**Core Concept**
Rheumatoid arthritis (RA) is an autoimmune disease that can lead to cardiac complications due to chronic inflammation and fibrosis. Corticosteroids and nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used to treat RA, but they can have adverse effects on the heart.

**Why the Correct Answer is Right**
Restrictive cardiomyopathy (RCM) is a type of heart disease characterized by stiffening of the heart muscle, which impairs the heart's ability to fill with blood. In patients with RA, chronic inflammation and fibrosis can lead to RCM. Corticosteroids can also contribute to RCM by promoting fibrosis and collagen deposition in the heart. Additionally, RA patients are at increased risk of developing systemic lupus erythematosus (SLE), which can also cause RCM.

**Why Each Wrong Option is Incorrect**
**Option A:** Constrictive pericarditis is a condition where the pericardium becomes scarred and stiff, leading to impaired diastolic function. While RA patients can develop constrictive pericarditis, it is less common than RCM.

**Option B:** Dilated cardiomyopathy (DCM) is characterized by enlargement of the heart chambers, leading to impaired systolic function. DCM is more commonly associated with conditions such as hypertension, coronary artery disease, and alcohol abuse, rather than RA.

**Option C:** Hypersensitivity myocarditis is a rare condition characterized by an allergic reaction to medications or other substances, leading to inflammation of the heart. While medications can cause myocarditis, hypersensitivity myocarditis is not a common complication of RA or corticosteroid use.

**Clinical Pearl / High-Yield Fact**
In patients with RA, early detection of cardiac complications, including RCM, is crucial to prevent progression and improve outcomes. Regular echocardiographic monitoring and cardiac biomarker assessment can help identify patients at risk.

**Correct Answer:**
✓ Correct Answer: D. Restrictive cardiomyopathy