Echocardiographic diagnosis of congenital membranous ventricular septal aneurysm in the dog and cat

Membranous ventricular septal aneurysm was diagnosed by echocardiography in 17 dogs and three cats. The aneurysm appeared as a thin membrane protruding into the right ventricle from the margins of a congenital ventricular septal defect (VSD). The aneurysm was intact in nine dogs and two cats and perforated by a small VSD in eight dogs and one cat. Other congenital heart defects were present in seven dogs. In all animals, the aneurysm was an incidental finding observed during echocardiographic examination, and it did not appear to directly cause any cardiac dysfunction.     

Double-outlet right ventricle in an Angus calf

Double-outlet right ventricle (DORV) is a conotruncal malformation where both great arteries arise from the right ventricle. Anatomic variations of DORV are classified according to the position of the great arteries in relation to each other, the relationship between a ventricular septal defect (VSD) and the great arteries, and the presence and degree of pulmonary stenosis. The prevalence of congenital cardiac defects in bovine fetuses has been reported at approximately 0.7 %, with VSDs representing the most common congenital cardiac defect. DORV has been described in veterinary literature in few cats and dogs, a foal, and 2 calves with variable clinical and pathologic documentation. In this report, we describe the angiographic, echocardiographic, and postmortem examination findings in a calf with a DORV with concurrent pulmonary stenosis, subaortic VSD, patent ductus arteriosus (PDA), aberrant left subclavian artery, and a tracheal malformation.     

COMPARISONS OF RADIOGRAPHIC AND ELECTROCARDIOGRAPHIC ABNORMALITIES IN CANINE HEARTWORM DISEASE

Thoracic radiographs and electrocardiograms from 137 dogs with heartworm infection were independently evaluated and comparisons were made of (1) the presence or absence of right ventricular enlargement as assessed by these two diagnostic tests and (2) the presence or absence of right-sided congestive heart failure relative to the degree of right ventricular enlargement and ECG criteria of RVH.
Radiographic evidence of severe, but not moderate, right ventricular enlargement was associated with right-sided congestive heart failure. Similarly the presence of three or more, but not fewer than three, ECG criteria of RVH were associated with right-sided congestive heart failure. If either the thoracic radiographs or the ECG indicated that severe right ventricular enlargement was absent, right-sided congestive heart failure was seldom present. The most accurate correlation of the radiographic evaluation of severe right ventricular enlargement was afforded by the presence of three or more ECG criteria of RVH. ECG criteria of RVH such as R/S^v4, + T^v10 MEA^x, and S¹¹ are highly specific tests; while S^V2 is a highly sensitive but not highly specific test. The ECG is a good confirmation test of the presence of severe right ventricular enlargement and is a good exclusion test for the absence of right-sided congestive heart failure.     

Persistent truncus arteriosus in a cat

A 5-month-old male domestic cat presented with a history of rapid, heavy breathing and cyanosis after exercise. Physical examination showed an abnormal respiratory pattern with an increased rate and stress-induced cyanosis. Auscultation revealed tachycardia and a grade 5/6 systolic murmur best heard over the left base. Radiographs showed evidence of right atrial and ventricular enlargement with distended pulmonary vessels and an enlarged ascending aorta. An echocardiographic examination revealed a dilated right atrium, eccentric right ventricular hypertrophy and an overriding aorta associated with a large ventricular septal defect (VSD). The pulmonary trunk could not be identified by echocardiography. Doppler and saline contrast studies showed large right-to-left shunting through the VSD. These findings were compatible with persistent truncus arteriosus, which was confirmed at necropsy.     

Ventricular septal defects in two goats

Two young goats with loud, holosystolic heart murmurs heard best over the left and right heart base were suspected to have interventricular septal defects. Cardiac catheterization with angiocardiography supported the clinical diagnosis in both goats and the ventricular septal defects were confirmed at necropsy. In one goat a ventricular septal defect was associated with a hypoplastic aorta and in the other, an ectopic ureter opened into the vagina.     

