Combined alpha-adrenergic blockade and radiofrequency ablation to treat junctional ectopic tachycardia successfully without atrioventricular block

Efficacy of a pure Ikr blockade with nifekalant in refractory neonatal congenital junctional ectopic tachycardia and careful attention to damaging the atrioventricular conduction during the radiofrequency catheter ablation in infancy

“…There are several ways to resolve JET, such as applying energy at the HBE recording site where the tachycardia rate can be decreased by the mechanical manipulation of the ablation catheter 15 or by the application of energy at the earliest retrograde atrial activation site when ventriculoatrial conduction is present 16 . In the first case, the JET converted to sinus rhythm by delivering RF energy at the HBE recording site, and there was no effect when RF applications were delivered at the distal HBE recording and SPP sites.…”

Atrial Pacing During Radiofrequency Ablation of Junctional Ectopic Tachycardia

“…[5][6][7][8][9] Hamdan et al applied RF current at the site of the earliest retrograde atrial activation during sinus rhythm in 9 patients with JET, and successful ablation without AV block was achieved in 7 of them. 9 However, in patients with JET lacking retrograde atrial activation, 1,4,10 the optimal site for ablation is determined (1) empirically, 9 (2) by observing the termination of JET by mechanical manipulation of the ablation catheter, 6 or (3) by observing the rate acceleration during a low-dose RF energy application.…”

“…[5][6][7][8][9] Hamdan et al applied RF current at the site of the earliest retrograde atrial activation during sinus rhythm in 9 patients with JET, and successful ablation without AV block was achieved in 7 of them. 9 However, in patients with JET lacking retrograde atrial activation, 1,4,10 the optimal site for ablation is determined (1) empirically, 9 (2) by observing the termination of JET by mechanical manipulation of the ablation catheter, 6 or (3) by observing the rate acceleration during a low-dose RF energy application. 8 We decided on the para-Hissian region as the ablation site in the present patient for the following reasons: (1) there was no evidence of retrograde atrial activation during JET, (2) it was considered to be safer to apply RF current in a region where a relatively small atrial potential and a large ventricular potential (small A/V ratio) could be recorded, because the His bundle is protected by the central fibrous body, 11,12 and (3) it has been reported that the paraHissian accessory pathway can be ablated successfully by RF current with preservation of normal AV conduction.…”

“…3,4 However, these therapies may result in the need for permanent cardiac pacing. Recently, selective ablation of the JET focus while preserving normal AV conduction was reported, [5][6][7][8][9] suggesting that the junctional focus is usually perinodal and that ablative lesions created over the anterior, mid or posterior septum, avoiding the His bundle, may be effective. However, in the present patient we believed that the automatic focus of the JET existed at a site ajacent to the His bundle.…”

Electrical/Ablational Therapeutic Cardiac Catheterization

“…Although some patients have been observed to experience spontaneous resolution or amelioration, most probably will require aggressive medical management. Ablation using RF energy has been occasionally applied to this rhythm with good success, targeting the region of the His bundle electrogram [8,43,48]. The major concern, however, is the likely creation of complete AV block with ablation lesions that attack the junctional focus.…”