Left ventricular filling dynamics: influence of left ventricular relaxation and left atrial pressure.

摘要: Peak rapid filling rate (PRFR) is often used clinically as an index of left ventricular relaxation, i.e., early diastolic function. This study tests the hypothesis that a function atrioventricular pressure difference and hence influenced by atrial well relaxation. As indexes, we chose at crossover (PCO), time constant (T) assumed exponential decline in pressure. We accurately determined magnitude timing parameters conscious dogs direct measurement phasic mitral flow (electromagnetically) high-fidelity chamber pressures. To obtain diverse hemodynamic data base, loading conditions were changed infusions volume angiotensin II. The latter was administered to produce change less than 35% (A-1) or peak greater (A-2). PRFR increased with loading, unchanged A-1, decreased A-2; T PCO all three groups (p .005 for changes). correlated strongly (r = .899, p .001) weakly both .369, .01) .601, .001). correlation improved significantly when included multivariate regression .797, .0001). thus relaxation should be caution