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[Evaluation of the arrhythmogenic potential 3 months after myocardial infarction]
1Laboratoire d'Electrophysiologie Cardiaque et Cardiologie B, Hôpital Trousseau, Tours.
Insights
Late ventricular potentials after myocardial infarction identify patients at high risk for serious ventricular arrhythmias, including sudden death and ventricular tachycardia. Absence of these potentials indicates a low risk of such events.
Area of Science:
- Cardiology
- Electrophysiology
- Clinical Medicine
Context:
- Assessing long-term risks following myocardial infarction (MI) is crucial for patient management.
- Ventricular arrhythmias pose a significant threat after MI, necessitating accurate risk stratification.
- Previous studies have explored various markers, but a comprehensive evaluation integrating multiple methods is valuable.
Purpose:
- To evaluate the potential for ventricular arrhythmias 3 months post-myocardial infarction.
- To determine the predictive value of late ventricular potentials and programmed ventricular stimulation for serious arrhythmic events.
- To identify patients at high risk for sudden death or ventricular tachycardia after MI.
Summary:
- This study assessed 90 patients 3 months post-myocardial infarction using Holter monitoring, exercise tests, late ventricular potentials (LVPs), and programmed ventricular stimulation (PVS).
- LVPs were present in 19 patients, and PVS induced monomorphic ventricular tachycardia in 10 patients (11.1%), with a higher prevalence of LVPs in this group (p < 0.01).
- Over 32 months, the risk of sudden death or ventricular tachycardia was significantly higher in patients with LVPs (21% positive predictive value) and those with inducible VT (66% positive predictive value), while the risk was low (2.8%) in their absence.
Impact:
- Identifies late ventricular potentials as a key marker for stratifying risk of serious ventricular arrhythmias post-myocardial infarction.
- Highlights the additive risk information provided by programmed ventricular stimulation in patients with late ventricular potentials.
- Informs clinical decision-making for post-MI patients, enabling targeted interventions for high-risk individuals to prevent sudden cardiac death.
Abstract:
An evaluation of the ventricular arrhythmia potential was conducted 3 months after a myocardial infarction (anterior n = 32, inferior n = 58) in 90 patients with a group mean age of 58 +/- 9.3 years, using 24-hour ambulatory ECG monitoring, an exercise test, recording of late ventricular potentials and programmed right ventricular stimulation. Eighteen patients (20%) had a ventricular extrasystole > or = Lown grade III on the Holter, which was more frequent in patients with ventricular dyskinesia (41% vs 15%; p < 0.05); 10 patients (11.1%) had ventricular extrasystoles > or = Lown grade III during the exercise test; 19 patients had late ventricular potentials. Programmed ventricular stimulation induced monomorphic ventricular tachycardia in 10 patients (11.1%) (sustained, n = 5, unsustained n = 5) and the prevalence of late ventricular potentials was higher in this group (60% vs 16.2%; p < 0.01). In the medium term (32 months), 2 patients had died: one suddenly and the other of a recurrence of myocardial infarction. Five patients had an episode of spontaneous ventricular tachycardia. The risk of sudden death or ventricular tachycardia was higher in patients with late ventricular potentials (positive predictive value = 21%) and in patients with electro-induced ventricular tachycardia (positive predictive value = 66%). In the absence of late ventricular potentials, the risk of a serious arrhythmic event is slight (2.8%). After myocardial infarction, the presence of late ventricular potentials can be used to isolate a group of patients with a high risk of serious ventricular arrhythmia; this risk is higher if programmed ventricular stimulation triggers monomorphic ventricular tachycardia.