多普勒超声心动图检测慢性心力衰竭患者心肌生物能量消耗水平的变化及临床意义

Value of Doppler echocardiography derived myocardial energy expenditure measurements in chronic heart failure patients

目的分析慢性心力衰竭（心衰）患者的多普勒超声指标心肌生物能量消耗（MEE）与左心室结构指标及其收缩、舒张、整体功能指标及心衰严重程度（NYHA心功能分级）、C反应蛋白（CRP）、N末端B型利钠肽原（NT—proBNP）之间的关系，探讨MEE用于评估慢性心衰心功能状况的临床价值。方法选择慢性心衰住院患者99例，据左室射血分数（LVEF）值分为LVEF正常的心衰（HFNEF）组37例，INEF降低的心衰（HFREF）组62例（其中LVEF〉35％、〈50％及≤35％分别为30例及32例）；据NYHA心功能分级分为Ⅱ级（26例）、Ⅲ级（42例）、Ⅳ级（31例）；对照组30例。采用多普勒超声心动图检测并计算MEE及常规结构指标，左心室收缩（LVEF、LVFS）、舒张（E／A、EDT、IVRT）及整体功能指标（Tei指数），并测定各组血清CRP、血浆NT—proBNP水平，分析各组间各参数的差异，探讨MEE与上述指标问的相关性。结果HFNEF组患者MEE水平与对照组差异无统计学意义（P〉0．05），HFREF组患者MEE水平较对照组明显增加（P〈0．01）；慢性心衰组MEE随LVEF的降低及NYHA心功能分级级别的升高而显著增加（P〈0．05）；双变量相关分析显示，MEE与心室结构及收缩、舒张、整体功能指标、NYHA心功能分级及血清CRP、血浆NT—proBNP水平之间均具有相关性，其中关系最密切的是左心室收缩功能指标，即MEE与LVEF、LVFS均呈明显负相关[分别为r=-0．540、P〈0．01，r=-0．454、P〈0．01]。结论随左心室收缩功能障碍及心衰程度的加重，慢性心衰患者的MEE水平逐步升高，MEE与现有的心功能评价指标（如LVEF值、NYHA分级、NT．proBNP等）均呈明显相关，特别与左心室收缩功能指标关系密切。MEE可从心肌生物能量学角度有效评定慢性心衰患者的心功能状况。

Objective To evaluate the relationship between myocardial energy expenditure （MEE） level and cardiac function in chronic heart failure （CHF） patients. Methods A total of 99 CHF patients were divided into 3 groups according to the LVEF （ HFNEF≥50%, n =37; HFREF1 35.1% -49. 9%, n=30; HFREF2 ≤35% , n=32） or the New York Heart Association （NYHA Ⅱ , n =26; Ⅲ, n =42; Ⅳ, n = 31 ） criteria. Thirty patients with cardiovascular disease and without CHF served as controls. Routine examinations including serum CRP （ELISA） and plasma NT-proBNP （chemiluminescence sandwich ELISA） were made on the next morning after admission; echocardiography was performed on the third day after admission. LVMW, LVMWI, RWT, LVIDd, LA, LV, LVEF, LVFS, E/A, EDT, IVRT, Tei index and MEE were measured or calculated. Results MEE was significantly higher in HFREF patients than in controls （ P 〈 O. 01 ） and similar between HFNEF patients and controls （ P 〉 0. 05 ）. MEE increased in proportion to decrease of LVEF and increase of NYHA grades in CHF patients （ all P 〈 0. 05 ） . Bivariate analysis confirmed that MEE was significant correlated with LVMW, LVMWI, RWT, LVIDd, LA, LV, LVEF （r = - O. 540, P 〈 0. 01 ）, LVFS （r = - 0. 454, P 〈 0. 01 ）, E/A, EDT, IVRT, Tei index, NYHA grades, CRP and NT-proBNP. Conclusion MEE derived from standard echocardiographic measurements is an effective indicator for myocardial bioenergetics and significantly correlated with cardiac function in CHF patients, especially in CHF patients with reduced LVEF.