Effects of tilt and exercise on signal-averaged electrocardiogram after acute myocardial infarction

F. Lombardi, M. L. Flnocchiaro, L. Dalla Vecchia, R. Sala, M. Garimoldi, G. Baselli, S. Cerutti, A. Malliani

Research output: Contribution to journalArticle

Abstract

To determine whether enhanced sympathetic activity could alter a non-invasive index of cardiac instability, we analysed the effects of 90° head-up tilt and submaximal exercise stress test on high amplification signal-averaged electrocardiogram in 64 patients after acute myocardial infarction. At rest, ventricular late potentials were detected in 25% of patients, characterized by a significant prolongation of filtered QRS complex (137 ± 3 vs 115 ± 2 ms) and of its components smaller than 40 μV (38 ± 2 vs 16 ± 1 ms), as well as by a reduced root mean square voltage calculated for the terminal 40 ms of QRS complex (RMS40 voltage) (19 ± 1 vs 75 ± 9 μV) in comparison to patients without micropotentials. Sympathetic activation induced by tilt caused a significant increase in heart rate (from 67 ± 3 to 79 ± 3 beats min-1) but did not modify either the incidence of ventricular late potentials or the values of any of the signal-averaged electrocardiogram parameters considered. In 19 patients, recordings were also obtained during a submaximal bicycle exercise stress test at a heart rate of 114 ± 4 beats min-1 and with systolic arterial blood pressure at 153 ± 6 mmHg. No effect on signal-averaged electrocardiogram parameters was detectable during this experimental intervention. These data indicate that after myocardial infarction, sympathetic activation does not seem to modify signal-averaged electrocardiogram parameters.

Original languageEnglish
Pages (from-to)421-428
Number of pages8
JournalEuropean Heart Journal
Volume11
Issue number5
Publication statusPublished - 1990

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Keywords

  • Exercise
  • Myocardial infarction
  • Signal-averaged electrocardiogram
  • Sympathetic activation

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Statistics, Probability and Uncertainty
  • Applied Mathematics
  • Physiology (medical)
  • Physiology

Cite this

Lombardi, F., Flnocchiaro, M. L., Dalla Vecchia, L., Sala, R., Garimoldi, M., Baselli, G., Cerutti, S., & Malliani, A. (1990). Effects of tilt and exercise on signal-averaged electrocardiogram after acute myocardial infarction. European Heart Journal, 11(5), 421-428.