Ablation index-guided catheter ablation of incessant ventricular tachycardia originating from the anterolateral papillary muscle

ICE Intracardiac echocardiography CS Coronary sinus LV Left ventricle PVC Premature ventricular contraction RV Right ventricle VT Ventricular tachycardia Sirs: ventricular tachycardia (VT) comprises a heterogenous group of cardiac arrhythmias.VT arising from the papillary muscles of the left ventricle was first described as a clinical syndrome in 2008 [1].As a clinical entity, papillary muscle VT is uncommon and occurs relatively rare as a sustained arrhythmia.VT from papillary muscles mostly occur due to focal mechanisms including enhanced automaticity and triggered activity [2].Today, catheter ablation has become a well-established therapy for symptomatic patients.In the following, we report about successful catheter ablation of incessant VT of the anterolateral papillary muscle guided by 3D mapping and ablation index only.A 50-year-old male patient was admitted to the emergency department because of palpitations.The patient was on no regular medication and had no pre-existing conditions.A family history of cardiac diseases was not present.An echocardiography showed a normal biventricular function without wall motion abnormalities.The baseline ECG showed a tachycardia around 120-140/bpm with broad QRS complexes and regular RR intervals with right bundle branch block morphology and right axis deviation (Fig. 1A).Adenosine was administered for differential diagnosis.After 18 mg of Adenosine, the tachycardia was not terminated,