“Ghost” Tachycardias: Electrophysiologic Study Diagnostic Approach

K. Gatzoulis, Iosif Koutagiar, D. Tsiachris, Petros Arsenos, Angeliki Rigatou, P. Dilaveris, A. Papadopoulos, A. Kritikos, S. Sideris, D. Tousoulis
First Cardiology Division and EP Lab, University of Athens, Hippokration Hospital, Greece

Aims: The etiology of palpitations cannot be established from patient‘s history, physical examination and 12-lead electrocardiogram in up to 16% of patients. The value of electrophysiologic study (EPS) in the identification of arrhythmic mechanism in patients with non-documented palpitations remains controversial. We evaluated the diagnostic yield of EPS in this population.
Methods: From January 2000 to December 2014, 76 patients (30 males, mean age 40.8 years old) with history of non-documented palpitations, normal resting ECG and 24h Holter recordings, underwent complete EPS. The clinical and electrophysiologic feautures were evaluated.
Results: The duration of palpitations was 1 hour) in 15.4%. Regarding the frequency of episodes, 13% of patients reported symptoms less often than once at six months, 22.2% had > 1 episodes at six months but less ofetn than 1 at month, 14.8% had >1 episode/month but less than 1/week and 50% had >1 episode/week. A total of 51 patients (67.1%) had inducible tachycardia. Tachycardias were induced with a typical study protocol in 53.9% of patients, after isoproterenol infusion in 9.2% and due to mechanical stimulation in 3.9%. The mean tachycardia’s cycle length was 320±64msec. Atrioventricular nodal reentrant tachycardia (AVNRT) was provoked in 32 patients (42.1%). Atrial tachycardia (AT) as the cause of palpitation was established in 9 patients (11.8%), atrial fibrillation (AF) in 2 patients (2.6%), atrioventricular reentry tachycardia (AVRT) in 2 patients (2,6%), ventricular tachycardia in 2 patients (2.6%) and sinus reentry tachycardia in other 2 patients (2.6%) and 2 patients with both AT and AVNRT. Among the 25 patients without inducible tachycardias, dual pathways at atrioventricular node ± echo beats were identified in 13 patients (17.1% of the total population). No complications related to the procedure were observed in our population study.
Conclusions: EPS constitutes a safe and feasible tool in the diagnostic approach of non-documented palpitations. Of utmost importance, 67% of patients with non-documented palpitations had some form of inducible tachycardias with AVNRT being the most frequent underlying arrhythmic mechanism.