Atrial infarction

Associate Editor-In-Chief:

Overview
Atrial infarction is ischemic necrosis of the upper chamber of the heart (the atrium). It is a disease that has not been well studied.

Incidence
In autopsy studies, the incidence is highly variable ranging from 0.7% to 42%. The largest series to date involved 182 patients, and the incidence in that study was 17%.

Pathophysiology
The right atrium is involved five times as often as the left, with the auricle the predominant site in either atria.

EKG Findings:
The following may be present: supraventricular arrhythmias, atrial rupture, hemodynamic compromise from loss of atrial "kick," and thromboembolic phenomena.

Electrocardiographic diagnostic criteria

Major criteria

 * PTa-segment elevation >0.5 mm in leads V3 and V6 with reciprocal depression of PTa segments in V1 and V2 leads.
 * PTa-segment elevation >0.5 mm in lead I with reciprocal depressions in leads II and III.
 * PTa-segment depression >1.5mm in precordial leads and 1.2mm in leads I, II and III, associated with any atrial arrhythmia.

Minor criteria

 * Abormal P-waves, flattening of P-wave in M, flattening of P-wave

Echocardiography
Transesophageal echocardiography may demonstrate abnormalities.