The Relation of Effort to Attacks of Acute Myocardial Infarction

In army experience the occurrence of acute myocardial infarction during or soon after strenuous effort is striking. The relation between effort and attacks of coronary occlusion or myocardial infarction has been the subject of considerable discussion because of the important clinical and other practical implications. 1 Thus, Master and his associates 2 analyzed the events preceding 530 attacks of coronary thrombosis and found that only 2 per cent followed unusual exertion, 5 per cent followed excitement and 37 per cent occurred during mild activity. They pointed out that, since half of the day of normal persons is spent in mild or moderate activity, one might well expect half of all attacks to occur during this period and concluded that effort is not a precipitating factor in causing myocardial infarction. These authors state that although both angina pectoris and coronary artery thrombosis have the same underlying pathologic condition, namely coronary sclerosis,