Acute Isolated Right Ventricular Infarction: Unusual Presentation of Anterior ST-Segment-Elevation Myocardial Infarction

Abstract

Acute right ventricular infarction presenting with ST-segment elevation in the anterior precordial electrocardiographic leads is an unusual event. Anterior ST-segment elevation typically suggests occlusion of the left anterior descending coronary artery. It should be recognized, however, that occlusion of a right coronary artery branch can cause isolated ST-segment elevation in leads V₁ and V₂ on a standard 12-lead electrocardiogram. We describe the cases of 2 patients who presented with acute chest syndrome with isolated ST-segment elevation in leads V₁ and V₂. Emergency coronary angiograms revealed that acute thrombotic occlusion of the right ventricular marginal branch of the dominant right coronary artery caused the clinical manifestations in the first patient, whereas occlusion of the proximal nondominant right coronary artery was the culprit lesion in the second patient. Both lesions caused right ventricular myocardial infarction. The patients underwent successful primary percutaneous coronary intervention. These cases illustrate the importance of carefully reviewing angiographic findings to accurately diagnose an acute isolated right ventricular myocardial infarction, which may mimic the electrocardiographic features of an anterior-wall myocardial infarction.

Keywords: Angina, unstable/physiopathology; ST-elevation myocardial infarction/diagnosis; coronary occlusion/diagnosis; diagnosis, differential; diagnostic errors/prevention & control; electrocardiography; myocardial infarction/pathology/therapy; stents; treatment outcome; ventricular function, right.

Fig. 1

Patient 1. Presenting 12-lead electrocardiogram shows ST-segment elevation in leads V₁ and V₂ (gain, 10 mm/mV; paper speed, 25 mm/s).

Fig. 2

Patient 1. Coronary angiogram shows acute occlusion (arrow) of the proximal right ventricular branch arising from the proximal dominant right coronary artery. An anomalous left circumflex coronary artery originates from the inferior portion of the ostial right coronary artery.

Fig. 3

Patient 1. Coronary angiogram shows a patent right ventricular branch after coronary stenting (arrow).

Fig. 4

Patient 1. After stenting of the occluded right ventricular branch, 12-lead electrocardiogram shows resolution of the ST-segment elevation in leads V₁ and V₂.

Fig. 5

Patient 2. Presenting 12-lead electrocardiogram shows ST-segment elevation in leads V₁ and V₂.

Fig. 6

Patient 2. Coronary angiogram shows acute occlusion (arrow) of the proximal nondominant right coronary artery.

Fig. 7

Patient 2. Coronary angiogram shows the nondominant right coronary artery after coronary stenting (arrow).

Fig. 8

Patient 2. After stenting of the occluded proximal nondominant right coronary artery, 12-lead electrocardiogram shows improvement in the ST-segment elevation in leads V₁ and V₂.