ANTIARRHYTHMIC EFFECT OF PREINFARCTION ANGINA IN PATIENTS WITH ST-SEGMENT ELEVATION MYOCARDIAL INFARCTION: ASSESSMENT BY 24-HOUR HOLTER MONITORING
Background: Preinfarction angina (PIA) can be considered as a surrogate marker of the phenomenon of ischemic preconditioning. It is associated with the better clinical outcome in patients with acute myocardial infarction (AMI). The antiarrhythmic effect of PIA was not well investigated.
The aim of this study was to clarify the effect of PIA on ventricular arrhythmias on the first day of AMI.
Methods: 72 consecutive patients (53 màle; 19 female; aged 57.5±11.5 years) were prospectively studied: 39 patients with anterior AMI (21 with and 18 without PIA) and 33 patients with inferior AMI (15 with and 18 without PIA). PIA was defined as at least one brief episode of angina which occurred within 2-72 hours before onset of AMI. The number of isolated ventricular premature beats (VBP), ventricular couplets (VC) and non-sustained ventricular tachycardia (NSVT) recorded by 24-hour Holter monitoring on the first day of AMI were estimated.
Results: PIA was associated with significantly lower total number of VC and NSVT (10.4±5.9 vs 44.9±19.5, ð=0.02; 9.6±4.1 vs 52.6±27.3, ð=0.01, respectively), protected against VC (odds ratio: 1.36, 95% Cl: 1.0 to 1.8) in patients with inferior AMI. However, there were no significant differences in those similar parameters in patients with anterior AMI.
Conclusion: PIA is associated with decrease of ventricular arrhythmias in patients with inferior AMI. This favorable effect may be detected by 24-hour Holter monitoring in the first day of AMI.