Abstract: Background – The coronary arteries (CAs) arise near the pulmonary annulus (PVA). In humans, < 3mm distance from CA to right ventricular outflow tract (RVOT) predicts risk for CA compression during intervention for pulmonary valve stenosis (PS).
Objective – Characterize proximity and course of the major CAs relative to the RVOT in dogs with PS by cardiac computed tomography (CCT).
Animals – Retrospectively-gated CCT datasets from 64 PS dogs.
Methods – Retrospective study. Studied vessels included right (RCA), left main (LCA), paraconal (LPc), circumflex (LCx), and septal (LSep) CAs. Distance from proximal CAs to RVOT was assessed at end-systole and end-diastole at five levels: right ventricular infundibulum, 5mm below the PVA, PVA, mid-sinus, and sinotubular junction. Site of closest proximity (both CA branch and RVOT level) was noted for each dog.
Results – Seven dogs (10.9%) had a CA anomaly. Median nearest distance between any CA and RVOT was 0.8mm (range=0.5 to 1.3mm) at end-diastole. The CA closest to the RVOT was the RCA in 31.3% of dogs, followed by the LPc (28.1%), LCA (28.1%), LSep (6.3%), and LCx (4.7%). The RCA was most seen adjacent to right ventricular infundibulum/subvalve, LCA was most visualized near sinotubular junction, and LPc was most visualized at the subvalve and PVA.
Conclusions – Dogs with PS have CAs proximate to the RVOT and would be considered at high risk for CA compression based on human guidelines. Further work to identify risk for, and prevalence of, CA compression in dogs undergoing PS intervention is warranted.
