Assessment of relationship between atrial synchrony and paroxysmal atrial fibrillation by two-dimensional speckle tracking imaging in patients with sick sinus syndrome / 中华医学超声杂志（电子版）

ABSTRACT

Objective To evaluate the relationship between atrial synchrony and paroxysmal atrial fibrillation (PAF) in patients with sick sinus syndrome (SSS) by two-dimensional speckle tracking imaging. Methods Forty-four SSS patients who underwent echocardiographic examination at Department of Ultrasound, No. 2 Hospital of Yinzhou in Ningbo City of Zhejiang Province from January 2015 to August 2016 were enrolled, including 25 without PAF and 19 with PAF. Twenty-eight normal adults who underwent echocardiographic examination at this department at the same time were included as a normal control group. The structural and functional parameters of the left ventricle of all enrolled subjects were evaluated by echocardiographic examination. After two-dimensional speckle tracking images of the right atrium free wall, atrial septum, and left atrium free wall were obtained, the time interval from the initial point of P wave on electrocardiograph to the second negative wave of the diastolic phase in two-dimensional speckle tracking images were measured to calculate the electrical-mechanical time of the right atrium free wall (P-RA), the electrical-mechanical time of the atrial septum (P-IAS), and the electrical-mechanical time (P-LA) of the left atrium free wall. Subsequently, the parameters of atrial synchrony were calculated. Conventional echocardiographic parameters, P-RA, P-IAS, P-LA, and the parameters of atrial synchrony were compared among the three groups by one-way ANOVA, and further comparisons between any two groups were performed by the SNK-q test. The relationship between the parameters of electrical-mechanical time, parameters of atrial synchrony, and PAF were analyzed by Spearman correlation analysis. Receiver operating characteristic curve (ROC) analysis was then performed to evaluate the value of the parameters of electrical-mechanical time and parameters of atrial synchrony in predicting PAF. Results The left atrial size was significantly larger in the SSS without PAF group and SSS with PAF group than in the normal control group (q=4.18, 5.37, both P＜0.05), although there was no significant difference between the SSS without PAF group and SSS with PAF group. The P-RA and P-IAS were significantly larger in the SSS without PAF group and SSS with PAF group than in the normal control group (q=4.03, 4.10; q=4.16, 4.31, all P＜0.05), but there was no significant difference between the SSS without PAF group and SSS with PAF group. The P-LA, right atrial intra-atrial synchrony, left atrial intra-atrial synchrony, and inter-atrial synchrony showed a gradually rising trend from the normal control group to the SSS without PAF group and SSS with PAF group, and the difference between any two groups was statistically significant (q=5.18, 11.23, 4.43; q=5.25, 11.74, 4.63; q=7.38, 14.67, 4.73; q=8.01, 16.37, 6.39, all P＜0.05). Spearman correlation analysis showed that P-LA, right atrial intra-atrial synchrony, left atrial intra-atrial synchrony, and inter-atrial synchrony were significantly positively correlated with PAF in patients with SSS (r=0.61, 0.55, 0.75, 0.78, all P ＜ 0.01), and the correlation between inter-atrial synchrony and PAF was the highest. ROC analysis demonstrated the optimal threshold of P-LA for prediction of PAF was 94 ms [sensitivity 68.42%; specificity 76.00%; the area under the ROC curve (AUC) 0.764 (95% CI 0.612-0.879)]; the optimal threshold of right atrial intra-atrial synchrony was 19 ms [sensitivity 57.89%; specificity 76.00%; AUC 0.714 (95% CI 0.558-0.840)];the optimal threshold of left atrial intra-atrial synchrony was 42 ms [sensitivity 78.95%; specificity 76.00%;AUC 0.860 (95% CI 0.722-0.946)]; and the optimal threshold of inter-atrial synchrony was 68 ms [sensitivity84.21%; specificity 84.00%; AUC 0.859 (95% CI 0.721-0.945)]. These results suggest that left atrial intra-atrial synchrony and inter-atrial synchronization are superior to right atrial intra-atrial synchrony in predicting PAF in patients with SSS. Conclusion Atrial electro-mechanical motion time parameters and synchrony parameters are closely related to PAF in patients with SSS, and left atrial intra-atrial synchrony and inter-atrial synchronization are the most effective parameters in predicting PAF in patients with SSS.