We studied nine men in horizontal and 30° head-up position during tidal breathing and Valsalva maneuvers. The ratio of peak slope of left ventricular volume curves during early rapid filling relative to that during atrial contraction (E/A ratio) and isovolumic relaxation time(interval from aortic component of second heart sound to early rapid filling onset) were measured with thoracocardiography and compared with Doppler-echocardiographic-derived indices of transmitral flow velocity.
Isovolumic relaxation times estimated by the two methods agreed closely (bias = -2 ms, limits of AGREEMENT = -28 to +24 ms, 75 comparisons). E/A ratios by thoracocardiography and Doppler echocardiography were significantly correlated (R = 0.53, N = 75, P < .001), but individual values differed. Both methods provided identical trends of changes in E/A ratios with interventions in 50 of 66 (76%) comparisons.
Thoracocardiography reflects characteristics of left ventricular filling similarto Doppler echocardiography. Because it does not require hand-holding a transducer, thoracocardiography has the potential for continuous monitoring of mechanical cardiac performance. 相似文献