Abstract:

Objective   To propose a set of differential procedure of narrow QRS complex tachycardia, based on pseudo r′ wave in lead V1 and terminal notching of QRS complex in lead avL, to observe and evaluate the clinical significance.   Methods   We randomly selected 277 in-patients with proximal supraventricular tachycardia who received radiofrequency ablation; observed the electrocardiograms of both sinus rhythm and tachycardia induced during the surgeries in 165 patients, including 90 in the atrioventricular nodal reentrant tachycardia (AVNRT) group, and 75 in the orthodromic atrioventricular reciprocating tachycardia (AVRT) group; proposed a set of differential procedure according to the sensitivity, specificity, PPV and NPV of differential algorithms. We then carried out a blinded prospective research on the other 112 patients’ electrocardiograms, and evaluated the accuracy of the procedure. Results   The following algorithms were of significant differences between the two groups (P<0.005): pseudo r′ wave in lead V1, terminal notching of  QRS complex  in lead avL, RP interval longer than 70ms, ST segment elevation in lead avR and depression over 0.2mV in precordial leads. With the new differential procedure, we could correctly diagnose 91.38% of AVNRT and 88.89% of AVRT. Conclusion    The differential procedure based on pseudo r′ wave in lead V1 and terminal notching of QRS complex in lead avL can improve the accuracy of differential diagnosis between slow-fast AVNRT and overt AVRT.

Key words: Pseudo r′ wave in lead V1; Terminal notching of QRS complex in lead avL; Narrow QRS complex  tachycardia; Differential procedure