rheumatoid arthritis and treated with NSAIDS and steroid, fx
A 52-year-old woman has long-standing rheumatoid arthritis (RA) and is being treated with corticosteroids and nonsteroidal anti-inflammatory drugs (NSAIDs). Which of the following cardiac complications may arise in this clinical setting?
A. Constrictive pericarditis
B. Dilated cardiomyopathy
C. Hypersensitivity myocarditis
D. Hypertrophic cardiomyopathy
E. Restrictive cardiomyopathy
The correct answer is E. What links rheumatoid arthritis (RA) to restrictive cardiomyopathy? Amyloid! Long-standing inflammatory conditions such as RA are associated with deposition of a form of amyloid known as AA (amyloid-associated protein), which may involve kidneys, heart, liver, skeletal muscle, and skin, for example. Amyloid deposition in the myocardium results in decreased compliance and impaired diastolic filling, i.e., restrictive cardiomyopathy. The myocardium has a rigid and waxy texture. This form of amyloid, as well as any other biochemical form, can be visualized on tissue section by staining with Congo red, which acquires a characteristic apple-green birefringence under polarized light.
Constrictive pericarditis (choice A) is due to any pathologic process that results in fibrous thickening of the pericardium, with resultant impaired compliance. Clinically, therefore, this condition manifests with a picture similar to restrictive cardiomyopathy because of impaired diastolic filling. Constrictive pericarditis is usually caused by previous episodes of acute pericarditis, especially hemorrhagic, suppurative, and caseous pericarditis.
Dilated cardiomyopathy (choice B) is characterized by massive ventricular dilatation and may be caused by genetic alterations, myocarditis, toxic insults (alcohol), metabolic disorders (hemochromatosis), etc. Most cases are idiopathic. The main pathophysiologic alteration is impaired contractility.
You may be tempted to think that this patient is prone to developing hypersensitivity myocarditis (choice C), but this form of myocardial disease has been reported after treatment with some antihypertensive agents, antibiotics, and diuretics — not with corticosteroids or NSAIDs. Furthermore, myocarditis manifests acutely with arrhythmias and heart failure, and chronically with dilated cardiomyopathy and congestive heart failure.
Most cases of hypertrophic cardiomyopathy (choice D) are familial and due to mutations in one of the genes encoding proteins of the sarcomeres, most frequently β-myosin heavy chain. This form of cardiomyopathy leads to asymmetric hypertrophy of the left ventricle, with predominant thickening of the interventricular septum. In this case, too, impairment of ventricular compliance is the basic mechanism leading to reduced diastolic filling and heart failure.