Coexistence of the Permanent Form of Junctional Reciprocating Tachycardia and Atrial Tachycardia

Abstract

he permanent form of junctional reciprocating tachycardia (PJRT) is a rare supraventricular tachycardia in which retrograde ventriculoatrial (VA) conduction occurs with a decremental property. 1,2 PJRT is frequently incessant and occasionally tachycardia-induced cardiomyopathy develops. The electrocardiographic feature of PJRT is a narrow QRS tachycardia with a long RP' interval. However, atypical forms of atrioventricular (AV) node reentry tachycardia (AVNRT) and atrial tachycardia (AT) show similar electrocardiographic findings. Therefore, a detailed electrophysiological study (EPS) must be done to establish the diagnosis. We describe a patient with coexisting PJRT and AT. Case ReportA 31-year-old woman was referred to hospital for recurrent episodes of palpitation, the first attack of which had occurred 1 year ago and since then, the frequency had increased 2 or 3 times a day. She was treated with verapamil, but it did not completely suppress the attacks. A 12-lead electrocardiogram during sinus rhythm did not show a delta wave, but a narrow QRS tachycardia characterized by a negative P wave in leads II, III, and aVF with a long RP' interval was documented during a palpitation attack. An extensive work up, including echocardiographic study, did not reveal any structural heart disease.She underwent an EPS after giving written informed consent. Two standard quadripolar electrode catheters were positioned at the high lateral right atrium (HRA) and right ventricular apex (RVA). An octapolar electrode catheter was positioned at the His bundle and a 2.5Fr 16-electrode catheter was positioned in the coronary sinus. At baseline, extrastimulation from the RVA induced slow VA conduction with a decremental property, and the narrow QRS Circulation Journal Vol.69, August 2005 tachycardia was not induced by any pacing protocols. However, after isoproterenol infusion, a clinically documented narrow QRS tachycardia (Tachycardia 1) was induced by a single extrastimulus from the RVA (Fig 1A). Intracardiac tracing during Tachycardia 1 revealed that the earliest atrial activation was recorded near the coronary sinus ostium and the RVA -HRA interval was 200 ms. A single ventricular extrastimulus, which was introduced from the RVA when the His bundle was refractory, delayed the subsequent atrial activation ("postexcitation" phenomenon) (Fig 2). A retrograde VA conduction time (St (RV)-A2) curve was obtained after a single ventricular extrastimulus during Tachycardia 1 (Fig 3). Shortening of the coupling intervals of the extrastimulus (RV-St (RV)) resulted in increases in St (RV)-A2, indicating that the retrograde VA conduction during Tachycardia 1 had a decremental property. Based on these observations, Tachycardia 1 was diagnosed as PJRT and radiofrequency catheter ablation (RFCA) performed at the earliest atrial activation site near the coronary sinus ostium was able to terminate it. However, the other narrow QRS tachycardia with a long RP' interval (Tachycardia 2; Fig 1B) was induced by a single extrastimulus from RVA with i...