In order to show that a heart attack was precipitated by exertion of the employee while in the course of his employment, it is only required that it be shown that the work engaged in was sufficiently strenuous, or of such nature that, combined with other factors in the case, it raises a natural inference through human experience that the exertion contributed toward the precipitation. Hoffman v. National Surety Corp., 91 Ga. App. 414 ( 85 S.E.2d 784). It may be shown by opinion evidence that the exertion, no matter how slight, or strenuous, when combined with other factors, such as pre-existing heart disease, precipitated the attack. J. D. Jewell, Inc. v. Peck, 116 Ga. App. 405, 406 ( 157 S.E.2d 806). Moreover, it has been held that "when the employee had a sudden attack while exerting himself at work, and there was no medical evidence that exertion at work did or did not contribute to the attack, an award of compensation was demanded."

Both doctors were of the opinion that the deceased would probably have died anyway had he stayed at home that night. In Hoffman v. National Surety Corporation, 91 Ga. App. 414, 417 ( 85 S.E.2d 784), Judge Townsend, speaking for this division of this court, after reviewing the facts and rulings thereon of the Court of Appeals and of the Supreme Court in several prior cases, said in stating what quantum of evidence is necessary in a workmen's compensation case like that now before the court in order to make out a case authorizing an award of compensation: "From the above, it must be concluded that it must be 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 precipitation of the attack. Where evidence as to the work engaged in shows it to be sufficiently strenuous, or of such a nature that, combined with the other facts of the case, it raises a natural inference through human experience that it did so contribute, this is

This case is, loosely termed, a heart attack case, and the factual issues in, such a case are (1) whether or not the employee suffered a heart attack or similar "accident" as that word is construed under the Workmen's Compensation Act, and if so (2) whether or not the attack or accident was caused by, or accelerated by, or contributed to by the deceased's exertion, however slight, while engaged in his work, or whether it was caused solely by the natural progression of a pre-existing physical condition completely unrelated in cause to his work. See Fireman's Fund Am. Ins. Co. v. Hester, 115 Ga. App. 39 ( 153 S.E.2d 622) (1967); Hoffman v. National Surety Corp., 91 Ga. App. 414 ( 85 S.E.2d 784) (1955). It is the duty of the board to weigh the evidence, decide what are the true facts, and make findings of the specific facts and on the material issues in the case.

"[I]t must be 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 precipitation of the attack." Hoffman v. National Surety Corp., 91 Ga. App. 414, 417 ( 85 S.E.2d 784). (Emphasis supplied).

The "natural inference" rule applicable to heart attacks is stated differently. In such cases, "... the evidence must show the work engaged in by the employee to have been sufficiently strenuous or of such a nature that, combined with the other facts of the case, it raises a natural inference through human experience that the exertion contributed toward the precipitation of the attack...." Hoffman v. National Surety Corp., 91 Ga. App. 414 ( 85 S.E.2d 784) (1955). The question before us is whether this "natural inference" is applicable to a heart attack following exertion at work where the first symptoms of such attack occur at a time when the employee is not engaged in the employer's business.

The basic issue in this case, the issue over which the Court of Appeals divided, is whether the "natural inference through human experience" will suffice to show causation in "heart attack comp cases." The insurance company contends that with the enactment of the 1963 amendment, the "natural inference" alone cannot be utilized to establish a causal connection between strenuous exertion and the heart injury. The natural inference rule was explained in the pre-1963 decision in Hoffman v. National Surety Corp., 91 Ga. App. 414 ( 85 S.E.2d 784) (1955); "[T]he evidence must show the work engaged in by the employee to have been sufficiently strenuous or of such a nature that, combined with the other facts of the case, it raised a natural inference through human experience that the exertion contributed toward the precipitation of the attack..."

