The opinion of the court was delivered by
Eeanois, J.
This is a heart death workmen’s compensation case. The Division of Workmen’s Compensation denied an award; the County Court and the Appellate Division affirmed. We granted certification.
Certification was allowed primarily to review the principle under which benefits are payable in heart attack cases, and the nature of the proof required in such cases to make them compensable.
Ciuba v. Irvington Varnish & Insulator Co., 27 N. J. 127 (1958), did away with the need for proof that the heart attack was caused or contributed to by an unusual employment effort or strain. That rule was supplanted by the doctrine that if the attack is caused or precipitated or contributed to by the ordinary stress or strain of the employment, a compensable accident comes into being. Thus, when an employee is suffering from an acute, or passively progressive or quiescent, heart condition, and the ordinary routine exertion of his regular work is too much for the heart, irrespective of whether the effort acts alone, or in conjunction or contribution with the weakness induced by the disease, to precipitate or accelerate or aggravate the attack, the resulting disability or death is within the statutory coverage. There is no requirement that the work effort be excessive in the sense of being unusual or not ordinarily engaged in. It is enough that a usual strain associated with the work was of itself too much at that time because of the condition of the heart, or that such routine effort in combination with the diseased condition of the heart produced the collapse. Compensability arises when[492]*492ever the required exertion is too great for the man undertaking the work, whatever the degree of exertion or condition of his heart.
The reasoning process by which the facts in a particular case are evaluated may be further aided by certain inquiries. Did the disabling or fatal attack result alone from the inexorable march of the disease? Was it the end result of the degenerative process in connection with which the employment stress was simply a coincidental condition, unrelated in any material way? Has it been shown by evidence, opinion or otherwise, that the exertion attendant upon the duties of employment, no matter how slight or how strenuous, and no matter with what other factors, such as pre-existing disease or predisposition to attack, it may be combined, was sufficient to contribute toward the attack or its aggravation? In short, where the heart has deteriorated to the point that potentially any appreciable degree of exertion carries a danger of precipitating, or so acting upon the condition as to accelerate, a disabling or fatal attack, if the effort or strain, which in fact precipitates or contributes to the attack, occurs during the course of the employment and as an ordinary or usual incident of the work, the resulting disability or death is compensable. Benefits are not lost because the amount of the work stress was such that it might or could be duplicated in routine activity about the home or in customary movements or effort while there. See Treloar v. Falmouth Docks & Engineering Co., Ltd., A. C. 481 (1933); 26 B. W. C. C. 214, 222. Nor is compensation to be denied because of proof that even if the accident had not happened the workman would have become totally disabled or would have died within a relatively short time by reason of the progress of his disease. Woodbury v. Frank B. Arata Fruit Co., 64 Idaho 227, 130 P. 2d 870 (Sup. Ct. 1942). As Dean Larson puts it:
“The general idea is that, even if the decedent would probably have died of cancer in any ease, the employment is deemed for compensation [493]*493purposes the cause of death if, due to a blow hastening the cancer, the employee dies today instead of six months from now.” 1 Workmen’s Compensation Law, § 12.20, p. 175.
See also: Welch v. County of Essex, 6 N. J. Super. 422 (Cty. Ct. 1949), affirmed 6 N. J. Super. 184 (App. Div. 1950); Milne v. Atlantic Machine Tool Works, Inc., 137 N. J. L. 583 (Sup. Ct. 1948); Voorhees v. Schoonmaker, 86 N. J. L. 500 (Sup. Ct. 1914).
It does not follow from what we have written that a heart attack which occurs at work is, without more, compensable. The work connection as a precipitating, aggravating or accelerating factor must appear. The basic idea intended to be conveyed (and which we approve) is expressed in very simple terms in the English case of Clover, Clayton & Co., Ltd. v. Hughes (1910) A. C. 242, 3 B. W. C. C. 275, cited with approval in both duba, supra, at page 135, and Hentz v. Janssen Dairy Corp., 122 N. J. L. 494, 496 (E. & A. 1939). There, Lord Loreburn expressed the test in this fashion:
“In other words, did he die from the disease alone or from the disease and employment taken together, looking at it broadly? Looking at it broadly, I say, and free from over nice conjectures: Was it the disease that did it or did the work he was doing help in any material degree?”
