Simultaneous surgical repair of a cardiac myxoma causing left ventricular outflow tract obstruction and a ventricular septal defect in a small dog.

Background: Cardiac myxomas are benign tumours that can occur in any heart chamber or valve. They are extremely rare in dogs. We present a novel case involving a cardiac myxoma in the left ventricular outflow tract (LVOT) and a ventricular septal defect (VSD) in a small dog. Case Description: A female miniature dachshund (age, 7 months; weight, 2.88 kg) presented with growth insufficiency, lethargy, and a cardiac murmur. Echocardiography revealed a small polypoid mass in the LVOT and a membranous VSD. Simultaneous surgeries were performed to resect the mass (aortotomy) and close the VSD (right atriotomy) using low-flow cardiopulmonary bypass with surface-cooling hypothermia and retrograde cardioplegia. The tumour was histopathologically identified as a myxoma. The dog survived with no cardiac complications for 11 years after surgery. Conclusion: To our knowledge, this is the first report of ante-mortem diagnosis and simultaneous surgical repair of a cardiac myxoma obstructing the LVOT and a VSD in a small-breed dog. In addition to describing this complicated case, this report presents what we believe is the first reported use of retrograde cardioplegia during open-heart surgery in a small-breed dog.

Successful interventional occlusion of muscular ventricular septal defect in a dog.

Ventricular septal defect (VSD) is a rare congenital heart disease in dogs. Hemodynamically important interventricular defects must be closed to improve the prognosis. This case report describes successful interventional transcatheter closure of a muscular VSD in a young Maltese and poodle mixed-breed dog with a large muscular interventricular defect (~5 mm in diameter) with a high rate of left-to-right shunt flow. The VSD was closed with a customized Amplatzer-type VSD occluder via a percutaneous transvenous (jugular) approach. We concluded that interventional occlusion of a muscular VSD with an Amplatzer-type occluder is a viable treatment option for dogs. A regular follow-up study for this dog is ongoing and has not detected complications. Key clinical message: Interventional occlusion of a muscular VSD with an Amplatzer-type occluder is a viable treatment option for dogs.

Occlusion interventionnelle réussie d'une communication interventriculaire musculaire chez un chien. La communication interventriculaire (VSD) est une maladie cardiaque congénitale rare chez le chien. Les anomalies interventriculaires hémodynamiquement importantes doivent être fermées pour améliorer le pronostic. Ce rapport de cas décrit la fermeture interventionnelle réussie par cathéter d'un VSD musculaire chez un jeune chien de race mixte (maltais et caniche) présentant un défaut interventriculaire musculaire important (~5 mm de diamètre) avec un débit de shunt élevé de gauche à droite. Le VSD a été fermé avec un obturateur VSD personnalisé de type Amplatzer via une approche trans-veineuse percutanée (jugulaire). Nous avons conclu que l'occlusion interventionnelle d'un VSD musculaire avec un obturateur de type Amplatzer est une option de traitement viable pour les chiens. Une étude de suivi régulière de ce chien est en cours et aucune complication n'a été détectée.Message clinique clé :L'occlusion interventionnelle d'un VSD musculaire avec un obturateur de type Amplatzer est une option de traitement viable pour les chiens.(Traduit par Dr Serge Messier).

Tricuspid atresia with atrial and ventricular septal defects in a kitten.

A 45-days-old mixed-breed female cat was referred to a veterinary specialty hospital for evaluation due to poor general condition, dyspnea of possible cardiac origin, and a heart murmur. The results of the physical examination, thoracic radiography, and echocardiography led to a diagnosis of hypotrophy of the right ventricle, tricuspid atresia, and atrial septal defect. Cardiovascular pathological findings confirmed the clinical diagnosis in addition to the observation of a ventricular septal defect. To the authors' knowledge, this is the first report of tricuspid atresia with atrial septal defect and ventricular septal defect in a cat.

Transjugular occlusion of large patent ductus arteriosus with an Amplatzer™ muscular ventricular septal defect occluder in a 3-month-old dog.

