The evidence presented by appellant Francis Nuanes is sufficient to establish both medical and legal causative exertion under the standards developed in our cases concerning employment-related cardiac attacks. Therefore, I would have reversed the order of the district court denying recovery under the Wyoming Worker's Compensation Act.
The trial court imposed a standard of proof with respect to medical causation, unsupported by our recent decisions. According to the judge's opinion letter, benefits would not be awarded absent an unqualified statement from the cardiac surgeon that the work effort had caused the attack:
"First, after a careful reading of the Doctor's deposition I cannot find where he states specifically that the moving of the filing cabinets was the direct casual [sic] connection between the work being performed and the cardiac attack."
We have said, however, that a medical expert can establish causation under § 27-12-603(b), W.S. 1977 (majority opinion at 88) with less degree of certainty than may be required in other cases. Wyoming State Treasurer ex rel. Wyoming Worker'sCompensation Division v. Schwilke, Wyo., 649 P.2d 218, 222 (1982). In Jim's Water Service v. Eayrs, Wyo., 590 P.2d 1346,1349 (1979), we said: *Page 91
"* * * [The pathologist] declined to say that he could determine to a reasonable medical certainty that the stress caused or precipitated the death and stated that James could have died in his sleep just as easily as on the job. However, he also testified that the stress was a `contributing factor' and that the arrhythmia `very likely' and `probably' was due to the physical exertion and strain. That is sufficient evidence of the causal connection."
From these and other cases we distilled the proper test of medical causation in Kaan v. State ex rel. Wyoming Worker'sCompensation Division, Wyo., 689 P.2d 1387, 1389 (1984):
"* * * The causal connection requirement is satisfied if a medical expert testifies that it is more probable than not that work exertion or stress contributed in a material degree to the precipitation, aggravation, or acceleration of a myocardial infarction."
Since the trial court in the instant case analyzed the expert's testimony under an erroneous test of medical causation, our usual, deferential standard of review concerning factual matters is inappropriate. We have the duty under these circumstances to examine the deposition of the medical expert and reach our own conclusion concerning causation, based upon this substantial evidence in the record. Scott v. Fagan, Wyo., 684 P.2d 805, 811 (1984). Dr. Robert M. Ristroph, the cardiac surgeon who treated appellant, testified concerning the causal relationship between the work effort and the subsequent heart attack. Although no statement pinpoints appellant's moving of the file cabinets as the sole causative factor, the totality of the doctor's testimony establishes that the exertion contributed in a material degree to the precipitation of the attack.
Portions of the expert's responses to direct examination are set out in the majority opinion. This testimony describes the causes of myocardial infarctions, in general, and establishes that any type of exertion by atherosclerotic individuals can place excessive demands on the heart muscle. The quoted testimony also affirms the possibility or probability of a causative connection between the moving of file cabinets and the cardiac attack within 15 minutes.
On cross-examination, counsel inquired as to whether Mr. Nuanes, in light of his occluded arteries, was predisposed to a heart attack, the only question being when. Dr. Ristroph estimated the constant known risk of a heart attack to be 3% to 5% per year for someone such as Mr. Nuanes with a double vessel disease. He further testified that Mr. Nuanes' risk might be above the 3% to 5% figure, given the 99% narrowing of his anterior descending artery. The doctor then concluded:
"A. Now, I don't know whether I could say would he have had it if he had not been employed and hadn't moved this hypothetical file cabinet. That type of thing is really, you know, asking for the mind of God, you know."
The final session of cross-examination produced the following:
"Q. As I understood your answer to a question Mr. Harris just asked you, there really isn't any way to testify today within any reasonable medical certainty whether the exertion that this patient had was or was not the cause of his heart attack, is that correct, from your standpoint, from your own knowledge of what you know about it?
