Cardiac Amyloidosis Presenting with Pre-Excitation Syndrome, Heart Failure, and Severe Factor X Deficiency as Part of Systemic Amyloid Light-Chain (AL) Amyloidosis - A Fatal Combination.

BACKGROUND Amyloid light-chain (AL) amyloidosis is a disease that results in systemic amyloid deposition, which may present with multi-organ dysfunction. It carries a poor prognosis at the time of diagnosis. CASE REPORT A 37-year-old patient with a history of Wolff-Parkinson-White syndrome and thyroiditis presented with syncope and hypovolemia. ECG showed non-specific T wave inversions in the lateral leads with no signs of ischemia. Laboratory investigations revealed deranged coagulation parameters with prolonged prothrombin time (PT) and activated partial thromboplastin time (aPTT) and follow-up factor assays revealed severe factor X deficiency. A transthoracic echocardiogram and subsequent cardiac MRI showed signs of cardiac amyloidosis. Bone marrow biopsy was consistent with AL amyloidosis, demonstrating period acid-Schiff (PAS)-positive adipose deposits and interstitial infiltration by clusters of lambda restricted plasma cells with aberrant expression of CD 56 and CD 117.The patient was treated with bortezomib, cyclophosphamide, and dexamethasone, but died early during his treatment due to cardiac arrest, suspected to be secondary to conduction abnormalities caused by cardiac infiltration. CONCLUSIONS This case represents a novel pattern of disease in AL amyloidosis with cardiac, thyroid, and hematological involvement as a result of systemic amyloid deposition.Our report highlights the need for physicians to be aware of cardiac amyloidosis-related complications and the morbidity and mortality associated with concurrent hematological involvement in these cases.