Abstract：
Echocardiographic assessment of diastolic function during atrial fibrillation (AF) remains challenging due to the irregular cardiac cycle length. We sought to assess whether the index-beat method, the beat following two preceding cardiac cycles of equal duration, could provide a more reliable measurement of E/e\' (mitral E wave/diastolic tissue Doppler velocity) than the conventional averaging of consecutive beats and hence facilitate the noninvasive estimation of elevated left atrial pressure (LAP) in patients with AF.
We prospectively studied 35 patients with persistent AF who had preserved left ventricular ejection fraction and underwent radiofrequency ablation. LAP was measured in conjunction with transseptal puncture during catheter ablation. Echocardiography was performed 24 h before ablation and E/e\' was determined using the recommended averaging of 10 beats and the index-beat method, with the observers blinded to the clinical details and LAP measurements.
Correlation analysis showed a strong positive correlation between two methods in terms of both septal E/e\' (r = 0.841, p < 0.001) and lateral E/e\' (r = 0.930, p < 0.001). Bland-Altman analysis also showed a good agreement between the two measurement methods in terms of E/e\'. E/e\' determined using both conventional averaging and the index-beat method was significantly correlated with LAP (p < 0.05). After Fisher Z transformation, we found that the index-beat septal E/e\' had a better correlation with LAP than did the conventional averaging E/e\' (r = 0.736 vs. r = 0.392, Zr = -2.110, p = 0.035). Furthermore, the index-beat method took significantly less time to measure E/e\' (mean 33.6 s; 95% confidence intervals [CIs]: 32.1 s-36.2 s) than did conventional averaging method (mean 96.2 s; 95% CI: 90.2 s-102.3 s; p < 0.001). Receiver operating characteristic curve analysis revealed that the optimal cut-off for predicting mean LAP >12 mm Hg was 11 (sensitivity 100%; specificity 77.3%) for index-beat septal E/e\' and 16 (sensitivity 61.5%; specificity 95.5%) for index-beat lateral E/e\'.
Good correlations were found between E/e\' and LAP in patients with AF, particularly with the index-beat method. Moreover, the index-beat method can easily measure E/e\' at an accuracy similar to that for the conventional averaging of consecutive beats, which can therefore be applied to assess the diastolic dysfunction and potentially improve the diagnosis of heart failure in patients with AF.
We prospectively studied 35 patients with persistent AF who had preserved left ventricular ejection fraction and underwent radiofrequency ablation. LAP was measured in conjunction with transseptal puncture during catheter ablation. Echocardiography was performed 24 h before ablation and E/e\' was determined using the recommended averaging of 10 beats and the index-beat method, with the observers blinded to the clinical details and LAP measurements.
Correlation analysis showed a strong positive correlation between two methods in terms of both septal E/e\' (r = 0.841, p < 0.001) and lateral E/e\' (r = 0.930, p < 0.001). Bland-Altman analysis also showed a good agreement between the two measurement methods in terms of E/e\'. E/e\' determined using both conventional averaging and the index-beat method was significantly correlated with LAP (p < 0.05). After Fisher Z transformation, we found that the index-beat septal E/e\' had a better correlation with LAP than did the conventional averaging E/e\' (r = 0.736 vs. r = 0.392, Zr = -2.110, p = 0.035). Furthermore, the index-beat method took significantly less time to measure E/e\' (mean 33.6 s; 95% confidence intervals [CIs]: 32.1 s-36.2 s) than did conventional averaging method (mean 96.2 s; 95% CI: 90.2 s-102.3 s; p < 0.001). Receiver operating characteristic curve analysis revealed that the optimal cut-off for predicting mean LAP >12 mm Hg was 11 (sensitivity 100%; specificity 77.3%) for index-beat septal E/e\' and 16 (sensitivity 61.5%; specificity 95.5%) for index-beat lateral E/e\'.