Background: Cardiologists close most patent ductus arteriosus (PDA) defects in dogs using the Amplatz® canine duct occluder via a transarterial approach. However, this approach can be problematic in small dogs due to the small femoral artery diameter. In such cases, cardiologists have opted to use coils or vascular plugs deployed from a transvenous approach. However, in small dogs with large PDA, the risk of device protrusion into the pulmonary artery, incomplete closure, or device embolization, often leads to surgical PDA closure via thoracotomy. Case Description: The present report describes a 3-month-old male 6 kg Border collie with a large, PDA which was successfully occluded using the Amplatzer™ muscular ventricular septal defect (mVSD) device from a transvenous approach after closure attempts with an Amplatzer™ vascular plug II failed. Conclusion: This is the first case report in veterinary medicine of PDA closure with an Amplatzer™ mVSD occluder device. This approach, described in PDA closure in people, could be considered in minimally invasive PDA closure in small dogs with challenging anatomy.

Cor triatriatum sinister with dextrocardia in association with ostium secundum atrial septal defect, subpulmonary ventricular septal defect and bicuspid pulmonary valve in a pig.

Necropsy of a 52-day-old Camborough pig revealed numerous cardiac malformations. The positional relationship of the atria, ventricles and great vessels was a mirror image type (I, L and L): inverted arrangement of the atria, with a left-sided right atrium and right-sided left atrium (situs inversus); inverted arrangement of the ventricles, with a left-sided morphological right ventricle and right-sided morphological left ventricle (L-loop); and aortic valve to the front left relative to the pulmonary valve (L-malposed). The major malformations included an ostium secundum atrial septal defect, cor triatriatum sinister (CTS), a subpulmonary ventricular septal defect and a bicuspid pulmonary valve. Histological examination revealed myocyte hypertrophy, focal myocardial necrosis and calcification in the left morphological right ventricle of the heart. To the best of our knowledge, this is the first report of CTS in pigs. Although the individual malformations found in the present case are not unique, an unusual combination of these cardiac malformations has not been described in animals.

Un cas de situs inversus complet associé à une communication interventriculaire et des anomalies oculaires chez une chienne croisée de 3 ans.

A case of complete situs inversus associated with an interventricular communication and ocular abnormalities in a 3-year-old mixed-breed female dog. A 3-year-old female dog was referred for exploration of a murmur concomitant with lethargy. An echocardiogram reveals an inversion of the position of the cardiac chambers and the presence of an interventricular communication. A computed tomography examination of the thorax and abdomen highlights the known cardiac abnormalities as well as the association of a complete situs inversus. The clinical examination also reveals ocular malformations (deviation of the eyeballs and asymmetry of the fundus). This article highlights the variety of abnormalities that can be associated with the complete inversion of the organs and demonstrates that there may be variants to the more classic picture usually encountered in humans (respiratory manifestations related to Kartagener syndrome).(Translated by Dr Serge Messier).

Surgical correction of an infundibular pulmonic stenosis and ventricular septal defect in a Shetland Sheepdog.

A four-month-old male Shetland Sheepdog presented with exercise intolerance. Physical examination revealed an IV/VI left cranial systolic heart murmur. Echocardiography showed a severe infundibular pulmonic stenosis and a concomitant restrictive ventricular septal defect. As clinical signs of congestive right-sided heart failure worsened and were refractory to medical treatment, surgical correction was advised. Via sternotomy, with cardiopulmonary bypass and cardioplegic cardiac arrest, ventricular septal defect closure and resection of the stenotic infundibular band were performed through right ventriculotomy, followed by patch enlargement. Postoperative recovery was uneventful and echocardiography showed complete resolution of the stenosis and successful closure of the ventricular septal defect. Follow-up echocardiography revealed restenosis after seven weeks and recurrence of right-sided heart failure three months postoperatively. Stenting of the restenosis was attempted via a hybrid procedure with sternotomy and direct transventricular approach. The dog developed fatal ventricular fibrillation during stent deployment. This is the first dog in which surgical right ventricular patch enlargement under cardiopulmonary bypass is reported for the treatment of a primary infundibular pulmonic stenosis.

Acquired infundibular pulmonary stenosis associated with a congenital membranous ventricular septal defect (Gasul phenomenon) in a dog and discussion regarding causes of infundibular stenosis.

