BACKGROUND: Reduced sleep quality is associated with impaired quality of life and increased mortality in patients with heart failure. The aim of this study was to observe changes in sleep fragmentation and sleep quality in patients with heart disease and preserved left ventricular ejection fraction (pEF) treated with adaptive servo-ventilation (ASV) therapy for treatment of emergent central sleep apnea (TECSA) or central sleep apnea (CSA). METHODS: 114 patients with structural heart disease and pEF introduced to ASV therapy between 2010 and 2015 were retrospectively analyzed. Patients were stratified into two groups; TECSA (n = 60) or CSA (n = 54). Changes of sleep fragmentation and sleep quality from baseline to ASV initiation were compared. RESULTS: ASV therapy leads to a significant reduction of apnea-hypopnea index (AHI) and arousal index in patients with TECSA and CSA (∆AHI: - 43 ± 21 vs. - 47 ± 22/h; ∆arousal index - 11 ± 15, vs. - 11 ± 21/h). ASV treatment leads to a significant increase in sleep efficiency in TECSA compared to CSA (∆SE: 10 ± 19 vs. 1 ± 18%, p = 0.019). Both groups had significantly longer stage N3 (N3) and rapid eye movement sleep (REM) on ASV (∆N3: 8 ± 11 vs. 9 ± 13%; ∆REM 7 ± 9 vs. 3 ± 8%; p < 0.05 for all comparisons baseline vs. ASV). CONCLUSIONS: In patients with heart disease and pEF, whose TECSA and CSA were treated with ASV, a significant reduction of AHI and arousal index as well as an increase of N3 and REM sleep was observed. Increase of sleep efficiency was significantly greater in TECSA compared to CSA. Hence, improvements of sleep quality were modestly greater in patients with TECSA compared to those with CSA.