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Continuous positive airway pressure treatment reduces ventricular arrhythmias in obstructive sleep apnea patients with nocturnal dominance of arrhythmias and in those with severe desaturations.

INTRODUCTION
Continuous positive airway pressure (CPAP) treatment is considered to be effective in reducing ventricular arrhythmias (VAs) in patients with obstructive sleep apnea (OSA).


OBJECTIVES
We aimed to assess this influence and to identify determinants of antiarrhythmic response.


PATIENTS AND METHODS
We included patients with OSA and VAs (corresponding with grades 2-5 in the Lown classification), who underwent CPAP treatment and controls, who refused CPAP therapy. Holter electrocardiographic monitoring was performed at baseline and after 3 months of follow-up.


RESULTS
The study consisted of 46 patients in a CPAP group and 30 controls. We observed a  significant reduction in premature ventricular contractions (PVCs) and non-sustained ventricular tachycardia events (P=0.007 and P=0.03, respectively) in a CPAP group after 3 months and no difference in controls. The effect of PVCs reduction was significant in patients with nocturnal dominance of PVCs (P=0.002) and with desaturations ≤80% (p=0.001). PVCs reduction rate (PVC at follow-up/PVC at baseline) correlated inversely with night/day PVC ratio at baseline (R=-0.36; P=0.02) and lowest saturation (R=0.32; P=0.03) in the CPAP group. After adjustment for clinical data, night/day PVC ratio was an independent predictor of PVCs reduction rate (unstandardized coefficient B=-0.19, 95% confidence interval -0.37-[-0.01], P<0.05). Its value ≥1.16 predicted good antiarrhythmic treatment response with sensitivity and specificity of 83% and 70%, respectively.


CONCLUSIONS
CPAP treatment decreases VAs in OSA patients, especially those with severe desaturations and nocturnal domination of PVCs. Night/day PVC ratio might be a useful clinical parameter predicting reduction of PVCs in these patients.