Correct Answer: A

Rationale: The correct answer is A: Myocardial infarction. Myocardial infarction, commonly known as a heart attack, occurs when the blood supply to part of the heart muscle is severely reduced or stopped, leading to tissue damage or death. Angina (choice B) is chest pain or discomfort that occurs when the heart muscle doesn't get enough oxygen-rich blood. Stroke (choice C) is a condition where the blood supply to the brain is interrupted or reduced. Congestive heart failure (choice D) is a chronic condition where the heart muscle doesn't pump blood as well as it should.

Correct Answer: A

Rationale: Valve replacement is the correct answer because it specifically involves surgically replacing a damaged or diseased heart valve with a prosthetic valve to address narrowing or blockage, thereby improving blood flow and heart function. Angioplasty (choice B) is a procedure to widen narrowed or obstructed arteries, typically using a balloon catheter. Stent placement (choice C) involves inserting a mesh tube to support a weakened artery. Coronary bypass surgery (choice D) is a procedure to create new routes for blood flow to the heart muscle by bypassing blocked arteries.

Correct Answer: B

Rationale: The correct answer is B. A heart rate of 58 bpm is considered low, and beta blockers can further decrease the heart rate. Therefore, the nurse's priority action should be to hold the beta blocker and notify the healthcare provider for further assessment. Choice A is incorrect because administering the beta blocker without considering the low heart rate can worsen the condition. Choice C is incorrect as increasing the dose of the beta blocker can lead to further slowing of the heart rate, which is not safe in this situation. Choice D is not the priority action; holding the medication and seeking guidance from the healthcare provider is more crucial.

Correct Answer: A

Rationale: Pericarditis is the correct answer because it is the inflammation of the pericardium, the outer lining of the heart. This condition commonly presents with symptoms like chest pain. Endocarditis (choice B) is the inflammation of the inner lining of the heart chambers and valves. Myocarditis (choice C) is the inflammation of the heart muscle itself. Valvular heart disease (choice D) refers to various conditions affecting the heart valves, not specifically the outer lining of the heart.

Correct Answer: A

Rationale: The correct answer is the Pulmonary valve. The Pulmonary valve prevents backflow of blood into the right ventricle from the pulmonary artery after it has been ejected. The Aortic valve (choice B) prevents backflow from the aorta into the left ventricle. The Tricuspid valve (choice C) prevents backflow of blood into the right atrium from the right ventricle. The Mitral valve (choice D) prevents backflow from the left ventricle into the left atrium.