Clements I P, Offord K P, Baron D W, Brown M L, Bardsley W T, Harrison C E
Mayo Clin Proc. 1984 Sep;59(9):604-11. doi: 10.1016/s0025-6196(12)62411-2.
Radionuclide angiography was used to study the effects of supine and upright bicycle exercise and handgrip exercise in 17 (12 well-trained) normal subjects before (control) and immediately after the administration of propranolol (160 mg/day for 4 days). Cardiac hemodynamic values were related to position in that control left ventricular volumes and the cardiac index were greater in the supine position than in the upright at rest but resting left ventricular ejection fraction was similar in both positions. The pressure volume index was greater in the upright position than in the supine. At maximal exercise before treatment, however, similar cardiovascular hemodynamic measurements were recorded in both positions. Propranolol increased left ventricular end-diastolic volume at rest and at maximal exercise. Left ventricular end-systolic volume, however, was substantially greater only in the upright position both at rest and at maximal exercise when compared with control values. Heart rate, systolic arterial pressure, cardiac index, and pressure volume index were decreased at rest and maximal exercise after treatment with propranolol. Ejection fraction was decreased in the upright position after propranolol administration but was unchanged in the supine position. Handgrip exercise primarily increased heart rate and arterial pressure and did not affect cardiac volume, and this response was unaffected by propranolol.
采用放射性核素血管造影术，对17名（其中12名训练有素）正常受试者在服用普萘洛尔（160毫克/天，共4天）之前（对照）和之后立即进行仰卧位和直立位自行车运动以及握力运动的效果进行了研究。心脏血流动力学值与体位有关，对照时左心室容积和心脏指数在仰卧位时比静息直立位时更大，但静息时左心室射血分数在两个体位相似。压力容积指数在直立位时比仰卧位时更大。然而，在治疗前的最大运动时，两个体位记录的心血管血流动力学测量值相似。普萘洛尔增加了静息和最大运动时的左心室舒张末期容积。然而，与对照值相比，左心室收缩末期容积仅在直立位静息和最大运动时显著更大。服用普萘洛尔后，静息和最大运动时心率、收缩期动脉压、心脏指数和压力容积指数均降低。服用普萘洛尔后直立位射血分数降低，但仰卧位射血分数无变化。握力运动主要增加心率和动脉压，不影响心脏容积，且这种反应不受普萘洛尔影响。
