Assessment of lead augmented vector left (aVL on surface electrocardiogram) for confirming atrioventricular nodal reentrant tachycardia

Background: Atrioventricular nodal reentrant tachycardia (AVNRT) stands as one of the most common forms of paroxysmal supraventricular tachycardia (PSVT), encompassing a wide spectrum of clinical presentations and diagnostic challenges. The aim of this study was to evaluate the assessment of lead aVL (surface ECG) for confirming AVNRT. Methods: This was a prospective observational study and was conducted at the Department of Cardiology and Electrophysiology, National Institute of Cardiovascular Diseases (NICVD), Dhaka, Bangladesh during the period from February 2019 to January 2020. Results: In our study 41 patients (66.1%) had AVNRT and 21 patients (33.9%) had AVRT on the final evaluation. Total 33.9% of patients had aVL notch on ECG. Among patients who had AVNRT, 46.3% had an aVL notch and among patients who had AVRT, 9.5% had an aVL notch on ECG. The difference was statistically significant (p=0.004). Among 21 patients who had aVL notch on ECG, 6 (31.6%) male patients had AVNRT, 13 (64.8%) female patients had AVNRT, 1 (50%) male patients had AVRT and 1 (50%) female patient had AVRT. Conclusions: In conclusion, the interpretation of electrocardiographic criteria, including the aVL notch, plays a pivotal role in confirming the diagnosis of AVNRT and guiding therapeutic interventions.