Premium
Cardiac autonomic modulation and long‐term use of amiodarone in patients with chronic Chagasic cardiopathy
Author(s) -
Fortes Silva Henriette Elena,
Almeida Renan Sandoval,
Silveira Danilo Batista,
Llaguno Maurício,
Resende Luiz Antônio Pertili Rodrigues,
Dias da Silva Valdo José,
Correia Dalmo
Publication year - 2018
Publication title -
pacing and clinical electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.686
H-Index - 101
eISSN - 1540-8159
pISSN - 0147-8389
DOI - 10.1111/pace.13384
Subject(s) - medicine , amiodarone , cardiology , chagas disease , term (time) , autonomic nervous system , heart rate , atrial fibrillation , blood pressure , pathology , physics , quantum mechanics
Background Patients with chronic Chagas cardiopathy (CCC), which may be associated with cardiac arrhythmias, frequently use amiodarone, an antiarrhythmic drug that, experimentally, appears to modulate the cardiac autonomic function. Objective The present cross‐sectional observational study aimed to evaluate autonomic cardiac modulation in patients with CCC undergoing chronic amiodarone therapy. Methods Three groups were investigated: Group 1 included patients with CCC not treated with amiodarone (n = 27); Group 2 included patients with CCC with prolonged use (at least 6 months) of amiodarone (n = 16); and Group 3 included non‐Chagasic control patients (n = 23). All patients underwent a complete clinical and laboratory assessment, followed by autonomic function tests, consisting of a basal continuous electrocardiogram in the resting supine position for 10 minutes, followed by a change the orthostatic posture for a further 5 minutes. Heart rate variability (HRV) parameters (median and interquartile interval) were quantified using linear methods in the time‐ and frequency‐domains (autoregressive spectral analysis) and nonlinear methods, including symbolic analysis. Results Patients with CCC using amiodarone had changes in HRV suggestive of an offset in the sympatho‐vagal balance with a vagal modulation predominance (normalized HF, 49.7[27.4] vs 31.1[22.8] [P < 0.05]; and percentage 2V, 40.1 [14.6] vs 21.5 [13.4] [P < 0.05] vs untreated CCC group). These changes were further accompanied by increases in parameters indicative of greater complexity of HRV. Conclusions The deviation in the sympatho‐vagal balance and the increase in the complexity of HRV strongly suggest that amiodarone may have a cardioprotective effect, in addition to its antiarrhythmic effects, which could increase the survival of these patients.