The cause-effect relationship of sympathovagal activity and the outcome of percutaneous transluminal coronary angioplasty

We studied 25 patients who underwent percutaneous transluminal coronary angioplasty (PTCA) to determine the association of sympathovagal imbalance and the outcome of coronary angioplasty. We examined the profiles of heart rate variability (HRV) using echocardiography, stress thallium scanning and radionuclide angiography before, immediately after and 1 month after the procedure. Coronary angiography was followed up at 6 months or if restenosis was suspected, to determine whether restenosis had occurred. Frequency domain (LF/HF) and time domain (SDNN, SDANN-ind, and r-MSSD) parameters were analyzed. According to the evolution of each parameter, we classified the patients into Group Ax (improved in HRV profile) and Group Bx (deteriorated in HRV profile) [x = 1 for LF/HF, 2 for SDNN, 3 for SDANN-ind, and 4 for r-MSSD]. We found that there was no definite association between Gensini score and HRV profiles at the baseline for each group. No significant changes existed between the HRV profiles before and immediately after PTCA. For the LF/HF ratio, 5 of 11 in Group B1 had restenosis while 0 of 14 in Group B2 and 1 of 19 in Group A2 had restenosis (p < 0.01). There were no significant predictive values for SDANN-ind and r-MSSD (p = 0.12 and 0.07, respectively). We conclude that the sympathovagal imbalance did not reflect the severity in coronary artery disease but was associated with restenosis after successful PTCA.