Epidemiological and morphological studies of double-chambered right ventricle in dogs

The double-chambered right ventricle (DCRV) is a rare congenital cardiac disease in dogs, and its detailed epidemiological and morphological features are not clearly understood. By investigating the profile, clinical signs, and characteristics of examination findings of eleven dogs with DCRV by means of a retrospective study, we attempted to clarify the epidemiology and morphology of the condition. The study group consisted of nine males and two females. Breeds included Pug (n=3), Miniature Dachshund (n=1), French Bull-dog (n=1), Shiba (n=1), and Retrievers (n=5). The attachment site of the anomalous muscular bundle was continuous with the cardiac apex in nine dogs, and it was attached to the right ventricle free wall in the other two dogs. In dogs with DCRV, at least one of the following conditions was present concurrently: congenital or acquired tricuspid valve regurgitation (TR), ventricular septal defect, and atrial septal defect. Also, the pressure difference between the two chambers increased over time, and progressive right-sided heart failure was observed. In summary, DCRV occurs in small breeds of dog as well as in large breeds of dog and it may be more prevalent in males. The existence of two types of DCRV in dogs was established. Dog with DCRVs will have a high incidence of concurrent cardiac abnormalities. Concurrent TR may be either congenital or acquired. DCRV is a congenital disorder, but the clinical condition progresses as the dog develops.     

Endocardial fibroelastosis in a dog

Endocardial fibroelastosis is an uncommon congenital heart disease in dogs that may be manifested by signs of left-sided congestive heart failure. A three-month-old, male, Fila Brasileiro dog developed signs of generalised heart failure. Physical examination revealed normal temperature, ascites, and pale and cyanotic mucous membranes. The pup died just after radiography which revealed ascites, hepatomegaly, severe cardiac enlargement and pulmonary oedema. At necropsy, serosanguineous fluid in the thorax and abdomen, pulmonary oedema, right ventricular dilatation, hypertrophy and dilatation of the left ventricle, and mitral valve incompetence were observed. The histopathological examination demonstrated that the thickening of the endocardium of the left atrium and left ventricle was due to the presence of elastic and collagen fibres, although there were no signs of an inflammatory process.     

Ventricular septal defects in the horse

Clinical, echocardiographic, and right-side cardiac catheterization data were collected in 6 horses with ventricular septal defects. The defects were confirmed by necropsy in 5 horses. On echocardiography, the cardiac dimensions were normal in 3 horses and enlarged in 2 others. A step-up in partial oxygen pressure between right atrium and right ventricle suggested a left-to-right shunt in 3 of the 4 horses catheterized. In 1 foal, a small defect without PO2 step-up was documented by angiocardiography. The oxymetry and pressure data were compared with previous cases from the reviewed literature, and the importance of pressure measurements to rule out concomitant defects was emphasized.     

Hybrid technique for ventricular septal defect closure in a dog using an Amplatzer® Duct Occluder II

A left-to-right shunting muscular ventricular septal defect (VSD) was diagnosed in a 4-month-old, female, 1.8 kg Bichon Frise – poodle mix dog. Echocardiographic evidence of cardiac remodeling, calculated pulmonary blood flow (Qp) to systemic blood flow (Qs) ratio of 2.8, and radiographic evidence of pulmonary edema supported the diagnosis of a hemodynamically important VSD. Using a combination of surgery and interventional catheter-based techniques to approach the VSD through the right ventricle, the VSD was occluded with an Amplatzer^® Duct Occluder (ADO) II device. The ADO II is a low profile, flexible device originally developed for patent ductus arteriosus closure in humans that has been used to close muscular and perimembranous VSD in children. This report describes the hybrid procedure and imaging that was essential for successful occlusion of the VSD in this dog.     

Partial atrioventricular canal defect in a dog

A case of a partial atrial canal defect is described in a nine-month-old female English setter. The patient had a large ostium primum atrial septal defect and a concurrent malformation of the mitral valve. Electrocardiographic and radiographic findings were suggestive of marked enlargement of the right heart and pulmonary overcirculation. Definitive diagnosis and assessment of the haemodynamic consequences were made using echocardiography. The magnitude of the left-to-right intracardiac shunt was estimated by measuring the pulmonary to systemic flow ratio (Qp/Qs) from Doppler-derived pulmonary and aortic blood flow. The results of this report suggest that dogs with a partial atrioventricular canal defect and concurrent mild mitral regurgitation may exhibit no clinical signs during the first years of life, even in cases with a Qp/Qs ratio of greater than 2.     

Anatomically corrected malposition (ACM) with subpulmonary infundibulum in a calf: clinico-morphologic case report.

