Effects of cardiac resynchronization therapy on muscle sympathetic nerve activity.

Introduction: Muscle sympathetic nerve activity (MSNA) is an independent prognostic marker in patients with heart failure (HF). Therefore, its relevance to the treatment of HF patients is unquestionable.

Objectives: In this study, we investigated the effects of cardiac resynchronization therapy (CRT) on MSNA response at rest and during exercise in patients with advanced HF.

Cardiac sympathetic activity pre and post resynchronization therapy evaluated by 123I-MIBG myocardial scintigraphy.

Background: Imaging with (123)I-metaiodobenzylguanidine (MIBG) is used for the assessment of cardiac sympathetic activity (CSA). We analyzed CSA before and after cardiac resynchronization therapy (CRT), and correlated these data with CRT response.

Methods And Results: Thirty patients with chronic heart failure and classic indications for CRT were prospectively studied before and at least 3 months after CRT.