[Elimination of periodic respiration in heart failure by heart transplantation]

Patients with heart failure are known to demonstrate periodic respiration during sleep. The mechanism behind periodic respiration is thought to be related to left heart enlargement causing an increased transit time between lung and chemoreceptors leading to an oscillation of the feed back loop controlling respiration. Additionally hyperventilation was shown to play an important role. We report of an 18 year old patient with idiopathic dilated cardiomyopathy (left atrial 52 mm, left ventricular end diastolic diameter 69 mm). Polysomnography revealed prolonged transit time and periodic respiration with impaired sleep. Hypocapnia and hyperventilation was demonstrated. Following successful cardiac transplantation periodic respiration was absent and transit time was normal. There was no hypocapnia or hyperventilation. Hypercapnic ventilatory response did no change. These findings support the model of an oscillation of the feed back loop controlling respiration as the main pathomechanism behind periodic respiration.