The answer is B. This EKG pattern is consistent with that of anterior wall myocardial infarction (MI). The LAD supplies the anterior wall of the myocardium. The left circumflex artery, the LAD, or a branch of the RCA supplies the lateral wall of the left ventricle. Proximal occlusion of the LAD will give ST elevation in leads V1-6, aVL and I (an anterolateral MI). Occlusion of a branch of the RCA will result in an inferolateral MI (ST elevation in leads II, III, aVF and I, aVL, V5 and V6). The RCA supplies the inferior wall and SA node. Occlusion in leads II, III and aVF causes an inferior MI. The right ventricle is usually supplied by the RCA or, less commonly, a dominant left circumflex. ST elevation in leads V4 and V5 of a right-side leads EKG suggests infarction of the right ventricle. A posterior MI (ST depression in V1-V3) results from occlusion of the RCA, its posterior descending branch, or a dominant left circumflex. The answer is C. This patient most likely has a PE and has a sufficient presentation to warrant immediate anticoagulation therapy with heparin unless contraindications are present. Risk factors for PE include history of deep venous thrombosis (DVT), recent surgery or pregnancy, limb immobilization, confinement to bed, or underlying malignancy. Other risk factors include HTN, obesity, estrogen replacement therapy or oral contraceptives, autoimmune diseases, and cancer. Symptoms of PE include: dyspnea, pleuritic chest pain, apprehension, cough, hemoptysis, sweating, and syncope. The diagnosis is made: (1) if DVT is demonstrated by duplex US, venography, CT, MRI or some other technique; (2) if V/Q scan is convincingly positive; or (3) if pulmonary angiography, spiral CT, or another convincing test is positive.