Right ventricular outflow tract arrhythmias in patients with obstructive sleep apnea- electrophysiological insights

Abstract Background Obstructive sleep apnea (OSA) was associated with atrial fibrillation and heart failure. Furthermore, the arrhythmic sudden death during sleep in patients with OSA raises serious concerns. Non-ischemic ventricular arrhythmias arise frequently from the right ventricular outflow tract (RVOT). The involvement of obstructive sleep apnea in the genesis of arrhythmia (premature ventricular contraction or tachycardia) originating specifically in the RVOT is not yet coherently established. Purpose This study aims to demonstrate the possible relationship between untreated obstructive sleep apnea and the occurrence of RVOT arrhythmia and to follow the electrophysiological features and outcomes after radiofrequency catheter ablation (RFA) in patients carrying this double burden. Methods One-hundred-twelve (112) consecutive asymptomatic and symptomatic patients admitted with RVOT arrhythmia ((PVCs and VTs) underwent a sleep study (polysomnography). Apnea was set out as the cessation of breathing and hypopnea was defined as shallow, slow, and restricted breathing occurring in episodes of ten seconds or more. The patients had normal left and right ventricle ejection fractions and no structural cardiovascular disease or other known extracardiac arrhythmia predisposing conditions. No significantly elevated systolic pressure in the pulmonary artery was assessed at echocardiography. Every patient was investigated by electrophysiologic study (EPS) and RFA of the clinical ventricular arrhythmia was immediately performed. Practicing and former professional athletes were excluded. Results Seventy-eight (69 %) of the included patients had an apnea-hypopnea index > 10/h. The included patients had the following characteristics: mean age 52 ± 8 years, 62% males, 81% had a BMI >30kg/m². The cardiac electrophysiologic study did not induce sustained VTs. The distribution of the PVCs and non-sustained VTs evidenced a predilection for the superior, septal and anterior (68%) and also superior and anterolateral aspects of the RVOT (23%). Radiofrequency catheter ablation (RFA) guided by activation mapping, precocity (the site of earliest activation > 30 ms before the setting of the QRS complex) and pace-mapping were performed in all patients. Immediate success was obtained in 98 patients (88%). After a mean follow-up of 24± 6 months, 28 patients (28%) from the success arm had a recurrence of the PVCs or the non-sustained VTs, 22 patients (22%) with and 6 patients (6%) without sleep apnea. Conclusions RVOT arrhythmia genesis and relapse after successful RFA seem highly associated with sleep apnea. Furthermore, patients with sleep apnea are more prone to have recurrent arrhythmias after radiofrequency catheter ablation in the absence of appropriate control of OSA.