Transcoronary pacing

Abstract

Transcoronary pacing is auseful therapeutic option for the treatment of unheralded bradycardias in the setting of percutaneous coronary interventions (PCI). In the present study, we investigated the influence of stent implantation and transient myocardial ischemia on the feasibility of transcoronary pacing in aporcine model. 7adult pigs underwent apercutaneous coronary intervention with implantation of acoronary stent under general anaesthesia in an animal catheterization laboratory. Transcoronary pacing was established by using astandard guidewire isolated with an angioplasty balloon positioned in the periphery of the right coronary artery serving as the cathode. As the indifferent anode, askin patch electrode at the back of the animal was used. The reliability of transcoronary pacing was assessed by measurement of threshold and impedance data and the magnitude of the epicardial electrogram at baseline, after implantation of acoronary stent and finally during myocardial ischemia. Effective transcoronary pacing could be demonstrated in all cases with the standard unipolar transcoronary pacing setup yielding alow pacing threshold at baseline of 1.3 ± 0.8 V with an impedance of 283 ± 67 Ω. Implantation of acoronary stent did not influence the pacing threshold (1.0 ± 0.4 V) and impedance (262 ± 63 Ω). Acute myocardial ischemia lead to asignificant but clinically nonrelevant increase of the pacing threshold to 2.0 ± 0.6 V and adrop in pacing impedance (137 ± 39 Ω). Transcoronary pacing in the animal model is not affected by implantation of acoronary stent in the same vessel used for pacing. Despite asignificant increase in pacing threshold, the transcoronary pacing approach is reliable in acute myocardial ischemia during apercutaneous coronary intervention.