Differential Utility Of The Avl Lead In The Surface Electrocardiogram For Atroventricular Nodal Re-Entrant Tachycardia

【Objective】Explore the differential utility of aVL lead for atrioventricular nodal re-entrant tachycardia to provide guides for the clinical treatment and radiofrequency ablation.【Methods】One hundred and seventy-eight consecutive patients referred for paroxysmal supraventricular tachycardia(PSVT) were evaluated. The first part, One hundred and twelve patients electrocardiogram(ECG)were analysised, including sixty atrioventricular nodal re-entrant tachycardia(AVNRT) and fifty-two atrioventricular re-entrant tachycardia(AVRT) to observe the frequency and type of standard criireria(pseudo-s-wave in lead V1 or pseudo-s-wave in the inferior lesds) ST-segment elevation in aVR lead,QRS alternans and aVL lead notch. The second part, sixty-six patients ECG were analysised prospectively to check the sensitivity and specificity of the aVL lead notch and compare it with the standard criireria(pseudo-r-wave in lead V1 or pseudo-s-wave in the inferior lesds), evalued the utility of aVL notch in the diagnosis of AVNRT and AVRT.[Results]1.There are no statistical significance between AVNRT and AVRT in age (45.1±16.2 and 45.3±14.0, P=NS), but the female was found more frequently in AVNRT than in AVNT (55.0% and 32.7%, P=0.04).2.The aVL notch and the standard criteria (pseudo-r-wave in V1 and pseudo-s-wave in inferior) were found more frequently in AVNRT than in AVRT(aVL notch:53.3% and 17.3%, P=0.0008; pseudo-R-wave:46.7% and 15.4%, P=0.0022; pseudo-S-wave:41.7% and 5.8%, P=0.0001).3.The ST-segment elevation in lead aVR was more frequently in AVRT than in AVNRT (71.2% and 36.7%, P=0.0001),73.0% were left side pathway.4.The QRS alternans have no statistical significance between AVRT and AVNRT (17.3% and 11.7%, P=NS).5.The aVL notch and pseudo r and s wave sensitivity and specificity to determine AVNRT were 50.0% and 85.0%,47.2% and 84.6%,33.3% and 96.7%, respectively.6.The aVL notch sensitivity to determine AVNRT was higher than standard criteria, although there was no statistical significance.[Conclusion]1.The presence of a notch in aVL lesd is more frequent in AVNRT.2.The aVL notch appeared to be as sensitive and specific as the standard electrocardiographic criteria for the differential diagnosis of AVNRT.3.The aVL notch can be a new criteria in the differential diagnosis between AVNRT and AVRT.