Breathing irregularities before sleep onset on polysomnography in patients with heart diseases

Purpose Severe cardiac dysfunction can manifest with diurnal breathing irregularity. However, it remains to be clarified whether or not diurnal breathing irregularity is observed in patients with heart diseases, including relatively mild chronic heart failure (CHF), compared to those without heart diseases. Methods In this cross-sectional study, consecutive inpatients who were admitted for evaluation of sleep-disordered breathing were enrolled. We extracted 3.5 min of stable respiratory signals before sleep onset using polysomnography, analyzed the airflow data using fast Fourier transform, and quantified breathing irregularities using Shannon entropy S. Results A total of 162 subjects were evaluated. Among these, 39 subjects had heart diseases, including ischemic heart disease (IHD), atrial fibrillation (Af), CHF, and a history of aortic dissection. The values of Shannon entropy S of airflow signals in subjects with heart diseases were significantly higher than in those without heart diseases ( p