Atrial myocardial infarction: A tale of the forgotten chamber

- We reviewed the etiology and pathophysiology of atrial infarction.
- We described the various ECG and echocardiographic findings in atrial infarction.
- Atrial infarction is associated with increased mortality and morbidity in STEMI.

It has been almost a century since atrial infarction was first described, yet data describing its significance remain limited. To date, there are still no universally accepted criteria for the diagnosis of atrial infarction. Atherosclerosis is the leading cause of atrial infarction but it has also been described in cor pulmonale and pulmonary hypertension. Atrial infarction almost always occurs concomitantly with ventricular infarction. Its clinical presentation depends largely on the extent and site of ventricular involvement. Atrial infarction can present with supraventricular tachyarrhythmias. Electrocardiographic (ECG) criteria for diagnosing atrial infarction have been described but none have yet to be validated by prospective studies. Atrial ECG patterns include abnormal P-wave morphologies, PR-segment deviations, as well as transient rhythm abnormalities, including atrial fibrillation, atrial flutter, atrial tachycardia, wandering atrial pacemaker (WAP) and atrioventricular (AV) blocks. Complications of atrial infarction include thromboembolic events and cardiogenic shock. There are no specific additional recommendations in the management of myocardial infarction with suspected involvement of the atria. The primary goal remains coronary reperfusion and maintenance of, or conversion to, sinus rhythm.