Plexogenic pulmonary arteriopathy in a Pembroke Welsh corgi.

A 21-month-old, male Pembroke Welsh corgi was referred for investigation of respiratory distress and progressive lethargy. Cardiac evaluation revealed a grade 4 pansystolic murmur over the left and right heart base. A heart murmur, dyspnoea, cyanosis, prolonged capillary refill time and ascites led to the tentative diagnosis of a cardiac malformation with a right-to-left shunt, with likely additional pulmonary disease. Pulmonary hypertension became evident during echocardiography, when the estimated systolic pulmonary artery pressure was over 70 mmHg. Angiography revealed abnormal pulmonary vascular markings consistent with pulmonary hypertension and a small right-to-left shunting patent ductus arteriosus (PDA). The diagnosis of PDA was confirmed at postmortem examination. Histology of the pulmonary arteries showed lesions of plexogenic pulmonary arteriopathy. The question of whether both conditions were separate or part of the same clinical syndrome is discussed in this report.

Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) in a Boxer.

ABSTRAST: A 3-year-old boxer bitch was evaluated for syncope and exercise intolerance. Physical examination revealed tachypnea, tachyarrhythmia and pulse deficit. Echocardiography demonstrated right atrial dilatation, thinning and hypokinesis of the right ventricular wall and normal contractility of the left ventricle. Three months after the first onset of clinical symptoms, the dog developed signs of congestive right heart failure despite treatment, and euthanasia was performed because of refractory ascites. The diagnosis of arrhythmogenic right ventricular cardiomyopathy (ARVC) was reached based of the clinical evolution of rapid progressive right ventricular heart failure and the particular form of isolated right atrial and right ventricular alterations without any echographic abnormalities of the pulmonic and tricuspid valves. Definitive confirmation was made by necropsy. In contrast to boxer type dilated cardiomyopathy (BDCM), dilatation occurred primary on the right atrium and ventricle and the right ventricular wall was thinner in subtricuspidal, apical and infundibular locations, similar to the "triangle of dysplasia" of human patient with ARVC. Histological lesions showed myocyte atrophy and replacement with adipose and fibrous tissue extended from the epicardium toward the endocardium in the right ventricle (RV) and right atrium (RA). In contrast to BDCM, where the lesions are multifocal, they take here the form of waves, with a large base against the epicardium and a spike towards the endocardium, known as lesions with a wave-front pattern, which are typical of ARVC. This report with supraventricular arrhythmias and echographic location in the RA and RV supports the hypothesis that ARVC is a progressive disease which may also have left ventricular free wall involvement if the patient lives long enough.

Atrioventricular Canal Defect (incomplete form of endocardial cushion defect) and Ostium Secundum Type Interatrial Septal defect in a dog.

A four-year-old German shepherd mixed-breed dog was presented with an asymptomatic heart murmur. An atrial septal defect associated with tricuspid and mitral dysplasia (atrioventricular canal defect) was diagnosed. The pulmonary to systemic blood flow ratio was in the range of 2.5:1 (Qp:Qs ratio). Echocardiography and flow pattern across the valves as well as the direction of the shunt allows a better description of the physiopathological consequences of this rare congenital heart disease. Additionally, an Ostium Secundum Type interatrial septum defect was found at necropsy.

[Tricuspid valve dysplasia in fifteen dogs]. / Trikuspidaldysplasie bei fünfzehn Hunden.

Clinical findings in fifteen dogs with tricuspid valve dysplasia are described. Thirteen dogs had loud systolic heart murmurs. Eleven of them hat a palpable precordial thrill over the same location. In 14 dogs, right heart enlargement was suspected on thoracic radiographs and electrocardiography. Right atrial dilation was seen echocardiographically in all dogs. Fourteen dogs had additional right ventricular dilatation, some with hypertrophy as well. Doppler echocardiography revealed tricuspid valve regurgitation. Seven dogs remained free of clinical symptoms to date. If symptoms of decompensation develop with tricuspid dysplasia, diuretics, ACE inhibitors and eventually positive inotrope drugs are indicated. Antiarrhythmic drugs may become necessary in cases of supraventricular tachyarrhythmias.

Effects of benazepril in the treatment of feline hypertrophic cardiomyopathy Results of a prospective, open-label, multicenter clinical trial.

OBJECTIVES: To evaluate the efficacy of benazepril on clinical signs and echocardiographic parameters in cats with primary hypertrophic cardiomyopathy (HCM). BACKGROUND: ACE-inhibitors have positive effects in man with HCM, and contribute to a reduction of myocardial hypertrophy. Addition of an ACE-inhibitor to the standard treatment of HCM in cats may have beneficial effects. METHODS: A total of 32 cats which were either asymptomatic or in stabilised congestive heart failure (ISACHC* class Ib, II or IIIa) were included in a one-year, prospective, open-label, clinical trial in 5 centres in Switzerland. 28 of these cats were allocated to one of two treatment groups: 1) standard therapy (ST) alone (n=9), consisting of a long-acting formulation of diltiazem (6-9 mg/kg sid) and optional acetylsalicylic acid (50 mg twice weekly, or 2) the same ST plus benazepril (0.33 - 0.75 mg/kg sid, n=19). RESULTS: Cats treated with benazepril showed a statistically significant decrease (mean +/- SEM, 0.11 +/- 0.03 mm/month, p = 0.002) in the left ventricular wall thickness (LVWD) from baseline, while no change (increase of 0.02 +/- 0.04 mm/month, p=0.66) was observed in cats on ST alone. Differences in LVWD between the two groups reached statistical significance (p=0.02). Benazepril treated cats showed more improvement in clinical signs (20-53%) than cats receiving ST alone (0-20%) but differences between the groups were not statistically significant (p>0.1). No change in septal thickness (IVSD) or left atrial to aortic root ratio (LA/Ao) was observed in either group. CONCLUSIONS: Benazepril had some beneficial effects on clinical signs and cardiac remodelling in cats with HCM and was well tolerated. These results, however, need to be confirmed in additional controlled studies. * ISACHC classification is described in the previous paper (Bench-study).

[A case of interatrial communication in a dog]. / Un case de communication interatriale (CIA) chez le chien.

A 4 month old female German Shepherd was presented for the work-up of a heart murmur that has been detected by the referring veterinarian. Clinical examination and thoracic radiography showed an enlargement of the right ventricle, and an increased pulmonary perfusion. Echocardiography showed an interatrial communication (atrial septum defect), and colour Doppler allowed the confirmation of a left to right shunt. The article discusses the diagnostic possibilities of this rare congenital cardiac malformation in the dog.