LEFT VENTRICULAR PERFORMANCE IN ASYMPTOMATIC AORTIC STENOSIS

有症状的主动脉狭窄患者表现为室壁异常 在运动过程中发挥作用。使用放射性核素血管造影术，我们研究了左侧 11例无症状患者的室壁收缩和舒张期表现 单纯性主动脉瓣狭窄(连续波多普勒静息梯度 +-31毫米汞柱，范围40-144毫米汞柱)，超声心动图显示左室肥厚。 患者与12名年龄和性别匹配的正常志愿者进行了比较。 从静息到运动射血分数、每搏量、心脏 每组的心输出量、舒张期末和收缩期末容量被量化 一群人。高血压患者静息时最大舒张期充盈率降低 与正常人相比，主动脉狭窄。在仰卧式自行车运动中， 无症状性主动脉瓣狭窄的患者显著减少 仰卧位时左心室射血分数的增加 锻炼身体。这与心输出量增加较少有关。 运动中每搏量和舒张末容量的实际下降 与正常志愿者的这些参数的增加相比。因此， 左心室收缩和舒张期功能异常限制了 心输出量对运动的反应，导致运动中的努力受限 有主动脉狭窄的患者，即使在临床上没有症状。

Symptomatic patients with aortic stenosis exhibit abnormal ventricular function during exercise. Using radionuclide angiography, we studied left ventricular systolic and diastolic performance in 11 asymptomatic patients with isolated aortic stenosis (rest gradient by continuous wave Doppler 64+-31 mmHg, range 40-144 mmHg) and left ventricular hypertrophy by echo. Patients were compared to 12 aged and gender-matched normal volunteers. Changes from rest to exercise ejection fraction, stroke volume, cardiac output, and end-diastolic and end-systolic volumes were quantified for each group. Peak diastolic filling rate at rest was reduced in patients with aortic stenosis compared to normals. During supine bicycle exercise, patients with asymptomatic aortic stenosis demonstrated significantly less of an increase in left ventricular ejection fraction during supine exercise. This was associated with less of an increase in cardiac output and actual falls in stroke volume and end-diastolic volume during exercise compared to increases in these parameters in the normal volunteers. Thus, abnormal left ventricular systolic and diastolic function limits the cardiac output response to exercise, resulting in effort limitation in patients with aortic stenosis, even when clinically asymptomatic.