| Heart rate variability (HRV) is known to be an accepted noninvasive tool for the assessment of cardiolvascular autonomic balance. Decreased heart rate variability is associated with increased mortality in patients with coronary artery disease especially those with prior myocardial infarction. In present study, time and frequency domain measures of HRV were analyzed in 129 patients with acute myocardial infarction(AMI) and 82 patients without recent myocardial infarction who were undergone coronary angiography (32 patients with prior myocardial infarction) . The purpose of this study was (1) to determine the correlation between measures of HRV, (2) to determine the relationship between HRV and clinical variables, (3) to assess the spontaneous changes in heart rate variability after AMI, (4) to determine the value of decreased HRV in predicting Cardiac death in patients with AMI, (5) to examine the relation between HRV and coronary angiograhphic variables in patients with coronary artery disease, (6) to determine the influence of percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass grafty (CABG) on HRV.METHODS Three-channel, 24-hour ambulatory ECGs were performed. HRV was analyzed from 24-hour ambulatory electrocardiagraphic recordings on a Holter analysis system(Del Mar Avionics 563, USA). After a normal QRS complex was chosen, computer-assisted rate and arrhythmia analysis was performed with technician overreading and editing. Excessive noise and artifact were excluded, and ectopy was quantified, after technician analysis and physician review of the entire recording. Time-domain analysis included SDNN, SDANN, RMSSD, SDNN index and HRV triangular index. Frequency-domain analysis included TF, LF and HF components. The LF/HF ratio was calculated. Time and frequency domain measures of HRV were analyzed in 129 patients with AMI and repeated at 3rd month, 6th month and 12th month after AMI in 23 patients. Long-... |
