The Clinical Study Of Relationship Between Changes Of Cardiac Function And Alterations Of Ventricular Depolarization In Patients With Chronic Heart Failure

Objective: To investigate the relationship between changes of cardiac function and alterations of ventricular depolarization by the study of relations of QRS duration and total QRS voltage to left ventricular ejection fraction (LVEF) in patients with chronic heart failure. Methods: Four hundred and ninety-two patients with chronic heart failure were analyzed retrospectively in our hospital be tween January 2003 and January 2007. According to inclusion criteria, two hundred and eighty-five patients were included in our study. All of the attendees accorded with NYHA class II～IV and LVEF<50%, as well as without prior myocardial infarction(suggestive clinical symptoms, diagnostic ECG changes, and diagnostic serum enzymes) or use of antiarrhythmic medications or prior permanent pacemaker implantation. Study participants (207 man, mean age 66.33±8.72 years; 78 women, mean age 65.26±8.43 years) underwent routine echocardiographic and electrocardiographic measurements. According to the different LVEF, all patients were divided into three groups: Group A: LVEF 40%～49%; Group B: LVEF 30%～39%; Group C: LVEF is less than 30%. QRS duration, total QRS voltage, LVEF and left ventricular end-diastolic volume (LVEDV) were analyzed. Results: There were significant differences in three groups regarding QRS duration (group A:114.22±23.87ms,group B:120.62±29.02ms,group C:127.44±27.12ms ,P<0.01). QRS duration was inversely related to LVEF (P＜0.01, R=0.412). With a progressive decrease in LVEF, the QRS duration prolonged significantly. In addition, QRS duration was positively related to LVEDV (P＜0.01, R=0.464). With a progressive increase in LVEDV, the QRS duration prolonged significantly. There were significant differences in three groups regarding total QRS voltage (group A:14.1 l±4.61mv, group B:15.05±4.83mv, group C:11.7±3.12mv, P＜0.01). Total QRS voltage in group C (LVEF<30%) is lower than that in other groups (P<0.01). Total QRS voltage decreased significantly in patients with serious left ventricular enlargement (LVEDV>70ml, P＜0.01). Conclusion: QRS duration prolongation predicts deterioration of cardiac function. Total QRS voltage decrease maybe is a maker of the end-stage heart failure approaches.