Naturally, the onus of establishing connection between a heart attack death and the work effort rests on the compensation claimant. The burden has been described in various ways but may be stated concisely in this fashion: Such claimant has the burden of showing by the preponderance of the believable evidence that the ordinary work effort or strain in reasonable probability contributed in some material degree to the precipitation, aggravation or acceleration of the existing heart disease and the death therefrom. In this context, the significance of “some material degree” cannot be stated with mathematical precision. It means an appreciable degree; a degree greater than de minimis; it [494]*494means that there was some employment exertion capable medically of helping the attack—of furthering its progress. We appreciate the difficulty in formulating a precise legal rule. There has been much discussion and agitation by cardiologists for and against the adoption of minimum medical criteria for use by the expert witness in assessing the probability of causal connection between work effort and heart attacks. But no such uniformly accepted standards have been approved. See McNiece, Heart Disease and The Law (Prentice-Hall 1961) ch. 11, § 2(c), p. 118. And, of course, the courts cannot state in advance whether such criteria would transgress legal standards by which they must determine causality. Id. 119; & ch. 18, § 4, p. 132. Moreover, whatever the difficulty may be in the medical profession in reaching common ground as to the test to be applied, the Division of Workmen’s Compensation and the judiciary cannot avoid their obligation to administer the compensation law. The Legislature has bestowed the right to monetary benefits for accidental injury arising out of and in the course of employment. And on the judicial scene existence of the right implies coexistence of effective means of enforcing it.
The rule outlined above is not just a catch phrase; it is not simply a formula to be mouthed in making an affirmative assertion of causal connection. The legal conclusion of cause and effect is ordinarily dependent upon evidence of medical causation advanced by physician witnesses in the form of opinion based upon the facts and circumstances attending the heart attack. But we repeat that the mere assertion of reasonably probable contributory work connection by a medical witness cannot justify an award. The facts of the situation under examination in their totality must demonstrate causality by the greater weight of the credible evidence. In this area the reasons for the assertion are more important than the assertion itself. Stanley Co. of America v. Hercules Powder Co., 29 N. J. Super. 545, 562 (App. Div. 1954); reversed on [495]*495other grounds 16 N. J. 295 (1954). Explanation of the physiological reactions of the diseased or ailing heart to the work strain in terms of sole or contributory cause and effect must generally be regarded as indispensable. The facts and circumstances surrounding the work effort and the heart attack, the medical opinion as to connection between the two, and the explanation of the connection from a medical viewpoint must coalesce in support of a finding by the greater weight of the evidence that the effort was at least contributorily responsible in some material way for the attack.
Some of the language running through the opinions of the various tribunals which have had this cause for consideration gives the impression that proof of a specific incident of work strain or effort coincidental with or immediately preceding the heart attack is regarded as an essential step in the establishment of causality. And the heart specialist whose testimony formed the basis for the denial of compensation said plainly that he would not regard a heart attack as resulting from employment unless there was “a stress or strain incident just prior to the onset of his initial symptom which is usually pain.” Proof of such a specific incident is not required as a matter of law, although it cannot be doubted that evidence of work effort closely followed by well recognized symptoms, such as pain, shortness of breath, collapse, etc., points with more probative force to a reasonably probable relation between the two events than if they were separated by a substantial period of time. This is not to say, however, that mere lapse of time between work effort and heart attack compels a conclusion of lack of connection. See McNiece, supra, ch. 4, § 2(b), p. 14. Solution of the problem depends on the facts of the particular situation considered in the light of the medical opinion adduced for and against the thesis of causal relation. On this aspect of the problem an important consideration must be noted. A single instance of work effort is not an essential element in proving causality; a succession of such efforts [496]*496over the entire work day is sufficient when followed by the heart attack in such time and under such circumstances thereafter as to demonstrate to the degree of probability required that the totality of work effort contributed to the attack. The right to compensation exists whether a single employment strain or a succession of such strains proved in whole or in material part to be greater exertion than the ailing heart could withstand. The Appellate Division, in Joy v. Florence Pipe Foundry Co., 64 N. J. Super. 13, 33 (1960), correctly stated the rule to be:
“Thus, if a strain occurs during the hours of actual employment, but no resulting symptoms are produced until after working hours, the disability, whether in the form of a heart attack * * *, a perforation of an ulcer * * *, or a cerebral hemorrhage, may nonetheless be compensable.”
Dean Larson, in his treatise on Workmen’s Compensation Law, likewise clearly states the applicable view:
“* * s> ¡n Workmen’s Compensation the controlling event is something done to, not Toy the employee, and since the real question is whether this something was an industrial accident, the origin of the accident is crucial, and the moment of manifestation should be immaterial.” 1 Larson, supra, § 29.22, p. 449. (Emphasis Larson’s)
To the author’s statement we add only as a cautionary note that the “moment of manifestation” is immaterial so far as the legal principle is concerned; it is not immaterial in the sense of having evidential value in deciding the factual issue of causal relation. Attention may be given here, also, to Whittle v. E.B.B.W. Vale Steel, Iron & Coal Co., 2 All. E. R. 1221 (1936), 29 B. W. C. C. 179, 198, where Lord Justice Slesser, in considering the matter of time interval between work effort and death, said:
“That' seems to me to be entirely a question of fact and of degree. I think if there had been a much longer interval that might have weighed with the learned county judge to say: ‘The interval is so long that I do not think in those circumstances I am satisfied that [497]*497the strain caused the death.’ But there can be no general principle that a man must die immediately he has received the strain; it is a question of fact to be decided on the evidence and the medical evidence.”
