Unusual presentation of rare Phe33Leu mutation in hereditary TTR cardiac amyloidosis

Introduction: Hereditary TTR cardiac amyloidosis (ATTRv-CM) is a progressive and rare autosomal dominant disease, causing the formation of insoluble amyloid fibrils that deposit in the heart and nervous tissue. Case description: The authors present a 64-year-old man who was found to have the Phe33Leu mutation causing ATTRv-CM without any neurological signs or symptoms. He presented with persistent atrial fibrillation that was refractory to anti-arrhythmic medications and multiple ablations. He was diagnosed with ATTRv-CM by a Tc-99m pyrophosphate cardiac amyloid scan. Intervention: He was treated with tafamidis, torsemide and spironolactone therapy. The patient suffered cardiac arrest and passed away. Conclusion: Clinicians should be aware of the atypical presentations of ATTRv-CM without neurological signs.