Systemic Amyloidosis With Probable Cardiac Involvement: Diagnostic Approach in a Resource-Limited Setting: A Case Report.

Systemic amyloidosis, which may involve the heart as an infiltrative cardiomyopathy, is frequently underdiagnosed, particularly in low-resource settings where access to advanced imaging and laboratory investigations for amyloid subtyping is limited. We report a case of a 57-year-old man from Ethiopia who presented with progressive symptoms of heart failure with preserved ejection fraction (HFpEF). Electrocardiography demonstrated low-voltage QRS complexes with poor R-wave progression, while transthoracic echocardiography revealed concentric left ventricular hypertrophy with severe diastolic dysfunction. The marked discordance between the electrocardiographic and echocardiographic findings raised suspicion of infiltrative cardiomyopathy, specifically systemic amyloidosis with probable cardiac involvement. Advanced diagnostic modalities, including serum protein electrophoresis and free light-chain assay, were unavailable because of financial constraints; however, an abdominal fat pad biopsy with Congo red staining confirmed amyloid deposition. Critically, amyloid subtyping could not be performed. The patient was managed with optimized diuretic therapy, resulting in symptomatic improvement. This case highlights the diagnostic approach integrating basic clinical findings, electrocardiography, echocardiography, and minimally invasive biopsy to confirm systemic amyloidosis with probable cardiac involvement in resource-limited settings. Amyloid subtyping remains essential for disease-specific therapy. Early recognition and careful diagnostic interpretation are critical for guiding appropriate management and improving outcomes.