Acute myocardial infarction due to isolated spontaneous coronary artery dissection in the first septal branch: a case report.

BACKGROUND

Myocardial infarction due to isolated spontaneous dissection in the septal branch of the coronary arteries is a rare cause of myocardial infarction with non-obstructive coronary artery disease and is challenging to diagnose.

CASE SUMMARY

A 61-year-old woman presenting with acute chest pain exhibited slight ST-segment elevation in leads V1-3 on electrocardiography. Echocardiography revealed mild hypokinetic septal wall motion. Contrast-enhanced computed tomography demonstrated a low-contrast area in the posterior septum. Emergency coronary angiography revealed delayed flow and stenosis in the first septal branch of the left anterior descending coronary artery. Intravascular ultrasound demonstrated a circumferential haematoma without an intimal tear or double lumen at the stenotic site. No balloon angioplasty or stent implantation was required because the flow delay in the septal branch disappeared after intravascular ultrasound procedure. The patient was conservatively managed with single antiplatelet therapy, calcium channel blocker, and statin. After 1 month, follow-up coronary computed tomography angiogram confirmed vascular patency of the first septal branch without narrowing, and the patient showed no recurrence.

DISCUSSION

Myocardial infarction due to isolated spontaneous coronary dissection in the septal branch of the coronary arteries is an often overlooked cause of myocardial infarction with non-obstructive coronary artery disease. Therefore, intravascular imaging and contrast-enhanced computed tomography should be performed in cases of myocardial infarction with a non-obstructive coronary artery to locate the site of infarction and identify the cause.