Nakamura N, Nonogi H, Miyazaki S, Nakanishi N, Yoshioka K, Haze K, Hiramori K
Department of Internal Medicine, National Cardiovascular Center, Osaka, Japan.
Heart Vessels. 1993;8(1):23-32.
To assess left ventricular diastolic properties in response to dynamic exercise, mitral inflow velocity integrals were measured by pulsed-wave Doppler echocardiography in ten patients with myocardial infarction and in ten normal subjects, and simultaneous left ventricular pressure was obtained with micromanometry in the patients. Early filling velocity integrals were maintained in the patients during exercise. Late filling velocity integrals were not augmented during exercise in the patients, but were increased in the normal subjects. In the patients, there was an increase in mitral valve opening pressure, left ventricular end-diastolic pressure, and the time constant of left ventricular isovolumic pressure decay. The lowest diastolic pressure and the number of time constants that had elapsed before the lowest diastolic pressure remained unchanged. These results show that in patients with myocardial infarction, early filling is maintained by an increase in driving pressure during exercise, despite incomplete relaxation. Augmentation of late filling, seen in normal subjects, is impaired in patients with myocardial infarction, probably due to an increase in left ventricular stiffness.
为评估动态运动时左心室舒张特性，采用脉冲波多普勒超声心动图测量了10例心肌梗死患者和10例正常受试者的二尖瓣流入速度积分，并通过微测压法在患者中同时获取左心室压力。患者在运动过程中早期充盈速度积分得以维持。患者在运动过程中晚期充盈速度积分未增加，但正常受试者增加。在患者中，二尖瓣开放压力、左心室舒张末期压力以及左心室等容压力衰减的时间常数均增加。最低舒张压以及达到最低舒张压之前经过的时间常数数量保持不变。这些结果表明，在心肌梗死患者中，尽管舒张不完全，但运动期间通过驱动压力增加维持了早期充盈。正常受试者中出现的晚期充盈增强在心肌梗死患者中受损，可能是由于左心室僵硬度增加所致。
