The variety of phenotypes behind 'double outlet right ventricle': clinical and imaging presentations in four dogs and a cat.

This report describes five cases of double outlet right ventricle (DORV) in four dogs (aged 3-18 months, two males and two females) and a domestic shorthair cat (aged 6 months, female) who presented with various clinical signs including tachypnea (n = 5), exercise intolerance (n = 5), mucous cyanosis (n = 3), delayed growth (n = 2), and/or lethargy (n = 2). The represented canine breeds were poodle, Yorkshire terrier, Samoyed, and Shetland sheepdog. For all animals, echocardiography revealed marked aortic dextroposition with both arterial trunks totally arising from the right ventricle, associated with a ventricular septal defect and various other congenital abnormalities, including subvalvular aortic stenosis (n = 2), minor aortic insufficiency (n = 5), subvalvular pulmonic stenosis with pulmonary trunk hypoplasia (n = 1), patent ductus arteriosus (n = 1), minor mitral and/or tricuspid dysplasia (n = 3). Subsequent cardiac remodeling was characterized by marked right ventricular hypertrophy for all patients, associated with right ventricular and right atrial dilation for most of them (4/5). Two dogs died soon after the initial DORV diagnosis (i.e. after 24 h and two months). A surgical correction attempted for another dog confirmed the presence of a DORV associated with patent ductus arteriosus, but the animal died during the procedure from sudden cardiac arrest. The fourth dog underwent a contrast-enhanced retrospective electrocardiogram-gated multidetector computed tomography angiography under general anesthesia, which confirmed the conotruncal malformation. Despite episodes of exercise intolerance, this dog is still alive, at the age of 53 months, as is the cat at the age of 21 months.

Successful transcatheter pulmonary valve implantation in a dog: first clinical report.

Transcatheter pulmonary valve (TPV) implantation is a therapeutic approach approved by the United States Food and Drug Administration for human patients with failing pulmonary conduits in 2010 and for failing bioprosthetic surgical pulmonary valves in 2017. We report here the first successful transcatheter implantation of a stented valve in a pulmonary position in a dog with congenital pulmonary valve disease. A 3-year-old, 10.9 kg, client-owned Beagle dog was referred for a follow-up visit after a percutaneous balloon valvuloplasty performed 22 months before for treatment of a severe type A valvular pulmonary stenosis. The Doppler-derived peak pressure gradient was 348 mmHg before the procedure and 66 mmHg 24 h after. The dog was lethargic. Echocardiography revealed a mild pulmonary stenosis (pressure gradient-43 mmHg), severe pulmonary regurgitation, and secondary severe right ventricular and right atrial dilation. Worsening of right heart dilation was observed 2 months later despite medical therapy. A TPV implantation was performed using a prestented Melody bovine jugular bioprosthetic valve. The dog recovered uneventfully and was discharged 10 days after the procedure. Right heart dilation resolved within 15 days. The dog was doing well 7 months after valve implantation. This case demonstrates that TPV implantation with a stented valve is technically feasible in dogs with severe pulmonary valve disease. Stringent postoperative care, with particular attention to thrombosis and infectious endocarditis, and appropriate sizing and positioning of the valve stent are keys to the success of this procedure.

Systemic arterial hypertension secondary to chronic kidney disease in two captive-born large felids.

Systemic arterial hypertension (SHT) has been widely described in the domestic cat (Felis catus). In these feline patients, SHT is considered as the most common vascular disorder of middle-aged to older animals, and secondary SHT related to chronic kidney disease (CKD) represents the most common form of the disease. We describe here the first two cases of spontaneous SHT in large felids, i.e. one 18-year old, 34.4 kg, male North-Chinese leopard (Panthera pardus japonensis, case #1) and one 20-year old, 28.7 kg, female snow leopard (Panthera uncia, case #2), both captive-bred and previously diagnosed with CKD. Both animals underwent complete echocardiographic examination under general anesthesia due to abnormal cardiac auscultation (heart murmur and/or gallop sound), and recurrent lethargy in case #1. The combination of left ventricular remodeling with moderate aortic regurgitation of high velocity was highly suggestive of SHT, which was confirmed by indirect blood pressure measurement (systolic arterial blood pressure of 183 mmHg for case #1 and 180 mmHg for case #2). Amlodipine was prescribed (0.35-0.70 mg/kg/day orally) for 31 and 6 months respectively after the initial diagnosis. In case #1, concurrent amlodipine and benazepril treatment was associated with decreased heart murmur grade and reduced aortic insufficiency severity. These reports illustrate that, similarly to domestic cats, SHT should be suspected in old large felids with CKD and that amlodipine is a well-tolerated antihypertensive drug in these species.

Antemortem diagnosis of a left auricular appendage herniation through a partial pericardial defect in a dog with degenerative mitral valve disease.

