Influence of cardiac resynchronisation therapy on different types of sleep disordered breathing

Abstract

Aims: This study investigates the influence of cardiac resynchronisation therapy (CRT) on sleep disordered breathing (SDB) in patients with severe heart failure (HF). Methods and results: Seventy-seven patients with HF (19 females; 62.6 ± 10 years) eligible for CRT were screened for presence, type, and severity of SDB before and after CRT initiation (5.3 ± 3 months) using cardiorespiratory polygraphy. NYHA class, frequency of nycturia, cardiopulmonary exercise, 6-minute walking test results, and echocardiography parameters were obtained at baseline and follow-up. Central sleep apnoea (CSA) was documented in 36 (47%), obstructive sleep apnoea (OSA) in 26 (34%), and no SDB in 15 (19%) patients. CRT improved clinical and haemodynamic parameters. SDB parameters improved in CSA patients only (apnoea hypopnoea index: 31.2 ±15.5 to 17.3 ±13.7/h, p < 0.001; SaO2min: 81.8 ± 6.6 to 84.8 ± 3.3%, p = 0.02, desaturation: 6.5 ± 2.3 to 5.5 ± 0.8%, p = 0.004). Daytime capillary pCO2 was significantly lower in CSA patients compared to those without SDB with a trend towards increase with CRT (35.5 ± 4.2 to 37.9 ± 5.7 mm Hg, ns). After classifying short term clinical and haemodynamic CRT effects, improved SDB parameters in CSA occurred in responders only. Conclusions: In patients with severe HF eligible for CRT, CSA is common and can be influenced by CRT, this improvement depends on good clinical and haemodynamic response to CRT. © 2007 European Society of Cardiology.