A Japanese black calf with cyanosis, tachycardia, tachypnea and systolic murmur died of hypoxemia and cardiac insufficiency on the 38th day after birth. We could not establish the diagnosis during it's life. However, anatomically corrected malposition (ACM) with ventricular septal defect was confirmed at autopsy. There was situs solitus of the viscera and atria with atrio-ventricular discordance and ventriculo-arterial concordance. The ventricles demonstrated l-loop, i.e. on the right-sided ventricle there was a markedly enlarged morphologic left ventricle, and on the left-sided ventricle there was a hypoplastic morphologic right ventricle with a stenotic tricuspid valve and Ebstein-like deformity. The right posterior aorta originated from the left ventricle. The pulmonary artery arose from the left-sided right ventricle via infundibulum. There was a fibrous continuity between the aortic and mitral valve. We considered that this is the first reported case of bovine ACM.     

Pulmonary hypertension as a cause of atrial fibrillation in young horses: four cases (1980-1989)

Four young horses of various breeds and suffering from atrial fibrillation died of heart failure. All had markedly high pulmonary arterial pressure, right-sided cardiomegaly, and lack of histologic lesions in the right atrium or pulmonary parenchyma. Three horses had hypertrophy and/or necrosis of the tunica media of the pulmonary vasculature. Clinical signs of disease, physiologic data, and pathologic findings indicated that these horses had primary pulmonary hypertension with secondary right-sided cardiac ventricular hypertrophy and dilatation, atrial fibrillation, and heart failure.     

Congenital cardiac disease in dogs

Patent ductus arteriosus (PDA) is thought to be inherited and occurs twice as often in females as in males, most commonly in Poodles, Collies, Cocker Spaniels and Shetland Sheepdogs. About half of untreated dogs develop left-sided heart failure by 8 months of age. Clinical signs include coughing, decreased exercise tolerance, pulmonary edema, a "machinery" murmur in the pulmonic-aortic region, and a bounding pulse. An ECG may reveal an increased amplitude of the R wave and a lengthened P wave. Plain LAT films reveal loss of the cranial and caudal cardiac waists, increased sternal contact of the heart, increased width and straightened caudal border of the cardiac silhouette, elevated carina, and an enlarged left atrium. Changes on plain DV films include an elongated cardiac silhouette, enlarged right ventricle, and 3 bulges on the left side of the cardiac silhouette. Nonselective angiocardiography can be used for a definitive diagnosis and to demonstrate a reverse right-to-left PDA, in which the ascending aorta, brachiocephalic trunk and left subclavian artery are not opacified by contrast medium. Animals with a right-to-left shunt PDA are cyanotic in caudal body parts. Treatment of left-to-right shunt PDA involves ligation with 2 nonabsorbable sutures. A right-to-left shunt PDA should not be ligated but is treated by restricted exercise and periodic phlebotomy.     

Congestive heart failure associated with myxomatous degeneration of the left atrioventricular valve in a parakeet

Congestive heart failure was diagnosed in a 27-year-old Indian ringneck parakeet with exercise-induced dyspnea. A grade IV/VI holosystolic murmur that radiated to the right sternal area was auscultated over the left side of the sternum. Radiography revealed progressive cardiomegaly, hepatomegaly, pulmonary edema, and accumulation of fluid within the coelomic cavity. Echocardiography revealed biatrial enlargement and enlargement of the right ventricle. Doppler recording revealed high velocity left and right atrioventricular valve regurgitation. Treatment with digoxin and furosemide alleviated clinical signs for approximately 10 months. Gross postmortem examination revealed cardiac enlargement and eccentric hypertrophy of both ventricles on cross-section. Pulmonary congestion and edema, hepatomegaly, hepatic congestion, and ascites were also evident. Histologic examination of the heart revealed myxomatous degeneration of the left atrioventricular valve, muscular hypertrophy of the right atrioventricular valve, and biventricular chronic myofiber degeneration and necrosis.     

Mineralized,obstructive cardiac myxoma with chondroid differentiation in a cocker spaniel

A 12-year-old castrated male cocker spaniel dog was referred for evaluation of signs consistent with right-sided heart failure. Thoracic radiography revealed mineralization in the region of the right atrium. Echocardiography identified a mass partially filling the right atrium and right ventricle and obstructing flow through the right heart. These findings were confirmed at necropsy and histopathologic features were consistent with myxoma with chondroid differentiation.     

