left anterior descending artery
Summary
The left anterior descending artery (LAD) is the main branch of the left coronary artery that supplies the anterior wall of the left ventricle and anterior interventricular septum. Often called the 'widow maker' due to high mortality from acute occlusion, LAD stenosis is the most common cause of anterior STEMI.
Detail
The LAD originates from the left main coronary artery and travels in the anterior interventricular groove toward the cardiac apex. It gives rise to diagonal branches (supply lateral LV wall) and septal perforators (supply anterior 2/3 of interventricular septum and bundle of His). The LAD supplies approximately 40-50% of the left ventricular myocardium, making it the most critical coronary vessel. Acute LAD occlusion typically presents as anterior STEMI with characteristic ECG changes in leads V1-V6, often with reciprocal changes in inferior leads. The vessel's extensive territory means occlusion can cause massive anterior wall MI, cardiogenic shock, and sudden cardiac death. Chronic LAD disease may present with exertional angina and is often the target of percutaneous coronary intervention (PCI) or surgical revascularization. The LAD's anatomy makes it particularly susceptible to atherosclerotic plaque formation at bifurcation points.
Sources
- Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine
- First Aid for the USMLE Step 1
- Netter's Atlas of Human Anatomy
- ACC/AHA Guidelines for Coronary Artery Disease
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