Trifascicular block as primary presentation of the cardiac amyloidosis; A rare case report

BACKGROUND: Amyloidosis is a severe systemic disorder produces by the accumulation of inappropriately amyloid deposition in tissues. Cardiac involvement, as a main type of amyloidosis, has a major impact on prognosis. We describe a biopsy-proven cardiac amyloidosis in an old man with unexpected presentation. CASE REPORT: A 70-year-old man, with a complaint of severe weakness, lightheadedness, and lower limb paresthesia, was admitted to the emergency department. Electrocardiography revealed right bundle branch block and Trifascicular block. Echocardiography study showed a moderately increased thickness of left ventricular wall with concentric pattern as well. Laboratory investigations including serum and urine electrophoresis, and serum free light chain examination as immunofixation assay revealed that κ chains predominated over λ chains in a ratio of 3:2. Our patient with final diagnosis of amyloid light-chain (AL) amyloidosis underwent chemotherapy with melphalan combined with high-dose dexamethasone, CPHPC and monoclonal antibodies for 2 weeks. CONCLUSION: It shows that rapid diagnosis of AL amyloidosis can enhance the prognosis. Applying an optimal strategy for the treatment leads to effective therapy, too.