A nurse is teaching a client who has acute pericarditis. Which of the following statements should the nurse include in the client teaching to explain the cause of pericarditis?

Choice A rationale Thickening of the ventricular walls and the septum is the hallmark of hypertrophic cardiomyopathy, not pericarditis. In that condition, the muscle tissue becomes abnormally thick, which can make it harder for the heart to pump blood and may lead to arrhythmias. Pericarditis does not involve the growth or thickening of the myocardium itself; it is strictly a disorder of the protective layers surrounding the heart. Explaining the condition this way would be scientifically inaccurate. Choice B rationale Acute pericarditis is defined as the inflammation of the pericardium, which is the thin, two-layered membranous sac that encloses the heart. This inflammation often leads to chest pain that worsens with deep breathing or lying flat and may produce a pericardial friction rub. The inflammation can be caused by infections, autoimmune disorders, or trauma. This statement correctly identifies the anatomical location and the pathological process involved, making it the most appropriate explanation for patient education. Choice C rationale Excessive stretching of the ventricles is associated with dilated cardiomyopathy, a condition where the heart chambers enlarge and the muscle weakens. This stretching results in a decreased ejection fraction and signs of heart failure. Pericarditis involves the external sac and does not primarily cause the heart muscle to stretch out. Using this description would confuse the patient about the nature of their diagnosis, as it describes a structural muscle failure rather than an inflammatory process. Choice D rationale Compression of the myocardium due to fluid accumulation describes a pericardial effusion or cardiac tamponade. While these can be complications of acute pericarditis, they are not the definition of the disease itself. Pericarditis is the inflammation of the membranes, which may or may not lead to significant fluid buildup. It is important to distinguish the primary inflammatory cause from the potential secondary effect of fluid pressure to ensure the patient understands why they have pain.