RESUMO
Drug-refractory atrial fibrillation (AF) can be highly symptomatic and warrant invasive ablation targeting the pulmonary veins. Although limited ablation for paroxysmal AF is associated with a high success rate, more extensive ablation appears to be indicated for persistent AF. The Substrate and Trigger Ablation for Reduction of Atrial Fibrillation Trial Part II (STAR AF II) showed that the addition of complex fractionated atrial electrogram (CFAE) ablation or linear ablation lesions did not result in an improved ablation outcome. However, novel techniques that allow assessment ]\of AF substrate, rotor mapping and AF trigger ablation have been associated with improved ablation outcome and randomised studies evaluating these techniques are currently being designed.
Assuntos
Fibrilação Atrial/cirurgia , Ablação por Cateter/métodos , Técnicas Eletrofisiológicas Cardíacas , Humanos , Estudos Prospectivos , Veias Pulmonares/cirurgiaRESUMO
BACKGROUND: Patients with a high ventricular rate during atrial fibrillation (AF) are at increased risk of receiving inappropriate implantable cardioverter defibrillator shocks. The objective was to demonstrate the feasibility of high frequency atrioventricular-nodal stimulation (AVNS) to reduce the ventricular rate during AF to prevent inappropriate implantable cardioverter defibrillator shocks. METHODS AND RESULTS: Patients with a new atrial lead placement as part of a cardiac resynchronization therapy and defibrillator implant and a history of paroxysmal or persistent AF were eligible. If proper atrial lead position was confirmed, AVNS software was uploaded to the cardiac resynchronization therapy device, tested, and optimized. AVNS was delivered via a right atrial pacing lead positioned in the posterior right atrium. Software allowed initiation of high frequency bursts triggered on rapidly conducted AF. Importantly, the efficacy was evaluated during spontaneous AF episodes between 1 and 6 months after implant. Forty-four patients were enrolled in 4 centers. Successful atrial lead placement occurred in 74%. Median implant time of the AVNS lead was 37 minutes. In 26 (81%) patients, manual AVNS tests increased the ventricular interval by >25%. Between 1 and 6 months, automatic AVNS activations occurred in 4 patients with rapidly conducted AF, and in 3 patients, AVNS slowed the ventricular rate out of the implantable cardioverter defibrillator shock zone. No adverse events were associated with the AVNS software. CONCLUSIONS: The present study demonstrated the feasibility of implementation of AVNS in a cardiac resynchronization therapy and defibrillator system. AVNS increased ventricular interval >25% in 81% of patients. AVNS did not influence the safety profile of the cardiac resynchronization therapy and defibrillator system. CLINICAL TRIAL REGISTRATION: clinicaltrials.gov; Unique Identifier: NCT01095952.