We used Doppler echocardiography to quantitate the changes in intracardiac blood flow velocities and right and left ventricular stroke volumes in 80 normal human fetuses from 19 to 40 weeks gestation. Blood flow velocity spectra across the aortic, pulmonary, tricuspid, and mitral valves were digitized to obtain peak velocities (m/sec) and flow velocity integrals. Aortic and pulmonary diameters ...

repetitive episodes of brief regional ischemia have been shown to reduce the severity of life-threatening ventricular anhythrnias and infarct size that occur during prolonged occlusion of the coronary artery. this phenomenon is known as ischemic preconditioning. during studies in anesthetized, open chest wistar rats, we accidentally observed that poorly ventilated animals had a reduced severity...

Objective: We tested a new surgical technique, the plication of the left ventricular free wall, to reduce left ventricular area and volume and improve left ventricular systolic function, without using a cardiopulmonary bypass. Methods: Dilated cardiomyopathy was induced in eight dogs by the injection of doxorubicin. Plication of the left ventricular free wall was performed in four dogs with ind...

The dynamic geometry of the left ventricle was assessed with the use of chronically implanted pulse-transit ultrasonic dimension transducers. The orientation of the transducers allowed the measurement of left ventricular minor and major axis diameters and equatorial wall thickness in the conscious dog. The left ventricle was modeled as a three-dimensional, prolate ellipsoidal shell. Left ventri...

A significant fraction of patients in whom mechanical left ventricular assist devices are implanted for refractory cardiac failure after open heart surgery have had the complication of right heart failure. To evaluate the effects of left ventricular assistance and pressure unloading on right ventricular function, we performed experiments in the normal hearts of open-chest, anesthetized, large m...

An echocardiographic study of left ventricular diameter was made in 27 patients with aortic regurgitation. Comparison was made with a group of 21 normal subjects and a group of 6 patients with large left ventricles without valvar regurgitation. Total stroke volume, total left ventricular output, and ejection fraction were derived by the method of cubing the left ventricular diameter to give app...

We studied the effect of cardiopulmonary bypass, transient acute coronary occlusion (2-5 minutes), prolonged coronary occlusion (> 60 minutes), and coronary reperfusion on the left ventricular diastolic pressure-volume curve, using an isovolumic working canine heart preparation in which heart rate, intraventricular volume, and aortic pressure were controlled. Cardiopulmonary bypass caused no si...

Electrocardiogram gated single photon emission computed tomography of the intracardiac blood pools is a recent development that involves the acquisition of images in multiple projections after in vivo erythrocyte labelling with technetium-99m and reconstruction of these images into tomographic sections in any desired plane. The technique was used in 25 subjects to measure left ventricular volum...

We investigated the effects of nifedipine on left ventricular diastolic function in 17 asymptomatic or minimally symptomatic patients with hypertrophic cardiomyopathy by simultaneously measuring left ventricular pressure and volume with a catheter-tipped manometer and biplane cineangiography. Studies were performed before and 20 minutes after sublingual administration of nifedipine (20 mg). Hea...

SUMMARY Clinically suspected coronary artery disease was assessed in 52 patients by 16-mm biplane left ven-triculography. Outward movement of the left ventricular wall was observed prior to mitral valve opening in normal patients and those with coronary artery disease. In the normal ventriculogram, outward movement was usually visible in the anterior wall and the apex. In the asynergic ventricl...