The Pseudo P Pulmonale

IT HAS BEEN generally accepted that the electrocardiographic pattern of a tall and peaked P wave with a normal duration in leads II, III, or aVF is characteristic of right atrial enlargement.1-3 Such a P wave is called the P pulmonale in contrast to a wide and notched P wave, usually best seen in leads I and II, due to left atrial enlargement, the P mitrale. During the course of interpretation of the routine electrocardiograms in a general hospital, the authors were impressed by the frequent appearance of such a P-pulmonale pattern in patients whose clinical diagnoses did not suggest the presence of right atrial enlargement. The purpose of the present study was to determine the specificity of such a P-pulmonale pattern by clinical correlation. Vectorcardiographic analysis of the P waves was done in many of the patients in an attempt to obtain additional useful information.