What type of medication is used to reduce high blood pressure by relaxing the blood vessels?

Correct Answer: A

Rationale: The correct answer is A: Calcium channel blocker. These medications work by relaxing the blood vessels, leading to lower blood pressure. They inhibit the entry of calcium into the smooth muscle cells of the blood vessels, causing vasodilation. Beta-blockers (B) reduce heart rate and contractility. ACE inhibitors (C) block the conversion of angiotensin I to angiotensin II, leading to vasodilation. Diuretics (D) work by increasing urine output to lower blood volume and pressure. In this case, the mechanism of action aligns with the desired effect of relaxing blood vessels to reduce high blood pressure.

Correct Answer: A

Rationale: The correct answer is A: Heart block. Heart block refers to a condition where the heart's electrical impulses are blocked or delayed, leading to a slower or irregular heartbeat. This occurs when there is interference with the electrical signals that control the heart's rhythm as they travel through the heart's conduction system. Atrial fibrillation (B) is an irregular and often rapid heart rate that can occur due to chaotic electrical signals in the heart's upper chambers. Tachycardia (C) is a condition where the heart rate is too fast, not slower or irregular. Bradycardia (D) refers to a slow heart rate but not necessarily due to electrical impulse blockage.

Correct Answer: A

Rationale: The correct answer is A: Dilated cardiomyopathy. This condition is characterized by the heart muscle becoming enlarged and weakened, leading to reduced pumping efficiency. This results in symptoms like fatigue, shortness of breath, and swelling. In contrast, hypertrophic cardiomyopathy (B) is characterized by thickening of the heart muscle, restrictive cardiomyopathy (C) involves stiffness of the heart muscle, and myocarditis (D) is inflammation of the heart muscle. These conditions do not specifically involve the enlargement and weakening seen in dilated cardiomyopathy.

Correct Answer: A

Rationale: The correct answer is A: Coronary artery disease (CAD). CAD is the condition where the coronary arteries become narrowed or blocked, leading to reduced blood flow to the heart muscle. The narrowing or blockage is typically caused by atherosclerosis, which is the buildup of plaque in the arteries. Atherosclerosis is a contributing factor to CAD, but CAD specifically refers to the reduced blood flow in the coronary arteries. Stroke (C) is a condition involving the brain's blood vessels, not the heart. Peripheral artery disease (D) involves narrowing of arteries outside the heart, typically in the legs. Therefore, the most appropriate choice is A as it directly relates to the narrowed or blocked coronary arteries causing reduced blood flow to the heart muscle.

Correct Answer: C

Rationale: The correct answer is C because hydrochlorothiazide is a diuretic that can lead to hypokalemia (decreased potassium levels), which increases the risk of digoxin toxicity as digoxin requires adequate potassium levels for proper function. Choice A is incorrect because hydrochlorothiazide does not increase digoxin levels. Choice B is incorrect because hydrochlorothiazide can actually increase digoxin levels due to potential electrolyte disturbances. Choice D is incorrect as digoxin does not affect the effectiveness of hydrochlorothiazide.