Utility of extended cardiac monitoring to detect atrial fibrillation in patients with severe obstructive sleep apnea.

Background: The relationship between obstructive sleep apnea (OSA) and increased risk for atrial fibrillation (AF) has been well established in previous studies. The relationship between OSA and silent AF is unknown. We hypothesized that patients with OSA but no known history of AF are at an increased risk for the arrhythmia and may be detectable by prolonged electrocardiogram (ECG) monitoring. In this study, we examined whether 7 days of extended cardiac monitoring with an ECG event recorder is an effective screening tool to detect intermittent, silent AF in patients with severe OSA.

Methods: The study was a prospective observational study. Randomly chosen patients with newly diagnosed severe OSA, apnea-hypopnea index (AHI) ≥ 30, were included. Demographic, medical history, and sleep data were collected. Patients with a history of AF or symptoms of palpitations were excluded from participating. Seven consecutive days of ambulatory ECG event recording (with Model ER920W, eCardio, Houston, TX) were performed prior to the initiation of CPAP treatment.

Results: A total of 20 subjects, with a BMI of 38.8 ± 12.2, successfully completed the study. The mean age group was 52.6 ± 12.6 years and mean AHI 63.5 ± 29.2. The majority of subjects (70 %) had no abnormal cardiac rhythms detected. AF lasting for 7 s was seen in one subject, and paroxysmal atrial tachycardia lasting for 3.6 s was seen in another. Clinically relevant AF was not detected in any of the subjects.

Conclusion: In patients with severe OSA without a known history of AF, 7 days of extended cardiac monitoring with an ECG event recorder did not detect clinically meaningful, silent AF.