Correct Answer: A

Rationale: Anticoagulants are medications specifically designed to prevent blood clots by thinning the blood. They work by interfering with the body's blood clotting process. Beta-blockers, ACE inhibitors, and calcium channel blockers are medications used for different purposes such as managing blood pressure, heart conditions, and regulating heart rhythm, respectively. However, they do not have the primary function of preventing blood clots like anticoagulants.

Correct Answer: A

Rationale: Paroxysmal nocturnal dyspnea is the correct answer. It is characterized by the sudden onset of shortness of breath during sleep, often associated with heart failure. Choice B, Sleep apnea, involves pauses in breathing during sleep but is not specifically associated with heart failure. Choice C, Orthopnea, is difficulty breathing that occurs when lying down and is relieved by sitting up, not necessarily associated with heart failure. Choice D, Dyspnea, is a general term for difficulty breathing and does not specifically describe the sudden onset at night associated with heart failure as seen in paroxysmal nocturnal dyspnea.

Correct Answer: A

Rationale: The correct answer is A, Deep vein thrombosis (DVT). Deep vein thrombosis occurs when a blood clot forms in a deep vein, usually in the legs. If the clot dislodges and travels to the lungs, it can lead to a serious condition called a pulmonary embolism. Choice B, pulmonary embolism, is incorrect as it is the consequence of a DVT clot traveling to the lungs, not the initial condition. Choices C and D, varicose veins, and Raynaud's disease, respectively, are unrelated conditions to the formation of blood clots in deep veins.

Correct Answer: A

Rationale: The correct answer is Angioplasty. Angioplasty is a procedure that uses a catheter to open up a blocked or narrowed coronary artery, often involving the placement of a stent. Echocardiogram is a diagnostic test that uses sound waves to create images of the heart. CT angiography is a type of imaging test that looks at blood vessels, but it does not involve the placement of a stent. Coronary artery bypass graft (CABG) is a surgical procedure to improve blood flow to the heart muscle by bypassing blocked coronary arteries.

Correct Answer: B

Rationale: The correct answer is B, Left circumflex artery. The circumflex artery is a branch of the left coronary artery that supplies blood to the left atrium and the lateral wall of the left ventricle. Choice A, the Right coronary artery, does not supply the mentioned areas. Choice C, the Left anterior descending artery, supplies the anterior wall of the left ventricle. Choice D, the Posterior descending artery, is a branch of the right coronary artery and supplies the inferior wall of the left ventricle and the posterior septum.