运动负荷超声在评估肥厚型心肌病梗阻类型中的应用

Exercise echocardiography in the evaluation of obstructive types of hypertrophic cardiomyopathy

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）〈50mm Hg（1mmHg=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〈30mm Hg的患者中，26例患者运动峰值LVOTG≥130mm Hg为潜在梗阻，25例运动峰值LVOTG〈30mm Hg为非梗阻。9例静息LVOTG30～49mmHg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）mmHg比（7．1±4．3）mmHg]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％C10．001～0．179，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。

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 echoeardiography. 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 septa｜ 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%CI0.001-0. 179, P =0.008）. Conclusions Approximately half of patients with nonobstructive HCM at rest have latent LVOTO. SAM and distribution of septal hypertrophy may be useful to identify patients with latent obstruction.