SERIAL P WAVE CHANGES IN ACUTE MYOCARDIAL INFARCTION

Tall, peaked P waves of normal duration were recorded in Lead 2 of the ECG in 24 patients during the course of acute myocardial infarction and were observed to be transient in 21 of these. No patient had evidence of valvular heart disease, pulmonary emboli, or other pulmonary pathology. Fourteen patients had manifestations of left-sided congestive heart failure during the time of greatest P-wave abnormality. Twelve patients had concomitant abnormal posterior rotation of the P-wave vector, indicative of left atrial overloading. The possible factors in the genesis of these P-wave alterations are discussed. The pattern of P pulmonale may occur during the course of an acute myocardial infarction in the absence of demonstrable pulmonary emboli or other pulmonary pathology. © 1969.