Clinical and electrophysiological characteristics, of concealed and manifest accessory pathway and intermediate term follow up after radiofrequency ablation

ABSTRACT

It is current opinion that concealed and manifest accessory pathways are indistinguishable with respect to their location, and contribution to orthodromic reciprocating tachycardia This study aimed at comparing the clinical and Electrophysiological characteristics of concealed and manifest accessory pathways, assessment of immediate results and complications of radiofrequency ablation and detection of the recurrence rates of accessory pathways after radiofrequency ablation. This study was carried out in National Heart Institute and Zagazig University Hospital and included 37 patients that were referred because of symptomatic supraventricular tachycardia [SVT] refractory to medical treatment. They were divided into two groups Group 1; twenty two patients with manifest accessory pathway on resting ECG and Group II; fifteen patients were proven retrogradly in the electrophysiological study [BPS] to have concealed pathway after exclusion of patients with AVNRT. Patients with more than one accessory pathway, Accessory pathway and associated SVT due to other mechanisms were excluded from the sturdy. All patients in both groups were subjected to Full history taking, Complete general and local examination of the heart, twelve lead surface ECG, Echo-Doppler Study and electrophysiological study to diagnose the mechanism of tachycardia and to localize the accessory pathway and radiofrequency ablation of accessory pathway. Then follow up was done to the patients for the next 6 months on regular basis in the outpatient clinic for recurrence of symptoms, resting ECG for resumed manifest pre-excitation, documented attacks of tachycardia, need for antiarrhythmic and need for redo. Symptoms pattern did not differ significantly between the two studied groups, with palpitation occurred in 100% in both groups, dizziness 40.4% in group I and 46.6% in group 11, syncope 18.18% in group I and 6.66% in group 11, dyspnea 27.27% in group I and 26.66% in group II, and sweating 18.18% in group land 13.33% in group II. Palpitation was the most common presenting symptom in both groups. Accessory pathway mediated tachycardia caused significantly higher rate of hospitalization in group II, There was no associated cardiac disease in any of our patients. We did not find any patient with accessory pathway and congenital heart disease. AVRT was correctly diagnosed in 8 patients [53%] in group II. The success of radiofrequency ablation of accessory pathways depends on accurate localization of accessory pathway. In our study 91% of group II patients had orthodromic tachycardia and 9% had antidromic tachycardia and 100% of group II patients had orthodromic tachycardia. Radiofrequency ablation was attempted in 21 patients in group I. In group II RF ablation was attempted in all patients. The acute success was comparable in both groups with no significant difference. In group I the acute success was 90% while in group II it was 85.5%. Complications in our study were met with in group I with one patient developed VF during catheter ablation, one patient developed RBBB, one patient had complete heart block necessitated insertion of permanent pacemaker, and one patient had deep vein thrombosis, and in group II one patient developed complete heart block, and one patient had deep vein thrombosis. The recurrence rate was 9% in group I while it was 6.6% in group H with non significant difference in both groups. Patients with concealed accessory pathway are older, has longer history of arrhythmia, and more frequent hospitalization than patients with manifest AR. Radiofrequency ablation is safe and effective therapy for AP mediated tachycardia with comparable success, complications, and recurrence in manifest and concealed AP