Heart rate turbulence for predicting new-onset atrial fibrillation in patients undergoing coronary artery bypass grafting

Abstract

BackgroundCardiac autonomic dysfunction reportedly contributes to the AF triggering and maintenance. Heart rate turbulence (HRT) is a promising noninvasive measure of cardiac autonomic function. We investigated whether ambulatory ECG-based HRT measurement could predict in-hospital new-onset atrial fibrillation (AF) after coronary artery bypass graft (CABG) surgery. MethodsHRT onset (TO) and slope (TO) were prospectively measured from 24-h Holter recording in 113 consecutive patients prior to CABG. Abnormal HRT was defined as at least one abnormal value in TO (>0%) and TS (<2.5ms/RR). ResultsPatients with abnormal HRT (n=60) showed a significantly higher AF incidence (47% versus 21%, P=0.005) and AF burden (29±9 versus 7±5h, P=0.043) than those with normal HRT (n=53). Abnormal HRT were identified as independent predictors for the new-onset postoperative AF. During the follow-up period (12.0±10.5months), the abnormal HRT group showed a worse prognosis versus the normal HRT group regarding the AF recurrence/postoperative stroke (P=0.018). Additionally, the postoperative AF incidence, in-hospital AF burden, and the rate of AF recurrence/postoperative stroke gradually elevated as the number of abnormal HRT values increased from 0 to 2. ConclusionsPreoperative abnormal HRT was significantly associated with worse short-term (in-hospital new-onset AF) and long-term outcomes (post-discharge AF recurrence/postoperative stroke) after CABG surgery. Additional studies incorporating preventive interventions depending on the preoperative HRT results might be worthwhile in this patient group.