Good correlations were found between E/e\' and LAP in patients with AF, particularly with the index-beat method. Moreover, the index-beat method can easily measure E/e\' at an accuracy similar to that for the conventional averaging of consecutive beats, which can therefore be applied to assess the diastolic dysfunction and potentially improve the diagnosis of heart failure in patients with AF.
摘要：
背景：由于不规则的心动周期长度，对心房颤动（AF）期间舒张功能的超声心动图评估仍然具有挑战性。我们试图评估指数节拍法，前两个相同持续时间的心动周期后的搏动，与传统的连续搏动平均相比，可以提供更可靠的E/e'（二尖瓣E波/舒张组织多普勒速度）测量值，因此有助于对房颤患者的左心房压升高（LAP）进行非侵入性评估。
方法：我们前瞻性研究了35例保留左心室射血分数并接受射频消融的持续性房颤患者。在导管消融术期间，结合经中隔穿刺测量LAP。在消融术前24小时进行超声心动图检查,使用推荐的平均10次搏动和指数搏动法确定E/e'。观察者对临床细节和LAP测量结果视而不见。
结果：相关分析表明，两种方法在间隔E/e'（r=0.841，p<0.001）和外侧E/e'（r=0.930，p<0.001）方面均呈强正相关。Bland-Altman分析也显示了两种测量方法在E/e'方面的良好一致性。使用常规平均和指数搏动法确定的E/e'与LAP显着相关（p<0.05）。经过FisherZ变换,我们发现指数搏动间隔E/e与LAP的相关性比传统平均E/e'更好(r=0.736vs.r=0.392,Zr=-2.110,p=0.035)。此外，指数节拍法测量E/e'的时间明显较少(平均33.6s；95%置信区间(CI)：32.1s至36.2s)，与常规平均方法相比（平均96.2s；95%CI：90.2s至102.3s；p<0.001）。受试者工作特征曲线分析显示，预测平均LAP>12mmHg的最佳临界值对于指数搏动间隔E/e'为11（敏感性100％；特异性77.3％），对于指数搏动外侧E/e'为16（敏感性61.5％；特异性95.5％）。
结论：在房颤患者中发现E/e与LAP之间存在良好的相关性，特别是指数节拍法。此外，指数搏动法可以很容易地测量E/E，其精度类似于传统的连续搏动平均，因此，该方法可用于评估舒张功能障碍，并有可能改善房颤患者心力衰竭的诊断。
方法：我们前瞻性研究了35例保留左心室射血分数并接受射频消融的持续性房颤患者。在导管消融术期间，结合经中隔穿刺测量LAP。在消融术前24小时进行超声心动图检查,使用推荐的平均10次搏动和指数搏动法确定E/e'。观察者对临床细节和LAP测量结果视而不见。
结果：相关分析表明，两种方法在间隔E/e'（r=0.841，p<0.001）和外侧E/e'（r=0.930，p<0.001）方面均呈强正相关。Bland-Altman分析也显示了两种测量方法在E/e'方面的良好一致性。使用常规平均和指数搏动法确定的E/e'与LAP显着相关（p<0.05）。经过FisherZ变换,我们发现指数搏动间隔E/e与LAP的相关性比传统平均E/e'更好(r=0.736vs.r=0.392,Zr=-2.110,p=0.035)。此外，指数节拍法测量E/e'的时间明显较少(平均33.6s；95%置信区间(CI)：32.1s至36.2s)，与常规平均方法相比（平均96.2s；95%CI：90.2s至102.3s；p<0.001）。受试者工作特征曲线分析显示，预测平均LAP>12mmHg的最佳临界值对于指数搏动间隔E/e'为11（敏感性100％；特异性77.3％），对于指数搏动外侧E/e'为16（敏感性61.5％；特异性95.5％）。
结论：在房颤患者中发现E/e与LAP之间存在良好的相关性，特别是指数节拍法。此外，指数搏动法可以很容易地测量E/E，其精度类似于传统的连续搏动平均，因此，该方法可用于评估舒张功能障碍，并有可能改善房颤患者心力衰竭的诊断。
