(concurring).
I regret that I am unable to join the majority opinion, mainly because I cannot understand the rule or rules it announces. If it intends to apply the rule requiring proof of “reasonable medical probability” for causation as announced in Insurance Company of North America v. Myers (Tex.Sup.1966), 411 S.W.2d 710 and interpreted in Otis Elevator Co. v. Wood (Tex.Sup.1968), 436 S.W.2d 324, then I cannot agree with the opinion. If the opinion holds that in certain areas of workmen’s compensation cases where there is a good deal of common and judicial medical knowledge, the jury will he permitted to determine causation *55without, or even in spite of, expert medical testimony, then I can agree with the result.
As I understand the Myers and Otis Elevator cases, there are areas in which the plaintiff has the burden to prove by a competent medical witness, that “in reasonable medical probability,” the alleged event or accident caused the injury. The opinions say that it is not critical, as a matter of semantics, that the doctor use the particular words “in reasonable medical probability” if that is, in context, the substance of his testimony.
Whether his testimony satisfies the “reasonable medical probability” test must be a question of law because it controls the submission of issues to the jury. The presence or absence of such testimony, for example, might be determinative as to whether a defendant would be entitled to an instructed verdict.
The doctor who was a witness here had been the plaintiff’s physician for some 20 years, and he was called to the stand by the plaintiff. The electrical shock occurred on July 14, 1965, when the plaintiff was approximately 59 years of age. The doctor had taken an electrocardiogram of the plaintiff in 1957; and it was his opinion that in the process of aging, (and omitting as many medical terms as possible) the plaintiff had a predisposition to vascular difficulties. Some time between 1957 and 1965, he began to have hardening of the arteries, and the condition or disease was progressive. This hardening of the arteries resulted in the substantial narrowing of the diameter of the blood vessel which fed the particular heart muscle which died. The doctor said that coronary arteriosclerosis (hardening of the arteries) was a primary cause of the plaintiff’s attack.
The doctor’s testimony was that the function of an electrocardiograph (here referred to as an EKG) was to pick up electrical impulses given off by the heart and its muscles. When this particular muscle was alive, it gave off a positive electrical impulse which was picked up by the machine. When the blood vessel became completely blocked, as in his opinion this one did, the heart muscle begins to die. His testimony was that under these circumstances the heart muscle does not die immediately; that even though there is blockage of the blood vessel (a coronary occlusion), the muscle remains alive and does not die for 1 to 3 days. So that on the day of the blockage of the blood vessel feeding the muscle, the muscle would continue to give off electrical impulses which would be picked up on the EKG as positive signals. When the muscle dies (myocardial infarct) it no longer gives off the positive electrical impulse, and the EKG machine records a negative impulse.
It was the doctor’s testimony that the plaintiff had been having pain in the epi-gastric region [in the vicinity of the heart] for several days before July the 14th, the day of his electrical shock. He went to the doctor on July 13th, giving the doctor the history of the pain, and the doctor took an EKG. It was normal. The doctor explained that the blood vessel could have already been blocked when he took the EKG on the 13th, but the heart muscle had not yet died and was continuing to give off the normal positive electrical impulses. When the plaintiff was brought to him around noon or thereafter on the 14th, the muscle probably had died; and the EKG was abnormal. The doctor could not “pin down” whether the plaintiff had had the coronary occlusion (blood vessel blockage) on the 13th or the 14th; and he could not testify where, in what vicinity, the plaintiff was when he had the attack. He testified that the attack may have started on the 13th. On cross examination, he stated that it was equally probable for the attack to have occurred if the plaintiff had been in bed or walking down the street. He also testified on direct examination that in reasonable medical probability, the attack might have occurred if the plaintiff had stayed in bed on the 14th. The doc*56tor then added, “It probably would have occurred anyhow.”
