Dept. of Cardiology, 5F, VU Univ. Medical Center, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands.
Am J Physiol Heart Circ Physiol. 2011 Jul;301(1):H129-37. doi: 10.1152/ajpheart.00077.2011. Epub 2011 Apr 13.
This study investigated the effects of alcohol septal ablation (ASA) on microcirculatory function and myocardial energetics in patients with hypertrophic cardiomyopathy (HCM) and left ventricular outflow tract (LVOT) obstruction. In 15 HCM patients who underwent ASA, echocardiography was performed before and 6 mo after the procedure to assess the LVOT gradient (LVOTG). Additionally, [(15)O]water PET was performed to obtain resting myocardial blood flow (MBF) and coronary vasodilator reserve (CVR). Changes in LV mass (LVM) and volumes were assessed by cardiovascular magnetic resonance imaging. Myocardial oxygen consumption (MVo(2)) was evaluated by [(11)C]acetate PET in a subset of seven patients to calculate myocardial external efficiency (MEE). After ASA, peak LVOTG decreased from 41 ± 32 to 23 ± 19 mmHg (P = 0.04), as well as LVM (215 ± 74 to 169 ± 63 g; P < 0.001). MBF remained unchanged (0.94 ± 0.23 to 0.98 ± 0.15 ml·min(-1)·g(-1); P = 0.45), whereas CVR increased (2.55 ± 1.23 to 3.05 ± 1.24; P = 0.05). Preoperatively, the endo-to-epicardial MBF ratio was lower during hyperemia compared with rest (0.80 ± 0.18 vs. 1.18 ± 0.15; P < 0.001). After ASA, the endo-to-epicardial hyperemic (h)MBF ratio increased to 1.03 ± 0.26 (P = 0.02). ΔCVR was correlated to ΔLVOTG (r = -0.82; P < 0.001) and ΔLVM (r = -0.54; P = 0.04). MEE increased from 15 ± 6 to 20 ± 9% (P = 0.04). Coronary microvascular dysfunction in obstructive HCM is at least in part reversible by relief of LVOT obstruction. After ASA, hMBF and CVR increased predominantly in the subendocardium. The improvement in CVR was closely correlated to the absolute reduction in peak LVOTG, suggesting a pronounced effect of LV loading conditions on microvascular function of the subendocardium. Furthermore, ASA has favorable effects on myocardial energetics.
这项研究调查了酒精室间隔消融术（ASA）对肥厚型心肌病（HCM）伴左心室流出道（LVOT）梗阻患者的微循环功能和心肌能量代谢的影响。在 15 名接受 ASA 的 HCM 患者中，在手术前和术后 6 个月进行超声心动图检查，以评估 LVOT 梯度（LVOTG）。此外，还进行了[（15）O]水 PET 以获得静息心肌血流（MBF）和冠状动脉扩张储备（CVR）。通过心血管磁共振成像评估左心室质量（LVM）和容积的变化。在 7 名患者的亚组中，通过[（11）C]乙酸 PET 评估心肌耗氧量（MVo（2））以计算心肌外效率（MEE）。ASA 后，峰值 LVOTG 从 41 ± 32mmHg 降至 23 ± 19mmHg（P = 0.04），LVM 从 215 ± 74g 降至 169 ± 63g（P < 0.001）。MBF 保持不变（0.94 ± 0.23 至 0.98 ± 0.15ml·min（-1）·g（-1）；P = 0.45），而 CVR 增加（2.55 ± 1.23 至 3.05 ± 1.24；P = 0.05）。术前，与休息时相比，充血时心内膜下至心外膜的 MBF 比值较低（0.80 ± 0.18 比 1.18 ± 0.15；P < 0.001）。ASA 后，心内膜下充血（h）MBF 比值增加至 1.03 ± 0.26（P = 0.02）。ΔCVR 与ΔLVOTG（r = -0.82；P < 0.001）和ΔLVM（r = -0.54；P = 0.04）相关。MEE 从 15 ± 6%增加至 20 ± 9%（P = 0.04）。梗阻性 HCM 中的冠状动脉微血管功能障碍至少部分可通过缓解 LVOT 梗阻来逆转。ASA 后，hMBF 和 CVR 主要在心内膜下增加。CVR 的改善与峰值 LVOTG 的绝对降低密切相关，这表明 LV 负荷条件对心内膜下微血管功能有明显影响。此外，ASA 对心肌能量代谢有有利影响。
