Heart rate variability after a discontinued 1-year period of post-AMI ACE-inhibition

To investigate possible autonomic sequelae of ACE-inhibition, the authors studied a group of 33 male post-infarction patients who were randomly assigned to a 1-year ACE-inhibition (15 patients) or placebo therapy (18 patients). HRV measurement sessions were 2 weeks after discontinuation of this therapy. The authors computed, in a 5 minute supine and in a 5-minute standing period, the mean heart rate, HR, the total spectral power (TSP, 0.01-0.40 Hz), and the absolute spectral powers in the very low frequency band (VLFabs, 0.01-0.05 Hz), the low frequency band (LFabs, 0.05-0.15 Hz), and the high frequency band (HFabs, 0.15-0.40 Hz). Finally, the authors computed the normalized powers VLF, LF, and HF, by dividing the absolute powers VLFabs, Lfabs, and Hfabs by the total spectral power TSP. No statistical significant differences were found between the anthropomorphic data, infarct sizes, and left ventricular ejection fractions. Also, the standing HRV parameters were not significantly different. However, the supine LF in the previously ACE-inhibited group was larger than in the placebo group (31/spl plusmn/12% vs. 23/spl plusmn/8%, respectively; P=0.03). Also TSP was much larger, but due to a wide distribution of the data this difference did not reach statistical significance. The here presented data are suggestive for autonomic sequelae of previous therapy with an ACE-inhibitor. As ACE-inhibitors are frequently prescribed drugs, it seems indicated to further investigate their interaction with the autonomic nervous system, during therapy, as well as after discontinuation.