This is an appeal by the employer and earner from a decision of the Workmen’s Compensation Board which determined that the claimant sustained an accidental injury on February 12, 1959 in the nature of a myocardial infarction. The appellants in their brief minimize the testimony of the claimant’s physician, but it was the carrier’s doctor who stated that the claimant suffered from a “very small infarction”: and that the final diagnosis at the hospital was “myocardial infarction”. While the issue of causal relation was in sharp conflict, which is not unusual in this type of case, the evidence was sufficient to give the board the right of election and which they have determined in favor of the claimant. The Referee’s decision was to the effect that the testimony of the claimant was unbelievable and the claim for compensation an afterthought, all of which related to his credibility. The board determined to the contrary which was within its sole and exclusive jurisdiction and not reviewable on appeal in this court. “ The record leaves us no course but to affirm.” (Matter of Palermo v. Gallucci & Sons, 5 N Y 2d 529, 533.) Decision unanimously affirmed, with costs to the Workmen’s Compensation Board. Present—Coon, J. P., Gibson, Herlihy, Reynolds and Taylor, JJ.