摘要目的:探讨心电图“掉头”现象评价左心功能不全方法的可行性。方法:本研究为多中心横断面研究。纳入2017年11月1日至2020年1月31日于6家医院（山东省临清市人民医院、山东省聊城市第二人民医院、清华大学附属北京清华长庚医院、西北大学附属医院、郑州大学第五附属医院和山东第一医科大学第一附属医院）心血管内科收治的器质性心血管病患者。根据入院诊断将患者分为心力衰竭（心衰）组（包括左心衰竭及全心衰竭）与无心衰组。采集患者入院时心电图，比较两组患者血浆脑钠肽等指标。采用盲法进行心电图掉头现象心衰诊断试验。筛选出r波生长不良（PrWG）住院病例（PrWG病例组），根据心电图波形是否合并心房颤动（房颤）和左束支传导阻滞（LBBB）建立房颤亚组和LBBB亚组，比较各组胸前导联掉头现象与双向波心衰的发生率。通过受试者工作特性（ROC）曲线模型评估心电图掉头现象中QRS波R/S预测比值等诊断左心衰竭的价值，确定其最佳截断值。结果:共纳入7 430例患者，年龄（65.2±12.1）岁，其中男占42.4%（3 153/7 430）。心衰组1 615例（21.7%，1 615/7 430）。心电图掉头现象诊断左心衰竭的敏感度为49.8%（804/1615）、特异度为95.6%（5 558/5 815）。PrWG病例组患者掉头心衰的发生率为75.7%（765 /1010），明显高于PrWG后相邻导联QRS双向波的发生率（45.9%，315 /686），差异有统计学意义（ χ 2=157.110， P<0.001）。ROC曲线分析表明，PrWG后相邻导联QRS波R/S比值诊断心衰的截断值为1.835，R/S比值曲线下面积为0.689（ P<0.001）。 结论:对于心血管病住院患者，心电图掉头评估左心衰竭可行，PrWG后相邻导联QRS波R/S比值≥2评价左心衰竭合理。

abstractsObjective:To investigate the feasibility of utilizing the electrocardiogram (ECG) U turn phenomenon to assess left ventricular dysfunction.Methods:This study adopted a multicenter, cross- sectional design. It included patients with organic cardiovascular diseases admitted to the cardiology depart- ments of six hospitals (Shandong Linqing People's Hospital, Shandong Liaocheng Second People's Hospital, Beijing Tsinghua Changgung Hospital affiliated with Tsinghua University, Northwestern University Affiliated Hospital, The Fifth Affiliated Hospital of Zhengzhou University, The First Affiliated Hospital of Shandong First Medical University) between November 1, 2017, and January 31, 2020.All patients were divided into heart failure group (including left ventricular failure and total heart failure) and non-heart failure group based on admission diagnoses. Indicators such as age, gender, underlying diseases, and plasma brain natriuretic peptide were compared between the two groups. A blinded envaluation was performed to assess the ECG U turn phenomenon for diagnosing heart failure. Hospitalized cases with poor r wave growth (PrWG case group) were selected and then stratified based on ECG findings into subgroups: an atrial fibrillation subgroup and a left bundle branch block (LBBB) subgroup, according to the presence of these concomitant conditions. The incidence of the precordial lead ECG U turn phenomenon and bidirectional wave heart failure was subsequently compared among these groups.The diagnostic value of the QRS R/S ratio in predicting left ventricular failure was assessed using a receiver operating characteristic(ROC) curve model to determine the optimal cut-off value.Results:A total of 7 430 cardiovascular inpatients [average age (65.2±12.1) years] were included, of which 3 153 were males (42.4%, 3 153/7 430), and 1 615 patients had heart failure (21.7%,1 615/7 430). The diagnostic performance of ECG U turn phenomenon for detecting left ventricular failure was as follows:sensitivity 49.8%(804/1 615), specificity 95.6% (5 558/5 815). The incidence of U turn heart failure in PrWG case group was 75.7% (765/1 010), significantly higher than that of bidirectional QRS waves in adjacent leads following poor r wave growth (45.9%,315/686), χ 2=157.110, P<0.001. ROC curve analysis showed that the cut-off value of the adjacent lead QRS complex R/S ratio for diagnosing heart failure after poor r wave growth was 1.835 ( P<0.001). A statistically significant area under the curve ( AUC) of 0.689 was observed for the R/S ratio ( P<0.001). Conclusion:For hospitalized patients with cardiovascular disease,the ECG U turn phenomenon is a feasible method for evaluating left ventricular failure. Additionally, when the QRS R/S ratio in adjacent precordial leads is ≥2 following poor r wave growth,it serves as a reasonable diagnostic criterion for left ventricular failure.