Atrial substrate in patients with rapid focal discharges: Triggering versus only mimicking atrial fibrillation

Abstract

34and tolerability of a new simplified procedure of LEIC, performed with a right atrium-esophagus configuration.Methods: 25 consecutive uts (19 M and 6 I? with oersistent AF were submitted to LEIC using a &p-up protocol (by steps of 50 V, starting from 200 V). A large surface area lead (cathode) was positioned into the esophagus, 45 cm from the nasal orifice. A second large surface area lead (anode) was positioned in the right atrium (RA). In the first 15 pts it was introduced via the femoral vein under fluoroscopic control, while in the following 10 pts via the right internal jugular vein and positioned in the RA under echocardiographic control; the correct position of this lead was then confirmed by fluoroscopy. A quadripolar lead was positioned at the right ventricular apex to achieve shock synchronization on the QRS. Esophageal endoscopy was performed at the end of the procedure and atIer 48 h.Results: SR was restored in 23 pts (92%) with a mean delivered energy of 15.74 J (range 7-27) and a mean impedance of 48 f 3 ohm. The mean duration of the procedure was 40.7 f 6.2 mitt and the mean time of fluoroscopy was 4 f 2 min. In all patients in whom the right atria1 lead was positioned under echocardioghraphic control, fluoroscopy confirmed the correct position of the catheter in the tight atrium. Under sedation the procedure was tolerated by all patients. In 2 patients small burns of the oesophageal mucosa were detected by endoscopy after the procedure. Such lesions spontaneously healed a&r 48 hours.Conclusions: This new technique of performing LEIC is effective and safe and avoid the positioning of a lead in the CS or in the LPA, thereby simplifying the procedure. In the future, LEIC could be performed without fluoroscopy, avoiding the need of the ventricular lead by synchronizing the shock on the QRS of the ECG of an external defibrillator provided with biphasic waveform. Low energy intracardiac cardioversion (LEIC) is a safe and effective method to achieve sinus rhythm (SR). Nevertheless, LEIC, compared to external cardioversion, has the disadvantage that requires to be performed in the EP lab using fluoroscopy. Aim of the study was to assess the feasibility, efficacy, safety and tolerability of a new procedure of LEIC, performed with a right atrium-esophagus configuration without the use of lluoroscopy and outside the EP Lab.Methods: 20 consecutive patients (pts) with persistent AF were submitted to LEIC using a "single shock" protocol (20 joules shock, followed, if necessary, by a second 30 joules shock). Sedation with Diazepam was used. A large surface area lead (cathode) was positioned into the esophagus, 45 cm from the nasal orifice. A second defibrillating (anode) was introduced in the right internal jugular vein (RIJV) and then gently advanced toward the right atrium (RA). The correct position of this lead in the RA was confirmed by the recording of an auial endocardial signal > 5 mV. Synchronization of shock on the QRS was achieved connecting 2 cutaneous electrodes on the thoracic wall with a Telectr...