To the extent that the language of Loew v. Union Beach, 56 N. J. Super. 93 (App. Div. 1959) and Jacobs v. Kaplan, 56 N. J. Super. 157 (App. Div. 1959) may be considered contrary to these views, it is disapproved.
References also appear in the opinions below to the need for proving an event or happening beyond the mere employment itself or for proving an effort greater than the stresses and strains of ordinary living. The import of such tests is somewhat obscure and deceptive. Does ‘beyond the mere employment” mean something greater than routine effort to which the employee has grown accustomed? Does it indicate a need to prove some employment strain greater than mere passive presence at the place of employment? Does the suggestion that proof must be adduced to show a work effort greater than the ordinary stress and strain of living merely signify a duty to show some employment effort greater than the exertion caused by breathing or moving one’s arms, legs or body in the fashion they would move routinely when away from work ? Whatever the precise connotation of those expressions, the rule governing compensability may be stated in this fashion: If the effort or strain, whether great or little, was an incident of the employee’s work and either alone or in combination with disease played a material part in causing, contributing to or accelerating a heart attack, the attack is compensable.
Since it is not entirely clear whether a test of the proper dimensions was applied in the earlier studies of the case, we feel that justice demands a revaluation of the record in the light of our observations as to the controlling legal rule for determining compensability.
Decedent, Gerald E. Dwyer, age 41, six feet tall, weighing about 200 pounds, was married and the father of four dependent children at the time of his death on April 30, 1958. [498]*498He had been in the employ of respondent, Eord Motor Company, for seven years and engaged primarily in factory laboring work. Apparently he was a steady worker and enjoyed good health prior to May 1956.
Around the end of May 1956 he began to experience pain in the chest which spread to his left arm and neck. On June 11, according to his widow, the chest pain became severe, his left arm went “dead” and the hand became “numb and cold.” The next day he was admitted to Christ Hospital, Jersey City, where he remained until June 30. The diagnosis on discharge, at which time he was “very much improved,” was “arthritis (rheumatoid)” and “angina pectoris.” These ailments were listed by the attending physician on the record in the “order of importance,” and his final note as to the heart condition was “Patient had typical anginal pains which were promptly relieved with nitroglycerine. E.CGs were negative.” It may be noted that these electro-cardiograms were produced and examined at the hearing in the Division by the specialists who testified for the parties. Dr. Saul Lieb, who appeared for petitioner, said they were suggestive of myocardial involvement and would corroborate a diagnosis of coronary disease and coronary insufficiency. Dr. Jerome G. Kaufman, who testified for respondent, did not specifically interpret them while on the stand but after looking at them he did say Dwyer was suffering from coronary sclerosis with insufficiency, known as angina pectoris.
After leaving the hospital, Dwyer remained at home under the care of a cardiologist for three weeks before returning to respondent's plant. His factory work was pursued regularly thereafter. On December 6, 1956, apparently after work, he called at the office of the family physician, Dr. Herman Kaplan, complaining of pain across his chest, radiating down his left arm. Electro-cardiograms were taken but they did not reveal any myocardial damage. The doctor said that if the electro-cardiograms taken in June 1956 at the Christ Hospital did show such damage, in his opinion the [499]*499signs of it had disappeared. However, he made a diagnosis of coronary insufficiency and prescribed vasodilator pills.
Dwyer continued to work until February 11, 1957, when Dr. Kaplan made a house visit in response to a call. After this, Dwyer stayed home until February 15. The record is unclear as to just what it was that kept him from employment. The sum of Dr. Kaplan’s testimony seems to be that Dwyer was again complaining of chest pains (for which he ordered a continuance of the pills), but that the reason for staying home until February 15 was an upper respiratory infection.
