Ritmo circadiano para o início dos sintomas dos casos clínicos de enfarte agudo do miocárdio. Os nossos primeiros quinhentos casos

Following previous studies, we conducted an inquiry into acute myocardial infarction in our ward (Medicine 2, St. John Hospital, Oporto) regarding the exact time of the onset of symptoms. The results now published are of the first five hundred cases. These results show three peaks of greater frequency in the onset of symptoms--morning, afternoon and evening, as well as a certain degree of nocturnal protection. Our intention is to continue this study.