Acute atrial infarction: arelatively neglected and under-recognized entity in clinical practice.

Abstract

Electrocardiograms (ECGs) and angiographic features indicative of acute atrial infarction (AAI) often go unnoticed and are under-recognized in clinical practice. In this retrospective observational study, we analyzed the data of 3981 out of 9803 patients (40.61%) who were referred to our hospital for angiography and/or percutaneous coronary intervention due to acute coronary syndrome (ACS). These patients were diagnosed with acute ST segment elevation myocardial infarction (AMI) affecting the inferior, posterior, and/or right ventricular regions. Of the 3981 patients, 270 (6.78%) had involvement of the main coronary atrial branch meeting the angiographic criteria for AAI. Among the 270 patients identified, the right coronary artery was diagnosed as the infarct-related artery (IRA) in 187 patients (groupR), while the left circumflex artery was the IRA in 83patients (groupL). The incidence of PR-segment deviation was similar between the two groups (65.2% in groupR vs.66.3% in groupL, p = 0.870), as was occurrence of atrial tachyarrhythmia (67.4% vs.55.4%, p = 0.059). The prevalence of P wave morphology abnormalities (29.9% vs.49.4%, p = 0.005) and sinus bradycardia or arrest (25.1% vs.66.3%, p < 0.001) was significantly lower in GroupR than in GroupL. Acute atrial infarction represents adistinct yet frequently overlooked clinical entity. Clinicians should consider the potential for atrial arrhythmias, thromboembolism, hemodynamic instability, and atrial rupture when diagnosing AAI.