Percutaneous transcatheter coil embolization of a ventricular septal defect in a dog

A 4-month-old male French Bulldog weighing 5.0 kg (11 lb) was referred for a heart murmur. A grade 3/6 systolic murmur was detected at the left heart base and a grade 4/6 systolic murmur was detected at the right heart base. By use of color-flow Doppler ultrasonography and cardiac catheterization, a diagnosis of supracristal ventricular septal defect (VSD) with accompanying aortic regurgitation was made. Percutaneous transcatheter coil embolization was used to close the VSD. Because residual shunt was detected via echocardiography after coil implantation, the residual shunt was followed periodically via echocardiography to detect spontaneous closure of the VSD. Volume overload in the left ventricle was detected in the dog 131 days after admission. Additional coils were placed 137 days after admission. Hemolysis resulting in hemoglobinuria was detected, but this complication was mild. In the dog of this report, results of coil occlusion for correction of VSD were promising. Thus, coil occlusion should be considered as an alternative treatment for VSD in dogs.     

Coexisting tricuspid valve dysplasia and ventricular septal defect in a young patas monkey (Erythrocebus patas).

A 1.5-kg, 6-mo-old male patas monkey (Erythrocebus patas) was cyanotic and panting. Evaluation of the heart by electrocardiography, thoracic radiography, two-dimensional echocardiography, and Doppler color-flow echocardiography revealed a ventricular septal defect (VSD) with right-to-left shunting as well as tricuspid valve dysplasia with dilated annulus of the tricuspid ring, dilated right atrium, dilated right ventricle, and deformity of the tricuspid valve. Because of the severity of the cardiac disease, the patas monkey had complications recovering from anesthesia and died 3 days later. Gross postmortem findings included VSD, tricuspid dysplasia, and cerebral hemorrhage.     

Pathophysiologic mechanism of cardiac dysfunction in experimentally induced heartworm caval syndrome in dogs: an echocardiographic study

In dogs with experimentally induced heartworm infection, the onset of caval syndrome (CS) was characterized by a murmur, loudest over the tricuspid valve, and a large worm mass in the right ventricular lumen detectable during diastole by use of M-mode echocardiography. Two-dimensional echocardiography indicated that the worm mass was located in the right atrium and venae cavae and was "flowing" into the right ventricle during rapid diastolic filling. Paradoxical septal motion and vigorous right ventricular cranial wall motion also were observed. Other echocardiographic changes included decreased size of the left atrium and ventricle, aortic root, and ratio of left-to-right ventricular diastolic luminal diameter, compared with values obtained 6 months after experimentally induced heartworm infection. Right ventricular end diastolic diameter increased considerably. Most echocardiographic indices of left ventricular function (fractional shortening, velocity of circumferential fiber shortening, ejection fraction, and preejection period) were not altered appreciably, but estimates of cardiac index and stroke volume were markedly decreased. Electrocardiography revealed ventricular and supraventricular premature complexes in 7 of the 8 dogs studied, evidence of right ventricular enlargement in 6 of the 8 dogs studied, and increased mean heart rate, compared with that measured 6 months after inoculation of infective larvae, before the onset of CS. Cardiac catheterization was performed in 3 days at the onset of CS. Severe pulmonary arterial and right ventricular hypertension and decreased cardiac index (compared with values obtained before inoculation) were observed. Evidence of right ventricular inflow obstruction was not detected. Mean aortic blood pressure decreased with the onset of CS, but right ventricular end diastolic pressure increased.(ABSTRACT TRUNCATED AT 250 WORDS)     

Common ventricle with separate pulmonary outflow chamber in a horse

On the basis of clinical and laboratory examinations, a ventricular septal defect or a variant of the tetralogy of Fallot was suspected in a 3-year-old filly with a history of poor growth rate and exercise intolerance. The filly was euthanatized and found to have a 3-chambered heart (cor triloculare biatriatum). The heart had 2 normally formed atria and a large common ventricle into which the right and left atrioventricular orifices opened and from which the aorta arose. There was a small separate chamber from which the pulmonary trunk originated. This chamber communicated with the common ventricle through a large oval opening along the dorsal border of the displaced, interventricular septum.