INTRODUCTION: A 14-year-old neutered male crossbreed dog was presented for weakness, cough and weight loss. Cardiac auscultation revealed tachycardia, arrhythmia and a grade V/VI left apical systolic heart murmur. Thoracic radiographs showed a large homogeneous soft tissue opacity in close contact with the cardiac silhouette in the left cranioventral mediastinum. Cardiac evaluation showed atrial fibrillation, degenerative mitral valve disease and a dilated left auricular appendage outside the pericardium consistent with herniation through a partial pericardial defect. Seven months after diagnosis, an atrial septal defect secondary to acquired atrial septal rupture was identified. The dog was euthanized thirteen months after initial presentation because of unresponsive clinical signs of congestive heart failure.

Systolic arterial blood pressure in small-breed dogs with degenerative mitral valve disease: a prospective study of 103 cases (2007-2012).

The objective of this prospective observational study was to assess systolic arterial blood pressure (SABP) in small-breed dogs with degenerative mitral valve disease (MVD) from different International Small Animal Cardiac Health Council (ISACHC) heart failure classes. For this purpose, 103 client-owned dogs weighing <20 kg (mean ± standard deviation, 8.5 ± 3.0 kg; aged 9.8 ± 2.9 years) and presenting with MVD diagnosed by echo-Doppler examination were enrolled. Nineteen healthy dogs (9.9 ± 2.3 years; 8.7 ± 4.2 kg) were concurrently recruited as controls. SABP was measured in unsedated dogs using the Doppler method according to the recommendations in the American College of Veterinary Medicine consensus statement. SABP was significantly increased in dogs in ISACHC class 1 (n=53; median, interquartile range 140 mmHg, 130-150 mmHg) and class 2 (n=21; 140 mmHg, 130-150 mmHg), compared to the control group (n=19; 130 mmHg, 120-140 mmHg; P<0.01 and P<0.05, respectively), but remained within the reference interval (≤ 160 mmHg). Conversely, dogs in ISACHC class 3 showed a significantly lower SABP (n=29, 120 mmHg, 110-130 mmHg) than those from all other ISACHC classes (P<0.001) and the controls (P<0.05). Additionally, SABP<120 mmHg was recorded in 13/103 dogs (13%). The 13 dogs were all ISACHC class 3 (3a or 3b) and were under medical treatment for heart failure. In conclusion, MVD was often associated with SABP values that were within the reference interval, but at its upper end. However, a significant decrease in SABP was observed in dogs with ISACHC heart failure class 3. Whether such low SABP values resulted from an MVD-related decrease in cardiac output, an afterload reduction owing to cardiac treatment, or both, remains to be determined.

Effects of dietary salt intake on renal function: a 2-year study in healthy aged cats.

BACKGROUND: Increasing salt intake to promote diuresis has been suggested in the management of feline lower urinary tract disease. However, high dietary salt intake might adversely affect blood pressure and renal function. OBJECTIVES: The objective of this study was to assess the long-term effects of increased salt intake on renal function in healthy aged cats. METHODS: This study was controlled, randomized, and blinded. Twenty healthy neutered cats (10.1 ± 2.4 years) were randomly allocated into 2 matched groups. One group was fed a high salt diet (3.1 g/Mcal sodium, 5.5 g/Mcal chloride) and the other a control diet of same composition except for salt content (1.0 g/Mcal sodium, 2.2 g/Mcal chloride). Clinical examination, glomerular filtration rate, blood pressure measurement, cardiac and kidney ultrasonography, and urinary and blood tests were performed before and over 24 months after diet implementation. Statistics were performed using a general linear model. RESULTS: Sixteen cats completed the 2 year study. The only variables affected by dietary salt intake were plasma aldosterone and urinary sodium/creatinine ratio, respectively, higher and lower in the control group all over the study period and urinary specific gravity, lower in the high salt diet group at 3 months. CONCLUSIONS AND CLINICAL IMPORTANCE: Glomerular filtration rate (GFR), blood pressure, and other routine clinical pathological variables in healthy aged cats were not affected by dietary salt content. The results of this 2 year study do not support the suggestion that chronic increases in dietary salt intake are harmful to renal function in older cats.

Comparative echocardiographic and clinical features of hypertrophic cardiomyopathy in 5 breeds of cats: a retrospective analysis of 344 cases (2001-2011).

