CHANGES IN EARLY AND LATE DIASTOLIC FILLING PATTERNS INDUCED BY LONG-TERM ADRENERGIC BETA-BLOCKADE IN PATIENTS WITH IDIOPATHIC DILATED CARDIOMYOPATHY

Background beta-Blockers have been used in patients with idiopathic di lated cardiomyopathy to improve cardiac performance and theoretically would be beneficial to diastolic function. However, there are few repo rts on changes in diastolic function during chronic pharmacological tr eatment of congestive heart failure. Methods and Results The present s tudy was a substudy in the international Metoprolol in Dilated Cardiom yopathy Trial. Transmitral Doppler echocardiography was used to evalua te diastolic function in 77 patients randomly assigned to placebo (n=3 7) or metoprolol (n=40). The patients were treated for 12 months. Chan ges in Doppler how variables in the metoprolol group implied a less re strictive filling pattern, expressed as an increase in E-wave decelera tion time (placebo, 185+/-126 to 181+/-64 ms; metoprolol, 152+/-63 to 216+/-78 ms; P=.01, placebo versus metoprolol). Maximal increase in de celeration time had occurred by 3 months, whereas systolic recovery wa s achieved gradually and maximal effect was seen by 12 months of treat ment. Although deceleration time was correlated to heart rate at basel ine, changes in deceleration time were not significantly correlated to changes in heart rate during treatment. Conclusions During the first 3 months of treatment, maximal effects on diastolic variables were rea ched, whereas the most prominent effect on systolic function was seen late in the study. It is suggested that effects on diastolic filling a ccount for subsequent later myocardial systolic recovery. The E-wave d eceleration time, which in recent studies has been shown to be a power ful predictor of survival, was significantly improved in the metoprolo l-treated patients.