Bedside programmed ventricular stimulation for sudden death risk stratification

Background: Patients with myocardial infarction and left ventricular dysfunction are at risk for sudden death. This research was conducted to determine the applicability and safety of a bedside programmed stimulation protocol to determine the risk for sudden death in these patients. Methods: Four hundred and twelve patients with acute myocardial infarction were studied. Left ventricular ejection fraction was evaluated by means of an echocardiogram. Ventricular arrhythmia, late potentials and heart rate variability were determined by means of Holter recordings. Fifty patients (60±14-year-old; 85% male) presented a left ventricular ejection fraction lower than 0.40 (0.36±0.10) associated with late potentials, low heart rate variability or ventricular arrhythmia greater than Lown I. After a central venous access was placed under fluoroscopy guidance and ECG monitoring, a quadripolar catheter was advanced to the right ventricular apex to perform programmed ventricular stimulation with up to three extrastimuli. The patients were followed-up to determine in-hospital morbidity and/or mortality. Results: No patient suffered complications. Ventricular tachycardia or ventricular fibrillation was induced in six patients. All of them received amiodarone and in five an automatic cardioverter-defibrillator was implanted. After a 22±6 month follow-up, five patients had received appropriate discharges from the implanted device and none had suffered from arrhythmic sudden death. Conclusion: Bedside programmed stimulation is a safe and useful means for sudden death risk stratification in post myocardial infarction patients. It moreover presents the advantage of being cheaper than conventionally used procedures.