When the doctor was asked the direct question by plaintiff’s counsel if in reasonable medical probability the electric shock and the heart attack were causally related, the doctor said, “I don’t know.” Upon further questioning on direct examination, he said that, “I think there is a possibility it could have”; “It could have”; and as stated in the majority opinion, he also said, “I think that the chronological events * * * make it a strong possibility that this [the electrical shock] could help precipitate a heart attack”; but he immediately added, “I don’t think you can say without medical doubt though because I have doubts whether it did or not, you see.” [Emphasis added.]
And as stated, on cross examination, in explaining the EKG readings, it was his opinion that the attack could have begun the day before, on the 13th; that he could not' say, in reasonable medical probability, whether the attack occurred on the 13th or 14th; and that it was equally medically probable that the attack would have occurred if the plaintiff had stayed in bed or was out walking.
Taking the above testimony in context, I cannot draw the legal conclusion that the substance of the doctor’s testimony is that in reasonable medical probability, the electric shock on the 14th caused the plaintiff’s heart attack. Singling out the particular words most favorable to the plaintiff, the doctor said there was a “strong possibility”; and, as I read his testimony, that is as far as he did go or intended to go-
The result is, in my opinion, that if the Court is of the opinion that expert medical testimony is required in heart attack cases such as this, it has substituted “strong possibility” of causation for “reasonable medical probability,” and the test of the Myers case is no longer the law. The next case may involve not “strong possibility” but “reasonable possibility” or just “possibility”; i. e., is it “possible” for radiation to cause cancer. Apparently “possibility” is not enough in the cancer case in view of the Court’s opinion handed down this date in Parker v. Employers Mutual Liability Insurance Co. of Wisconsin, Tex., 440 S.W.2d 43.
The Court apparently is unsure as to whether the doctor’s testimony amounts to “reasonable medical probability” because at the end of the opinion, it concludes, in substance, that even if it is not, the doctor did not negative that possibility. As to that, the burden is on the plaintiff to prove causation; and either medical testimony of “reasonable medical probability” is necessary or it is not. I fail to see how the failure of the plaintiff’s doctor to negative a necessary element of the plaintiff’s case helps the plaintiff establish anything, including reasonable medical probability.
It seems to me that the case stands for this: we give a liberal construction in workmen’s compensation cases; and we think that juries should be entitled to decide causation with or without medical testimony in areas of common experience. Let us suppose that a 60 year old workman had been working hard all day in extreme heat and humidity and had hurriedly climbed ten flights of stairs carrying a 100 pound object. At the top of the stairs, he faints and falls out and dies or becomes seriously ill and is thereafter unable to work; he is completely incapacitated. I believe that we would let that case go to the jury without medical testimony. That is, such evidence in a workmen’s compensation case established a prima facie case. If the defendant tendered a doctor who testifies that the man had a heart attack, but that in his opinion physical exertion, however violent or prolonged, bears no relation to heart attacks, his testimony would not demolish the plaintiff’s case and could be accepted or not accepted by the jury. The result would be that the courts would not allow a doctor’s testimony to destroy the workman’s case in the area where *57courts and juries have common experience and knowledge.
There would he cases where the medical testimony was so strong and uniform, and the common experience and knowledge so speculative and unreliable that the medical testimony would completely destroy the plaintiff’s prima facie case. I would be willing to say that such is not the case here. The workman had a predisposition to a heart attack. He was old, tired, and ill. He was hot and sweaty. He had been exerting himself considerably, holding and working with an electric drill above his head. He had climbed a ladder and received an electric shock which he testified went throughout his entire body. He became seriously ill very soon after the shock and was taken to a doctor. It is undisputed that he had a serious heart attack.
I would prefer to say that under these circumstances, the plaintiff made out a prima facie case for the jury, with or without medical testimony, or even in spite of it, to the holding that the doctor’s testimony in this case rose to “reasonable medical probability,” or that the failure of the doctor to negative reasonable medical probability somehow satisfied the plaintiff’s burden of producing medical testimony and of proving reasonable medical probability of causation.