Correct Answer: A

Rationale: Heart block is the correct answer. It is a condition where the electrical impulses in the heart are blocked or delayed, resulting in a slower or irregular heartbeat. This can lead to symptoms like dizziness, fainting, or other issues. Atrial fibrillation (B) is characterized by rapid, irregular heartbeats. Tachycardia (C) is a condition where the heart rate is too fast. Bradycardia (D) is the opposite of tachycardia, where the heart rate is too slow.

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: The correct answer is A: Dilated cardiomyopathy. Dilated cardiomyopathy is a type of heart disease where the heart muscle becomes enlarged and weakened, reducing its ability to pump blood effectively, which can lead to heart failure. Hypertrophic cardiomyopathy (B) is characterized by abnormal thickening of the heart muscle, not enlargement. Restrictive cardiomyopathy (C) involves the heart muscle becoming stiff and less flexible, limiting its ability to fill with blood properly. Myocarditis (D) is inflammation of the heart muscle, which can affect the heart's function but is different from dilated cardiomyopathy.

Correct Answer: A

Rationale: The correct answer is A: Cardioversion. Cardioversion is the procedure used to restore a normal heart rhythm in patients with arrhythmias by delivering controlled electrical shocks to the heart. Choice B, Defibrillation, is incorrect because defibrillation is used to treat life-threatening arrhythmias by delivering an unsynchronized high-energy shock to the heart. Choice C, Ablation, is incorrect as it involves destroying abnormal tissue that causes arrhythmias, not necessarily restoring normal heart rhythm. Choice D, Angioplasty, is unrelated to heart rhythm restoration and is a procedure to open blocked or narrowed blood vessels.

Correct Answer: A

Rationale: Calcium channel blockers are medications that reduce high blood pressure by relaxing the blood vessels, facilitating easier blood flow through the vessels. Beta-blockers work by reducing the heart rate and the heart's workload. ACE inhibitors help relax blood vessels by blocking the production of a chemical that narrows blood vessels. Diuretics help the body get rid of excess sodium and water to lower blood pressure, but they do not directly relax blood vessels like calcium channel blockers do.