风心病二尖瓣置换术后有效瓣口面积的超声定量评估价值

Assessment of effective orifice area after mitral valve replacement in patients with rheumatic heart disease by echocardiography

目的 比较压差降半时间法（PHT）和连续方程法（CE）对于二尖瓣置换术后瓣口狭窄程度的评估价值。方法 将2012年12月～2015年12月在四川大学华西医院、中南大学湘雅三医院因风湿性心脏病二尖瓣病变行单纯二尖瓣机械瓣置换术且在术后≥1年进行超声心动图随访的61例患者纳入本研究。根据术前心律，分为房颤心律组（AF）和窦性心律组（SR）。测量二尖瓣血流平均跨瓣压差（PG）、采用PHT法和CE法分别计算二尖瓣有效瓣口面积EOA-PH和EOA-CE，进行比较和相关分析。结果 61例患者PG为5.24±1.84mmHg， EOA-PHT、EOA-CE分别为2.18±0.36cm2、1.82±0.42cm2,无论是否合并房颤，EOA-PHT测值均明显高于EOA-CE。整体分析：PG、EOA-PHT、EOA-CE之间呈两两相关， PG与EOA-CE之间的相关性强于PG与EOA-PHT之间的相关性。分组分析：SR组PG、EOA-PHT、EOA-CE两两之间相关性良好。AF组PG与EOA-CE、EOA-PHT与EOA-CE仍有良好相关性，但PG与EOA-PHT相关性差。结论 压差降半时间法和连续方程法均可较为准确地评价二尖瓣置换术后瓣口的狭窄程度，但对于合并房颤的患者，连续方程法对有效瓣口面积的评价更为稳定。

Objective The aim of our study was to compare the assessment of effective orifice area in patients with mitral valve replacement, calculated by pressure half-time （PHT） method and continuity equation （CE） method. Methods A total of 61 patients who underwent mitral valve replacement from December 2012 to December 2015 in West China Hospital of Sichuan University and The Third Xiangya Hospital of Central South University were enrolled in this study. They had been followed up with echocardiography one year after operation. According to preoperative heart rhythm, they were divided into patients with atrial fibrillation and patients with sinus rhythm. Mean PG, EOA-PHT and EOA-CE were measured, and their relationships were analyzed. Results Mean PG was 5.24±1.84mmHg, EOA-PHT and EOA-CE were 2.18±0.36cm2 and 1.82±0.42cm2 respectively. EOA-PHT was significantly larger than EOA-CE. Mean PG, EOA-PHT and EOA-CE were significantly correlated with each other. In patients with atrial fibrillation, there was no significant correlation between mean PG and EOA-PHT. Conclusions Both EOA-PHT and EOA-CE can be used to assess the extent of mitral stenosis after mitral valve replacement. For patients with atrial fibrillation, EOA-CE is more stable than EOA-PHT.