Effect of exercise training on cardiovascular autonomic and muscular function in subclinical Chagas cardiomyopathy: a randomized controlled trial

Author(s):Show less -

Sarmento, Adriana Oliveira ^[1] ; Antunes-Correa, Ligia M. ^[1] ; Alves, Maria J. N. N. ^[1] ; Bacurau, Aline V. N. ^[2] ; Fonseca, Keila C. B. ^[1] ; Pessoa, Fernanda G. ^[1] ; Lobo, Denise M. L. ^[1] ; Moreira, Leila D. P. ^[1] ; Trombetta, Ivani C. ^[3] ; Rondon, Maria U. P. B. ^[2] ; Rondon, Eduardo ^[2] ; Vieira, Marcelo L. C. ^[1] ; Ramires, Felix J. A. ^[1] ; do Brasileiro-Santos, Maria Socorro ^[4] ; Brum, Patricia C. ^[2] ; Mady, Charles ^[1] ; Negrao, Carlos E. ^{[2, 1]} ; Thomas, Scott ^[5] ; Ianni, Barbara M. ^[1]

Affiliation

^[1] Univ Sao Paulo, Heart Inst InCor, Med Sch, Unidade Reabilitacao Cardiovasc & Fisiol Exercici, Av Dr Eneas de Carvalho Aguiar 44, BR-05403000 Sao Paulo, SP - Brazil

^[2] Univ Sao Paulo, Sch Phys Educ & Sports, Sao Paulo - Brazil

^[3] Univ Nove Julho, Sao Paulo - Brazil

^[4] Univ Fed Paraiba, Postgrad Program Phys Educ Univ Pernambuco, Joao Pessoa, Paraiba - Brazil

^[5] Univ Toronto, Fac Kinesiol & Phys Educ, Toronto, ON - Canada

• Document type: Journal article
• Source: CLINICAL AUTONOMIC RESEARCH; v. 31, n. 2 SEP 2020.
• Web of Science Citations: 0

Abstract

Purpose Patients with chronic chagasic cardiomyopathy with preserved ventricular function present with autonomic imbalance. This study evaluated the effects of exercise training (ET) in restoring peripheral and cardiac autonomic control and skeletal muscle phenotype in patients with subclinical chronic chagasic cardiomyopathy. Methods This controlled trial (NCT02295215) included 24 chronic chagasic cardiomyopathy patients who were randomizedinto two groups: those who underwent exercise training (n = 12) and those who continued their usual activities (n = 12). Eight patients completed the exercise training protocol, and 10 patients were clinically followed up for 4 months. Muscular sympathetic nerve activity was measured by microneurography and muscle blood flow (MBF) using venous occlusion plethysmography. The low-frequency component of heart rate variability in normalized units (LFnuHR) reflects sympathetic activity in the heart, and the low-frequency component of systolic blood pressure variability in normalized units reflects sympathetic activity in the vessels. The infusion of vasoactive drugs (phenylephrine and sodium nitroprusside) was used to evaluate cardiac baroreflex sensitivity, and a vastus lateralis muscle biopsy was performed to evaluate atrogin-1 and MuRF-1 gene expression. Results The baroreflex sensitivity for increases (p = 0.002) and decreases (p = 0.02) in systolic blood pressure increased in the ET group. Muscle blood flow also increased only in the ET group (p = 0.004). Only the ET group had reduced resting muscular sympathetic nerve activity levels (p = 0.008) and sympathetic activity in the heart (LFnu;p = 0.004) and vessels (p = 0.04) after 4 months. Regarding skeletal muscle, after 4 months, participants in the exercise training group presented with lower atrogin-1 gene expression than participants who continued their activities as usual (p = 0.001). The reduction in muscular sympathetic nerve activity was positively associated with reduced atrogin-1 (r = 0.86; p = 0.02) and MuRF-1 gene expression (r = 0.64; p = 0.06); it was negatively associated with improved baroreflex sensitivity both for increases (r = -0.72; p = 0.020) and decreases (r = -0.82; p = 0.001) in blood pressure. Conclusions ET improved cardiac and peripheral autonomic function in patients with subclinical chagasic cardiomyopathy. ET reduced MSNA and sympathetic activity in the heart and vessels and increased cardiac parasympathetic tone and baroreflex sensitivity. Regarding peripheral muscle, after 4 months, patients who underwent exercise training had an increased cross-sectional area of type I fibers and oxidative metabolism of muscle fibers, and decreased atrogin-1 gene expression, compared to participants who continued their activities as usual. In addition, the reduction in MSNA was associated with improved cardiac baroreflex sensitivity, reduced sympathetic cardiovascular tone, and reduced atrogin-1 and MuRF-1 gene expression. (AU)

• FAPESP's process: 13/15651-7 - Effects of Aerobic Exercise Training Associated with Inspiratory Muscle Training on Skeletal Myopathy in Patients with Heart Failure
• Grantee: Lígia de Moraes Antunes Corrêa
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 11/17533-6 - Autonomic, metabolic and inflammatory aspects of metabolic syndrome associated with obstructive sleep apnea: effect of hypocaloric diet and physical training
• Grantee: Ivani Credidio Trombetta
• Support Opportunities: Regular Research Grants
• FAPESP's process: 10/50048-1 - Cellular and functional bases of exercise in cardiovascular diseases
• Grantee: Carlos Eduardo Negrão
• Support Opportunities: Research Projects - Thematic Grants