The following are multiple choice questions (with answers) about medical knowledge.   **Question:** A 75-year-old man presents to the emergency department with a racing heart and lightheadedness for 3 hours. He has had similar episodes in the past, but the symptoms never lasted this long. He denies chest pain, shortness of breath, headaches, and fevers. He had a myocardial infarction 4 years ago and currently takes captopril, metoprolol, and atorvastatin. His pulse is irregular and cardiac auscultation reveals an irregular heart rhythm. Laboratory reports show: Serum glucose 88 mg/dL Sodium 142 mEq/L Potassium 3.9 mEq/L Chloride 101 mEq/L Serum creatinine 0.8 mg/dL Blood urea nitrogen 10 mg/dL Cholesterol, total 170 mg/dL HDL-cholesterol 40 mg/dL LDL-cholesterol 80 mg/dL Triglycerides 170 mg/dL Hematocrit 38% Hemoglobin 13 g/dL Leucocyte count 7,500/mm3 Platelet count 185,000 /mm3 Activated partial thromboplastin time (aPTT) 30 seconds Prothrombin time (PT) 12 seconds Cardiac enzymes Negative An ECG shows the absence of P-waves with an irregular RR complex. A few hours later, his symptoms subside and he is discharged with an additional anticoagulation drug. Which of the following mechanisms explains how this new medication will exert its effects?   (A) Activation of the antithrombin enzyme   (B) Inhibition of the cyclooxygenase enzyme   (C) Inhibition of vitamin K-dependent clotting factors   (D) Blockage of glycoprotein IIb/IIIa receptors
['(C) Inhibition of vitamin K-dependent clotting factors <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) Activation of the antithrombin enzyme \n (B) Inhibition of the cyclooxygenase enzyme \n (C) Inhibition of vitamin K-dependent clotting factors \n (D) Blockage of glycoprotein IIb/IIIa receptors <> possible answers', '  A 75-year-old man presents to the emergency department with a racing heart and lightheadedness for 3 hours. He has had similar episodes in the past, but the symptoms never lasted this long. He denies chest pain, shortness of breath, headaches, and fevers. He had a myocardial infarction 4 years ago and currently takes captopril, metoprolol, and atorvastatin. His pulse is irregular and cardiac auscultation reveals an irregular heart rhythm. Laboratory reports show:\nSerum glucose 88 mg/dL\nSodium 142 mEq/L\nPotassium 3.9 mEq/L\nChloride 101 mEq/L\nSerum creatinine 0.8 mg/dL\nBlood urea nitrogen 10 mg/dL\nCholesterol, total 170 mg/dL\nHDL-cholesterol 40 mg/dL\nLDL-cholesterol 80 mg/dL\nTriglycerides 170 mg/dL\nHematocrit 38%\nHemoglobin 13 g/dL\nLeucocyte count 7,500/mm3\nPlatelet count 185,000 /mm3\nActivated partial thromboplastin time (aPTT) 30 seconds\nProthrombin time (PT) 12 seconds\nCardiac enzymes Negative\nAn ECG shows the absence of P-waves with an irregular RR complex. A few hours later, his symptoms subside and he is discharged with an additional anticoagulation drug. Which of the following mechanisms explains how this new medication will exert its effects? <> context@']