The cardiac-vascular nurse reviews risk factor reduction with a patient who is newly diagnosed with a myocardial infarction. The patient states, 'I don’t know why you’re making such a big deal about this stuff. I feel fine, and the doctor said that my heart attack was small.' The nurse’s most effective action is to:

Correct Answer: A

Rationale: Assessing the patient’s perception with open-ended questions uncovers denial or misunderstanding, enabling tailored education. B, C, and D assume understanding and may not address the patient’s minimization.

Correct Answer: D

Rationale: The mediastinum is the central compartment of the thoracic cavity, containing the heart, esophagus, trachea, and major blood vessels. The lungs, however, are located in the pleural cavities on either side of the mediastinum, not within it.

Correct Answer: A

Rationale: The 'lub' sound (first heart sound, S1) occurs at the start of systole when the atrioventricular (AV) valves (tricuspid and mitral) close, preventing backflow into the atria as the ventricles contract.

Correct Answer: B

Rationale: Edema results from high blood pressure (increased hydrostatic pressure), protein leakage (reduced osmotic pressure), or lymphatic obstruction. Increased plasma protein concentration raises osmotic pressure, pulling fluid into capillaries, thus preventing edema.

Correct Answer: D

Rationale: The innermost lining of the heart is called the endocardium. The myocardium is the middle, muscle layer of heart tissue. The membrane that surrounds the heart is the pericardium. The mediastinum is the area of the thoracic cavity between the two lungs. (Source: Document, Pretest Answer 1, p. 76)