[Remission of nocturnal pathological respiratory patterns after orthotopic heart transplantation. A case report and overview of current status of therapy]

Abstract

Background: Cheyne-Stokes respiration is characterized by recurrent phases of central apneas during sleep alternating with a crescendo-decrescendo hyperventilation. This abnormal respiratory pattern is often observed in patients with severe congestive heart failure and associated with fragmentation of sleep, excessive daytime sleepiness, and a relatively high mortality. Increased peripheral and central chemosensitivity, prolonged circulation time, and reduced blood gas buffering capacity are the major factors contributing to the pathology. However, the exact pathophysiologic mechanisms are not clear yet. Respiratory stimulants, oxygen and continuous or bilevel positive airway pressure (CPAP or BiPAP) might reduce the severity of Cheyne-Stokes respiration but have little effect on daytime sleepiness and cardiac function. There is only limited data supporting the assumption that intensive heart failure therapy has an effect on Cheyne-Stokes respiration.

Case report: A 55-year-old male patient with dilative cardiomyopathy (NYHA IV) suffered excessive daytime sleepiness (Epworth Sleepiness Scale: 24 points). The patient was a heavy snorer with a normal body mass index. Treatment was initiated including ACE-inhibitors, beta-receptor blockers, diuretics and digoxin. The patient underwent sleep analysis with a Somno-Check system which demonstrated Cheyne-Stokes breathing (Respiratory Disturbance Index RDI: 40/h, lowest desaturation 76%) and body position dependent snoring. Oxygen therapy (21/min) had no effect on daytime sleepiness. Due to the cardiac condition, the patient was accepted for heart transplantation. Three weeks after transplantation sleep analysis was repeated and demonstrated a lack of evidence for periodic breathing (RDI 1/h, no desaturations below 90%), while snoring remained unchanged. Daytime sleepiness improved significantly (Epworth Sleepiness Scale: 6 points). Three weeks after normalizing left ventricular function a complete recovery from severe Cheyne-Stokes respiration was observed.

Conclusion: Adequate therapy of the underlying cause of Cheyne-Stokes breathing such as end-stage congestive heart failure might sufficiently abolish any breathing abnormalities.