Mitral Regurgitant Flow Research Articles

Clinical and hemodynamic observations in pure mitral insufficiency ∗

The clinical and hemodynamic findings in 23 patients with pure mitral insufficiency are described. Electrocardiographic, roentgenographic and clinical features in the ten patients with pulmonary hypertension are contrasted with findings in the patients without pulmonary hypertension. In the former group pulmonary vascular resistance was elevated, and clinical evidence of right heart failure was frequently present. In general, marked fatigability was noted in patients with abnormally low resting cardiac outputs. The left atrial pressure pulse contour was characteristic in 20 patients; similar changes in the left atrial pressure contour occurred in the remaining three patients following the infusion of norepinephrine. Left atrial pressure contour analysis proved to be of considerably greater diagnostic value than analysis of the pulmonary capillary wedge pressure tracing. Left atrial Z point pressures were significantly elevated in 17 of the 23 patients and left ventricular end diastolic pressures were elevated in seven of 12 patients. Histologic examination of the lungs in four patients with pulmonary hypertension showed extensive proliferative changes in the pulmonary vasculature. The possible interrelationships between mitral regurgitant flow and left ventricular function in the production of pulmonary hypertension and right heart failure are discussed.

Hemodynamic effects of quantitatively varied experimental mitral regurgitation.

Mitral regurgitation was produced in the open-chest dog by permitting blood to flow from left ventricle through a flow meter into the left atrium during systole. The hemodynamic effects of known amounts of regurgitation were studied. Two liters per minute of mitral regurgitant flow had relatively little effect on effective cardiac output, aortic pressure, left atrial pressure and on the left ventricular function curve.