An aclinical Havanese dog was diagnosed with a membranous restrictive ventricular septal defect. The patient was represented later in their natural history due to the development of syncope. At that time the patient was diagnosed with acquired pulmonary infundibular stenosis. Balloon dilation of the stenosis was performed successfully twice over the patient's lifetime. The patient died suddenly approximately 14 months after the second balloon dilation. A discussion regarding primary infundibular pulmonary stenosis versus causes of acquired infundibular pulmonary stenosis including anomalous muscle bundles (double chamber right ventricle), tetralogy of Fallot, and infundibular stenosis is presented.

Echocardiographic changes in the progress of reverse shunt and improvement to left-to-right shunt after medical treatment in dogs with bidirectional patent ductus arteriosus or ventricular septal defect: A report of two cases.

Two Maltese dogs were referred for evaluation of a congenital heart disease: one was diagnosed with patent ductus arteriosus and the other was diagnosed with a ventricular septal defect. The PDA patient was diagnosed with congenital heart disease 2 weeks ago and the VSD patient about 11 months ago at another hospital. Echocardiographic findings revealed a bidirectional shunt condition, and the dogs were treated with medical management using sildenafil and oxygen inhalation. After medical management, the dogs returned to clinically normal conditions, and echocardiographic findings revealed a return to left-to-right shunt tendency. These dogs had no clinical signs associated with heart disease 3 years after treatment. This case report describes changes in echocardiography findings according to the progression of the reverse shunt and the possibility of improvement to a left-to-right shunt after medical treatment.

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.

Spontaneous closure of an isolated congenital perimembranous ventricular septal defect in two dogs.

BACKGROUND: Though spontaneous closure of isolated congenital ventricular septal defects in humans is very common, it has been rarely reported in dogs. CASE PRESENTATION: A 4 month old Havanese dog and a 4.5 month old Chihuahua x Jack Russell terrier cross were presented for murmur evaluation to the authors' institution. Both puppies were clinically healthy and had a loud systolic murmur on the right hemithorax. Echocardiography in both dogs revealed a small, isolated, restrictive perimembranous congenital ventricular septal defect. No echocardiographic signs of left ventricular volume overload or pulmonary hypertension were present. Re-check auscultation in both dogs revealed the absence of a murmur, and echocardiography showed no flow through the interventricular septum. In the 9 kg Havanese dog and the 4 kg mixed breed dog, spontaneous closure occurred at 13-17 months and 12-30 months, respectively. CONCLUSIONS: In both dogs the spontaneous closure of a congenital perimembranous ventricular septal defect took place in a young adult age. The mechanism of closure remains unclear.

Spontaneous closure of a traumatic acquired Gerbode defect in a dog.

A one-year-old female English Springer Spaniel with no previous history of cardiac disease presented to the Queen's Veterinary School Hospital following a blunt traumatic incident with an acquired, direct Gerbode defect and associated third-degree atrioventricular block. Two months after the initial incident, follow-up echocardiography showed a nearly closed Gerbode defect with just trivial residual flow. A 24-h Holter monitor indicated second-degree atrioventricular block with occasional junctional tachycardia. A reassessment 22 months later confirmed spontaneous closure of the previously acquired traumatic Gerbode defect, with 2:1 second-degree atrioventricular block. The dog remained clinically asymptomatic, and free of treatment. To our knowledge, this is the first reported case of spontaneous closure of a previously acquired traumatic Gerbode defect in a dog.

Presumed congenital Gerbode defect in an American Domestic Shorthair cat.

A five-month-old, intact female Domestic Shorthair cat presented to the Kansas State Veterinary Health Center for evaluation of a murmur and exercise intolerance. Physical exam revealed a grade V/VI right, parasternal, holosystolic murmur. On echocardiogram, there was an abnormality in the membranous interventricular septum and tricuspid valve, allowing blood to shunt from the left ventricle to the right atrium. This lesion is consistent with an infravalvular Gerbode defect. The Gerbode defect is a rare, left ventricle-to-right atrial shunt that can be congenital or acquired, and in cats, has only been reported once. At the time of submission, the patient is alive and is maintaining a good quality of life.

Trifoliate left atrioventricular valve with and without intact septal structures in four dogs: echocardiographic findings and surgical repair.

