Identifying high risk patients post myocardial infarction with reduced left ventricular function using loop recorders INSPIRE-ELR clinical study

Aims: Sudden cardiac death (SCD) continues to be a devastating complication amongst survivors of myocardial infarction (MI). Mortality is high in the initial months after MI. The aims of the INSPIRE-ELR study were to assess the proportion of patients with significant arrhythmias early after MI and the association with mortality during 12 months of follow-up. Methods: The study included 249 patients within 14 days after MI with left ventricular ejection fraction (LVEF) _x0001_35% at discharge in 11 hospitals in India. Patients received a wearable external loop recorder (ELR) 5 ± 3 days after MI to monitor arrhythmias for 7 days. Results: Patients were predominantly male (86%) with a mean age of 56 ± 12 years. In 82%, reperfusion had been done and all received standard of care cardiovascular medications at discharge. LVEF was 32.2 ± 3.9%, measured 5.1 ± 3.0 days after MI. Of the 233 patients who completed monitoring (7.1 ± 1.5 days), 81 (35%) experienced significant arrhythmias, including Ventricular Tachycardia/Fibrillation (VT/ VF): 10 (4.3%); frequent Premature Ventricular Contractions (PVCs): 65 (28%); Atrial Fibrillation (AF): 8 (3.4%); chronic atrial flutter: 4 (1.7%); 2nd or 3rd degree Atrioventricular (AV) block: 4 (1.7%); and symptomatic bradycardia: 8 (3.4%). In total, 26 patients died. Mortality was higher in patients with clinically significant arrhythmia (at 12 months: 23.6% vs 4.8% with 19 vs 7 deaths, hazard ratio (HR) ¼ 5.5, 95% confidence interval (CI) 2.3 to 13.0, p < 0.0001). Excluding 7 deaths during ELR monitoring, HR ¼ 4.5, p < 0.001. Conclusion: ELR applied in patients with acute MI and LV dysfunction at the time of discharge identifies patients with high mortality risk.

Brugada syndrome unmasked by sodium channel blockade.

We report the case of a 29-year-old male suffering from recurrent syncope and palpitations. He had a structurally normal heart and his baseline electrocardiogram was normal. His electrophysiologic study revealed an inducible, nonsustained polymorphic ventricular tachycardia on programmed electrical stimulation. With the administration of intravenous Flecainide, there was typical ST-segment elevation in leads V2 and V3, indicative of the Brugada syndrome. He underwent an implantable cardioverter defibrillator implantation. The cardioverter defibrillator delivered an appropriate shock when the patient suffered ventricular fibrillation during follow-up one year later. This report illustrates the role of pharmacologic challenge in the diagnosis of the Brugada syndrome.