Use of ECG-gated CT angiography for informed therapy decision making in dogs with pulmonic stenosis

Abstract

Background: Pulmonic Stenosis (PS) is one of the most common congenital cardiac diseases in dogs. It is most commonly treated with balloon valvuloplasty (BVP), but the choice of therapy depends on careful reviewing of the heart to identify and characterize the underlying defects of the heart and its major vessels. Aim: To determine whether ECG-gated computed tomography (CT) angiography is a reliable tool to aid in the informed decision making process to treat PS with BVP in dogs. Methods: CT angiography images of 31 dogs were reconstructed using retrospective ECG-gating and reviewed in the systolic and diastolic phase, to measure attenuation of the CT images, determine whether (aberrant) coronary arteries (CAs) were detectable and to measure the pulmonary valve annulus (PVa) and aortic valve annulus (AVa). Results: All measurements for PVa and AVa were obtained successfully. All CAs could be reviewed and categorized. Attenuation was sufficient in the majority of the cases. The measurements of the PVa and AVa were reliable with a mean coefficient of variation of 5.29%. CAs could be reviewed in all 31 dogs and aberrant CAs were identified in six dogs (19.4%). Four dogs (12.9%) had a single right coronary ostium and two (6.5%) had a single left coronary ostium. Four dogs with an aberrant CA were bulldogs, one was a Chihuahua and one was a German shorthair pointer. Discussion: CT angiography can be used to identify defects of the heart and its major vessels and can therefore contribute to the decision making process concerning therapy for PS in dogs. Previously undetected aberrant CAs posing a threat during BVP were reliably identified. Annulus measurements were precise, but in order to determine whether the annulus measurements of the CT images are accurate, CT angiography will be compared to fluoroscopy and TTE in a follow up study.