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Abstract

Objective: To evaluate specificity, sensitivity and diagnostic accuracy of r’ deflection at the end of the QRS complex in leads aVR and V1 of ECG for diagnosis of AVNRT
Study Design: Descriptive cross sectional study.
Place and Duration of Study: This study was conducted at AFIC/NIHD Rawalpindi from Nov 2014 to Jan 2015.
Material and Methods: Sixty two patients presenting to AFIC/NIHD for catheter ablation from November 2014 to January 2015 were enrolled in the study. The ECGs were evaluated for r’ deflection in leads V1, AVR and pseudo S wave in the inferior leads prior to performing an electrophysiology study. The diagnosis was confirmed by cardiac electrophysiology study.
Results: The AVNRT was correctly diagnosed in 88.5% of cases. For AVNRT diagnosis, r’ deflection in AVR (sensitivity 90.1%, specificity 100%), r’ deflection in V1 (sensitivity 90.1%, specificity 100%) and pseudo S wave (sensitivity 86.6%, specificity 100%) predicted AVNRT in 93%, 91% and 85% of cases, respectively. Therefore the presence of r’ deflection in V1 and aVR leads; and pseudo S wave in the inferior leads were found to be reliable predictors of AVNRT.
Conclusion: The standard ECG criterion of pseudo r’ deflection and pseudo S wave is an accurate method of diagnosing AVNRT.