( A ) Sheath for delivery of a permanent neurostimulation lead. The small pictures are enlargements of the tip of the sheath with the incorporated electrodes (1: lateral view; 2: frontal view). The sheath has a lumen (3) which can be used for angiographic imaging of the coronary sinus and lead advancement. The incorporated electrodes allow probatory electrical stimulation to exclude ventricular capture and identify areas with negative dromotropy during high-frequency stimulation without repetitive screw-in attempts of the lead. The electrode design offers bipolar electrical stimulation with myocardial contact either in a lateral (4: electrode surface) or in a frontal (5: electrode surface) plane. 6: Wiring at the shaft of the sheath. ( B ) Left-lateral fluoroscopy of the canine heart during acute study. An additional atrial lead was implanted for induction and maintenance of AF and a ventricular lead for recording of ventricular rate. Via the guiding catheter, a coronary sinus angiography is performed to ease identification of the RIGP. Once an effective stimulation site has been identified by probatory stimulation via the bipolar electrodes at the tip of the sheath, the permanent electrode can be advanced through the sheath and immediately fixed at this site without exchange or movement of the sheath. A pigtail catheter is positioned in the left ventricle. ( C ) Screw-in electrode positioned in the RIGP for neurostimulation.