Cardiovascular System Exam

Correct Answer: A

Rationale: Hypertrophic cardiomyopathy is the correct answer. It is a condition characterized by the abnormal thickening of the heart muscle without an obvious cause, which impairs the heart's ability to effectively pump blood. Dilated cardiomyopathy (choice B) involves the enlargement and weakening of the heart chambers, not thickening. Restrictive cardiomyopathy (choice C) refers to the stiffening of the heart muscle, limiting its ability to fill properly. Myocarditis (choice D) is inflammation of the heart muscle usually caused by a viral infection, not thickening.

Correct Answer: A

Rationale: The correct answer is A, Coronary artery bypass graft (CABG). This surgical procedure involves grafting a blood vessel to bypass a blocked coronary artery, improving blood flow to the heart muscle. Choice B, Valve replacement, is a procedure to replace a damaged heart valve and is not directly related to bypassing blocked arteries. Choice C, Stent placement, involves inserting a mesh tube to keep blocked arteries open and is different from grafting a blood vessel. Choice D, Angioplasty, is a procedure to widen narrowed or blocked arteries, typically using a balloon catheter, and does not involve grafting a blood vessel.

Correct Answer: A

Rationale: The correct answer is A: Muscle pain. Muscle pain can be a sign of rhabdomyolysis, a serious side effect of statins like atorvastatin. Rhabdomyolysis is a condition where muscle fibers break down rapidly and release their contents into the bloodstream, which can lead to kidney damage. Headache, nausea, and dizziness are not commonly associated with atorvastatin use and are less likely to indicate a serious adverse reaction compared to muscle pain.

Correct Answer: A

Rationale: Ventricular tachycardia is the correct answer. It is a condition characterized by the heart's electrical system malfunctioning, leading to very fast heartbeats originating from the ventricles. Ventricular tachycardia can be life-threatening as it may progress to ventricular fibrillation, causing cardiac arrest. Atrial fibrillation (choice B) involves rapid, irregular beating of the atria, not the ventricles. Supraventricular tachycardia (choice C) originates above the ventricles and does not involve ventricular malfunction. Bradycardia (choice D) is the opposite of tachycardia, characterized by an abnormally slow heart rate.

Correct Answer: A

Rationale: The correct answer is Purkinje fibers. Purkinje fibers are specialized conducting fibers that distribute the electrical impulse to the ventricles, leading to their contraction. The SA node (sinoatrial node) is responsible for initiating the electrical impulse in the heart, the AV node (atrioventricular node) delays the impulse to allow for proper atrial contraction before ventricular contraction, and the Bundle of His transmits the impulse from the AV node to the ventricles. Therefore, choices B, C, and D are not the correct options for fibers directly distributing the impulse to the ventricles.