Objective We investigated the changes of heart rate turbulence (HRT) in sleep apnoea- hypopnoea syndrome (SAHS).

Methods 75 patients underwent overnight polysomnography for clinically suspected SAHS and simultaneous Holter monitoring (23:00–6:00), According to the apnoea-hypopnoea index (AHI), the patients were assigned to group SAHS (+) (AHI ≥5, n=52) or group SAHS (-) (AHI <5, n=23). HRT (onset, slope) of two groups were compared.

Results Turbulence slope (TS) of group SAHS (+) was significantly lower in group SAHS (-) (p<0.01), turbulence onset of two groups all smaller than zero, turbulence onset of group SAHS (+) were higher than group SAHS (-)’s, but no significant difference, the number of ventricular premature contractions of group SAHS (+) were more than group SAHS (-)’s, but also no significant difference.

Conclusions Heart rate turbulence phenomenon diminishes in sleep apnoea- hypopnoea syndrome patients, indicating demages in cardiac autonomic activity in SAHS, turbulence slope decreasing could be considered as prognosis index of SAHS.