Incidence and time frame of life-threatening arrhythmias in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention

BACKGROUND: Life-threatening arrhythmias may complicate the hospital course of patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI). The optimal duration of electrocardiographic monitoring in such patients is not well established. We aimed to determine the incidence and the time of occurrence of life-threatening arrhythmias in STEMI patients undergoing PPCI. METHODS: Data of 382 consecutive patients with STEMI undergoing PPCI were analysed regarding the occurrence of ventricular fibrillation (VF), sustained ventricular tachycardia (sVT) or bradycardia necessitating temporary or permanent pacing. RESULTS: Of these patients, 55% had inferior STEMI, 41% anterior and 4% lateral STEMI. The infarct-related arteries were the right in 41%, the left anterior descending in 41%, the left circumflex in 16%, the left main stem in 1% and a vein graft in <1%. During hospitalisation, 27 (7.0%) patients developed 29 life-threatening arrhythmias (incidence 7.6%): 19 episodes occurred during PPCI (VF n = 11, bradycardia n = 8), 9 episodes during the first 24 hours after PPCI (VF n = 7, sVT n = 2), and 1 sVT episode in a hypokalemic patient on the 4th post-procedural day. A total of 17 patients (4.5%) died within the first 30 days, and 3 of these died during the PPCI procedure. CONCLUSIONS: Life-threatening arrhythmias occur in a considerable proportion of STEMI patients undergoing PPCI during hospitalisation. Most of these arrhythmias occur during the PPCI procedure. Post-procedural life-threatening arrhythmias are virtually limited to the first 24 hours after PPCI. Thus, routine electrocardiographic monitoring beyond the first 24 hours after PPCI might not be required in most patients with uncomplicated STEMI.