Right Ventricular Volumes in Patients with and without Heart Failure

SINCE Starling first related the force of myocardial contraction to end-diastolic fiber length,' most studies have evaluated ventricular performance in terms of end-diastolic pressure. End-diastolic volume (EDV), a closer approximation to fiber length, has been generally neglected because satisfactory methods for measuring it in vivo were not available. Angiocardiographic technics, recently applied by several investigators for estimating ventricular volumes,2-7 seemingly give reasonable approximations. However, the calculated volumes are measured when the heart (and coronary circulation) are filled with the hypertonic contrast media, which produce immediate, profound circulatory effects.8 9 Consequently, the volumes and tensions (which can be estimated from knowledge of simultaneous shape, pressure, and volume) obtained may not be those in the steady state prior to injection of the media. Furthermore, because of the shape of the right ventricle, angiocardiographic estimations of ventricular volumes in man have been limited to the left ventricle. Reedy and Chapman'0 recently estimated total ventricular volume and subtracted that of the left ventricle to estimate right ventricular volume in the dog. The indicator-dilution technic may be used to estimate ventricular volumes if the in-