| Objective:To carry on the preliminary discussion of the influence of intraoperative vagal reflex on autonomic nervous function and postoperative long-term success rate in patients with paroxysmal atrial fibrillation, who receive circumferential pulmonary vein isolation. The method used is heart rate variability analysis.Methods:One hundred and eight patients with paroxysmal atrial fibrillation were enrolled in this study from April 2013 to March 2015. These patients received catheter radiofrequency ablation(RFCA) for the first time at the Second Hospital of TianJin medical university. All patients received transeophageal ecocardiography(TEE)before the ablation to exclude left atrial appendage thrombus or severe spontaneous echo contrast. The patients were divided into positive group and negative group based on the intraoperative vagal reflex appearance. All these patients had received transthoracic echocardiography before the ablation and within one year post the ablation.They received 24-hour dynamic electrocardiogram before the ablation and within three days post the ablation. Preoperative and postoperative heart rate variability(HRV) parameters were used to evaluate the changes of autonomic nervous function. The changes of cardiac structure and function before the ablation and one year post the ablation was compared by ultrasoundcardiography. Following up the patients at the 3rd months, the 6th months, the9 th months and the12 th months after discharge, the presence or absence of recurrence of atrial fibrillation was comfimed.The time-domain parameters of HRV include the standard deviation of all NN intervals(SDNN) reflecting the time-domain change, standard deviation of the average values of the NN intervals in all 5-min segments(SDANN), root mean square of the differences between adjacent NN intervals(rMSSD), percentage of adjacent NN interval differences >50 ms(PNN50). The frequency-domain parameters of the HRV included low-frequency(LF: 0.04–0.15Hz) power, high-frequency(HF: 0.15–0.40Hz)power, and the ratio of the LF to HF power(LF/HF). Late recurrence of atrial fibrillation was defined as typical symptom of tachycardia the patients,or electrocardiogram recording of atrial fibrillation, atrial flutter, atrial tachycardia,or 24 hours dynamic electrocardiogram recording of atrial fibrillation, atrial flutter, atrialtachycardia for 30 seconds or more.Results:(1) Before circumferential pulmonary vein isolation, the general data, Mean HR and HRV parameters between the positive and negative groups show no significant difference.After circumferential pulmonary vein isolation, all HRV parameters of the positive and negative groups were significantly lower than before, which means that both sympathetic nervous and vagus nervous function were lower than before.(2) After circumferential pulmonary vein isolation, since the vagus nervous function in positive group reduced significantly, HF reflecting the vagus nerve decreased significantly. However, LF reflecting sympathetic nerve didn’t reduce obviously, which made LF/HF reflecting the sympathetic and vagus nerve balance to increase significantly.(3) In the positive group, the success rate that one year post the ablation was86.4% in 22 cases. In the negative group, the success rate that one year post the ablation was 61.6% in 86 cases. One year post the ablation,the LAD of the positive group and negative group both reduced obviously, and the positive group decreased more significantly, the LVEF had no obvious change.Conclusion:1.Circumferential pulmonary vein isolation had damage on both the sympathetic nerve and vagus nerve in a certain degree, and vagus nerve of positive group wasdamaged more significantly.2.Vagal reflex during circumferential pulmonary vein isolation might indicate more significant damage on vagus nerve.3.Vagus denervation could reduce late recurrence of circumferential pulmonary vein isolation, improve the long-term success rate, inhibit atrial remodeling, and narrow atrial inner diameter. |
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