Hamada M, Shigematsu Y, Ikeda S, Hara Y, Okayama H, Kodama K, Ochi T, Hiwada K
Second Department of Internal Medicine, Ehime University School of Medicine, Japan.
Circulation. 1997 Sep 2;96(5):1520-4. doi: 10.1161/01.cir.96.5.1520.
The class Ia antiarrhythmic drug disopyramide relieves the outflow tract obstruction of hypertrophic obstructive cardiomyopathy (HOCM). Disopyramide, however, has several adverse effects, such as dysuria and thirst, resulting from its anticholinergic activity. A new class Ia antiarrhythmic drug, cibenzoline, has little anticholinergic activity. The aim of this study is to elucidate whether cibenzoline attenuates left ventricular pressure gradient (LVPG) in patients with HOCM.
Ten patients with HOCM (mean age, 59+/-12 years) participated in this study. LVPG and left ventricular functions were measured before and 2 hours after administration of a single oral dose of 150 or 200 mg cibenzoline. LVPG decreased from 123+/-60 to 39+/-33 mm Hg (P=.0026). The E/A ratio in transmitral Doppler flow increased from 1.20+/-0.84 to 2.00+/-1.72 (P=.029). Isovolumic relaxation time increased from 73+/-16 to 101+/-23 ms (P=.0026). Left ventricular diastolic dimension remained unchanged, but left ventricular systolic dimension enlarged significantly, from 21.6+/-2.4 to 26.2+/-3.3 mm (P=.0004). Fractional shortening decreased from 47.6+/-6.1% to 34.6+/-8.8% (P=.0007). Left ventricular ejection time index decreased significantly, and preejection period index increased in all the patients. Decreased LVPG remained maintained even in the long-term treatment with cibenzoline. Conclusions These results indicate that cibenzoline can markedly attenuate LVPG in patients with HOCM. A decrease in myocardial contractility seems to be closely related to a marked decrease in LVPG.
I a类抗心律失常药物双异丙吡胺可缓解肥厚性梗阻性心肌病（HOCM）的流出道梗阻。然而，双异丙吡胺因其抗胆碱能活性会产生多种不良反应，如排尿困难和口渴。一种新型I a类抗心律失常药物西苯唑啉几乎没有抗胆碱能活性。本研究的目的是阐明西苯唑啉是否能减轻HOCM患者的左心室压力阶差（LVPG）。
10例HOCM患者（平均年龄59±12岁）参与了本研究。在单次口服150或200 mg西苯唑啉前及给药后2小时测量LVPG和左心室功能。LVPG从123±60 mmHg降至39±33 mmHg（P = 0.0026）。二尖瓣血流频谱E/A比值从1.20±0.84增至2.00±1.72（P = 0.029）。等容舒张时间从73±16 ms增至101±23 ms（P = 0.0026）。左心室舒张末期内径保持不变，但左心室收缩末期内径显著增大，从21.6±2.4 mm增至26.2±3.3 mm（P = 0.0004）。射血分数从47.6±6.1%降至34.6±8.8%（P = 0.0007）。所有患者的左心室射血时间指数显著降低，射血前期指数增加。即使长期使用西苯唑啉，LVPG降低仍得以维持。结论这些结果表明，西苯唑啉可显著减轻HOCM患者的LVPG。心肌收缩力降低似乎与LVPG显著降低密切相关。
