Value of the aVR lead in differential diagnosis of atrioventricular nodal reentrant tachycardia

Despite the several electrocardiographic (ECG) criteria, misclassification may still occur in differential diagnosis of the regular paroxysmal supraventricular tachycardia (PSVT). The aim of the present study was to evaluate the diagnostic accuracy of the aVR lead in ECG differentiation of atrioventricular nodal reentrant tachycardia (AVNRT) and atrioventricular reciprocating tachycardia (AVRT).

A 12-lead ECG was recorded in 150 consecutive patients (96 women, mean age, 45 ± 13.5 years) with drug-refractory regular PSVT during both sinus rhythm and tachycardia. All ECGs were reviewed by two experienced electrophysiologists who had no knowledge of the tachycardia mechanism. The ECG recordings were evaluated for standard criteria as well as our newly proposed criterion of pseudo-r′ in the lead aVR. Mechanism of arrhythmia was confirmed by the electrophysiological study and the successful catheter ablation. Patients with AVNRT were older (50 ± 10 vs. 37 ± 15 years, P = 0.001), predominantly female (71 vs. 53%, P = 0.03), and presented with slower tachycardia (175 ± 25 vs. 186 ± 26 b.p.m., P = 0.01). Among the ECG criteria of the AVRT diagnosis, visible P-wave with RP interval ≥100 ms had highest diagnostic accuracy (sensitivity 79%, specificity 87%, and positive predictive value 79%). For AVNRT diagnosis, pseudo-r′ in aVR had a higher sensitivity, specificity, and predictive values compared with the conventional criteria of the pseudo-r′ in V1 and pseudo-s in inferior leads (all P < 0.05).

New criterion of pseudo-r′ in lead aVR appears to be more accurate than the standard ECG criteria for ECG diagnosis of AVNRT.