Short-Coupled Variant of "Torsades de Pointes" and Polymorphic Ventricular Tachycardia

Intermediate-coupled premature ventricular complexes and ventricular tachycardia during exercise recovery

“…Short-coupled PVCs triggering polymorphic VT have been described as a rare cause of cardiac arrest in adult patients, 5 , 6 , 7 with early reports indicating a high mortality risk despite traditional medical treatment with beta blockers or calcium channel blockers. 8 Leenhardt and colleagues 5 were first to describe a series of patients with structurally normal hearts who developed potentially lethal polymorphic VT despite the presence of normal QT intervals. A minority (30%) of these cases also had a positive family history of SCD.…”

“…Verapamil is the only identified effective treatment for SCTdP and placement of an ICD is strongly recommended. 5 , 7 , 8 Catheter ablation of PVCs should also be strongly considered to reduce the incidence of polymorphic VT. 8 Notably, all 3 of our patients showed a positive response to treatment with verapamil and did not have recurring arrhythmia on repeat exercise stress testing.…”

Catecholaminergic Polymorphic Ventricular Tachycardia

“…However, the onset of the SC-TdP is not related to adrenergic stimuli and is not associated with the typical bidirectional pattern of CPVT tachycardia. 32 Another heritable cause of polymorphic VT is familial ST depression syndrome, although its presentation is not related to exercise and some patients will have left ventricular systolic dysfunction. [37][38][39]…”

“…Asymptomatic patients with positive pathogenic mutations for CPVT and negative exercise tests have lower arrhythmic event rates on long-term follow-up (4.4 per 1,000 person-years), nevertheless, they may be considered for prophylactic β-blocker therapy. 32,23 Although β-blockers are the mainstay treatment for CPVT, they are not fully effective in all patients. Van der Werf et al reported 37% of patients on β-blocker will continue to develop ventricular arrhythmias at 8 years follow-up.…”

Catheter ablation of short-coupled variant of torsade de pointes

“…The short-coupled variant of torsade de pointes (sc-TdP) was originally described by Leenhardt et al in 1994 who reported 14 patients with structurally normal hearts, absence of QT interval prolongation, and TdP induced by a premature ventricular contraction (PVC) with late transition left bundle branch block (LBBB) pattern, left superior axis, and a coupling interval of less than 300 ms consistent with a right ventricular (RV) moderator band (MB) origin [1][2][3]. However, based on the introduction of imaging techniques such as 3D-mapping [4] and intracardiac echocardiography (ICE) [5], sc-TdP and idiopathic ventricular fibrillation (iVF) from the MB have been characterized as different clinical entities which still translates into different therapeutic approaches [1][2][3]: Verapamil is still considered the first-line therapy in sc-TdP [6] whereas catheter ablation is the treatment of choice for iVF from the MB [2,3]. Over the past 25 years, numerous reports have highlighted the malignant phenotype of sc-TdP and the insufficient pharmacological treatment (failure of amiodarone, β-blocker, Mg 2+ , lidocaine, procainamide, quinidine, and cilostazol) while catheter ablation is not widely adopted [1,[7][8][9][10][11].…”