VASODILATOR RESERVE IN ASYMTOMATIC HYPERTROPHIC CARDIOMYOPATHY

以前的工作已经证明，胸痛和肥厚性心肌病患者 心肌病（HCM），或胸痛和正常的冠状动脉，可能有 与正常人相比，血管扩张储备受损。为了 确定胸痛和非阻塞性肥厚性胸壁 心肌病，以前曾被证明有血管舒张功能受损 储备，不同于非阻塞性肥厚性 没有胸痛的心肌病患者，我们比较了心肌 8例无症状HCM患者的代谢和冠状动脉血流动力学 26例伴有胸痛的非梗阻性肥厚型心肌病患者。心大静脉 血流，局部冠状动脉阻力，心肌耗氧量 在静息时和以150 bpm起搏后测量乳酸盐提取量。 与有症状的HCM患者相比，无症状的HCM患者有更大的 GCV流量增加和冠状动脉血管阻力下降， 起搏时心肌需氧量增加。更多症状性HCM患者 (42%）有缺血证据，起搏时产生乳酸， 无症状HCM患者（14%）。因此，HCM中的缺血和心绞痛似乎是 至少部分原因是血管扩张储备受损，但有些人 无症状的HCM患者也可能有无症状的局部缺血。

Previous work has demonstrated that pts with chest pain and hypertrophic cardiomyopathy (HCM), or chest pain and normal coronary arteries, may have impaired vasodilator reserve compared to normal individuals. In order to determine if pts with chest pain and nonobstructive hypertrophic cardiomyopathy, who have previously been shown to have impaired vasodilator reserve, differ from individuals with nonobstructive hypertrophic cardiomyopathy who do not have chest pain, we compared myocardial metabolism and coronary vascular hemodynamics in 8 asymptomatic HCM pts with 26 nonobstructive HCM pts with chest pain. Great cardiac vein (GCV) flow, regional coronary vascular resistance, myocardial oxygen consumption and lactate extraction were measured at rest and after pacing at 150 bpm. Compared to symptomatic HCM pts, asymptomatic HCM pts had a greater increase in GCV flow and fall in coronary vascular resistance, for similar increases in myocardial oxygen demand with pacing. More symptomatic HCM pts (42%) had evidence of ischemia and produced lactate with pacing compared to asymptomatic HCM pts (14%). Thus, ischemia and angina in HCM appears to be due, at least partly, to impaired vasodilator reserve, but some asymptomatic HCM pts may also have ischemia which is silent.