EFFECTS OF SURGERY FOR HYPERTROPHIC CARDIOMYOPATHY ON EXERCISE HEMODYNAMICS

梗阻性肥厚型心肌病（间隔型）的手术治疗 肌切开术/肌切除术或二尖瓣置换术）改善了许多患者的症状， 但不是所有的肥厚型心肌病患者。评估哪些 手术前后的血流动力学变化与 手术后的运动益处，14例肥厚型 心肌病患者进行了平板运动试验（布鲁斯方案）， 术前和术后6个月最大耗氧量测量 手术术后运动研究表明， 持续时间，但最大氧含量仅略有改善 消费最大耗氧量的改善 与术前研究相比，手术与 左心室流出道梯度和左心室 心室舒张末期压5例无改善的患者， 最大耗氧量，包括2例梯度大于50 mmHg的患者 降低，左心室舒张末期降低小于5 mmHg 压力术后最大值增加的9例患者中有7例 耗氧量的梯度降低大于或等于65 mmHg; 2例梯度减小较小的患者的血压大于8 mmHg 左心室舒张末期压降低。因此，受益于 手术后的运动能力可能取决于 左心室充盈压降低幅度为 手术后梯度降低。

Surgery for obstructive hypertrophic cardiomyopathy (septal myotomy/myectomy or mitral valve replacement) improves symptoms in many, but not all patients with hypertrophic cardiomyopathy. To assess which hemodynamic changes before and following surgery best correlate with exercise benefit following surgery, 14 patients with hypertrophic cardiomyopathy underwent treadmill exercise testing (Bruce protocol) with measurement of maximum oxygen consumption before and 6 months following surgery. The post-operative exercise study demonstrated improved exercise duration but with only a marginal improvement in maximum oxygen consumption. The improvement in maximum oxygen consumption following surgery compared to the preoperative study correlated directly with the magnitude of reduction in left ventricular outflow gradient and left ventricular end-diastolic pressure. The 5 patients with no improvement in maximum oxygen consumption, including 2 with greater than 50 mmHg gradient reduction, had less than 5 mmhg reduction in left ventricular end-diastolic pressure. Seven of the 9 patients with increased post-operative maximum oxygen consumption had a gradient reduction greater than or equal to 65 mmhg; the 2 with lesser gradient reduction had greater than 8 mmhg reduction in left ventricular end-diastolic pressure. Thus, benefit in exercise capacity following surgery may be determined as much by the reduction in the left ventricular filling pressures as by the magnitude of gradient reduction following surgery.