Trifoliate left atrioventricular (AV) valve with common atrioventricular junction is considered part of the spectrum of atrioventricular septal defect. This valve morphology is typically associated with defects in the AV septum resulting in communication at the atrial or ventricular level, but has also been described as an isolated defect in the setting of a common AV junction without AV septal defect. Trifoliate left AV valve exhibits a line of apposition between the bridging leaflets that is directed toward the inlet interventricular septum, distinguishing it from isolated mitral valve cleft in which the orientation of the bridging leaflets are toward the left ventricular outflow tract. The echocardiographic findings of four dogs with trifoliate left AV valve are described; two with intact septal structures and two with large ostium primum defects. Three dogs underwent open surgical repair using different approaches depending on the presence or absence of a septal defect. One of these underwent concurrent surgical repair for right AV valve dysplasia. One dog with intact septal structures underwent interventional closure of a concurrent patent ductus arteriosus. Current terminology associated with trileaflet left AV valve malformations is reviewed.

Prevalence and characteristics of ventricular septal defects in a non-racehorse equine population (2008-2019).

BACKGROUND: Ventricular septal defects (VSDs) are the most common congenital cardiac defect in horses. OBJECTIVES: To identify prevalence, age, breed, and sex distribution of VSD and to describe associated clinical and ultrasonographic findings. ANIMALS: Hospital-based population of 21 136 horses presented to the equine internal medicine department. METHODS: Medical records over a 12-year period were reviewed for VSD confirmed by ultrasonography. Age, breed, sex, sport discipline, murmur, clinical signs, outcome, VSD type, VSD size, shunt velocity, cardiac dimensions, concomitant cardiac anomalies, and valvular regurgitations were recorded. RESULTS: From 1894 horses that underwent echocardiography, 54 had a VSD: 42 as an isolated lesion and 12 as part of complex congenital heart disease (CHD). Median age was 5 years (range, 0-26) and 1 year (range, 0-8), respectively. Warmbloods and males were overrepresented. In the isolated VSD group, only 15% had associated clinical signs and most horses had a perimembranous VSD (pmVSD; 36/42). Horses with a pmVSD and clinical signs showed a significantly lower maximal shunt velocity (3.77 vs 5.20 m/s; P < .001), higher VSD/Aortic root (Ao) diameter (0.52 vs 0.38; P = .05), higher left atrium/Ao diameter (1.94 vs 1.22; P < .001), and higher pulmonary artery/Ao diameter (1.15 vs 0.88; P = .005) compared to horses without clinical signs. All horses with complex CHD had clinical signs and abnormal cardiac dimensions. CONCLUSION AND CLINICAL IMPORTANCE: Most isolated VSD were diagnosed only at a later age and were not associated with clinical signs. Horses with complex CHD were more likely to have or develop clinical signs at younger age.

Persistent truncus arteriosus with an anomalous coronary artery in a cat.

A 6-month-old, female, domestic shorthair cat weighing 1.8 kg presented with cardiomegaly seen on radiographs taken at a primary care veterinary center. Echocardiography revealed a single enlarged vessel overriding a ventricular septal defect and severe hypertrophy of the right ventricular free wall. There was no evidence of a pulmonary arterial trunk originating from the heart. The blood flow through the ventricular septal defect exhibited right-to-left shunting. The cat suddenly experienced dyspnea and died at home, and a postmortem examination was performed. A single large vessel was noted leaving the heart, from which the right and left pulmonary arteries arose separately; a main pulmonary artery was absent. There was only one single anomalous coronary ostium that arose from the brachiocephalic artery and divided into two branches. The walls of the extracardiac coronary artery were thick, but neither infarcts nor narrowing was observed within the coronary arteries. There were no abnormalities in the intracardiac coronary artery. These findings revealed a persistent truncus arteriosus with an anomalous coronary artery. A combination of these anomalies might have contributed to the early death of the cat.

Common arterial trunk in a cat: a high-resolution morphological analysis with micro-computed tomography.

