Validation of qrs-polarity algorithm with special emphasis in parahisian pathways.

Background: In 1996 Iturralde et al. published an algorithm based on the QRS polarity to determine the location of the accessory pathways (AP), this algorithm was developed before the massive practice of invasive electrophysiology.

Purpose: To validate the QRS-Polarity algorithm in a modern cohort of subjects submitted to radiofrequency catheter ablation (RFCA).

BASIC AND CLINICAL INSIGHTS IN CATECHOLAMINERGIC (FAMILIAL) POLYMORPHIC VENTRICULAR TACHYCARDIA.

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a potentially lethal disease, whose characteristic ventricular tachycardias are adrenergic-dependent. Although rare, CPVT should be considered in the differential diagnosis of young individuals with exercise-induced syncope. Mutations in five different genes (RYR2, CASQ2, CALM1, TRDN, and TECRL) are associated with the CPVT phenotype, although RYR2 missense mutations are implicated in up to 60 % of all CPVT cases.