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Cardiac pacing in patients with left ventricular dysfunction and permanent atrial fibrillation

Grant number: 12/15163-0
Support type:Regular Research Grants
Duration: March 01, 2013 - February 29, 2016
Field of knowledge:Health Sciences - Medicine - Medical Clinics
Principal Investigator:Martino Martinelli Filho
Grantee:Martino Martinelli Filho
Home 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
Assoc. researchers: Anísio Alexandre Andrade Pedrosa ; Giselle de Lima Peixoto ; Mariana Moreira Lensi ; Ricardo Alkmim Teixeira ; Roberto Costa ; Sérgio Freitas de Siqueira ; Silvana Angelina D'Orio Nishioka

Abstract

Atrial fibrillation is the most prevalent sustained cardiac arrhythmia and is associated with higher mortality. The prevalence of AF increases with heart failure (HF) and can worse its prognosis. Conventional cardiac pacing can correct the occurrence of long-short cycles and RR variability; when there is ventricular dysfunction, ventricular resynchronization therapy (VRT) can prevent intraventricular dyssynchrony. Atrioventricular node ablation has been recommended in refractory cases and also to improve the results of VRT. Dual-chamber pacemakers (PM) can be used to promote VRT in patients with permanent AF. Primary end-point: to evaluate the role of cardiac pacing in clinical and functional behavior of patients with permanent AF and severe systolic dysfunction with no indication of catheter ablation. Secondary end-points: to identify the occurrence of left ventricle (LV) reverse remodeling and to assess the impact of VRT in survival. METHODS: Three hundred HF patients, with permanent AF, will be randomized (1:1) into two groups. GROUP 1: VRT, GROUP 2: control. Outcomes: Primary: death from any cause or hospitalization due to cardiovascular causes. Secondary: improvement of HF (NYHA), occurrence of sudden cardiac death, ventricular arrhythmias, spontaneous reversion of AF, left atrium volume, left ventricular end-systolic volume, mitral regurgitation and LVEF variation, peak VO2 evolution. Patients in group 1 will undergo dual chamber PM implant (LV lead connected to the atrial channel - TRV). Device programming: DVIR, basic rate 70ppm, AV interval 15 ms. Those patients will be divided into two groups: 1A (baseline HR < 50bpm) and 1B (HR > 50bpm). After 3 months of inclusion, patients with persistent biventricular pacing < 85% (PM and Holter analysis) will be submitted to AV ablation. Patients in the control group will also be divided into two groups: 2A (HR < 50bpm) and 2B (HR > 50bpm) and may be submitted to conventional single-chamber ventricular pacing for therapeutic support. EXPECTED RESULTS: It is expected clinical and functional improvement with resynchronization therapy . (AU)