Abstract 17230
Respiratory Sinus Arrhythmia Quantified from Standard ECG for Risk Stratification of Post-Infarction Patients
- Sinnecker, Daniel
- Barthel, Petra
- Müller, Alexander
- Laugwitz, Karl-Ludwig
- Schmidt, Georg
Objectives: Respiratory sinus arrhythmia (RSA) reflects modulation of the sinoatrial node discharge frequency by the autonomic nervous system. Impaired autonomic function is associated with adverse outcome in cardiac patients. We developed a method for calculating RSA from standard ECG recordings and investigated its association with mortality in survivors of acute myocardial infarction.
Methods: Consecutive patients (n=941, mean age 61 years, 19% female) presenting with acute myocardial infarction and sinus rhythm were enrolled between May 2000 and March 2005 and followed up until August 2010. The main study outcome was 5-year all-cause mortality. Patients underwent 30-minute ECG recordings. Auxiliary respiratory muscle activity derived from high pass-filtered ECG signal was used to define respiratory phase. The influence of expiration on RR intervals (RRI) was assessed by bivariate phase-rectified signal averaging (PRSA), and RSAPRSA was quantified by Haar wavelet analysis. RSAPRSA ≤0 was defined as abnormal.
Results: During the follow-up, 72 patients died. Five-year mortality rates in patients with normal and abnormal RSAPRSA were 4% and 14%, respectively. Under univariable analysis, RSAPRSA was a significant predictor of death (p<0.001), as were GRACE score (p<0.001), LVEF (p<0.001), and the presence of diabetes mellitus (p<0.001). Under multivariable analysis, RSAPRSA, GRACE score, LVEF, and diabetes mellitus were independently and significantly associated with outcome.
Conclusions: Respiratory sinus arrhythmia, quantified by bivariate PRSA from standard ECG recordings, is an independent predictor of mortality risk in post-infarction patients.