Polymorphic Ventricular Tachycardia and Long QT Syndromes

摘要: Based on the morphological features of QRS complex, ventricular tachycardia can be classified as monomorphic or polymorphic [1]. Polymorphic is defined a rapid irregular with alteration morphology almost from beat to at 150 300 beats per minute (Figure 16-1) [2]. Various terms have been used depict this form tachycardia. These include “par oxysmal fibrillation,” “transient recurrent “cardiac ballet,” and “atypical tachycardia” [3–8]. The torsade de pointes also that specifically occurs in association long QT syndromes [9–17]. During pointes, changes its direction simulating torsion around an imaginary isoelectric line. Classically onset preceded by “ short-long-short sequence” RR intervals (Figures 16-2 & 16-3), although variant initiated short interval [18].