Affiliation:
1. Institute of Internal Medicine, Cardiology, and Heart Surgery, University of Naples Federico II, Italy.
Abstract
BACKGROUND
Heart period variability provides useful prognostic information on autonomic cardiac control, and a strong association has been demonstrated after myocardial infarction (MI) between cardiac mortality, sudden death, and reduced total power, ultralow-frequency (ULF) power, and very-low-frequency (VLF) power. Converting enzyme inhibitors are widely used in MI patients, but their influence on heart period variability remains to be defined.
METHODS AND RESULTS
Time- and frequency-domain measures of heart period variability were calculated from 24-hour Holter monitoring in 40 patients with a first uncomplicated MI. After baseline examination between 48 and 72 hours after symptom onset, patients were randomly assigned to placebo or captopril administration, and on the third day, 24-hour Holter monitoring was repeated. No changes in time and frequency domain were detectable after placebo. After captopril, the SD of all normal RR (NN) intervals (SDNN) increased from 90 +/- 29 to 105 +/- 30 milliseconds (P < .01); the SD of the average NN intervals for all 5-minute segments (SDANN index) and the mean of the SDs of all NN intervals for all 5-minute segments (SDNN index) also increased from 74 +/- 24 to 90 +/- 26 milliseconds (P < .01) and from 45 +/- 17 to 49 +/- 15 milliseconds (P < .05), respectively. The root mean square successive difference (r-MSSD) and the percent of differences between adjacent NN intervals > 50 milliseconds (pNN50) remained unchanged. In regard to frequency-domain measures, after captopril, total power (ln unit) increased from 8.28 +/- 0.42 to 8.47 +/- 0.30 (P < .01); considering the frequency bands, a significant increase was observed in ULF (P < .01), VLF (P < .05), and low-frequency (LF) power (P < .05), whereas high-frequency (HF) power remained unchanged.
CONCLUSIONS
This study supports the hypothesis that the renin-angiotensin system modulates the amplitude of ULF and VLF power. Furthermore, it demonstrates that in MI patients, converting enzyme inhibition favorably modifies measures of heart period variability strongly associated with a poor prognosis.
Publisher
Ovid Technologies (Wolters Kluwer Health)
Subject
Physiology (medical),Cardiology and Cardiovascular Medicine
Reference37 articles.
1. Effect of Captopril on Mortality and Morbidity in Patients with Left Ventricular Dysfunction after Myocardial Infarction
2. Effect of ramipril on mortality and morbidity of survivors of acute myocardial infarction with clinical evidence of heart failure;The Acute Infarction Ramipril;Lancet.,1993
3. Effect of captopril on ventricular arrhythmias and sudden death in patients with left ventricular dysfunction after myocardial infarction: SAVE trial;Packer M;J Am Coll Cardiol.,1993
4. Autonomic Disturbance at Onset of Acute Myocardial Infarction
5. Schwartz PJ Zaza A Pala M Locati E Beria G Zanchetti A. Baroreflex sensitivity and its evolution during the first year after myocardial infarction. J Am Coll CardioL 1988;12:629- 636.
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