Correct Answer: A

Rationale: The correct answer is A, pulmonary embolism. Pulmonary embolism is a condition where a blood clot blocks one of the pulmonary arteries in the lungs, resulting in symptoms like chest pain, shortness of breath, and other related signs. Choices B, C, and D are incorrect because pneumothorax refers to a collapsed lung, pulmonary edema is the build-up of fluid in the lungs, and pulmonary hypertension is high blood pressure in the arteries of the lungs - none of which directly involve a blood clot blocking the pulmonary arteries.

Correct Answer: A

Rationale: Excitability is the correct term that describes the ability of cardiac cells to respond to an impulse by contracting. Excitability refers to the cell's ability to respond to stimuli and generate an action potential. Choice B, Contractility, is incorrect as it refers to the ability of cardiac cells to contract after receiving a stimulus, not the response to the impulse itself. Choice C, Rhythmicity, is incorrect as it pertains to the heart's ability to contract rhythmically without external stimulation. Choice D, Conductivity, is incorrect as it refers to the ability of cardiac cells to transmit an impulse from cell to cell, not the direct response to the impulse by contracting.

Correct Answer: A

Rationale: When a client on amiodarone develops pulmonary fibrosis, a serious side effect, the immediate action the nurse should take is to notify the healthcare provider. This is crucial because pulmonary fibrosis can lead to severe respiratory compromise and requires prompt evaluation and management by the healthcare provider. Continuing the medication (choice B) can worsen the condition, and delaying action by reducing the dose and monitoring respiratory status (choice D) may not be appropriate given the seriousness of pulmonary fibrosis. Discontinuing the medication and starting oxygen therapy (choice C) may be necessary, but the priority is to notify the healthcare provider first for further assessment and guidance.

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, pulmonary embolism. Pulmonary embolism is a condition where a blood clot blocks one of the pulmonary arteries in the lungs, resulting in symptoms like chest pain, shortness of breath, and other related signs. Choices B, C, and D are incorrect because pneumothorax refers to a collapsed lung, pulmonary edema is the build-up of fluid in the lungs, and pulmonary hypertension is high blood pressure in the arteries of the lungs - none of which directly involve a blood clot blocking the pulmonary arteries.