Intraventricular pumping at the mitral ring in mitral regurgitation.
This study aims at evaluating the effect of a small spherical balloon functioning during acute mitral regurgitation. Acute mitral regurgitation was produced in 11 mongrel dogs with a specially designed curved blade introduced through the left ventricular apex. Left atrial pressure, electrocardiogram, left ventricular pressure (in 8 dogs) and aortic flow (in 7 dogs) were monitored. The mean left atrial pressure increased by 9.45 +/- 2.44 mmHg (p less than 0.01) and the v wave by 14.09 +/- 2.94 mmHg (p less than 0.001). The systolic left ventricular pressure and the aortic flow decreased. The heart remained in sinus rhythm & the rate did not change significantly. After the production of mitral regurgitation, a small spherical balloon (9 to 16 cc capacity) mounted on a catheter was introduced to the left ventricle through the apex and positioned in the mitral ring. The balloon was inflated by means of a pump during systole and deflated during diastole. During its function the mean left atrial pressure decreased by 4.37 +/- 0.84 mmHg (p less than 0.001) and the v wave by 8.64 +/- 1.23 mm Hg (p less than 0.001). The systolic left ventricular pressure and the aortic flow increased. The peak systolic gradient across the mitral valve increased by 20.5 +/- 3.86 mmHg (p less than 0.01). The heart rate did not change. It is suggested that in acute mitral regurgitation the function of a small balloon could improve the hemodynamic condition by acting as a valve at the mitral ring for reduction of regurgitation and possibly by improving systolic function in severe heart failure.
D000818:Animals; D002404:Catheterization; D004285:Dogs; D006350:Heart Valve Prosthesis; D006439:Hemodynamics; D008943:Mitral Valve; D008944:Mitral Valve Insufficiency / Q000503:physiopathology / Q000601:surgery*