Judgment, Supreme Court, New York County (B. Nadel, J.), entered September 8, 1982 vacating determination of respondent New York City Employees’ Retirement System denying petitioner accident disability retirement, and directing said respondent to grant petitioner accident disability retirement pursuant to section 207-k of the General Municipal Law is reversed, on the law, and the petition is dismissed, without costs. The expert *652opinion of the medical board was that the type of heart disease from which petitioner suffered — valvular heart disease with aortic insufficiency — was of a kind that is not related to the stresses of occupational activities or the performance and discharge of police duties, but rather to childhood diseases. In our view this expert medical opinion constituted “competent evidence” sufficient to justify the medical board in finding that the case fell within the “unless” clause of subdivision a of section 207-k of the General Municipal Law (the heart bill), which provides a presumption that heart disease was incurred in the performance and discharge of duty, “unless the contrary be proved by competent evidence.” (Accord Matter of Vecchiarello v Board of Trustees, 115 Mise 2d 241, affd 96 AD2d 1153.) Concur — Sullivan, Asch, Silverman and Milonas, JJ.