Spontaneous rupture of the right aortic sinus resulting in a sterile aorto-atrial fistula in a pet rabbit (Oryctolagus cuniculus).

Aortocardiac fistula is a broad term used to describe defects between the aorta and other cardiac chambers that can occur in humans and animals. A 1.5-year-old, 1.7 kg, male castrated Holland lop rabbit (Oryctolagus cuniculus) was presented for a two-week history of a heart murmur with corresponding cardiomegaly on radiographs. Physical examination confirmed a grade-V/VI continuous heart murmur on the right sternal border with a regular rhythm and a gallop sound. Echocardiography revealed an aortic-to-right-atrial fistula causing severe left-sided volume overload. Based on the echocardiographic findings, rupture of the right aortic sinus was suspected. Due to the poor prognosis, euthanasia was elected. On necropsy, a fistula was found connecting the right aortic sinus with the right atrium, without evidence of an inflammatory response nor evidence of an infectious etiology. The sudden onset of a heart murmur supported acquired fistulation from a ruptured aortic sinus (also known as the sinus of Valsalva), though a congenital malformation could not be completely excluded.

Transcatheter closure of aneurysmal perimembranous ventricular septal defect with the canine duct occluder in two dogs.

Congenital membranous ventricular septal aneurysm has been reported in dogs and can be associated with a perimembranous ventricular septal defect (VSD). The windsock-like ventricular septal aneurysm is formed by tissue of the membranous ventricular septum and portions of the septal leaflet of the tricuspid valve. We report two dogs that underwent transcatheter closure of perimembranous VSD associated with membranous ventricular septal aneurysm using a commercial device marketed for transcatheter closure of patent ductus arteriosus, the canine duct occluder. Partial closure was achieved in the first dog with reduction in left heart dimensions documented on echocardiography both at one day and nine months after procedure. In the second dog, three-dimensional transesophageal echocardiography, cardiac computed tomography, and a three-dimensionally printed whole heart model were used to evaluate feasibility for transcatheter device closure. Complete closure of the VSD was subsequently achieved. Both cases had good short- to medium-term outcomes, no perioperative complications were observed, and both dogs are apparently healthy and receiving no cardiac medications at 34 months and 17 months after procedure. Transcatheter attenuation of perimembranous VSD with membranous ventricular septal aneurysm is clinically feasible using the canine duct occluder, and multimodal cardiac imaging allows accurate assessment and planning prior to transcatheter intervention for structural heart disease in dogs.

A multicenter prospective evaluation of owner medication adherence for feline cardiovascular disease in the referral setting.

OBJECTIVE: The aim of this paper is to evaluate owners' chronic medication adherence for management of feline cardiovascular disease in the small animal referral setting. ANIMALS, MATERIALS AND METHODS: A questionnaire-based study of owners at five multispecialty, small animal referral centers was conducted. Owners completed a written survey evaluating demographics, degree of medication adherence, and difficulties encountered for medication adherence. Owners were free to decline participation in the study. RESULTS: Fifty-four questionnaires were available for review. The most common diagnosis was hypertrophic cardiomyopathy (n = 31, 57.4%). Clopidogrel was the most cited medication that was difficult to administer consistently (n = 13, 24.0%) although twenty owners (37.0%) reported no difficulty consistently administering medications. "Taste of medication" (n = 14, 25.9%) was the most reported reason for difficulty medicating their cat, and most owners (n = 36, 66.7%) stated twice daily was the highest frequency of heart medications they feel they can consistently administer. Fifty owners (92.6%) met the criteria for medication adherence. CONCLUSIONS: Chronic medication adherence in this study population was high. Clopidogrel was the most difficult medication to consistently administer, and twice a day dosing was the highest frequency of medication administration most owners could achieve. Cardiologists should be aware of these factors when determining optimal treatment protocols for the management of cardiovascular disease in cats.

Echocardiographic Assessment of Right Ventricular Size and Function in Cats With Hypertrophic Cardiomyopathy.

BACKGROUND: Studies evaluating right ventricular (RV) structural and functional abnormalities in feline hypertrophic cardiomyopathy (HCM) are limited. HYPOTHESIS: Right ventricular structural and functional abnormalities are present in cats with HCM and are associated with clinical severity. ANIMALS: Eighty-one client-owned cats. METHODS: Retrospective 2-dimensional (2D) echocardiographic study. Right atrial diameter (RAD), RV free wall thickness (RVFWd), RV internal dimension (RVIDd), RV fractional area change (FAC), and tricuspid annular plane systolic excursion (TAPSE) were measured in control cats (n = 26), cats with subclinical HCM (subclinical HCM; n = 31), and cats with HCM and congestive heart failure (HCM + CHF; n = 24). RESULTS: Right heart size (RAD, RVFWd, and RVIDd) and RV function (FAC and TAPSE) significantly (all P < .05) increased and decreased, respectively, in the HCM + CHF group compared with controls. In the subclinical HCM group, only RVFWd was significantly (P < .05) higher than in controls. Compared with reference intervals derived from controls, 29% of cats with HCM had increased RVFWd. Increased left ventricular free wall thickness, increased RVIDd and decreased TAPSE independently correlated with increased left atrial size. Cats with HCM and pleural effusion were significantly more likely to have increased RVFWd and had increased RAD and decreased TAPSE compared with cats without pleural effusion. CONCLUSIONS AND CLINICAL IMPORTANCE: Right ventricular remodeling and dysfunction occur in some cats with HCM and may be associated with clinical severity. Our results support involvement of RV in the pathophysiology of HCM in some cats and support echocardiographic assessment of the RV in cats with HCM.