运动负荷超声在评估肥厚型心肌病梗阻类型中的应用

目的 评估肥厚型心肌病(HCM)患者静息和运动中左室流出道梗阻的情况.方法 连续入选的60例静息左室流出道压差(LVOTG) ＜50 mm Hg(1 mm Hg=0.133 kPa)的HCM患者,超声测量静息LVOTG和运动峰值LVOTG.51例静息LVOTG＜ 30 mm Hg的患者中,26例患者运动峰值LVOTG≥30 mm Hg为潜在梗阻,25例运动峰值LVOTG＜ 30 mm Hg为非梗阻.9例静息LVOTG30 ～49 mm Hg为静息梗阻.分析不同类型梗阻的形态学特征.结果 潜在梗阻与非梗阻患者相比,二尖瓣前叶收缩期前向运动(SAM)征(73.1％比8.0％)、流出道狭窄(46.2％比4.0％)更常见、二尖瓣反流程度更重、静息LVOTG(16.9±7.2) mm Hg比(7.1 ±4.3)mm Hg]更高,室间隔肥厚部位分布差异有统计学意义(P值均＜0.05).多因素logistic回归分析,SAM征(OR 6.431,95％ CI2.323 ～291.112,P=0.002)和室间隔肥厚部位(OR0.011,95％ CI0.001 ～0.179,P=0.008)为发生潜在梗阻的独立预测因素.结论 约半数静息无梗阻的HCM患者存在潜在梗阻.SAM征和室间隔肥厚部位有助于潜在梗阻的识别.

Exercise echocardiography in the evaluation of obstructive types of hypertrophic cardiomyopathy

Objective To assess the condition of left ventricular outflow tract obstruction (LVOTO) under resting conditions and physiological exercise in hypertrophic cardiomyopathy (HCM) patients.Methods A total of 60 patients with HCM and left ventri cular outflow tract gradient (LVOTG) <50 mm Hg (1 mm Hg=0.133 kPa) at rest were enrolled consecutively, and LVOTG at rest and exercise were measured by echocardiography. Of 51 patients with gradients <30 mm Hg at rest，26 were latent LVOTO with exercise peak value LVOTG≥30 mm Hg, 25 were non LVOTO with exercise peak value LVOTG<30 mm Hg, and 9 were resting obstruction with LVOTG 30-49 mm Hg. The morphological characteristics of different types of obstruction were analyzed.Results Patients with latent LVOTO were more likely to have SAM(73.1% vs 8.0%), narrow of LVOT(46.2% vs 4.0%), higher resting gradients (16.9±7.2) mm Hg vs (7.1±4.3) mm Hg] and mitral regurgitation grade at rest than patients with non-obstructive (all P values <0.05). The distribution of septal hypertrophy were different in the two groups (P<0.05). Multivariate logistic regression analysis showed independent predictors of latent LVOTO were SAM (OR 6.431, 95%CI 2.323-291.112, P=0.002) at rest and distribution of septal hypertrophy(OR 0.011, 95%CI 0.001-0.179, P=0.008).Conclusions Approximately half of patients with non-obstructive HCM at rest have latent LVOTO. SAM and distribution of septal hypertrophy may be useful to identify patients with latent obstruction.