Association Between Flow Impairment in Dominant Coronary Atrial Branches and Atrial Arrhythmias in Patients With ST-Segment Elevation Myocardial Infarction

Abstract

ObjectivesThe impact of atrial ischemia in the occurrence of atrial arrhythmias may vary based on the amount of jeopardized myocardium. We sought to determine the association between coronary flow impairment in dominant coronary atrial branches (CAB) and atrial arrhythmias at 1-year follow-up in ST-segment elevation myocardial infarction (STEMI) patients. MethodsPatients with STEMI involving the right or circumflex coronary artery were included. Dominant CAB was defined as the most developed CAB. Patients were followed-up during 1 year, including 24-h Holter ECG at 3 and 6 months. Atrial arrhythmias were defined as atrial fibrillation/flutter, atrial tachycardia (≥3 consecutive supraventricular ectopic beats) and excessive supraventricular ectopic activity (>30 supraventricular beats/h or runs ≥20 beats). ResultsA dominant CAB was identified in 897 of 900 patients STEMI (age 61 ± 12 years, 79% male). TIMI flow < 3 at the dominant CAB was present in 69 (8%) patients. Compared to those with dominant CAB preserved flow, patients with dominant CAB flow impairment presented with higher levels of troponin T (3.9 [2.2–8.2] vs. 3.1 [1.3–5.8], P = 0.008)and higher rates of atrial tachycardia at 3 months (68% vs. 37%, P = 0.007) and more supraventricular ectopic beats both at 3 months (58 [21–235] vs. 33 [12–119], P = 0.02) and at 6 months (62 [24–156] vs. 32 [12–115]; P = 0.04) on 24-h Holter ECG. Age and an impaired coronary flow at the dominant CAB were independently related to a higher risk of developing atrial arrhythmias at 1-year follow-up. ConclusionDominant CAB flow impairment is infrequent and is associated with the occurrence of atrial arrhythmias, in the form atrial tachycardia and supraventricular ectopic beats, at follow-up.