Premium
Cardiac Resynchronization Therapy Upregulates Cardiac Autonomic Control
Author(s) -
CHA YONGMEI,
OH JAE,
MIYAZAKI CHINAMI,
HAYES DAVID L.,
REA ROBERT F.,
SHEN WINKUANG,
ASIRVATHAM SAMUEL J.,
KEMP BRAD J.,
HODGE DAVID O.,
CHEN PENGSHENG,
CHAREONTHAITAWEE PANITHAYA
Publication year - 2008
Publication title -
journal of cardiovascular electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.193
H-Index - 138
eISSN - 1540-8167
pISSN - 1045-3873
DOI - 10.1111/j.1540-8167.2008.01190.x
Subject(s) - medicine , cardiology , cardiac resynchronization therapy , ejection fraction , heart failure , heart rate variability , cardiac function curve , ambulatory , cardiomyopathy , heart rate , autonomic nervous system , blood pressure
Objective : To determine the effect of cardiac resynchronization therapy (CRT) on sympathetic nervous function in heart failure (HF).Background : Neurohormonal dysregulation and cardiac autonomic dysfunction are associated with HF and contribute to HF progression and its poor prognosis. We hypothesized that mechanical resynchronization improves cardiac sympathetic function in HF.Methods : Sixteen consecutive patients receiving CRT for advanced cardiomyopathy and 10 controls were included in this prospective study. NYHA class, 6‐minute walk distance, echocardiographic parameters, plasma norepinephrine (NE) were assessed at baseline, 3‐month and 6‐month follow‐up. Cardiac sympathetic function was determined by 123 iodine metaiodobenzylguanidine ( 123 I‐MIBG) scintigraphy and 24‐hour ambulatory electrocardiography.Results : Along with improvement in NYHA class (3.1 ± 0.3 to 2.1 ± 0.4, P < 0.001) and LVEF (23 ± 6% to 33 ± 12%, P < 0.001), delayed heart/mediastinum (H/M) 123 I‐MIBG ratio increased significantly (1.8 ± 0.7 to 2.1 ± 0.6, P = 0.04) while the H/M 123 I‐MIBG washout rate decreased significantly (54 ± 25% to 34 ± 24%, P = 0.01) from baseline to 6‐month follow‐up. The heart rate variability (HRV) measured in SD of normal‐to‐normal intervals also increased significantly from baseline (82 ± 30 ms) to follow‐up (111 ± 32 ms, P = 0.04). The improvement in NYHA after CRT was significantly associated with baseline 123 I‐MIBG H/M washout rate (r = 0.65, P = 0.03). The improvement in LVESV index was associated with baseline 123 I‐MIBG delayed H/M ratio (r =−0.67, P = 0.02) and H/M washout rate (r = 0.65, P = 0.03).Conclusion: After CRT, improvements in cardiac symptoms and LV function were accompanied by rebalanced cardiac autonomic control as measured by 123 I‐MIBG and HRV.