Longitudinal analysis of quality of life, clinical, radiographic, echocardiographic, and laboratory variables in dogs with myxomatous mitral valve disease receiving pimobendan or benazepril: the QUEST study.

BACKGROUND: Myxomatous mitral valve disease (MMVD) is an important cause of morbidity and mortality in dogs. OBJECTIVES: To compare, throughout the period of follow-up of dogs that had not yet reached the primary endpoint, the longitudinal effects of pimobendan versus benazepril hydrochloride treatment on quality-of-life (QoL) variables, concomitant congestive heart failure (CHF) treatment, and other outcome variables in dogs suffering from CHF secondary to MMVD. ANIMALS: A total of 260 dogs in CHF because of MMVD. METHODS: A prospective single-blinded study with dogs randomized to receive pimobendan (0.4-0.6 mg/kg/day) or benazepril hydrochloride (0.25-1.0 mg/kg/day). Differences in outcome variables and time to intensification of CHF treatment were compared. RESULTS: A total of 124 dogs were randomized to pimobendan and 128 to benazepril. No difference was found between groups in QoL variables during the trial. Time from inclusion to 1st intensification of CHF treatment was longer in the pimobendan group (pimobendan 98 days, IQR 30-276 days versus benazepril 59 days, IQR 11-121 days; P = .0005). Postinclusion, dogs in the pimobendan group had smaller heart size based on VHS score (P = .013) and left ventricular diastolic (P = .035) and systolic (P = .0044) dimensions, higher body temperature (P = .030), serum sodium (P = .0027), and total protein (P = .0003) concentrations, and packed cell volume (P = .030). Incidence of arrhythmias was similar in treatment groups. CONCLUSIONS AND CLINICAL IMPORTANCE: Pimobendan versus benazepril resulted in similar QoL during the study, but conferred increased time before intensification of CHF treatment. Pimobendan treatment resulted in smaller heart size, higher body temperature, and less retention of free water.

[Prevalence of heart murmurs, aortic and pulmonic stenosis in boxers presented for pre-breeding exams in Switzerland]. / Prävalenz von Herzgeräuschen, Aorten- und Pulmonalstenosen bei Zuchtuntersuchungen von Boxern in der Schweiz.

Boxer are predisposed to subaortic (SAS) and pulmonic stenosis (PS). To decrease the prevalence, pre-breeding cardiologic exams were performed in the last years. In our study the results of 309 pre-breeding exams of boxers presented between 1999 and 2008 were evaluated retrospectively. The overall prevalence of heart murmurs was 26.5 %. A SAS was diagnosed in 25 (8.1 %) and a PS in 10 (3.3 %) dogs. A combination of both defects was found in 7 (2.3 %) Boxers. Animals with a heart murmur of at least grade 3/6 had a significantly higher peak aortic flow velocity (VmaxAo) than animals without or only soft heart murmurs. Over the study period both the frequency of heart murmurs and diagnosis of SAS and PS decreased.

Effect of pimobendan or benazepril hydrochloride on survival times in dogs with congestive heart failure caused by naturally occurring myxomatous mitral valve disease: the QUEST study.

BACKGROUND: Myxomatous mitral valve disease (MMVD) continues to be an important cause of morbidity and mortality in geriatric dogs despite conventional therapy. HYPOTHESIS: Pimobendan in addition to conventional therapy will extend time to sudden cardiac death, euthanasia for cardiac reasons, or treatment failure when compared with conventional therapy plus benazepril in dogs with congestive heart failure (CHF) attributable to MMVD. ANIMALS: Two hundred and sixty client-owned dogs in CHF caused by MMVD were recruited from 28 centers in Europe, Canada, and Australia. METHODS: A prospective single-blinded study with dogs randomized to PO receive pimobendan (0.4-0.6 mg/kg/d) or benazepril hydrochloride (0.25-1.0 mg/kg/d). The primary endpoint was a composite of cardiac death, euthanized for heart failure, or treatment failure. RESULTS: Eight dogs were excluded from analysis. One hundred and twenty-four dogs were randomized to pimobendan and 128 to benazepril. One hundred and ninety dogs reached the primary endpoint; the median time was 188 days (267 days for pimobendan, 140 days for benazepril hazard ratio = 0.688, 95% confidence limits [CL]=0.516-0.916, P= .0099). The benefit of pimobendan persisted after adjusting for all baseline variables. A longer time to reach the endpoint was also associated with being a Cavalier King Charles Spaniel, requiring a lower furosemide dose, and having a higher creatinine concentration. Increases in several indicators of cardiac enlargement (left atrial to aortic root ratio, vertebral heart scale, and percentage increase in left ventricular internal diameter in systole) were associated with a shorter time to endpoint, as was a worse tolerance for exercise. CONCLUSIONS AND CLINICAL IMPORTANCE: Pimobendan plus conventional therapy prolongs time to sudden death, euthanasia for cardiac reasons, or treatment failure in dogs with CHF caused by MMVD compared with benazepril plus conventional therapy.

