Assessment of myocardial flow reserve by echocardiography with real time myocardial perfusion in patients with left ventricular dysfunction, before and after cardiovascular rehabilitation by supervised exercise training / Avaliação da reserva de fluxo miocárdico pela ecocardiografia com perfusão miocárdica em tempo real em pacientes com disfunção ventricular esquerda, antes e após reabilitação cardiovascular por exercício físico supervisionado

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Introduction: Heart failure is a clinical, complex and progressive syndrome, which may result from any structural or functional heart disorder that changes its capacity of filling and/or ejection, and the majority of patients perform evolution with left ventricular dysfunction (DVE). The exercise training is accepted as an important adjuvant in the treatment of this clinical condition by promoting significant improvement in patients functional capacity; however the mechanisms by which this occurs are still not fully elucidated. In this context, Echocardiography with Real Time Myocardial Perfusion (EPMTR) can be a very useful method as much the evaluation of hemodynamic parameters as myocardial perfusion, facilitating a better understanding of the physiopathologic changes promoted by the cardiovascular rehabilitation by supervised exercise training (RCVEFS) and consequently, its therapeutic impact on the prognosis of this critical group of patients. Objective: Evaluate if the RCVEFS can improve the myocardial flow reserve, measured by echocardiography with real time myocardial perfusion, in patients with non-ischemic etiology DVE. Methods: We prospectively evaluated 40 patients over 18 years old with left ventricular dysfunction defined by ejection fraction of left ventricle (LVEF) calculated by Simpson Method <45% and without limitations of physical exercise practice, that were invited to a RCVES program in a period of 4 months. Patients were randomly assigned to a training group or control group. There were performed in their study beginning and after 04 months of group attendance, ergo spirometry and EPMTR. The perfusion analysis was performed by an independent examiner (blind), that verified the myocardial peak intensity regularized by the acoustic cavity intensity (An), micro bubbles refilling speed after their complete destruction with a high ultrasonic energy beam (ß) and myocardial blood flow (An x ß), using Q-Lab Philips Ultrasound Program. Results: From 40 patients initially selected, 23 concluded the study, being 13 in training group (average age 53 ± 13 years, 09 male, 15% smokers, 38% Dyslipedemia, 85% high blood pressure (HBP), 15 % mellitus diabetes (DM) and 31% Chagas disease) and 10 in the control group (mean age 59 ± 12 years, 04 male, 10% smokers, 50% dyslipidemia, hypertension 90%, 30% and 10% DM Chagas disease). There was no LVEF improvement in the group training (26 + 14 to 26 + 13) and the control group (26 + 6 to 27 + 6). In the training group there was An increase of 1.21 to 1.43 (p = 0.02) of ß from 1.51 to 2.20 (p = 0.0001) and An x ß of 1.81 to 3.05 (p = 0001), there was also VO2 peak improvement of 21.75 ml / kg / min to 24.76 ml / kg / min (p = 0, 0005). In the control group there was An increase of 1.14 to 1.15 (p = 0.91), ß decrease from 1.72 to 1.46 (p = 0.03) and reduction in An x ß of 1.89 to 1.55 (p = 0.01), there was also VO2 peak deterioration 21.14 ml/kg/min to 20.7 ml/kg/min (p =0.58). Conclusion: The Cardiovascular Rehabilitation Program by Supervised Physical Training improved the myocardial flow reserve, in patients with Left Ventricular Dysfunction of non-ischemic etiology.

ASSUNTO(S)

circulação coronária exercício coronary circulation microcirculação insuficiência cardíaca dilated cardiomyopathy cardiovascular physiology disfunção ventricular esquerda endotélio endoteliun fisiologia cardiovascular microcirculation exercise heart failure contrast echocardiography cardiomiopatia dilatada left ventricular dysfunction ecocardiografia de contraste

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