Study On The Atrial Synchronicity And The Diurnal Variation Of PR Interval In Dilated Cardiomyopathy Patients

Objectives To detect the atrial synchronicity and the diurnal variation of PR interval in dilated cardiomyopathy patients. It might be a satisfied way to improve the symptoms of heart failure that adjusting the CRT for patients with NYHA III or IV.Methods All the subjects were divided into two groups:the Control group and the DCM group. To measure the indexes of atrial synchronicity and the indexes of Holter.Results The indexes of atrial synchronicity:Inter-and Intra-atrial synchronicity:P-RA, P-LA and P-IAS were significantly prolonged in DCM group when it was compared with the control group(p<0.01). Therefore, the RA, interatrial and LA synchronicity in DCM group, compared with the controls, were all obviously significant(p<0.01), which reveals that inter-and intra-atrial asynchronies indeed exist in the patients with DCM.The indexes of Holter:P wave duration, QRS wave duration and the QTc duration were significantly increased in DCM group as compared to controls(p<0.05). Moreover, the day of PR interval and the night of PR interval were both significantly increased in patents with DCM. With the aggravation of cardiac function, the diurnal variation of PR interval were further significantly prolonged in the patients with NYHA â…¢ or IV. However, the difference between the diurnal variation of PR interval was significantly reduced with the aggravation of cardiac function. Conclusion With the aggravation of cardiac function, the day and night of PR interval were further significantly prolonged in the patients with NYHA III or IV. But the difference between the diurnal variation of PR interval was significantly reduced with the aggravation of cardiac function, indicating the imbalance of sympathetic and vagal systems.It reveals that inter-and intra-atrial asynchronies indeed exist in the patients with DCM. Therefore, it might be a satisfied way to improve the symptoms of heart failure that adjusting the CRT for patients with NYHA III or IV based on the diurnal variation of PR interval.