Atrial transport and aortic insufficiency.

Abstract

Twelve patients with aortic insufficiency and 10 normal patients were studied by right and left heartcatheteriza-tion. Both the P waves and the P-R intervals of the group with aortic insufficiency were demonstrated to be significantly longer. The delayed A-V conduction in this group was attributed to the massive dilatation of the left ventricle. The broadened P wave may be explained on the basis of an enlarged left atrium due to the greater volume demands placed upon this chamber. These volume requirements stem from the premature closure of the mitral valve, which foreshortens the period during which the atrium functions as a conduit and prolongs the phase during which it acts as a reservoir. These studies suggest that with a P-R interval prolongation, atrial systole plays an important role in atrial transport in the presence of an insufficient aortic valve.