In any event, on February 15, 1957, Dwyer returned to work and engaged constantly in his duties, without further attention by a doctor, for over 14 months until Sunday, April 27, 1958. Shortly before lunch on that day, according to his wife, he had severe pain in his chest and could hardly breathe; perspiration poured from him; there was severe pain in the left arm, and the hand was cold and numb. Mrs. Dwyer called Dr. Kaplan, who prescribed nitroglycerin pills which she obtained from a nearby drug store. These pills were taken at intervals íot the remainder of the day. During the night Dwyer had difficulty sleeping and assumed a propped-up, partial sitting position in the bed. Dr. Kaplan came to the house early Monday morning, diagnosed coronary insufficiency and advised continuance of the pills. It is obvious from the testimony that Dwyer had improved considerably. He did not go to work on Monday (his workday began at 3:30 p. m.) but “just stayed at home.” Mrs. Dwyer did not sayffie remained in bed that day and there-is no testimony that the severe chest pain, breathing difficulty or left arm and hand difficulty continued that day. Hor does it appear that he slept other than in normal fashion on Monday night.
On Tuesday morning, although he looked pale and fatigued and showed the results of his attack, he felt well enough to want to go to work. The inference is fully justified that he considered he had sufficiently responded to [500]*500the medication, as he had on previous occasions, to warrant resuming the employment duties. Mrs. Dwyer called Dr. Kaplan, discussed the matter with him and, although she was not permitted to recite the conversation, it is beyond question that the doctor considered him sufficiently improved to return to work and sanctioned his return. In the doctor’s testimony on direct examination, he said he approved the return to the factory but advised against “heavy lifting, heavy pushing, and things like that.” On cross-examination, he conceded lack of any independent recollection as to just what advice he gave that morning but said that he had told Dwyer “all along” to do only light work. Nevertheless, with respect to April 29, apparently on the basis of his general knowledge of the ease, he said: “Oh, yes, he could go to work.”
Dwyer left for work in the afternoon, taking lunch and the nitroglycerin pills along. He drove his car to the plant, an hour’s drive, picking up some fellow workers on the way. It must be regarded as unlikely that he could or would have driven for that distance if his left arm were painful and the hand numb or if he had the severe chest pain or difficulty in breathing which he had experienced on Sunday. In fact, one of the fellow workers who rode in the car made no reference in his testimony to any difficulty in operating the car, although he did describe Dwyer as pale, drawn and fatigued looking; and he saw him put a pill in his mouth during the trip.
One of Dwyer’s usual duties was to “line up” a barrel filled with a chemical substance on a stand three or four feet above the floor. Erom that position the barrel when needed would be pushed on to a bonderizing machine to replace the barrel then on the machine, when its contents had been used up. Because of the weight and bulk of the barrel, it had to be lifted by the workman with a steel chain block and fall. The block and fall was attached to the barrel by hooks and the barrel then raised by hand. When raised, it was kept in the hanging position until [501]*501needed, then the chain of the block was loosened and the barrel pushed into place. The fellow employee, Iiintze, spoken of above, saw Dwyer engage in that operation fairly early in the workday and asserted that when it was finished he looked white, strained, and started to puff, something that he had never done before. The witness added that in fact Dwyer had previously handled the movement with ease. The added portion of the answer was stricken as a voluntary comment. In our view, the striking was improper. It was responsive to the question, and assuming that the intended reason for the action was that the answer represented a conclusion which the witness had not been qualified to give, it must be kept in mind that all conclusions of laymen are not objectionable. There are certain matters of opinion which the ordinary person, by reason of everyday knowledge, experience and judgment is qualified to express. See VII Wigmore on Evidence (3d ed. 1940), § 1974, p. 113; 1 Conrad, Modern Trial Evidence (1956), § 642, p. 531. A conclusion based on previous observation that a person handled with ease a physical operation or movement of the type involved here is clearly within the category.
Around 6:30 p. m. Hintze saw Dwyer remove an empty barrel from the bonderizing machine, slacken the chain of the block and fall and push a filled, hanging barrel into place. At this time he looked extra tired, worse than when he had arrived at work; he looked like a “sad sack”; on being asked if he needed water, he said yes. Shortly thereafter he moved a hand truck about 350 feet down an aisle, put a filled barrel on it and pushed it back to his working station. His movements were “a lot slower”; he walked slowly, although he was usually a fast walker. At 7:45, when the lunch break came, he did not eat his lunch or drink his coffee; he took a nitroglycerin pill; he looked as though he could not carry on his usual work.
Part of decedent’s work entailed the making of hooks from metal wire. Each one weighed about three-quarters of a pound. When 50 or 60 pounds of them had been made, [502]*502they were put in boxes and carried by hand to the point where they were to be used. Dwyer was observed on two occasions that night carrying such boxes. Around 10:30 p. m. he rolled another barrel of chemicals 15 or 20 feet to the bonderizing machine. At this time he looked worse than he had previously.
