Henein M Y, Das S K, O'Sullivan C, Kakkar V V, Gillbe C E, Gibson D G
Department of Cardiology, Royal Brompton Hospital, London.
Heart. 1996 Feb;75(2):151-8. doi: 10.1136/hrt.75.2.151.
To assess the effect of acute alterations in afterload by aortoiliac clamping, during peripheral vascular surgery, on left ventricular function.
Prospective examination of the left ventricular long axis and transmitral Doppler flow preoperatively and intraoperatively; before aortic clamping, during clamping and 5 min, 15 min, and 5 days after unclamping.
A tertiary referral centre for cardiac and vascular disease equipped with invasive and non-invasive facilities.
20 patients (11 men; mean (SD) age 61 (8) years) with significant aortoiliac disease and documented coronary artery disease and 21 normal controls of similar age.
Preoperatively: long axis function was abnormal compared with that in normal controls. In systole total long axis excursion and peak shortening rate were reduced, onset of shortening delayed, and there was pre-ejection lengthening (P < 0.001). In diastole there was abnormal shortening during isovolumic relaxation, delaying the onset of long axis lengthening (P < 0.001). Peak lengthening rate was also reduced and A wave excursion increased (P < 0.001). Transmitral Doppler showed increased A wave velocity and reduced peak E/A diastolic flow velocities ratio (P < 0.001). Intraoperatively: preclamping results did not differ from those before operation. With clamping the extent of systolic and diastolic abnormalities promptly increased as to a lesser extent did those of transmitral flow velocity, although heart rate and blood pressure did not change significantly. Total long axis excursion and A wave amplitude were more reduced by aortic than iliac clamping, whereas the onset of lengthening was more delayed and the lengthening velocity more reduced with iliac clamping. Some 5 min after unclamping systolic long axis function had already returned towards normal; total excursion increased, as did the peak shortening rate, and the onset of shortening became less delayed (P < 0.001). In diastole the delayed onset of lengthening regressed, its lengthening velocity increased, and A wave excursion fell (P < 0.001). Early diastolic transmitral flow velocity also increased. This improvement in systolic and diastolic long axis function had progressed 15 min after unclamping but showed no further change at 5 days. At 5 days after operation, however, systolic and diastolic measurements had improved compared with those preoperatively.
Resting left ventricular long axis function is abnormal in patients with combined coronary artery disease and peripheral vascular disease. It is unaffected by anaesthesia but deteriorates with aortic or iliac clamping, although blood pressure remains unchanged. It promptly improves with unclamping after successful peripheral arterial reconstruction. Thus, even in apparently stable coronary artery disease, resting subendocardial function is labile, showing pronounced alterations with changing after-load, even when arterial pressure itself does not change.
评估在周围血管手术期间，通过主髂动脉钳夹使后负荷急性改变对左心室功能的影响。
术前及术中对左心室长轴和经二尖瓣多普勒血流进行前瞻性检查；在主动脉钳夹前、钳夹期间以及松开钳夹后5分钟、15分钟和5天进行检查。
一家配备有有创和无创设备的心脏和血管疾病三级转诊中心。
20例患者（11例男性；平均（标准差）年龄61（8）岁）患有严重的主髂动脉疾病且有冠状动脉疾病记录，以及21名年龄相仿的正常对照者。
术前：与正常对照者相比，长轴功能异常。在收缩期，总长轴偏移和峰值缩短率降低，缩短起始延迟，且有射血前延长（P<0.001）。在舒张期，等容舒张期存在异常缩短，延迟了长轴延长的起始（P<0.001）。峰值延长率也降低，A波偏移增加（P<0.001）。经二尖瓣多普勒显示A波速度增加，舒张期峰值E/A血流速度比值降低（P<0.001）。术中：钳夹前结果与手术前无差异。钳夹时，收缩期和舒张期异常程度迅速增加，经二尖瓣血流速度异常程度增加较小，尽管心率和血压无显著变化。主动脉钳夹比髂动脉钳夹使总长轴偏移和A波幅度降低更明显，而髂动脉钳夹使延长起始延迟更明显，延长速度降低更明显。松开钳夹约5分钟后，收缩期长轴功能已开始恢复正常；总偏移增加，峰值缩短率增加，缩短起始延迟减少（P<0.001）。在舒张期，延长起始延迟的情况消退，延长速度增加，A波偏移降低（P<0.001）。舒张早期经二尖瓣血流速度也增加。收缩期和舒张期长轴功能的这种改善在松开钳夹15分钟后仍在进展，但在5天时无进一步变化。然而，术后5天时，收缩期和舒张期测量值与术前相比有所改善。
合并冠状动脉疾病和周围血管疾病的患者静息左心室长轴功能异常。它不受麻醉影响，但随着主动脉或髂动脉钳夹而恶化，尽管血压保持不变。在成功进行外周动脉重建后松开钳夹，其功能迅速改善。因此，即使在看似稳定的冠状动脉疾病中，静息心内膜下功能也不稳定，即使动脉压本身不变，随着后负荷的变化也会出现明显改变。
