Which pa of the hea is infarcted in case of occlusion of the anterior descending branch of Left Anterior Descending aery?
**Core Concept**
The anterior descending branch of the Left Anterior Descending artery (LAD) supplies blood to the anterior wall of the left ventricle, including the anterior two-thirds of the interventricular septum. Occlusion of this artery can lead to a significant area of myocardial infarction.
**Why the Correct Answer is Right**
Occlusion of the anterior descending branch of the LAD results in ischemia and subsequent infarction of the anterior wall of the left ventricle, including the anterior two-thirds of the interventricular septum. This is due to the fact that the LAD is a major branch of the left coronary artery, which provides blood supply to the anterior wall of the left ventricle. The infarcted area typically includes the anterior wall of the left ventricle, the anterior two-thirds of the interventricular septum, and sometimes the apex of the left ventricle.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the right coronary artery primarily supplies the right atrium, right ventricle, and the posterior third of the interventricular septum, not the area supplied by the anterior descending branch of the LAD.
**Option B:** This option is incorrect because the circumflex artery typically supplies the lateral and posterior walls of the left ventricle, not the anterior wall.
**Option C:** This option is incorrect because the posterior descending artery primarily supplies the inferior wall of the left ventricle and the posterior third of the interventricular septum, not the area supplied by the anterior descending branch of the LAD.
**Clinical Pearl / High-Yield Fact**
The "3Ds" of myocardial infarction due to LAD occlusion are: **Dyspnea** (due to pulmonary congestion), **Diaphoresis** (due to catecholamine release), and **Dysrhythmias** (due to ischemia of the conduction system).
**Correct Answer: C. The anterior wall of the left ventricle and anterior two-thirds of the interventricular septum.**