Aakhus S, Bjørnstad K, Hatle L
Department of Medicine, University Hospital, Trondheim, Norway.
Clin Physiol. 1994 Sep;14(5):581-94. doi: 10.1111/j.1475-097x.1994.tb00416.x.
Left ventricular function and systemic haemodynamics were noninvasively assessed during cardiac stress testing with dipyridamole (0.84 mg kg-1 i.v.) in 10 subjects (44-61 years) with normal coronary arteries (group 1), and in 14 patients (46-77 years) with coronary artery disease either without (group 2, n = 6) or with (group 3, n = 8) echocardiographic evidence for myocardial ischaemia during test. Left ventricular wall motion and dimensions, and aortic root pressure and flow were obtained by Doppler echocardiography combined with an externally traced subclavian artery pulse calibrated with brachial artery pressures. Peripheral arterial resistance, total arterial compliance, and aortic characteristic impedance were estimated from aortic root pressure and flow, by use of a three-element windkessel model of the systemic circulation. Left ventricular ejection fraction improved from baseline to peak stress in group 1 (mean +/- SD: 62 +/- 6% vs. 65 +/- 6%, P = 0.05), whereas it was not significantly changed in group 2 (58 +/- 10% vs. 56 +/- 6%) and decreased in group 3 (53 +/- 10% vs. 43 +/- 10%, P < 0.05). Otherwise, the haemodynamic response was similar in the three groups: heart rate and cardiac index increased by at least 30% and 37%, respectively, whereas stroke index and arterial pressures were maintained at or slightly above baseline. Peripheral resistance decreased by at least 22%, and total arterial compliance and aortic characteristic impedance were not significantly altered during test. The worsening of wall motion abnormality at peak stress in group 3 was not significantly related to the change in systemic haemodynamics. Thus, dipyridamole acted predominantly on the arterioles without significantly influencing the large systemic arteries. Myocardial ischaemia during test impaired regional and global left ventricular function, but did not influence the systemic haemodynamic response.
在心脏应激试验中，使用双嘧达莫（0.84mg/kg静脉注射）对10名冠状动脉正常的受试者（44 - 61岁，第1组）、14名患有冠状动脉疾病的患者（46 - 77岁，其中第2组6名患者无、第3组8名患者有超声心动图显示的心肌缺血证据）进行了左心室功能和全身血流动力学的无创评估。通过多普勒超声心动图结合经肱动脉压力校准的外部追踪锁骨下动脉脉搏，获取左心室壁运动和尺寸以及主动脉根部压力和血流。利用体循环的三元风箱模型，根据主动脉根部压力和血流估算外周动脉阻力、总动脉顺应性和主动脉特征阻抗。第1组左心室射血分数从基线到应激峰值有所改善（平均值±标准差：62±6%对65±6%，P = 0.05），而第2组无显著变化（58±10%对56±6%），第3组则下降（53±10%对43±10%，P < 0.05）。此外，三组的血流动力学反应相似：心率和心脏指数分别至少增加30%和37%，而每搏指数和动脉压维持在基线水平或略高于基线。外周阻力至少降低22%，试验期间总动脉顺应性和主动脉特征阻抗无显著改变。第3组在应激峰值时壁运动异常的加重与全身血流动力学变化无显著相关性。因此，双嘧达莫主要作用于小动脉，而对大的全身动脉无显著影响。试验期间的心肌缺血损害了局部和整体左心室功能，但不影响全身血流动力学反应。