The work period ended at midnight. Dwyer drove home, taking four fellow workers with him. They were dropped off at intervals along the way. He drove more slowly than usual, and was seen to take a pill during the trip. As he came into the house, it was obvious that he had severe pain. His wife said he was “in awful pain.” She immediately called Dr. Kaplan and, being unable to reach him, telephoned the police who took him to the North Hudson Hospital.
On admission to the hospital he complained of severe precordial pains which “started about” three hours prior to admission. Electro-cardiograms were taken and disclosed acute coronary occlusion with posterior wall infarction. Death occurred at 3:20 A. m. April 30, 1958, 50 minutes after admission.
Two specialists in internal medicine testified on the subject of causal connection between the work effort on April 29 and the acute coronary occlusion; one for petitioner and one for respondent. Their testimony reveals agreement on a basic medical principle that stress or strain can be a contributory factor in the aggravation of an existing coronary insufficiency. (See also the testimony of respondent’s physician in Loew v. Union Beach, supra, at p. 103.) Consequently, they approached the question of medical causation from common ground, i. e., effort or strain can contribute to an aggravation or acceleration of an existing coronary insufficiency. Thus, the crucial issue calling for their expert opinion became: Did employment strain so contribute? And they recognized that the answer to the question was one of medical fact, that is, it depended on the nature of the particular employment effort or strain to [503]*503which Dwyer was subjected and the physiological reactions which followed in its wake.
Dr. Saul Lieb, in answer to a hypothetical question based substantially on the facts outlined above, said that the cumulative effect of the work effort expended on April 29 aggravated or accelerated Dwyer’s pre-existing heart condition and resulted in the coronary occlusion. In his opinion, the described work activity was “a major contributing factor” in producing the acute occlusion.
In discussing his conclusion, the doctor said that, starting on Sunday, April 27, and continuing on April 28, Dwyer had suffered a spontaneous worsening of his pre-existing coronary disease, more specifically air attack of acute coronary insufficiency, which continued. There was no indication that he was going to die of it if he had not gone to work on April 29. Such an attack carries with it a certain amount of hazard but, as Dwyer’s own previous history indicated, a person can survive many attacks of acute coronary insufficiency. Respondent’s physician, Dr. Kaufman, put it this way: some persons die from the first attack, some from the second, and some live “many years.”
Dr. Lieb recognized that the acute attack had improved or subsided by the time Dwyer went to work on April 29. There was no indication that the chest pain or shortness of breath persisted as it had on the two previous days, although he showed the effects of the attack. That conclusion Dr. Lieb felt was supported by Dr. Kaplan’s permission for Dwyer to return to work. The doctor agreed with Dr. Kaplan that no work requiring physical exertion should have been engaged in; in fact, he opined that Dwyer would have been “well advised” to have remained in bed that day. Such inactivity is advisable because repeated physical exertion puts a greater demand on the heart for blood, and if the patient is suffering from coronary insufficiency the greater demand, if it could not be accommodated, would result in increased coronary insufficiency and eventuate in an acute myocardial infarction. And in this case the repeated work [504]*504exertion during the day, as described to him, coupled with the evidence of puffing, physical slowing down as the work progressed, and the worsening of his appearance, provided a “clear indication” that Dwyer’s cardiovascular condition kept deteriorating during the work interval, so that he became a “very sick man” by the time he went home. In sum, Dr. Lieb asserted that on the total history the cumulative effect of the repeated exertion (which was inadvisable for a person who had had previous attacks of this type of coronary insufficiency) was such as to increase the extent of his coronary insufficiency so as to be a major contributing factor in producing an acute myocardial infarction.
Dr. Jerome G. Kaufman took the contrary view. On the basis of the history given, he said Dwyer sustained a severe attack of coronary insufficiency on April 27, which persisted thereafter until his death on April 30 which was due to a myocardial infarction resulting from the prolonged attack of insufficiency. In his opinion, there was no causal relationship between the work effort and the death.
In Dr. Kaufman’s opinion, Dwyer should have remained in bed after the onset of the attack on April 27. He should not have been working in the throes of his attack because physical exertion of any kind would cause a greater demand on the heart for blood. Under such circumstances he might “lift something and collapse while lifting it and have a rupture of his heart if he had an infarction already existent or this might contribute to a strain incident and I would only have my conscience to bother me * * But in this instance he ruled out any causal connection between the obviously substantial work effort and the fatal attack because it is his belief that in order for such connection to exist in any case “there must be a stress or strain incident just prior to the onset of his initial symptom which is usually pain.” For purposes of appraising that statement, we must assume that it represents his view as a physician, and not an expression of what he conceives to be the legal test. Even as a medical concept, it poses difficulty for the [505]*505judge in the absence of further elucidation. Does “just prior” mean immediately prior? If not, what time interval marks the outermost boundary of acceptable sequence from the medical standpoint? Does the concept mean that no matter how diseased the heart or how great the ordinary work effort may be, medicine does not accept any relation of cause and effect between the effort and a heart attack, if the pain or other relevant symptom does not appear until after the employee reaches home? Moreover, does the reference to “a stress or strain incident” indicate that causal connection will not be considered to exist from a medical standpoint unless the attack follows immediately after a single work effort; that if the collapse comes in the train of a succession of work strains, medicine recognizes no causality, in whole or in part ?
