Cardiac resynchronization therapy improved stroke volume index by 10% (P=0.011) and myocardial efficiency by 13% (P=0.024) without increasing global left ventricular oxidative metabolism.
Observational (n=8)
Does cardiac resynchronization therapy improve myocardial oxidative metabolism and efficiency in patients with NYHA class III-IV congestive heart failure?
Cardiac resynchronization therapy improves left ventricular function and myocardial efficiency without increasing global oxidative metabolism in patients with severe heart failure.
p-value: p=0.024
Background— Recent studies have demonstrated increased left ventricular contractility with cardiac resynchronization therapy (CRT) using atriobiventricular stimulation. This study evaluated the effect of CRT on myocardial oxidative metabolism and efficiency. Methods and Results— Eight patients with New York Heart Association functional class III-IV congestive heart failure were studied during atrial pacing (control) and atriobiventricular stimulation at the same rate. The monoexponential clearance rate of 11 Cacetate (k mono ) was measured with positron emission tomography to assess myocardial oxidative metabolism in the left and right ventricles (LV and RV, respectively). Myocardial efficiency was measured using the work metabolic index (WMI). Stroke volume index improved by 10% ( P =0.011) with CRT, although both global LV and RV k mono were unchanged compared with control. Septal k mono increased by 15% ( P =0.04), and the septal/lateral wall k mono ratio increased by 22% ( P =0.01). WMI increased by 13% ( P =0.024) with CRT. Conclusions— CRT improves LV function without increasing global LV oxidative metabolism, resulting in improved myocardial efficiency. Oxidative metabolism of the interventricular septum increases relative to the lateral wall, which suggests successful resynchronization.
Ukkonen et al. (Tue,) conducted a observational in New York Heart Association functional class III-IV congestive heart failure (n=8). Cardiac resynchronization therapy (atriobiventricular stimulation) vs. Atrial pacing (control) was evaluated on Myocardial efficiency (work metabolic index) (p=0.024). Cardiac resynchronization therapy improved stroke volume index by 10% (P=0.011) and myocardial efficiency by 13% (P=0.024) without increasing global left ventricular oxidative metabolism.
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