Recovery from Left Ventricular Asynergy in Ischemic Cardiomyopathy following Long-Term Beta Blockade Treatment

Abstract

It has been suggested that long-term beta blockade treatment in congestive heart failure might be less effective in patients with ischemic cardiomyopathy as compared with patients having idiopathic dilated cardiomyopathy. This study was performed to evaluate the effect of long-term adrenergic beta blockade treatment on regional myocardial function in patients with ischemic cardiomyopathy. The regional wall motion (RWM) was evaluated in 12 patients with ischemic cardiomyopathy before and after long-term open treatment with metoprolol. On average, the patients were treated over 11 months (range 6-36 months). The regional left ventricular function was assessed using two-dimensional echocardiographic recordings by two independent blinded observers. The RWM score was evaluated in 16 segments of the left ventricle on a scale from 0 (hypercontractility) to 5 (dyskinesia). Following treatment, there was an improvement in general ventricular function (ejection fraction 0.24-0.31; p = 0.01) as well as in RWM (86 improved segments, 48 deteriorated, 49 unchanged; p < 0.002). Ventricular segments with poor contractility (RWM score ≧ 3.5) tended to improve (53 improved segments, 16 deteriorated, 13 unchanged; p < 0.0001), whereas less severely impaired segments (RWM score < 3.5) did not improve (33 improved segments, 32 deteriorated, 36 unchanged; NS). It is suggested that poorly contracting myocardial segments might improve following beta blockade treatment, while an effect on less impaired segments might be lacking. An improvement in overall myocardial function would then be harder to detect.