CORONARY FLOW AND OPERATIVERESULT IN HYPERTROPHIC CARDIOMYOPATHY

左心室流出道梗阻的手术解除有所改善 大多数(但不是全部)肥厚型患者的症状 心肌病。为了调查术前测量是否 冠状动脉血流储备预测疗效，20例患者 对冠脉流量、乳酸和氧代谢的研究 在心肌内、在基础状态下和在快速心房期间 把心率调到150。这六位患者的血流量较多 大于175ml/min的基础左心室显著增大 流出障碍(90加或减30对50加或减 32毫米汞柱，P<0.01)，其余14例患者。 两组的缺血严重程度相似，6例中有5例 高流量患者和其余14名患者中的8名 在起搏应激过程中产生乳酸。在手术后 解除流出道梗阻、起搏应力的研究 在相当低的流量中(216个加或减18个操作前到151个 术后加或减46毫升/分钟，P<0.05) 高流量患者与较轻的血流减少相比 其他14名患者(术前138例加或减19例，加或减123例 停药后43ml/min，NS)。此外，还有一个相当大的 这6名患者的乳酸代谢得到改善(28.6+ 或-23.9 mm x ml/min，而不是-32.8正负 术前30.5 mm x ml/min，p<0.05)，无患者 产生乳酸盐。相比之下，总体上没有净变化。 对B组患者乳酸代谢的影响。此外，所有6个人都很高 Flow患者的起搏速度有10次/分钟或更大的改善 心绞痛阈值，而14例低流量患者中有5例没有 进步。 因此，较高的峰值流量对压力的响应一致地预示着 术后起搏应激的改善。结果在患者中 峰值流量较低时，响应是不同的，这表明了机制 除梗阻(小血管疾病、心肌纤维化、 舒张期功能异常，这可能导致症状和 不太可能从左心室的缓解中受益 流出障碍。

Operative relief of left ventricular outflow obstruction improves symptoms in most, but not all, patients with hypertrophic cardiomyopathy. To investigate whether pre-operative measurement of coronary flow reserve predict efficacy, twenty patients underwent study of coronary flow and lactate and oxygen metabolism within the myocardium, in the basal state and during rapid atrial pacing to a heart rate of 150. The six patients with flows more than 175 ml/min had significantly greater basal left ventricular outflow obstruction (90 plus or minus 30 vs. 50 plus or minus 32mmHg, p less than .01) compared to the remaining 14 patients. Severity of ischemia was similar in the two groups with 5 of 6 of the high flow patients and 8 of 14 of the remaining patients producing lactate during pacing stress. During post-operative study with relief of outflow obstruction, pacing stress resulted in substantially lower flows (216 plus or minus 18 pre-op to 151 plus or minus 46 ml/min post-op, p less than .05) in the 6 pre-op high flow patients compared to a lesser reduction in flow in the other 14 patients (138 plus or minus 19 preop to 123 plus or minus 43 ml/min postop, NS). Further, there was a substantial improvement in lactate metabolism in these 6 patients (28.6 plus or minus 23.9 mM x ml/min postoperative, versus -32.8 plus or minus 30.5 mM x ml/min preoperatively, p less than .05) with no patient producing lactate. In contrast, there was no net change overall in lactate metabolism in the Group B patients. Further, all 6 high flow patients had a 10 beat/min or greater improvement in pacing angina threshold, whereas 5 of the 14 low flow patients had no improvement. Thus, a higher peak flow response to stress consistently predicts postoperative improvement to pacing stress. Results in patients with lower peak flow responses are variable, suggesting mechanisms other than obstruction (small vessel disease, myocardial fibrosis, abnormal diastolic function, which might contribute to symptoms and be less likely to be benefited by relief of left ventricular outflow obstruction.