Influence of Orthotopic Heart Transplantation on Breathing Pattern Disorders in Patients with Dilated Cardiomyopathy

Cheyne-Stokes respiration is well-known in patients with congestive heart failure. One of the causes might be a prolonged circulation time or diminished pulmonary gas stores. Improvement of cardiac function by heart transplantation might abolish Cheyne-Stokes respiration. We examined 29 male patients (age 24 to 63 years) with polysomnographically verified Cheyne-Stokes respiration before and 3 to 9 weeks after orthotopic heart transplantation. All patients suffered from congestive heart disease. Left ventricular ejection fraction (LVEF) was between 8 and 19%. We analyzed sleep stages, respiratory events, oxygen saturation, and cardiac function (echocardiography and ergometry). Before heart transplantation all patients showed periodic breathing (apnea-hypopnea index [AHI] 13.2-51.6/h). Oxygen saturation dropped to a minimum of 63%. Sleep was severely disturbed. After heart transplantation LVEF was significantly higher in all patients (xmean = 64%). Twenty-three of 29 patients showed no more evidence of periodic breathing. However, even with normalized cardiac function, 6 patients still suffered from Cheyne-Stokes respiration. Cheyne-Stokes respiration is often associated with dilated cardiomyopathy. Our results demonstrate that normalization of cardiac function improves Cheyne-Stokes respiration. Even after normalization of cardiac function, some patients suffer from Cheyne-Stokes respiration further on. We suggest that breathing control centers may be permanently damaged in these patients.