A 6-month-old female cat presented with respiratory distress. Physical examination showed a grade 5/6 holosystolic murmur with prominent precordial impulse over the left cranial chest wall. Echocardiography revealed bilateral hypertrophy of the ventricular walls, a dilated ascending aorta overriding the interventricular septum, a membranous ventricular septal defect and no obvious pulmonary trunk or pulmonary artery branches. Turbulent blood flow was detected around the ventricular septal defect and ascending aorta. Follow-up assessment, 12 months later, revealed marked and progressive biatrial dilation and biventricular hypertrophy. Four months after that, the cat died of severe congestive heart failure. To make a definitive postmortem diagnosis, we performed contrast enhanced micro-computed tomography (CT) on the ex vivo heart with micron-scale spatial resolution imaging and three-dimensional reconstruction. Micro-computed tomography analysis confirmed a common arterial trunk that bifurcated into the left pulmonary artery and aorta 5-mm distally from the truncal valve. The pulmonary trunk was absent. Slightly distal to the first branching, the common arterial trunk further branched into the right pulmonary artery and ascending aorta, indicating the aortic dominant form. Although CT angiography would be a preferred imaging modality for living animals, micro-computed tomography is a valuable tool for the ex vivo diagnosis of complex cardiac anomaly, such as presented in this cat.

Congenital Heart Disease in Dogs: A Retrospective Study of 95 Cases.

The aim of the study was to estimate the prevalence of congenital heart diseases in dogs attending 2 veterinary hospitals in Brazil and to identify possible associations between these conditions and epidemiological characteristics. A retrospective study was carried out in the cardiology sections of 2 veterinary hospitals during a period of 70 months from January 2012 and October 2017. Of a total of 6710 dogs that attended the cardiology sections of the hospitals, 109 congenital heart diseases were identified in 95 patients, representing a prevalence of 1.6%. Findings consistent with previous literature included subaortic stenosis and pulmonic stenosis as the most commonly diagnosed conditions, in addition to a higher predisposition of females to patent ductus arteriosus (PDA). In contrast, the novel findings included a higher prevalence of atrial septal defect and a lower prevalence of patent ductus arteriosus. The majority of the animals included were over 1 year of age at the time of diagnosis (67%) especially in the subaortic stenosis group. Also, a predisposition of the Maltese to ventricular septal defect was observed. The information obtained in the present study contributes to research that describes epidemiological characteristics of dogs with congenital heart disease in a previously unreported location.

Infective aortic valve endocarditis in a cat with patent ductus arteriosus and perimembranous ventricular septal defect.

A 3-year-old, male neutered, domestic short-haired cat presented for evaluation of respiratory distress. Transthoracic echocardiography revealed a left-to-right shunting ventricular septal defect, a left-to-right shunting patent ductus arteriosus, and a vegetative growth on the aortic valve leaflet consistent with aortic valve endocarditis. Because of poor response to therapy, the owner elected euthanasia, and a necropsy was performed. Gross necropsy examination confirmed the congenital cardiac defects, and aortic valve endocarditis was noted on the echocardiogram. Histopathological examination revealed diffuse interstitial pneumonia and evidence for systemic septic embolism including renal infarcts and brain microabscesses. To the authors' knowledge, this is the first case report of aortic valve endocarditis in a cat in association with congenital cardiac malformations.

Partial atrioventricular septal defect in an adult sport horse.

A partial atrioventricular septal defect, represented as a large ostium primum atrial septal defect and common (bridging) atrioventricular valve leaflets with cleft septal leaflet of the mitral valve, was diagnosed incidentally in a nine-year-old warmblood gelding used for show jumping. Initial examination findings and a three-year follow-up are documented in this report. The horse was first presented for the evaluation of chronic coughing. A left-sided, grade 4/6 holosystolic (band-shaped) murmur was identified along with a similar right-sided, grade 3/6 heart murmur. Echocardiography revealed a 6.4 cm diameter communication in the ventral atrial septum, considered an ostium primum atrial septal defect, with bidirectional shunting. A hypertrophic septomarginal trabecula, a thickened tricuspid valve, a cleft septal leaflet of the mitral valve, moderate mitral and tricuspid regurgitation likely related to leaflet prolapse, mild aortic regurgitation, and signs of moderate right ventricular volume overload were found as well. Electrocardiography showed no arrhythmias neither at rest nor during treadmill exercise. The owner continued to use the horse for show jumping. No exercise intolerance or other signs of disease were noted. Follow-up examination was performed three years after initial presentation. Contrast echocardiography confirmed the presence of right-to-left shunting through the atrial septal defect. Compared with the initial examination, the left ventricular internal diameter on M-mode echocardiography had increased. Occasional ventricular premature depolarizations were noted on the resting and exercise electrocardiogram. This is the first description of a clinically asymptomatic partial atrioventricular septal defect in an adult sport horse.