Cardiovascular System Exam

Correct Answer: A

Rationale: The PR interval measures the time it takes for the electrical impulse to travel from the atria to the ventricles. It is crucial in diagnosing heart rhythm disorders, as abnormalities in this interval can indicate conduction abnormalities between the atria and ventricles. Choices B, C, and D are incorrect. The QRS complex represents ventricular depolarization, the QT interval represents the duration of ventricular repolarization, and the ST segment represents the time between ventricular depolarization and repolarization.

Correct Answer: A

Rationale: The correct answer is A: Coronary artery bypass graft (CABG). This surgical procedure is used to redirect blood flow around a blocked or narrowed artery by using a graft from another part of the body. Choices B, C, and D are incorrect because valve replacement involves replacing heart valves, aneurysm repair addresses the treatment of aneurysms, and atherectomy is a procedure to remove plaque from blood vessels, none of which match the description provided in the question.

Correct Answer: A

Rationale: The correct answer is A, the carotid body. The carotid body is the major chemoreceptor of the heart responsible for detecting changes in blood oxygen, carbon dioxide, and pH levels. This specialized structure helps regulate the cardiovascular system's response to maintain appropriate oxygen levels in the blood. Choices B, C, and D are incorrect as they are not directly involved in chemoreception in the heart. The aortic body is primarily involved in blood pressure regulation, the vagus nerve is a cranial nerve responsible for parasympathetic innervation, and the SA node is known as the heart's natural pacemaker.

Correct Answer: A

Rationale: The correct answer is A: Peripheral artery disease (PAD). PAD is a condition where the arteries in the legs or arms become narrowed or blocked, leading to pain and mobility issues. Choice B, Atherosclerosis, refers to the buildup of fats, cholesterol, and other substances in and on the artery walls, not specifically the narrowing or blockage in the extremities. Choice C, Raynaud's disease, is characterized by reduced blood flow to the extremities, leading to coldness, numbness, and color changes in the skin, but it is not primarily about narrowed or blocked arteries. Choice D, Varicose veins, involves enlarged, twisted veins usually in the legs, but it is not related to narrowed or blocked arteries causing pain and mobility issues.

Correct Answer: A

Rationale: In this scenario, the nurse's priority action should be to hold the digoxin and notify the healthcare provider. A heart rate of 48 bpm is low, and digoxin, being a medication that can further decrease the heart rate, should be withheld. Administering the digoxin as ordered (Choice B) would not be appropriate in this situation as it can exacerbate bradycardia. Atropine (Choice C) is not the initial treatment for this scenario; holding the digoxin is the first action. Increasing the dose of digoxin (Choice D) would be contraindicated due to the client's bradycardia. Therefore, the correct action is to hold the digoxin and inform the healthcare provider for further guidance.