"A. The exertion — I mean, it is general medical knowledge that exertion can produce a heart attack given that the person already has narrowing of his coronary arteries. Whether it's fair to say that the exertion causes the heart attack, is not clear to me. All right. Because the same exertion with someone without the narrowing of the coronary arteries, would obviously not cause a heart attack."
In sum, the doctor testified repeatedly that an infarction can occur when a person with atherosclerotic arteries exerts more than usual, thereby placing an excessive demand on the heart muscle. He confirmed the possibility or probability of a *Page 92 causal connectiion between the moving of the file cabinets and Mr. Nuanes' attack 15 minutes later. When asked specifically whether that exertion was or was not the cause of the heart attack, Dr. Ristroph answered:
"* * * [I]t is general medical knowledge that exertion can produce a heart attack given that the person already has narrowing of his coronary arteries."
Dr. Ristroph's complete testimony establishes that Mr. Nuanes' work effort contributed in a material degree to the precipitation of the heart attack. The majority, perhaps as a result of some of the language in our earlier cases, focus on select phrases in this testimony and conclude that it establishes no more than a possible causal link between the exertion and the attack. In my view, however, the expert's meaning should be gleaned from the totality of the information produced during direct and cross-examination. Considered in this manner, the evidence is sufficient to satisfy the requirement of medical causation under our worker's compensation statutes.
In addition to medical causation, the trial court based its holding on an absence of sufficient evidence to establish legal causation. That is, the court found no indication that the moving of heavy file cabinets by Mr. Nuanes constituted the unusual or abnormal stress required by § 27-12-603(b), supra.
We first delineated the proper rule for proof of unusual or abnormal exertion in Mor, Inc. v. Haverlock, Wyo.,566 P.2d 219, 222 (1977):
"* * * [T]he exertion in question must only be unusual to the employee — it need not necessarily be unusual to others engaged in the same employment. [Citations.] To sustain his burden of proof, as to legal causation, the statute requires that the employee show that the causative exertion was clearly something beyond his normal routine — something more than the worker's usual work."
We reaffirmed the validity of this rule in Jim's Water Servicev. Eayrs, supra, 590 P.2d at 1349; Wyoming State Treasurer exrel. Wyoming Worker's Compensation Division v. Schwilke, supra, 649 P.2d at 221; Yost v. Wyoming State Treasurer ex rel. WyomingWorker's Compensation Division, Wyo., 654 P.2d 137 (1982); andCreek v. Town of Hulett, Wyo., 657 P.2d 353 (1983). We said inJim's Water Service v. Eayrs, supra, that the test is satisfied when the exertion, although not different in kind from the employee's regular work, is greater in degree than normal.
When judged against this standard, the evidence in the present case supports only a finding that the moving of loaded file cabinets amounted to an unusual exertion for Mr. Nuanes. The uncontradicted testimony of appellant establishes that he typically moved furniture and equipment with the help of an apprentice or a laborer. He said that as a journeyman painter he was entitled to an apprentice to assist in the preparation of rooms for painting. He testified that the inadequate number of available laborers at the time of his heart attack necessitated his moving office furniture unassisted. A superintendent for the employer, the only other person to testify at trial, said that appellant was to contact him when helpers were needed to move furniture.
We faced an almost identical situation in Mor, Inc. v.Haverlock, supra. There the employee usually carried cement with the assistance of helpers or a hoisting device. On the day of his heart attack, he had no helpers, nor did he use a hoist. We held this evidence sufficient to establish unusual exertion.
The record in the present case establishes that appellant typically moved heavy objects with the aid of an apprentice or laborer. Prior to his heart attack, he moved four filing cabinets, each weighing 200 to 300 pounds, without help. This activity amounted to unusual exertion under § 27-12-603(b) and our prior cases.
The evidence of Mr. Nuanes' exertion on the day of his heart attack and the expert medical testimony concerning causation, when measured against the proper standards, establish appellant's entitlement to *Page 93 worker's compensation benefits. I would have reversed the order of the district court.