Obstructive sleep apnea (OSA) is recognized as a risk factor for the development of various electrocardiographic disorders.

We aimed to investigate the impact of Continuous Positive Airway Pressure (CPAP) on these electrocardiographic manifestations.


We conducted a retrospective study from January 2016 to December 2020, including patients with severe OSA. We noted the electrocardiographic disorders at the time of the diagnosis of severe OSA and 3 months after CPAP treatment using a Holter electrocardiogram monitor.


We included 110 patients with severe OSA, mainly women (70%). Mean age was 66,84 years.

Atrial fibrillation (AF) was noted in 51 cases (46.4%).

Thirty-two of them were adherent to CPAP therapy. AF only recurred in one of these adherent patients, showing a significant decrease in AF under CPAP therapy (p<0.05). AF recurred in all the patients who were not adherent to CPAP therapy (19 cases).

Ventricular hyperexcitability was noted in 9 cases (8.8%). These patients were compliant with CPAP therapy and showed a significant reduction in the burden of ventricular extrasystoles (1890/24h vs 208/24h, p<0.05).

In addition, a significant decrease in the mean value of corrected QT interval was noted in patients adherent to CPAP (459,7 ms vs. 418,1 ms, p<0.001), unlike in those with poor compliance, where this decrease was not significant (p>0.05).

Twenty patients had first- degree atrioventricular block (18,18%). The mean PR space decreased significantly in patients compliant with CPAP therapy (220 ms vs 180 ms, p<0.05).


CPAP therapy plays an effective role in improving many electrocardiographic disorders in patients with severe OSA.