Atrioventricular Nodal Reentrant Tachycardia and Orthodromic Reentrant Tachycardia in Patients of Narrow Complex Tachycardia During Electrophysiological Study

Abstract

Tachyarrhythmiasare dangerous heart rhythms that can disturb the hemodynamics of the patient leading to cardiac arrest and death. Knowing the exact burden of AVRT and AVNRT in our population can help in early diagnosis and management with radiofrequency ablation.Aim of this study was to determine the frequency AVNRT and AVRT in relation with concealed and manifested types of accessory pathways, in patients with previous history of Narrow Complex Tachycardia (NCT).

Methods: In this retrospective study, 160 patients were enrolled from Punjab Institute of Cardiology, Lahore, Electrophysiology Department. All patients who had experienced two or more episodes of narrow complex tachycardia (NCT) were included. Main outcome variable was primary etiology of NCT as seen on EP study. Age, gender, co-morbid conditions like diabetes and hypertension were documented for each patient.

Results: Mean age of the patients was 38.25 SD 13.6 years, 60% were females and only 8 patients had diabetes (5%) all were above 50 years of age, 24 patients had hypertension (15%) with majority of case of age 31-50 years. On electrophysiological (EP) study, patients of NCT were later diagnosed to be AVNRT in 60% (n: 96) cases and ORT in 40% cases (n: 64), (24 of 64 cases of manifested type and 40 of 64 cases of concealed type). Among the factors like diabetes, hypertension, old age, old age with hypertension and old age with diabetes, old age alone was a significant risk factor, p=0.03.

Conclusion: Narrow complex tachycardia (NCT) patients should be follow-up for EP study to determine the cause and manage using catheter ablation. The percentages and statistics concluded in our study are more or less in coherence with international studies. We have not been able to identify any significant differences which could initiate the basis and lead us to another study.

Keywords: AVNRT, ORT, SVT, Re-entery tachycardia, Arrhythmia, Electrohysiology, EP