Pharmacological Agents for Induction of Supraventricular Tachycardia during Electrophysiology Study: A Retrospective Cohort Analysis

Abstract

Objectives: Most supraventricular tachycardia (SVT) can be induced using standard electrophysiological pacing maneuvers, pharmacological agents are often required when tachycardia is not inducible at baseline. This study aimed to evaluate the need for pharmacological agents and to determine their success rates in inducing SVT during EPS among patients in whom tachycardia could not be induced using standard electrophysiological maneuvers. Methodology: A retrospective cohort study was conducted at the National Institute of Cardiovascular Diseases, Karachi, including patients who underwent EPS for SVT induction between 1st January 2022 and 31st December 2023. Of 1,217 EPS procedures performed, 1,201 patients were included after excluding cases with incomplete data or repeat procedures. The primary outcomes were the proportion of patients requiring pharmacological induction and the success rate of SVT induction following drug administration. Results: The mean age of the cohort was 42.9 ± 17.1 years, with a female predominance (59.4%). SVT was successfully induced using electrophysiological maneuvers alone in 939 patients (78.2%). Pharmacological agents were required in 262 patients (21.8%), with an overall induction success rate of 38.2% in this subgroup. Atropine was administered in 245 cases and successfully induced SVT in 100 patients (40.8%). Metoprolol and epinephrine did not result in successful induction. Among pharmacologically induced SVTs, atrioventricular nodal reentrant tachycardia (AVNRT) was the most common subtype. Conclusion: Most SVTs can be induced using electrophysiological maneuvers alone. In cases refractory to pacing, atropine facilitated SVT induction in a limited proportion of patients, while other agents demonstrated minimal utility.