Apart from these academic medical questions which the judiciary is not qualified to answer, let us look at the testimony of both expert witnesses in the light of the controlling legal test and the facts of the specific case before us, in a search for the greater weight of the evidence as to whether the total employment effort on April 29 in reasonable probability played a material part in the aggravation or acceleration of Dwyer’s fatal heart attack. There is no doubt that he had a bad heart or that he had one of a succession of attacks on April 27. The experts agree that bed rest was the required treatment. So commonly known and accepted is that course that judicial notice has been taken of it. Johnson v. Aetna Casualty & Surety Co., 174 F. Supp. 308 (D. Tenn. 1959); Prudential Ins. Co. of America v. Gang, 184 Tenn. 188, 197 S. W. 2d 806 (Sup. Ct. 1946). It is plain also from their statements that heavy work of any kind is dangerous for the patient who suffers from cardiac insufficiency, the degree of danger mounting in mathematical proportion to the extent of the effort, as well as the state of advancement and acuteness of the insufficiency. In all of the following eases involving awards of compensation the workman’s heart disease was in an advanced state or in [506]*506acute attack when he undertook to engage in regular work exertion. The medical opinion in each was to the effect that rest was the treatment required and physical strain was hazardous. Central Electric Power Association v. Hicks, 236 Miss. 378, 110 So. 2d 351 (Sup. Ct. 1959); Coleman v. Coker, 204 Tenn. 310, 321 S. W. 2d 540 (Sup. Ct. 1959); Johnson v. Aetna Casualty & Surety Co., supra; Reynolds Metals Co. v. Robbins, 231 Ark. 230, 328 S. W. 2d 489 (Sup. Ct. 1959); Sweat v. United States Fidelity & Guaranty Co., D. C., 169 F. Supp. 155; Goodnite v. Farm Equipment Co., 234 Miss. 342, 103 So. 2d 391, 104 So. 2d 298, 106 So. 2d 383, 683 (Sup. Ct. 1958); Poole v. R. F. Learned & Son, 234 Miss. 362, 103 So. 2d 396, 105 So. 2d 162 (Sup. Ct. 1958); Cramer v. Sunshine Biscuits, Inc., 2 A. D. 2d 719, 152 N. Y. S. 2d 375 (App. Div. 1956); General Motors Corp. v. Hall, 93 Ga. App. 181, 91 S. E. 2d 57 (Ct. App. 1956); Schilling v. Mississippi State Forestry Commission, 226 Miss. 858, 85 So. 2d 562 (Sup. Ct. 1956); Thompson-Weinman Co. v. Yancey, 90 Ga. App. 213, 82 S. E. 2d 725 (Ct. App. 1954); Lumbermen’s Mut. Casualty Co. v. Kitchens, 81 Ga. App. 470, 59 S. E. 2d 270 (Ct. App. 1950); Workman v. Johnson Bros. Const. Co., 164 Kan. 478, 190 P. 2d 863 (Sup. Ct. 1948); see also McNiece, supra, ch. 5, § 3, p. 20.
A number of heart attack cases in New Jersey have spoken of a duty on the part of the claimant for compensation to overcome the “presumption” that the disability or death resulted from “natural physiological causes.” The expression seems to have appeared for the first time in Schlegel v. H. Baron & Co., 130 N. J. L. 611, 612 (Sup. Ct. 1943). Experience with workmen’s compensation cases over the intervening years has now convinced us that the “presumption” rule has imported an unnecessary and artificial factor into their determination at both trial and appellate levels. The applicable basic and controlling principle, as we have already stated it, is simply that the person seeking statutory benefits has the burden of establishing by the [507]*507greater weight of the believable evidence that the heart attack was caused or contributed to in a material way by the employment exertion. Addition of subsidiary or intermediate formulas such as the duty to overcome an antagonistic threshold presumption brings nothing to the inquiry in the way of clarification of the nature of the ultimate burden of proof. Rather, the tendency is to obscure the standard and time-tested rule and to convey the impression that something more than preponderance of the credible evidence is necessary to prove causality. See Aromando v. Rubin Bros. Drug Sales Co., 47 N. J. Super. 286, 292 (App. Div. 1957); Dalton v. Consolidated Laundries Corp., 134 N. J. L. 27 (Sup. Ct. 1946). It must be remembered that a presumption of fact of the character of the one under discussion is emptied of all probative force and disappears from the case upon the introduction of any proof to the contrary. Obviously, in a given situation if no evidence of causal connection were offered the burden of proof would not be met and there could be no recovery. To say in such a case that the petitioner has failed to overcome the presumption that the heart attack was due to natural causes, does not contribute either to the clarity or ease of administration of the basic rule. Practical utility being absent, therefore, the presumption must be eliminated as a factor in evaluating the weight of evidence.
