Breathing during sleep is often impaired in patients with atrial fibrillation. In the current edition of Deutsches Ärzteblatt International (Dtsch Arztebl Int 2009; 106(10): 164-70), Thomas Bitter and his coauthors from the Ruhr University in Bochum investigate how often sleep-disordered breathing occurs in this form of cardiac arrythmia and what the different types are.
The authors used cardiorespiratory polygraphy to investigate whether 150 patients (110 men and 40 women) with atrial fibrillation suffered from sleep-disordered breathing. To avoid statistical bias, they only included patients with normal systolic left ventricular function. The mean age of the patients was around 65 years.
Breathing during sleep was impaired in 74% of the patients. 43% of the group suffered from obstructive sleep apnea (OSA). This means that the upper respiratory tract is constricted during the night, leading to oxygen deficiency. The authors found that 31% of patients suffered from central sleep apnea (CSA). This type of disorder is characterized by periodic decreases and increases in the respiratory depth and rate. Breathing becomes flatter and flatter, until it is interrupted for an interval.
Awareness of OSA already plays an important role in the primary and secondary prevention of atrial fibrillation. According to the authors, the results indicate that central sleep apnea is also relevant.