To determine the effect of filling pressure on the pattern of left ventricular filling in humans, the mitral flow velocity profile was measured by pulsed wave Doppler echocardiography during right and left heart catheterization in 11 patients before and during nitroglycerin infusion. Nitroglycerin reduced mean arterial pressure from 90 +/- 9 to 80 +/- 11 mm Hg (p less than 0.001) and mean pulmonary capillary wedge pressure from 9 +/- 4 to 4 +/- 2 mm Hg (p less than 0.001). Cardiac output fell from 6.6 +/- 1.5 to 5.5 +/- 1.4 liters/min (p less than 0.001) and heart rate increased from 60 +/- 13 to 65 +/- 14 beats/min (p less than 0.002). The time constant of isovolumic relaxation (TI.) decreased from 51 +/- 9 to 46 +/- 8 ms (p less than 0.01), indicating faster left ventricular relaxation. Nitroglycerin altered the Doppler characteristics of the early filling (E) wave but not those of the atrial contraction (A) wave. Peak velocity of the E wave decreased from 56 +/- 14 to 44 +/- 9 cm/s (p less than 0.001), peak velocity of the A wave did not change and the ratio of peak velocities of the E and A waves decreased from 0.97 +/- 0.33 to 0.77 +/- 0.20 (p less than 0.02). The deceleration of the E wave decreased from 289 +/- 138 to 186 +/- 71 cm/s2 (p less than 0.02). The ratio of velocity-time integral of the A wave to total velocity-time integral (that is, contribution of atrial contraction to total filling) increased from 0.31 +/- 0.09 to 0.36 +/- 0.08 (p less than 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)
The relation of the Doppler transmitral flow velocity profile to left ventricular loading conditions and diastolic properties remains poorly described. We studied seven adult mongrel dogs with an open-chest right heart bypass model in which left atrial pressure, representing preload, was varied by controlling blood flow into the pulmonary artery and left ventricular systolic pressure, representing afterload, was controlled independently by pumping blood into or from the femoral arteries. Heart rate was kept constant by crushing the sinus node and pacing the right atrium.Mitral inflow velocity profiles were measured by pulsed-wave Doppler echocardiography at multiple left atrial and left ventricular systolic pressures. In individual dogs, the peak E-wave velocity increased linearly with increasing left atrial V-wave pressure at constant left ventricular systolic pressure and decreased with increasing left ventricular systolic pressure at constant left atrial pressure. Stepwise multiple linear regression analysis of data pooled from all experimental stages in all dogs identified left atrial V-wave pressure, the time constant of relaxation (TL), and left ventricular systolic pressure, in order of decreasing significance, as predictors of the peak E-wave velocity (n = 82, multiple r= 0.87, p<0.OOOl). Multivariate analysis with the same three factors in individual dogs yielded higher r values (mean r= 0.89; range, 0.85-0.97), suggesting the presence of important interdog differences that were not accounted for by these three factors alone. When the values of codeterminant hemodynamic factors were kept within narrower limits, correlations between peak E-wave velocity and left atrial V-wave pressure (n = 35, multiple r= 0.83, p<0.0001), TL (n = 76, multiple r= -0.54, p
Mitral-valve prolapse is a common cardiac valvular disorder with a wide range of severity and diverse clinical outcomes. The lack of a standard definition of mitral-valve prolapse may explain the variation in reported complication rates. To identify high-risk and low-risk subgroups, we retrospectively analyzed clinical and two-dimensional echocardiographic data from 456 patients with mitral-valve prolapse. Mitral-valve prolapse was defined on the basis of echocardiographic findings as systolic displacement into the left atrium of one or both leaflets beyond the plane of the mitral annulus in the parasternal long-axis view. Two groups of patients were compared: those with thickening of the mitral-valve leaflets and redundancy (designated the classic form; n = 319) and those without leaflet thickening (designated the nonclassic form; n = 137). The two groups were similar in age and sex ratio. Complications or a history of complications was more prevalent in the classic than the nonclassic form: infective endocarditis, 3.5 percent and 0 percent, respectively (P less than 0.02); moderate-to-severe mitral regurgitation, 12 percent and 0 percent (P less than 0.001); and the need for mitral-valve replacement, 6.6 percent and 0.7 percent (P less than 0.02). However, the frequency of stroke was similar in the two groups: 7.5 percent and 5.8 percent (P not significant). We conclude that in a selected population of patients with mitral-valve prolapse, those with the classic form (leaflet thickening and redundancy) are at higher risk than those without these features for the infectious and hemodynamic complications of mitral-valve prolapse, but not for stroke.
We studied 130 patients undergoing percutaneous balloon mitral valvotomy. The relation between valvular morphology according to a previously described echocardiographic scoring system and hemodynamic outcome expressed as qualitative ("good" and
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