Posterior Rotation of the Atrial Vector

ACUTE left ventricular failure frequently, if not always, produces acute left atrial distention. Such distention, if clinically recognizable, would be a useful sign of left ventricular failure, a disorder that notoriously may lack discriminatory findings. Angiocardiography that may specifically diagnose left atrial distention, and cardiac catheterization that may specifically diagnose acute left ventricular failure are not practical procedures simply to establish such diagnoses. The purpose of this study is to show that acute changes in the electrocardiographic P waves are useful and perhaps sensitive signs of acute left ventricular failure.