LEFT VENTRICULAR PERFORMANCE IN ASYMPTOMATIC AORTIC STENOSIS

无症状主动脉瓣狭窄的左心室表现

• 批准号: 3858119
• 负责人: R CANNON
• 金额: --
• 依托单位: NATIONAL HEART, LUNG, AND BLOOD INSTITUTE
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3858119
• 关键词: angiography; aortic valve stenosis; blood volume; cardiac output; cardiovascular stress test; electrocardiography; exercise; heart function; hemodynamics; human subject; intracardiac volume; myocardial ischemia /hypoxia; radionuclide diagnosis; stroke; ventricular hypertrophy

Patients with heart disease may have myocardial ischemia or left ventricular dysfunction without symptoms. We studied the exercise responses of 14 asymptomatic patients with significant aortic stenosis with valve gradients ranging from 40 to 144 mmHg, using treadmill testing, thallium-201 scintigraphy, and radionuclide angiography. Compared to age and gender-matched controls, patients with aortic stenosis demonstrated reduced exercise tolerance and maximum oxygen consumption associated with a lower peak systolic blood pressure response to exercise. Ten of 14 patients demonstrated ischemic-appearing ECG responses to exercise, of whom only 3 had reversible thallium defects. Radionuclide angiographic studies showed that aortic stenosis patients tended to have higher left ventricular ejection fractions at rest and significantly lower early peak filling rates suggesting abnormal diastolic function at rest, compared to controls. During maximum supine exercise, aortic stenosis patients had less of an increase in left ventricular ejection fraction associated with a decrease in end-diastolic volume and stroke volume from baseline measurements compared to controls who increased end-diastolic volume and stroke volume during exercise. The abnormal volume changes during exercise correlated directly with effort limitation in these patients. Thus, despite the absence of symptoms, patients with aortic stenosis demonstrated limited effort tolerance with abnormal systemic and left ventricular hemodynamics, which is most likely a consequence of inability to augment end-diastolic volume during exercise.

心脏病患者可能有心肌缺血或左 无症状的心功能不全。我们研究了这项练习 14例无症状的主动脉明显狭窄患者的治疗反应 瓣膜倾斜度在40至144毫米汞柱之间，使用跑步机 测试、铊-201闪烁照相和放射性核素血管造影术。 与年龄和性别匹配的对照组相比，主动脉病变患者 狭窄表现为运动耐量和最大含氧量降低 与较低峰值收缩压反应相关的消耗 锻炼身体。14例患者中有10例表现为缺血性心电 对运动的反应，其中只有3人有可逆性的铊缺陷。 放射性核素血管造影术研究表明，主动脉狭窄患者 静息状态下的左心室射血分数往往较高 早期峰值充盈率显著降低，提示异常 与对照组相比，静息状态下的舒张期功能。在最大仰卧位时 运动后，主动脉瓣狭窄患者左、右动脉的增加较少 左室射血分数与舒张期末期心肌梗死的关系 基线测量值和每搏出量与对照组的比较 世界卫生组织在运动过程中增加了舒张末期容量和每搏量。 运动过程中的异常体积变化与 这些患者的努力受限。因此，尽管没有 症状，主动脉狭窄患者表现出有限的努力 对全身和左心室血流动力学异常的耐受性 很可能是由于无法增加舒张末容量所致 在锻炼的时候。