title: Acquired tricuspid valve stenosis due to intentionally redundant transvenous lead placement for VDD pacing in two small dogs.
abstract: Placement of an endocardial VDD pacing lead in small dogs (<12 kg) may necessitate a redundant lead remaining looped in the right atrium for appropriate sensing and pacing. This report documented acquired tricuspid valve stenosis in two small dogs between 8 months and 4 years after VDD pacemaker placement for third-degree atrioventricular block. Echocardiography and Doppler echocardiography identified elevated transtricuspid flow velocities, prolonged pressure half-times, decreased valve leaflet excursions, and tricuspid regurgitation in both cases. Both cases were euthanized secondary to this pacing complication. Necropsy was performed in one case and confirmed adherence between the redundant lead loop, atrial and valve tissue. While VDD pacing in dogs has proven hemodynamic benefits, these benefits have not been demonstrated in terms of survival benefit or clinical signs. The requirement of redundant lead placement in small dogs for appropriate VDD lead function creates potential deleterious effects that should be weighed against the possible clinical value of VDD pacing in these patients.
authors.affiliation: W.R. Pritchard Veterinary Medical Teaching Hospital, University of California, Davis, One Shields Ave, Davis, CA 95616, USA.
authors.forename: Catherine T
authors.initials: CT
authors.lastname: Gunther-Harrington
authors.affiliation: W.R. Pritchard Veterinary Medical Teaching Hospital, University of California, Davis, One Shields Ave, Davis, CA 95616, USA.
authors.forename: Adam O
authors.initials: AO
authors.lastname: Michel
authors.affiliation: Department of Medicine & Epidemiology, School of Veterinary Medicine, University of California, Davis, One Shields Ave, Davis, CA 95616, USA. Electronic address: jstern@ucdavis.edu.
authors.forename: Joshua A
authors.initials: JA
authors.lastname: Stern
mesh_terms: D000818:Animals; D003937:Diagnosis, Differential; D004283:Dog Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000209:etiology; D004285:Dogs; D006327:Heart Block / Q000628:therapy / Q000662:veterinary; D008297:Male; D010138:Pacemaker, Artificial / Q000009:adverse effects*; D011859:Radiography; D014264:Tricuspid Valve Stenosis / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000209:etiology
keywords: Complete heart block; Complications; Pacemaker; Third-degree atrioventricular block