Whipple's Disease, a Rare Cause of Constrictive Myopericarditis and Right-Sided Heart Failure.

Whipple's disease is a rare, chronic multisystemic infection caused by Tropheryma whipplei. Although the disease typically presents with arthritis, diarrhea, fever, and lymphadenopathy, it may also involve the heart. Cardiac involvement is uncommon but may include constrictive myopericarditis, a potentially life-threatening cause of right-sided heart failure. We report the case of a 67-year-old woman admitted with decompensated right-sided heart failure. Echocardiography and chest CT revealed constrictive pericarditis with an intrapericardial mass initially suspicious for malignancy. Duodenal and pericardial biopsies demonstrated Periodic acid-Schiff (PAS)-positive macrophages, and polymerase chain reaction (PCR) confirmed T. whipplei infection. The patient had a history of chronic seronegative arthritis and later developed diarrhea and severe malnutrition, consistent with Whipple's disease. Standard antibiotic therapy was initiated with intravenous ceftriaxone, followed by trimethoprim-sulfamethoxazole. Her course was complicated by suspected immune reconstitution inflammatory syndrome, ongoing inflammation, and nutritional decline, rendering surgical pericardiectomy unsafe. A trial of oral corticosteroids in addition to antibiotics resulted in clinical improvement and significant regression of the pericardial mass. This case highlights an unusual cardiac manifestation of Whipple's disease and emphasizes the importance of considering this diagnosis in patients with unexplained constrictive pericarditis and systemic symptoms. To our knowledge, this is the first reported case of constrictive myopericarditis due to Whipple's disease successfully managed without pericardectomy. Our report underscores the potential role of a conservative medical approach in frail or high-risk patients and illustrates the need for a better understanding of immunopathogenesis to guide therapeutic strategies.