BACKGROUND: Primary hypertrophic cardiomyopathy (HCM) is the most common feline heart disease and has been demonstrated to be inherited in some breeds. However, few studies have compared HCM phenotypes and survival according to breed. OBJECTIVES: To compare epidemiological characteristics, clinical findings, left ventricular (LV) geometric patterns, and survival in several breeds of cats with HCM. ANIMALS: Three hundred and forty-four cats from 5 different breeds (Persian, Domestic Shorthair [DS], Sphynx, Maine coon [MC], and Chartreux) with primary HCM diagnosed by conventional echocardiography. METHODS: Retrospective study. Cats were classified according to breed and clinical status. RESULTS: Age at the time of diagnosis was lower (P < .001) in MC (median age, 2.5 years) and Sphynx (3.5 years) than in other breeds (OB), ie, 8.0, 8.0, and 11.0 years for DS, Chartreux, and Persians, respectively. The prevalence of LV outflow tract obstruction was higher (P < .001) in Persians (23/41; 56%) than in OB (115/303; 38%). Age at the first cardiac event was lower (P < .01) in MC (median age, 2.5 years) than in OB (7.0 years). All cats surviving > 15 years of age were DS, Persians, or Chartreux. Sudden death (representing 24% of all cardiac deaths) was observed only in 3 breeds (DS, MC, and Sphynx). CONCLUSION AND CLINICAL IMPORTANCE: As in humans, feline HCM is characterized by marked phenotypic variability with several breed-dependent features regarding epidemiology, LV geometric patterns, and clinical course (ie, age at diagnosis, 1st cardiac event, and cause of death).

Renal resistive index in 55 dogs with degenerative mitral valve disease.

BACKGROUND: Azotemia occurs frequently in dogs with degenerative mitral valve disease (DMVD). It could indicate changes in renal hemodynamics. HYPOTHESIS/OBJECTIVES: To assess the renal resistive index (RI) in dogs with DMVD, and the statistical link between heart failure class, azotemia, echo-Doppler parameters, several plasma variables, and RI. ANIMALS: Fifty-five dogs with naturally occurring DVMD were used (ISACHC class 1 [n = 28], 2 [n = 19], and 3 [n = 8]). METHODS: Observational, blinded study, performed under standardized conditions. Physical examination, renal ultrasonography, and echo-Doppler examinations were performed in awake dogs. The RI of the renal, interlobar, and arcuate arteries were measured. Plasma creatinine, urea, and N-terminal pro-B-type natriuretic peptide concentrations (NT-proBNP) were determined. Statistical links between variables and RI were tested by means of a general linear model. RESULTS: Although the RI of renal and arcuate arteries were unaffected by ISACHC class, the left interlobar RI increased (P < .001) from 0.62 ± 0.05 (mean ± SD) in class 1 to 0.76 ± 0.08 in class 3. It was also higher (P < .001) in azotemic (0.74 ± 0.08) than in non-azotemic (0.62 ± 0.05) dogs. Similar findings were observed for right interlobar RI. Univariate analysis showed a positive statistical link between NT-proBNP (P = .002), urea (P < .001), creatinine (P = .002), urea-to-creatinine ratio (P < .001), left atrium-to-aorta ratio (P < .001), regurgitation fraction (P < .001), systolic pulmonary arterial pressure (P < .001), shortening fraction (P = .035), and RI. CONCLUSION AND CLINICAL IMPORTANCE: In dogs with DMVD, interlobar RI increases with heart failure severity and azotemia but a cause and effect relationship remains to be established.

Echocardiographic and tissue Doppler imaging alterations associated with spontaneous canine systemic hypertension.

BACKGROUND: Feline systemic arterial hypertension (SHT) is associated with a wide spectrum of left ventricular (LV) geometric patterns as well as diastolic, and to a lesser extent, systolic myocardial dysfunction. However, little is known about SHT-related cardiac changes in dogs. HYPOTHESIS: SHT in dogs is responsible for morphological and functional cardiac alterations. ANIMALS: Thirty dogs with spontaneous untreated SHT and 28 age- and body weight-matched healthy dogs as controls. METHODS: Prospective observational study. Conventional echocardiography and 2-dimensional color tissue Doppler imaging were performed in SHT dogs by trained observers and compared with controls. RESULTS: Forty-seven percent of SHT dogs (14/30) had diffuse concentric hypertrophy. None had left atrial dilatation and 10/30 (33%) had aortic insufficiency (AoI) associated with proximal aortic dilatation. Longitudinal diastolic left ventricular free wall (LVFW) motion was altered in all SHT dogs at the base (early to late diastolic wave ratio, E/A = 0.5 ± 0.1 versus 1.3 ± 0.3 for controls, P < .0001) and the apex (E/A = 1.6 ± 1.7 versus 3.9 ± 3.1, P < .05). Longitudinal motion of the interventricular septum at the base (E/A = 0.7 ± 0.4 versus 1.1 ± 0.1, P < .01) and radial LVFW motion in the subendocardium (E/A = 0.9 ± 0.5 versus 1.6 ± 0.3, P < .01) were also altered in dogs with SHT. Longitudinal LVFW systolic velocities and gradients were also significantly decreased (P < .05) in SHT dogs. CONCLUSION AND CLINICAL IMPORTANCE: As in SHT in cats, SHT in dogs is associated with myocardial dysfunction independently of the presence of myocardial hypertrophy. However, unlike feline SHT, it results in a homogeneous LV geometric pattern with a relatively high prevalence of AoI.