Table of Contents
ISRN Cardiology
Volume 2012, Article ID 912672, 9 pages
http://dx.doi.org/10.5402/2012/912672
Clinical Study

Effect of Acute Mental Stress on Heart Rate and QT Variability in Postmyocardial Infarction Patients

1Dipartimento di Medicina Clinica e Molecolare, Azienda Ospedaliera S. Andrea, “Sapienza” Università degli Studi di Roma, 00185 Rome, Italy
2Dipartimento di Scienze Cardiovascolari, Respiratorie, Nefrologiche e Geriatriche, Prima Clinica Medica, Policlinico Umberto I, “Sapienza” Università degli Studi di Roma, 00185 Rome, Italy

Received 20 April 2012; Accepted 16 May 2012

Academic Editors: K. Aalto-Setala and K. Nakamura

Copyright © 2012 Damiano Magrì et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Emotionally charged events are associated with an increased risk of sudden cardiac death (SCD). In this study we assessed RR and QT variability index (QTVI) at baseline during anger recall test (AR). We calculated QTVI from a 5-min ECG recording and from a 10-beats segment around the presumed maximum sympathetic activation in thirty post-myocardial infarction patients under β-blocker therapy and 10 controls underwent. In all groups, the low-frequency component of RR and SBP increased during AR. In all recordings, the QTVI calculated on a 5-min ECG recording and the Q T V I 1 0 b e a t s were higher in patients than in controls (P < 0.05). The QTVI during AR remained unchanged from baseline within each group. Conversely, during AR, the Q T V I 1 0 b e a t s in controls diminished significantly (P < 0.05) from baseline whereas in patients remained unchanged. The inability to buffer an acute stress-induced increase in sympathetic activity could explain why events charged with acute stress are associated with an increased risk of ventricular arrhythmias in this setting of patients and support the role of cognitive behavior stress management strategies.