The preponderance of the proof in the present record establishes that Dwyer’s attack had substantially improved or subsided because of the rest and treatment on April 27 and 28. Certainly he felt himself capable of coping with the work on April 29. Also, his awareness of his own experience with previous attacks and return to work thereafter cannot be overlooked. But, even if he overestimated his capacity to withstand the routine employment strain, compensation is not to be denied if the strain was too much for the weakened heart, i. e., played a material part in aggravating or accelerating the attack. Cramer v. Sun[508]*508shine Biscuits, supra; Larson, supra, § 38.64(c), p. 555; § 38.83, p. 566; McNiece, supra, ch. 5, § 3, p. 20.
The sequence of events while at work is of extreme significance, even utilizing Dr. Kaufman’s demand for timely appearance of symptoms of effect on the heart after strain incidents. As has been set forth earlier, within a relatively short time after inception of the workday, Dwyer undertook to put a heavy barrel in position for use by the bonderizing machine. The effect of this effort was unusual. He began to puff, which he had not done before, and he looked strained. This same operation was engaged in about an hour before the lunch period at 7:45. On doing this, he looked extra tired, worse than on arrival at work; like a “sad sack,” and acknowledged a need for water. Then, at 7:45, he did not eat or drink; he took a nitroglycerin pill. After further heavy work, such as carrying boxes of hooks weighing 50 or 60 pounds, around 10:30 p. m. he again handled one of the heavy barrels of chemicals. At this time his appearance was worse than previously. These events over the hours involved are fairly indicative of an adverse effect of the physical work strain on the ailing heart and also of a gradual worsening of the heart condition on the heels of the exertions. The reasonableness of these inferences finds some support in the North Hudson Hospital history which reveals that severe precordial pains began around 11:30 p. m., just before Dwyer finished work. Further corroborative significance is also provided by the testimony that by the time he arrived home his pain was so desperate as to require immediate hospitalization for marked coronary insufficiency and acute coronary occlusion. The acuteness and severity of the attack are shown by the failure of four nitroglycerin pills taken in the three hours before admission to give any relief.
Consideration of the entire factual framework in which this decedent’s fatal heart attack has been presented stimulates in us a strong feeling of probability that the succession of employment strains described—as distinguished from a [509]*509single incident immediately followed by pain or other symptoms—participated in a material way in the acceleration of the attack. We are convinced that the series of exertions so acted on the seriously diseased heart as to join with it to an appreciable extent in hastening the fatal attack. Our emphasis is placed on the total or cumulative effect of the work effort, and not on any single act or any single exertion beyond that usually associated with the work, because of the uncertainty previously mentioned as to the underlying concept on which benefits were denied by the tribunals below.
The circumstance that Dwyer may have gone to work suffering from or weakened by a wholly or partially relieved attack of coronary insufficiency cannot, of itself, be treated as a bar to compensation. For example, in Johnson v. Aetna Casualty & Surety Co., supra, the workman’s attack began in the morning before he left home to go to work. He had pains in his chest and difficulty in breathing and departed for the place of employment in spite of his wife’s protestations. The attack seemed to ease to some extent on the way but began anew, or continued to get worse, as he engaged in his usual tasks which, incidentally, were not as laborious as those of Dwyer in this case. He went to the dispensary because of the pain, remained there about two hours, felt relieved and returned to duty. About four hours later his condition became much worse and he died. The court said: “Any kind of exertion * * * at his work was too much for his heart to withstand in its then grievously impaired condition.”
In Sweat v. United States Fidelity & Guaranty Co., supra, Sweat began to suffer from difficult breathing and “smothering spells” on returning home from work on Thursday. On Priday, only a half day’s work was required. He rested over the week-end but could not report on Monday because of the distress in his chest. On Tuesday, in spite of the continuing breathing difficulty, he returned to work for fear of losing his job. He made no complaints during [510]*510the morning of laboring work, but shortly after lunch he suddenly fell from a bench on which he was sitting and died almost immediately. There was substantial medical testimony that the work effort was the primary or contributing cause of the death. Compensation was allowed.
