Correct Answer: B

Rationale: The correct answer is to hold the digoxin and notify the healthcare provider. A potassium level of 3.0 mEq/L indicates hypokalemia, which can increase the risk of digoxin toxicity. Digoxin and low potassium levels can lead to serious cardiac arrhythmias. Administering a potassium supplement (choice A) without healthcare provider guidance can worsen the situation. Continuing the current digoxin dose (choice C) can further increase the risk of toxicity. Administering Digibind (choice D) is used in severe cases of digoxin toxicity, not for addressing low potassium levels.

Correct Answer: A

Rationale: The correct answer is an echocardiogram. This test utilizes sound waves to generate images of the heart, enabling doctors to evaluate both the function and structure of the heart. Choice B, MRI, uses magnetic fields and radio waves to produce detailed images of the body's organs and structures, not specifically focused on the heart. Choice C, CT scan, employs X-rays to create detailed cross-sectional images of the body, not primarily for the heart. Choice D, X-ray, uses electromagnetic radiation to produce images of internal structures, but it does not provide the detailed pictures of the heart's function that an echocardiogram does.

Correct Answer: A

Rationale: The correct answer is A: Heart failure. Heart failure is a chronic condition characterized by the heart's inability to pump blood effectively, resulting in fluid accumulation in the lungs and other body tissues. Myocardial infarction (choice B) refers to a heart attack caused by a blocked coronary artery, leading to damage of heart muscle tissue. Pericarditis (choice C) is the inflammation of the pericardium, the protective sac around the heart. Pulmonary edema (choice D) is a condition where fluid builds up in the lungs, often as a result of heart failure.

Correct Answer: B

Rationale: The correct answer is to hold the digoxin and notify the healthcare provider. A potassium level of 3.0 mEq/L indicates hypokalemia, which can increase the risk of digoxin toxicity. Digoxin and low potassium levels can lead to serious cardiac arrhythmias. Administering a potassium supplement (choice A) without healthcare provider guidance can worsen the situation. Continuing the current digoxin dose (choice C) can further increase the risk of toxicity. Administering Digibind (choice D) is used in severe cases of digoxin toxicity, not for addressing low potassium levels.

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.