Does percutaneous transluminal coronary angioplasty influence T wave alternans and heart rate variability based risk predictors?

The aim of the study was to determine whether Percutaneous Transluminal Coronary Angioplasty (PTCA) influences T wave alternans and standard spectral parameters of heart rate variability. We measured high resolution ECGs in 28 patients before and after PTCA of one coronary. For each ECG the T wave alternans ratio (TWAR) was measured according to the algorithm of Rosenbaum (1996). In addition, we constructed the time series of RR-intervals (RR), and calculated the low (LF) and high (HF) frequency components of the power spectrum of RR as well as the ratio between LF and HF (LF/HF). TWAR did not show any systematic changes after PTCA. However, there was a significant increase in the LF/HF ratio of RR-intervals. The results suggest that TWAR is not influenced by PTCA in our study design. The increase in LF/HF may indicate alternations in the autonomic nervous control of heart after PTCA.