In Workman v. Johnson Bros. Const. Co., supra, on the evening before his death the employee came home complaining of severe pain in the chest. His face was pale and his lips blue. The medical witnesses said at the later hearing that he had suffered an occlusion. They said also that he should have been put to bed because very slight activity by a man in that condition is dangerous. He returned to his regular employment as a carpenter the next day and apparently dropped dead at his place of work between three and four o’clock in the afternoon. Compensation was allowed on the basis of medical testimony that driving nails into wood (which decedent had been doing) “could be considered a contributory fact to his sudden collapse”; that it was “entirely probable” that such effort intensified or accelerated his disease so as to cause the death; that probably the work made the “event come on perhaps quicker”; that it was possible that any exertion of any kind at that time “would be the precipitating factor, or the final straw resulting in his death.”
In Poole v. R. F. Learned & Son, supra, the proof showed the onset of coronary thrombosis on Saturday, while Poole was out hunting. On the Monday following the attack, Poole returned to work, as a “log scaler” (measurer of log footage) and worked all that day. The next day Poole drove in his jeep to a woodsite where he scaled two truckloads of logs and then drove 30 miles to the sawmill and scaled three truckloads. A half hour later, while talking with the mill foreman, Poole suffered a coronary thrombosis attack and died. He had shortly before complained “of a pain in his chest and of a discomfort which had been present since the prior Saturday.” The medical testimony was to the effect that he should have been put to [511]*511bed on Saturday because all the conditions affecting the circulatory system and heart are aggravated by exertion and physical activity would produce a dangerous complication. Denial of statutory benefits by the attorney-referee, Workmen’s Compensation Commission and circuit court, was reversed.
Again, in General Motors Corp. v. Hall, supra, the evidence showed that Hall’s heart attack began around three o’clock in the morning when he was in bed. He reported for work at 6:45 A. m. and after walking up two flights of steps took his usual place in the assembly line. Very soon thereafter he complained of severe smothering pain in his chest which was radiating into both arms. He told fellow employees that the pain had begun at 3 a. m., but said to one of them that it had “eased off” and to another that it had become intermittent. He was taken home, then to the hospital where he succumbed five days later of coronary thrombosis. The Georgia Court of Appeals said:
“A finding is authorized that the employee, if he had a heart attack at 3, recovered from this attack sufficiently to go on about his daily duties, and that while climbing the steps he suffered another fatal attack.”
Reynolds Metals Co. v. Robbins, supra, another heart death case, reveals that the attack began prior to the beginning of work which required physical exertion in a room where the temperature was 20 to 30 degrees hotter than outside. Medical testimony was adduced that when the acute attack began, Robbins should have been put to bed immediately, that any exertion would aggravate the condition because the “heart tends to work faster when one is walking or taking physical exercise” because there is “a greater demand on the coronary artery.” The testimony showed also that if such a patient is put to bed immediately, he “would have a far better chance of surviving” than if he engages in physical exertion.
[512]*512All that we have said projects once again the idea that in administering the Workmen’s Compensation Act the law does not consider the state of a workman’s heart, i. e., whether sound or far gone in disease, at the time it is subjected to work effort, as a crucial criterion in the determination of his right to benefits for a heart attack. No standard of health is required of an employee and the employer takes him as he is. Whatever the condition of his heart may be at the time of exposure to work strain, if that strain contributes materially to producing or aggravating or accelerating an attack, compensability exists. We recognize the difficulty of applying the rule so as to achieve justice in a given case between employer and employee. Ordinarily the courts must turn to the medical profession for help and guidance. But here we find discord; on the same set of facts one expert finds etiological causation in whole or in part; another denies it. We must assume, from all of the cases appearing in the reports, that even though work effort or. strain is accepted medically as a possible aggravating factor, honest differences of opinion may exist within the profession as to whether, under given circumstances, the particular exertion should be considered as having been causally related to a heart attack. The ultimate judicial decision in a specific case, then, must be reached through an evaluation of the conflicting opinions in the light of the facts surrounding the work effort which are relied on by the witnesses as the basis for their views. The delicate nature of that task is the reason why the law must underline so heavily the demand that the medical experts describe the operative factors which have led to their conclusions. As Dean McNieee says: “To the extent * * * that the quality of medical testimony can be improved, the task of courts and commissions in deciding the legal consequences of that testimony will be made easier.” Heart Disease and the Law, supra, at page 132, § 4.
For the reasons expressed, our review of the record in the light of the rule of law to be applied satisfies us that [513]*513legal causation to the required degree has been shown by a preponderance of the evidence. Accordingly, the judgment is reversed and the matter is remanded to the Workmen’s Compensation Division for entry of an appropriate award.