178 ARRHYTHMIC STORM IN ATTR WILD TYPE AMYLOIDOSIS: AN UNUSUAL COMBINATION

Abstract Cardiac amyloidosis (CA) is characterized by extracellular protein fibril deposition in the myocardium leading to restrictive heart failure. Both atrial and ventricular arrhythmias are common CA. Study have shown up one half of patients with CA die suddenly. However, most cause sudden death has been historically through be secondary electromechanical dissociation rather than a lethal arrhythmia. We present case 84 years old man, history hypertension, dyslipidaemia, prior smoking. In June 2020 patient was admitted emergency room our hospital due an episode hemodynamically unstable sustained tachycardia (SVT). The underwent electrical cardioversion restoration sinus rhythm. An echocardiogram that showed slightly reduced ejection fraction (FE = 45%), severe concentric hypertrophy, grade 3 diastolic dysfunction high pressures left (LV) cavity, GLS (-13.8%) typical apical-sparing aspect. A cardiac magnetic resonance (Fig.1). performed showing diffuse area LGE subepicardial pattern involving segments, compatible myocardial storage disease. order complete diagnostic workout, we bone scintigraphy (Fig.2). (Positive for CA, Perugini score 2), genetic test (negative hATTR-CA mutations) free light chain serum AL-CA). discharged at home after ICD implantation prevention prescribed appropriate failure therapy. May 2022 readmitted dyspnea during arrhythmic storm several SVTs interventions, fibrillation (FA). After stabilization clinical parameters, hospitalized ward. optimized medical therapy metaprololo 100 mg 1 cp BID, cordarone 600 ev mexiletina 200 BID. During hospitalization succeeded reducing SVT burden. PVCs slow remained. For this reason, decided perform electrophysiological study (EPS) followed catheter ablation. EPS found two low voltage areas (Fig.3). first were under aortic valve; second dense scar fragmented potentials along basal-posterior wall. ablation removing PVCs. procedure complicated required advanced life support many shocks. absence further episodes At three moths follow no events recorded.