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 [11C]acetate (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.
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 [11C]acetate (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.
Authors: Emirhan Nemutlu; Song Zhang; Yi-Zhou Xu; Andre Terzic; Li Zhong; Petras D Dzeja; Yong-Mei Cha Journal: J Card Fail Date: 2015-04-22 Impact factor: 5.712
Authors: Simone C S Brandão; Silvana A D Nishioka; Maria C P Giorgi; Ji Chen; Rubens Abe; Martino Martinelli Filho; Viviane T Hotta; Marcelo L Vieira; Ernest V Garcia; José C Meneghetti Journal: Eur J Nucl Med Mol Imaging Date: 2009-01-14 Impact factor: 9.236
Authors: Juhani Knuuti; Jan Sundell; Alexandru Naum; Erik Engblom; Juhani Koistinen; Antti Ylitalo; Kira Q Stolen; Riikka Kalliokoski; Stephan G Nekolla; K E Jeroen J Bax; K E Juhani Airaksinen Journal: Eur J Nucl Med Mol Imaging Date: 2004-07-29 Impact factor: 9.236