Post-Heart Attack Patients Suffer from Arrhythmias

A new study has detected arrhythmias in 46% of patients who had previously suffered an acute myocardial infarction (AMI), using an insertable cardiac monitor (ICM).

Researchers at Gentofte University Hospital (Copenhagen, Denmark), St Antonious Hospital (Nieuwegein, The Netherlands), and other institutions conducted a multicenter, prospective study to investigate the incidence and prognostic significance of arrhythmias following an AMI. The study population comprised 1,393 of 5,869 patients (24%) screened in the acute phase of an AMI who had left ventricular ejection fraction less than or equal to 40%. After exclusions, 297 patients (21%) with a mean age of 64 years and a mean left ventricular ejection fraction of 31% received an ICM and were followed up every 3 months for an average of almost two years. The end points used in the analysis were cardiac death and all-cause mortality.

The results showed that clinically significant bradyarrhythmias and tachyarrhythmias were documented in a substantial proportion of patients; of those diagnosed with arrhythmias, 27% experienced new onset atrial fibrillation (AF), 9.8% had high-degree atrioventricular (AV) block, 6.7% had sinus bradycardia, and 13% had nonsustained ventricular tachycardia. Additionally, 56 patients received an implantable cardioverter-defibrillator (ICD), and 15 patients received a pacemaker. Cox regression analysis revealed that high-degree AV block was the most powerful predictor of cardiac death. The study was published in the September 28, 2010, issue of Circulation.

"For the first time there are data showing that continuous long-term monitoring allows detailed insight into post-AMI arrhythmias,” said lead author Poul Erik Bloch Thomsen, M.D. "Additional information about post-AMI patients can help physicians determine appropriate medical intervention, such as an implantable cardioverter-defibrillator, pacemaker, or modified drug therapy.”

Related Links:
Gentofte University Hospital
St Antonious Hospital