1. The testimony of nonexpert witnesses who observed the exertion of an employee exercised in the discharge of the duties of his employment and the appearance of such employee, his obvious weakness and apparent state of being in considerable pain immediately after such exertion, together with his declarations that he was in need of medical attention and other surrounding circumstances such as the fact that he dies shortly thereafter without recovering from such seizure, even in the absence of expert medical testimony, is sufficient evidence to make an issue of fact on a hearing before the Workmen's Compensation Board as to whether the employee's death was caused by an accident arising out of and in the course of his employment. U.S. Cas. Co. v. Smith, 162 Ga. 130 ( 133 S.E. 851); Fidelity Cas. Co. v. Adams, 70 Ga. App. 297 ( 28 S.E.2d 79); Travelers Ins. Co. v. Young, 77 Ga. App. 512 ( 48 S.E.2d 748); Hartford Accident c. Co. v. Waters, 87 Ga. App. 117 ( 73 S.E.2d 70); Hoffman v. National Surety Co., 91 Ga. App. 414 ( 85 S.E.2d 784); Crescent W. W. Co. v. Cyr, 200 F.2d 633, 637. As held in Lumbermen's Mut. Cas. Co. v. Griggs, 190 Ga. 277 ( 9 S.E.2d 84), it is not essential to the validity of an award in favor of the employee's dependents that the exertion be greater than that customarily employed by him in the course of his employment. See also Hardware Mut. Cas. Co. v. Sprayberry, 195 Ga. 393 ( 24 S.E.2d 315); Williams v. Maryland Cas. Co., 67 Ga. App. 649 ( 21 S.E.2d 478); Lumbermen's Mut. Cas. Co. v. Bridges, 81 Ga. App. 395, 404 ( 58 S.E.2d 849).

" Guye, supra at 215-216. The "natural inference" rule has been stated as follows: "`[T]he evidence must show the work engaged in by the employer to have been sufficiently strenuous or of such a nature that, combined with the other facts of the case, it raises a natural inference through human experience that the exertion contributed toward the precipitation of the attack . . . .' Hoffman v. Nat. Surety Corp., 91 Ga. App. 414 ( 85 S.E.2d 784) (1955)." Southwire Co., supra at 897.

But, in Guye v. Home Indem. Co., 241 Ga. 213 ( 244 S.E.2d 864) and in Southwire Co. v. Cato, 250 Ga. 895, 897 ( 302 S.E.2d 91), the Supreme Court held that when the death is explained as heart attack, there arises a natural inference the death was work-related if the evidence shows the work engaged in by the employee was sufficiently strenuous or of such a nature that, combined with the other facts of the case as to raise such a natural inference through human experience that the exertion contributed toward the precipitation of the attack. Hoffman v. Nat. Surety Corp., 91 Ga. App. 414 ( 85 S.E.2d 784). This is not the same inference that arises when a death is unexplained. The Supreme Court has also held this inference does not disappear upon the presentation of medical testimony ( Southwire Co., supra at p. 898); but, by itself, it can satisfy the statutory requirement of "preponderance of competent and creditable evidence" where there is no medical evidence to the contrary.

The "natural inference" rule, as applicable in cases of heart attacks is, as follows: "Where evidence as to the work engaged in [by the employee] shows it to [have been] sufficiently strenuous, or of such a nature that, combined with the other facts of the case, it raises a natural inference through human experience that [the exertion] did . . . contribute [toward the precipitation of the heart attack], this is sufficient" to authorize a finding of a compensable injury and, thus, to support an award in the claimant's favor. Hoffman v. Nat. Surety Corp., 91 Ga. App. 414, 417 ( 85 S.E.2d 784) (1955). See also Guye v. Home Indem. Co., 241 Ga. 213 ( 244 S.E.2d 864) (1978); Southwire Co. v. Cato, 250 Ga. 895 ( 302 S.E.2d 91) (1983); Brown Transport Corp. v. Jenkins, 129 Ga. App. 457 ( 199 S.E.2d 910) (1973).