Sundstedt Milena, Hedberg Pär, Jonason Tommy, Ringqvist Ivar, Henriksen Egil
Department of Clinical Physiology and Centre of Clinical Research, Uppsala University, Central Hospital, Västerås, Sweden.
Clin Physiol Funct Imaging. 2007 Jan;27(1):36-41. doi: 10.1111/j.1475-097X.2007.00715.x.
Doppler echocardiography was used to describe left ventricular filling and ejection during upright bicycle exercise in 24 healthy male endurance athletes. The transmitral pressure gradient was estimated and isovolumetric relaxation, filling and ejection time and transmitral and aortic flow velocities were measured at rest and during exercise. From rest to peak exercise (at a heart rate of 160 bpm), the mean left ventricular filling time was shortened by 73%, the ejection time by 31%, while the isovolumetric relaxation time was shortened by 62%. At peak exercise, the maximum aortic flow velocity almost doubled and the maximum transmitral flow velocity more than doubled, with a tenfold increase in the mean transmitral pressure gradient. The increase was significant (P<0.001) at each level of exercise. The left ventricular filling rate measured as volume per time was 185 +/- 62 ml s(-1) at rest and it increased to 986 +/- 192 ml s(-1) at peak exercise. This study demonstrates large changes in diastolic filling indices during upright exercise and it shows that the heart is able to increase its filling rate five times from rest to peak exercise.
采用多普勒超声心动图对24名健康男性耐力运动员直立自行车运动时的左心室充盈和射血情况进行了描述。估算了二尖瓣压力阶差，并测量了静息及运动时的等容舒张时间、充盈时间、射血时间以及二尖瓣和主动脉血流速度。从静息状态到运动峰值（心率160次/分钟），左心室平均充盈时间缩短了73%，射血时间缩短了31%，而等容舒张时间缩短了62%。在运动峰值时，主动脉最大血流速度几乎翻倍，二尖瓣最大血流速度增加了一倍多，二尖瓣平均压力阶差增加了10倍。在每个运动水平，这种增加均具有显著性（P<0.001）。以单位时间容积衡量的左心室充盈率在静息时为185±62 ml s⁻¹，在运动峰值时增至986±192 ml s⁻¹。本研究表明直立运动期间舒张期充盈指标发生了巨大变化，且显示心脏从静息到运动峰值时能够将其充盈率提高五倍。
