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Effects of Cardiac Resynchronization Therapy on Muscle Sympathetic Nerve Activity

Authors

  • RICARDO R. KUNIYOSHI M.D., Ph.D.,

    1. Centrocor Cardiologia, Vitória, Espírito Santo, Brazil
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  • MARTINO MARTINELLI M.D., Ph.D.,

    Corresponding author
    1. Heart Institute (InCor), do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
    • Address for reprints: Martino Martinelli Filho, MD, Instituto do Coração (InCor), Hospital das Clínicas da Universidade de São Paulo, Av. Enéas de Carvalho Aguiar, 44 – CEP 05403-000, São Paulo, SP, Brasil. Fax: 55-11-30817148; e-mail: martino@incor.usp.br

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  • CARLOS E. NEGRÃO Ph.D.,

    1. Heart Institute (InCor), do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
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  • SÉRGIO F. SIQUEIRA M.Sc.,

    1. Heart Institute (InCor), do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
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  • MARIA U. P. B. RONDON Ph.D.,

    1. Heart Institute (InCor), do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
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  • IVANI C. TROMBETTA Ph.D.,

    1. Heart Institute (InCor), do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
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  • FATIMA H. S. KUNIYOSHI Ph.D.,

    1. Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic and Foundation, Rochester, Minnesota
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  • MATEUS C. LATERZA Ph.D.,

    1. Faculdade de Educação Física e Desportos da Universidade Federal de Juiz de Fora (FAEFID-UFJF), Minas Gerais, Brazil
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  • SILVANA A. D’ÓRIO NISHIOKA M.D., Ph.D.,

    1. Heart Institute (InCor), do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
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  • ROBERTO COSTA M.D., Ph.D.,

    1. Heart Institute (InCor), do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
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  • WAGNER T. TAMAKI M.D., Ph.D.,

    1. Heart Institute (InCor), do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
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  • ELIZABETH S. CREVELARI M.D.,

    1. Heart Institute (InCor), do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
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  • GISELLE DE LIMA PEIXOTO M.D.,

    1. Heart Institute (InCor), do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
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  • JOSÉ A. F. RAMIRES M.D., Ph.D.,

    1. Heart Institute (InCor), do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
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  • ROBERTO KALIL M.D., Ph.D.

    1. Heart Institute (InCor), do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
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Abstract

Introduction

Muscle sympathetic nerve activity (MSNA) is an independent prognostic marker in patients with heart failure (HF). Therefore, its relevance to the treatment of HF patients is unquestionable.

Objectives

In this study, we investigated the effects of cardiac resynchronization therapy (CRT) on MSNA response at rest and during exercise in patients with advanced HF.

Methods

We assessed 11 HF patients (51 ± 3.4 years; New York Heart Association class III–IV; left ventricular ejection fraction 27.8 ± 2.2%; optimal medical therapy) submitted to CRT. Evaluations were made prior to and 3 months after CRT. MSNA was performed at rest and during moderate static exercise (handgrip). Peak oxygen consumption (VO2) was evaluated by means of cardiopulmonary exercise test. HF patients with advanced NYHA class without CRT and healthy individuals were also studied.

Results

CRT reduced MSNA at rest (48.9 ± 11.1 bursts/min vs 33.7 ± 15.3 bursts/min, P < 0.05) and during handgrip exercise (MSNA 62.3 ± 13.1 bursts/min vs 46.9 ± 14.3 bursts/min, P < 0.05). Among HF patients submitted to CRT, the peak VO2 increased (12.9 ± 2.8 mL/kg/min vs 16.5 ± 3.9 mL/kg/min, P < 0.05) and an inverse correlation between peak VO2 and resting MSNA (r = –0.74, P = 0.01) was observed.

Conclusions

In patients with advanced HF and severe systolic dysfunction: (1) a significant reduction of MSNA (at rest and during handgrip) occurred after CRT, and this behavior was significantly superior to HF patients receiving only medical therapy; (2) MSNA reduction after CRT had an inverse correlation with O2 consumption outcomes.

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