Sustained Ventricular Tachycardia as the First Presentation of Hereditary Transthyretin Amyloidosis With the Glu109Gln Mutation.

BACKGROUND: Transthyretin amyloid cardiomyopathy (ATTR-CM) most commonly presents with heart failure symptoms. Sustained ventricular tachycardia (VT) is an uncommon initial manifestation. CASE SUMMARY: A 57-year-old man presented with hemodynamically unstable monomorphic VT requiring cardioversion. Imaging suggested cardiac amyloidosis and bone scintigraphy demonstrated Perugini grade 3 uptake. Genetic testing revealed a pathogenic p.Glu109Gln variant in the transthyretin gene. An implantable cardioverter-defibrillator (ICD) was implanted, and ATTR-stabilizer therapy was initiated. The patient remains stable without recurrent VT after 2.5 years. DISCUSSION: This case highlights VT as a rare initial presentation of ATTR-CM and emphasizes the limited evidence guiding the management of ventricular arrhythmias and the role of ICDs in these patients. Notably, the patient remained free of recurrent ventricular arrhythmias and ICD therapies during 2.5 years of follow-up without antiarrhythmic therapy. TAKE-HOME MESSAGES: VT may represent an atypical presentation of ATTR-CM. Management of ventricular arrhythmias remains individualized due to limited evidence.