Cardiac Sympathetic Reserve and Response to Cardiac Resynchronization Therapy

Yong-Mei Cha et al. (Mayo clinic and others)

Background—The objective of the study was to investigate the effect of cardiac resynchronization therapy (CRT) on cardiac autonomic function.

Methods and Results—This prospective study included 45 consecutive patients with heart failure who received CRT devices with defibrillator and 20 age-matched healthy controls. At baseline, 3 months and 6 months after CRT, we assessed New York Heart Association (NYHA) class, 6-minute walk distance, plasma sympathetic biomarker nerve growth factor, echocardiography, heart rate variability and cardiac presynaptic sympathetic function determined by iodine 123 metaiodobenzylguanidine scintigraphy. After CRT, NYHA class improved by 1 class (p<0.001), p="0.004)" p="0.004)," p="0.03)," p="0.01)." p="0.003)," p="0.003)">

Conclusions—CRT improved sympathetic function. Cardiac sympathetic reserve may be a marker for the reversibility of failing myocardial function.