Dr Reena Mehra, of Case Western Reserve University School of Medicine, Cleveland has found a link between apnea (brief pauses in breathing) or hypopnea (shallow breathing) and abnormal heart rhythms (arrhythmias) in older men.
The study involving 2,911 men showed that having more episodes of paused or shallow breathing was associated with increased odds of two types of arrhythmias-one involving the heart's upper chambers (atria) and one involving the heart's lower chambers (ventricles).
Obstructive sleep apnea-the most common type, involving a partial or complete blockage of the airways-was associated with irregular heartbeats caused by a problem with the lower chambers or ventricles.
In addition, lower blood oxygen levels also appeared to be associated with this type of arrhythmia.
But central sleep apnea, involving a malfunction in brain signals controlling breathing muscles, was more strongly associated with arrhythmias in the atria or upper chambers.
According to the authors, more severe cases of sleep-disordered breathing were associated with higher odds of arrhythmia; in addition, "there also seems to be a threshold effect such that moderate-to-severe sleep-disordered breathing confers the greatest increased odds of clinically significant arrhythmias independent of self-reported heart failure and cardiovascular disease."
"The strong associations between central sleep apnea and atrial fibrillation [arrhythmia originating in the heart's upper chambers] suggest that central sleep apnea may be a sensitive marker of underlying abnormalities in autonomic or cardiac dysfunction associated with atrial fibrillation," they added.
The study appears in Archives of Internal Medicine, one of the JAMA/Archives journals.