Real-time cross-sectional echocardiography was performed to record the interatrial septal echogram by right atrium-interatrial septum-left atrium (ASA) direction of the ultrasound beam by positioning the transducer to the right of the sternum. The configuration of the interatrial septum (IAS) and the change of the configuration through each cardiac cycle were studied in 10 normal subjects and 2...

Studies were made with standard time motion and B-scan echocardiography on 48 patients including 5 with idiopathic hypertrophic subaortic stenosis (hypertrophic obstructive cardiomyopathy), undergoing diagnostic cardiac catheterization. The dimensions of the left ventricular outflow (O) and inflow (I) tracts were measured on the B-scan images. The outflow tract was significantly narrowed in idi...

We developed a novel technique for estimating ventricular contractility using intraventricular pulse wave velocity (PWV). In eight isolated, cross-circulated canine hearts, we used a fast servo pump to inject a volume pulse into the base of the left ventricular chamber at late diastole and at late systole. We measured the transit time of the volume pulse wave as it traversed the distance from b...

We studied a number of dynamic events associated with the pulsatile flow of blood in the pulmonary arterial system of six healthy men in the supine position. We used the nitrous oxide-body plethysmograph method to record the pulmonary capillary blood flow pulse and the phonocardiogram to determine the time of opening and closing of the pulmonary valve. The pattern of right ventricular ejection ...

Aortic valve leaflets undergo extraordinary flexion due to the complete reversal of their curvature during billions of cardiac cycles. The flexion stresses in the leaflet depend on its elastic modulus which we investigated in vivo and in vitro. In six dogs, we placed radiopaque markers on an aortic leaflet. Leaflet length was calculated from the marker positions recorded fluoroscopically. Aorti...

The fourth heart sound consists of low frequency vibrations which are heard in presystole during sinus rhythm. Fourth heart sounds have been described during various phases of diastole in subjects with ventricular pacemakers, by virtue of complete atrioventricular dissociation and/or block.’ Although such sounds are commonly heard during diastole, there has not been adequate emphasis on their o...