From the Research
Definition of Obtuse Margin Infarct
An obtuse margin infarct, also known as a myocardial infarction, occurs when the obtuse marginal (OM) artery, a branch of the left circumflex coronary artery, becomes occluded, leading to damage or death of the heart muscle tissue it supplies.
Characteristics of Obtuse Margin Infarct
- The obtuse marginal artery supplies blood to the lateral wall of the heart, and occlusion of this artery can lead to a myocardial infarction in this region 1.
- Patients with acute occlusion of the left circumflex or obtuse marginal arteries can present with ST-elevation myocardial infarction (STEMI) or non-ST elevation myocardial infarction (NSTEMI) 1.
- The location of the occlusion, whether proximal or distal, can affect the outcome of the myocardial infarction, with proximal occlusions tend to have worse outcomes 2.
Clinical Presentation and Outcomes
- Patients with obtuse margin infarcts may present with symptoms such as chest pain, shortness of breath, and fatigue, similar to other types of myocardial infarctions 1.
- The clinical outcomes of patients with obtuse margin infarcts can vary depending on factors such as the location and severity of the occlusion, as well as the presence of other underlying health conditions 1, 2.
- In some cases, spontaneous dissection of the distal obtuse marginal coronary artery can occur, leading to sudden death 3.
Diagnosis and Assessment
- Cardiac MR (CMR) can be used to assess microvascular obstruction, which is often seen in patients with acute myocardial infarction following reperfusion therapy 4.
- The diagnosis of an incomplete myocardial infarction, which can occur in the context of an obtuse margin infarct, involves considering clinical, electrocardiographic, and echocardiographic findings, as well as serum cardiac enzyme elevations 5.