the circumstances, as a matter of record, the basis for a hypothetical question I think has been presented in that the testimony that has been presented as a matter of record in this case indicates that Mr. Edwards was a fireman, was summoned to drive the fire truck, which I believe was a tanker fire truck, to the scene of a fire. He was in the process of doing this when he was directed to *84 return to the fire hall. As he was backing the fire truck into the garage, he suffered this cardiac experience. Based on those hypothetical facts and based on your prior treatment of Mr. Edwards, can you state with reasonable medical certainty whether the strain or excitement of the situation encountered by Mr. Edwards could have been a substantial contributing cause of his death?
A. The facts I knew surrounding the event as so stated, as far as the question itself, yes, I definitely feel that the event that was surrounding his cause of death was a direct result as to what he was doing at the time.
Deposition of Dr. Stone at 6-10.
A hypothetical question must be based on facts which appear in the record. Borough of Morrisville v. Workmen's Compensation Appeal Board, 54 Pa.Commonwealth Ct. 41, 419 A.2d 813 (1980). If a hypothetical question is based upon facts not of record, the response to the question is not competent. Lamoreaux v. Workmen’s Compensation Appeal Board, 92 Pa.Cmwlth. 1 , 497 A.2d 1388 (1985). The hypothetical question posed to Dr. Stone contains a reference to “strain or excitement of the situation encountered by Mr. Edwards — ” The only evidence of record of any stress was the following question put to the fire chief, Donald Hines:
Q. Is there any anxiety — do you experience any anxiety or aggravation in fighting a fire?
A. Yes.
However, there was no evidence that Decedent actually fought a fire on the day of his death, or that he was subjected to extreme over-exertion in a time of stress or danger. As a result, the hypothetical was based upon facts not in the record, and the connection between extreme over-exertion, stress or danger, and Decedent’s death, was not established by the record.
Finally, the majority’s reliance upon Marcks v. Workmen's Compensation Appeal Board (City of Allentown), *85 119 Pa.Commonwealth Ct. 214, 547 A.2d 460 (1988) is misplaced. In Marcks the record established that the Claimant had been exposed to smoke, fumes, and gases for the statutory period. This evidence is lacking in this case. While the record indicates that Decedent was a volunteer fireman for 21 years, the record also only indicates that Decedent served as treasurer, drove a truck and was a dispatcher. The record contains no evidence that Decedent was exposed to smoke, fumes, or gases for more than four years, or that he engaged in extreme over-exertion in times of stress or danger. Without such evidence, even if Decedent had a disease of the heart, no occupational disease can be found, as a matter of law.
Accordingly, for the above reasons, I would affrm the decision of the Board.
. The Employer’s theory was that Decedent choked to death. Dr. Stone testified on this issue as follows:
Q. Doctor, did you review the emergency room record with regard to his admission when he was DOA?
A. I don’t remember doing that, no.
Q. Do you know whether or not they found a wad of tobacco lodged in his throat?
A. I don’t know?
Q. Do you know whether or not, the history in the record indicate [sic] that he was gasping for air and that he appeared to be, had a straight ahead stare and was holding his throat?
A. I don’t recall that, no.
Q. Doctor, would that be consistent with an asphyxiation?
A. I’m sure that if the patient suffered some kind of cardiac event that he could also asphyxiate if he had anything in his mouth, including saliva or any other foreign.
Whether the asphyxiation occurred first or a coronary event occurred first, I don’t have an opinion to that.
Q. Doctor, if the record showed that he had food particles and a wad of tobacco lodged in his throat and which were blown out by suction, could he have choked to death as a cause of death?
A. I think there’s a reason that he could, yes.
Deposition of Dr. Stone at 23-24.