Correct Answer: A

Rationale: The correct answer is A: Cardiac output. Cardiac output is the volume of blood pumped by the heart per minute. It is calculated by multiplying the stroke volume (the amount of blood pumped out of the heart in each beat) by the heart rate (number of heartbeats per minute). This question specifically asks for the total amount of blood pumped through the circulatory system in a minute, which is represented by cardiac output. Choices B, C, and D are incorrect because stroke volume refers to the amount of blood pumped out of the heart in each beat, end-diastolic volume is the volume of blood in the heart at the end of diastole, and ejection fraction is the percentage of blood pumped out of the heart with each contraction, not the total amount pumped per minute.

Correct Answer: D

Rationale: The correct answer is D: Decreases blood pressure. Calcium channel blockers primarily work by relaxing the blood vessels, leading to a decrease in blood pressure. Choice A, 'Decreases heart rate,' is incorrect because calcium channel blockers do not significantly affect heart rate. Choice B, 'Increases heart rate,' is incorrect as calcium channel blockers do not have a primary effect of increasing heart rate. Choice C, 'Increases blood pressure,' is incorrect as the primary effect of calcium channel blockers is to decrease blood pressure by vasodilation.

Correct Answer: B

Rationale: The correct answer is B, Aortic valve. The aortic valve is a semilunar valve located between the left ventricle and the aorta. It prevents the backflow of blood from the aorta into the left ventricle. The pulmonary valve (choice A) is located between the right ventricle and the pulmonary artery, not in the Valsalva's sinus area. The tricuspid valve (choice C) is situated between the right atrium and right ventricle, and the mitral valve (choice D) is located between the left atrium and left ventricle, making them incorrect choices for this question.

Correct Answer: A

Rationale: The correct answer is A: Blood pressure. When a client is on dobutamine, it is crucial to closely monitor their blood pressure as dobutamine can cause significant changes in blood pressure. While heart rate is also important to monitor during this time, blood pressure is the most critical parameter to assess. Oxygen saturation and respiratory rate are also important parameters to monitor in a patient receiving dobutamine, but they are not as crucial as blood pressure in this scenario.

Correct Answer: A

Rationale: When a client on amiodarone reports shortness of breath, it can be indicative of pulmonary toxicity, a severe side effect associated with this medication. The nurse's priority is to notify the healthcare provider immediately to assess the situation and determine the appropriate course of action. Choice B is incorrect because shortness of breath with amiodarone should not be dismissed as a common side effect. Instructing the client to monitor symptoms at home (Choice C) may delay necessary intervention. Suggesting the client reduce physical activity (Choice D) does not address the potential serious nature of the symptom and the need for prompt evaluation.