RESUMEN
Objective Study the differential diagnosis value of the axis of "no man's land" in wide QRS complex tachycardia.Methods Retrospectively analyse the axis of "no man's land" in 137 patients with wide complex tachycardia who had undergone intracardiac electrophysiologic studies,use the algebraic sum of the deflections in leads I and III to plot the QRS axis,to observe the rule of arrhythmia of "no man's land" appearance.Results Eighteen of 137 patients who had wide complex tachycardia had the axis of "no man's land",among which 16 patients had left idiopathic ventricular tachycardia,and 2 patients had wide complex supraventricular tachycardia they had accessory pathway conduct anterogradely.Conclusion The axis of "no man's land" is helpful in differential diagnosis of ventricular and supraventricular tachycardias with abberency or bundle branch block.
RESUMEN
PURPOSE: In dealing with wide-complex tachycardia (WCT), it is important to distinguish between ventricular tachycardia (VT), supraventricular tachycardia with aberrancy (SVTAC), and preexcited tachycardia by using an accessory pathway. The aim of this study was to investigate and compare the Brugada and the Bayesian algorithms and to analyze the parameters. METHODS: Between January 1999 and December 2003, the Brugada and the Bayesian approaches were retrospectively analyzed in 103 WCTs confirmed by electrophysiologic studies. RESULTS: Seven-eight (75) VTs and 25 SVTs were found. The sensitivity and the specificity for VT achieved by using the Brugada approach were 91.0 and 68.0%, respectively, whereas those achieved by using the Bayesian approach were 84.6 and 60.0%. In the Brugada approach, the most important step was the fourth step (odds ratio: 4.33; 95% CI: 1.75-12.14). In the Bayesian approach, triphasic rsR' or rR' morphology (odds ratio: 3.93; 95% CI: 1.46-10.56), r > or = 0.04 s or notched S downstroke or delayed S nadir > 0.06 s in the V1 or the V2 lead (odds ratio: 5.75; 95% CI: 1.26?26.28), and intrinsicoid deflection > or = 0.08 s in the V6 lead (odds ratio: 6.88; 95% CI: 1.33-27.79) were more important parameters. Seven (7) VTs of 103 tachycardias were mis-classified when the Brugada approach was used. Applying additional criteria (QRS width > 0.16 s and intrinsicoid deflection > or = 0.08 s in V6 lead), three of those VTs were diagnosed correctly. CONCLUSIONS: The Brugada algorithm achieved a lower sensitivity and specificity than those reported by Brugada et al. If both the V1 and the V6 leads do not fulfill the criteria for VT, additional parameters should be evaluated.