Electrophysiology transvenous internal cardioversion for atrial fibrillation: A randomized comparison between catheters with different Coll length

Objectives The aim of this study was to evaluate the effects of 2 different right atrial electrode Coll lengths on energy and voltage requirements for transvenous atrial cardioversion. Methods Twenty-six patients (mean age 61 ± 11 years) with chronic persistent atrial fibrillation (AF) (mean duration 11 ± 10 months) underwent transvenous cardioversion. A 6F catheter with a 5.5-cm Coll was positioned in the coronary sinus. Another catheter with either a 5.5-cm or an 8-cm Coll was positioned along the lateral wall of the right atrium, according to a randomized allocation. R wave-synchronized biphasic shocks were delivered according to a step-up proto- col. After cardioversion of baseline AF, AF was reinduced, the right atrial catheter was substituted, and cardioversion was repeated with the alternative right atrial Coll. Results Successful cardioversion was obtained in all of the patients. Leading edge voltage of effective shocks was significantly lower when catheters with an 8-cm Coll in right atrium were used compared with the alternative 5-cm Coll cathe- ters (301 ± 80 volts vs 340 ± 78 volts, P < .001), and delivered energy (6.75 ± 4.25 joules vs 7.86 ± 4.29 joules, P = .043) and shock impedance (60 ± 9 ohm vs 66 ± 10 ohm, P < .001) were lower. Moreover, shocbinduced discomfort, evaluated by assessment of pain score, was reduced (3.69 ± 1.09 vs 4.12 ± 0.99, P = .035). Conclusions The use of a longer right atrial Coll results in lower shock impedance, lower energy and voltage requirements, and lower discomfort during transvenous atrial cardioversion. The results of the current study are of value either for transvenous internal cardioversion of chronic persistent AF or for implantable atrial defibrillators.