[Long-term effects and mortality of biventricular pacing therapy in patients with congestive heart failure]

To study the long-term effects and mortality of biventricular pacing therapy in patients with congestive heart failure.

Twenty-five patients, 18 men and 7 women, aged 34-75 [mean aged of (61.42 +/- 10.36)] years, with a cardiac function of New York Heart Association (NYHA) class III (n = 10) or IV (n = 15) received biventricular pacing therapy from Mar. 2001 to Feb. 2005. The etiologies of heart failure were idiopathic dilated cardiomyopathy (16 cases), hypertensive heart disease (3 cases) and ischemic heart disease (6 cases). Left ventricular end-diastolic dimension (LVEDD) was > 60 mm, Left ventricular ejection fraction (LVEF) was < 0.40 and QRS duration was > 130 ms in all the patients. Heart function parameters were repeatedly measured before and 3 months, 6 months, 1 year, 2 years and 3 years after pacemaker implantation. Mortality was also determined. The average follow up period was (20.88 +/- 11.51) months.

(1) Mortality: 5 patients died during follow-up (3 non-cardiac and 1 cardiac sudden death and 1 acute myocardial infarction). (2) The mean 6-min walking distance was increased significantly (P < 0.05) at 3 months to 3 years of follow-up. (3) NYHA class: The cardiac function of all patients improved significantly, with a reduction of mean NYHA class of more than one grade at 3 months to 3 years follow-up. (4) LVEDD: LVEDD reduced significantly (P < 0.05) at 3 months to 3 years follow-up. (5) LVEF: LVEF increased significantly (P < 0.05) at 3 months to 2 years follow-up. LVEF also improved at third year's follow-up, but the difference was not significant statistically.

Cardiac resynchronization, a pacemaker-based therapy for heart failure, may enhance quality of life and heart function and reverse LV remodeling. The long-term effects of treatment were stable, leading to the reduction of mortality from advanced heart failure.