The Clinical Study Of Relationship Between Changes Of Cardiac Function And Alteration Of Cardiac Electrophysiology In Patients With Chronic Heart Failure

Objective: To investigate the relationship between changes of cardiac function andalterations of cardiac electrophysiology by the study of relations of QRS duration, totalQRS voltage, QT interval, and QT dispersion to left ventricular ejection fraction (LVEF)in patients with chronic heart failure, and try to find a convenient, fast, accurate indicatorto reflect the severity and the prognosis of the disease; To investigate the occurrence ofarrhythmias in patients with chronic heart failure. Methods:212patients with chronicheart failure and left ventricular ejection fraction of less than50%were analyzedretrospectively in our hospital. According to the different LVEF，all patients were dividedinto three groups: Group A: LVEF less than30%; Group B: LVEF30%-39%; Group C:LVEF40%-49%. We analyze the relations of QRS duration, total QRS voltage, QTinterval, and QT dispersion to LVEF between the three groups. Results:(1)There weresignificant differences in three groups regarding total QRS voltage. Total QRS voltagewas positively related to LVEF (P<0.01, r=0.355). With a progressive decrease in LVEF,the total QRS voltage reduced significantly. And Total QRS voltage was inversely relatedto LVEDD (P<0.01, r=-0.429).(2)There were significant difference between group A.Band group A.C regarding QRS duration (P<0.017). The QRS duration in group A is longerthan in other groups, and the difference of QRS duration between group B and C is nosignificance (P>0.017).(3)There were significant differences in three groups regardingQT interval (P<0.017). QT interval was inversely related to LVEF (P<0.01, r=-0.337).With a progressive decrease in LVEF，the QT interval prolonged significantly. And QT interval was positively related to LVEDD (P<0.01, r=0.476).(4)The QT dispersion ofgroup A and B are longer than one of group C, but there are no significant differencebetween group A and B (P>0.017).(5)There were60.8%patients with cardiacarrhythmias in212patients with chronic heart failure, including52patients of atrialfibrillation,27patients of left bundle branch block,17patients of right bundle branchblock,13patients of not stereotypes of intraventricular conduction block. Conclusion:Total QRS voltage decrease, QRS duration prolongation, QT interval and QT dispersionextention maybe predict deterioration of cardiac function and are makers of the end-stageof heart failure. More than half of patients with chronic heart failure occur atrialfibrillation and intraventricular conduction block mainly.