The effects of sympathectomy upon myocardial

• Grant number: 12/02772-8
• Support Opportunities: Regular Research Grants
• Duration: August 01, 2012 - July 31, 2014
• Field of knowledge: Health Sciences - Medicine - Medical Clinics
• Principal Investigator: Felix José Alvarez Ramires
• Grantee: Felix José Alvarez Ramires
• Host Institution: Instituto do Coração Professor Euryclides de Jesus Zerbini (INCOR). Hospital das Clínicas da Faculdade de Medicina da USP (HCFMUSP). Secretaria da Saúde (São Paulo - Estado). São Paulo , SP, Brazil

Abstract

Sympathectomy is a therapeutic modality used to treat certain diseases for decades. Recently, some studies suggest the application of this technique in the treatment of heart failure to replace the use of beta-blockers. However, its physiological effects upon the heart have been slightly studied. The objective of this study is to evaluate the effects of sympathectomy on variables related mainly to the autonomic nervous system as the case for chronotropic properties at rest and stress, autonomic modulation of the heart, peripheral and myocardial catecholamines and beta-adrenergic receptors in the myocardium. Also the effects of this procedure on ventricular function and myocyte size will be analyzed. We will study rats undergone to a sympathectomy caused by sclerosis of the stellate ganglion by puncture and injection of absolute alcohol. The study will cover five groups of 15 animals each: control, left unilateral sympathectomy, bilateral sympathectomy, bilateral sympathectomy with carvedilol and carvedilol without sympathectomy. The variables proposed for the analysis will be obtained by resting ECG, echocardiography, maximal exercise test, heart rate variability and the efforts of HR and SBP measured in the time domain (variance) and frequency domain. The myocardial information about receptors, myocardial and peripheral catecholamines and myocyte size will be obtained by PCR, ELISA, Western Blot and myocyte morphometry, respectively. We hope to demonstrate the effect of sympathectomy in the effective reduction of sympathetic activity at different levels in the myocardium and thus clarify the real value of this technique and better define their effects in normal myocardium and potential applicability in diseased myocardium. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

JORDAO, MAURICIO RODRIGUES; PESSOA, FERNANDA G.; FONSECA, KEILA C. B.; ZANONI, FERNANDO; SALEMI, VERA M. C.; SOUZA, LEANDRO E.; RIBEIRO, ORLANDO N.; FERNANDES, FABIO; IRIGOYEN, MARIA CLAUDIA; MOREIRA, LUIZ FELIPE P.; et al. Effects of sympathectomy on myocardium remodeling and function. Clinics, v. 76, 2021. (12/02772-8)