Heart failure in two West Highland white terriers caused by congenital angiomatous cardiac anomaly.

The paper describes the clinical and pathological characteristics of an unusual cystic congenital cardiac anomaly that caused clinical signs of congestive heart failure, respiratory distress and cardiac arrhythmias in two West Highland white terrier puppies. In both dogs a definitive diagnosis was made postmortem.

Prevalence of heart disease in symptomatic cats: an overview from 1998 to 2005.

A total of 408 cats with various cardiovascular problems has been presented to two investigational clinics during the last 8 years. The number of yearly examinations has steadily increased during this period. Definitive cardiovascular disease was diagnosed in 287 cats, whereby hypertrophic cardiomyopathy (HCM) was the most common diagnosis with 67.6%. Congenital cardiovascular malformations were found in 11.8% of the cases. Ventricular septal defect (VSD) was the most frequent anomaly, in contrast to previously published studies. The ECG was found to be relatively non-specific and insensitive for the diagnosis of heart disease: Its usefulness lies in the recognition and diagnosis of cardiac arrhythmias. The radiographically recognized changes were also non-specific for certain heart diseases. Radiographs of the thorax are especially useful in the evaluation of cardiomegaly, and secondary signs of congestion.

Echocardiographic screening of purebred cats: an overview from 2002 to 2005.

During the last 3 years, a total of 144 cats underwent echocardiographic screening at two investigational clinics before being admitted for breeding. The number of cats presented for that purpose has constantly increased. 8.3% of cats were diagnosed as having hypertrophic cardiomyopathy and 6.9% were diagnosed as suspicious. Male cats were more affected than females (9.4% vs 7.7%). In 4.2 of all presented cats, a congenital cardiac malformation was recognised, most often tricuspid valve dysplasia.

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.

[The use of memoprint in the cat]. / Utilisation du Memoprint chez le chat.

In this study, done in the context of normal veterinary practice, the possibilities of using Memoprint have been evaluated. The values of systolic arterial pressure (SAP), diastolic arterial pressure (DAP) and pulse rate (PR) in healthy cats (n = 72) have been determined, as well as the values of SAP, DAP and PR before (n = 26), during (n = 40) and after (n = 16) an anaesthesia for routine surgery. The results show that Memoprint allows a quick, convenient and correct determination of SAP (average: 122.7 mmHg) and DAP (88.5), but an imprecise determination of the PR. The measures are not highly repeatable with conscious cats (SAP: 0.68, DAP: 0.51), unlike that obtained before (0.90, 0.86), during (0.96, 0.90) and after (0.88, 0.58) the anaesthesia, indicating once again the importance of the cats' familiarity and cooperation with the veterinarian. An analysis of the variance of the values of blood pressure shows their direct relationship with age, sex, breed and style of life of the cats and an increase in pressure in those over ten years of age.

[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.

Guidelines for the echocardiographic studies of suspected subaortic and pulmonic stenosis.

INTRODUCTION: Subaortic stenosis (SAS) and pulmonic stenosis (PS) are, with PDA, the most common canine congenital heart defects in almost all epidemiological studies or frequency tabulations of the various European countries and the United States. As dog breeder's associations of highly affected breeds such as Boxers and Newfoundlands are attempting to screen breeding stock clinically as well as echocardiographically and are trying to eliminate these defects through the exclusion of affected individuals from breeding programs, it behooves the group of veterinary cardiologists and echocardiographers engaged in these screening programs to use a standardized approach to the echocardiographic examination procedure. This should warrant obtaining comparable studies with little interobserver variability due to the data acquisition procedure. Such uniformly acquired studies would also be easier to review by a board of experts, should this become necessary in the future. The recommendations stated below are valid for the examinations of dogs as well as cats. The present article represents the combined professional opinions of Drs. Bussadori, Le Bobinnec, Amberger and Lombard. REQUIRED EQUIPMENT: Any commercial echocardiographic unit with 2.5 to 7.5 MHz sector transducers is suitable for imaging. Transducers with small "footprints" (contact surface) are easier to couple to the chest wall in small patients with narrow intercostal spaces. A so-called cardiac package is also required and provides the software for standardized M-mode, 2D- and Doppler measurements. An ECG-tracing must be included on all recordings. It is mandatory to record clear and artifact-free imaging sequences of adequate length of each required view and of each Doppler measurement on a videotape or digital archive system, with proper patient identification, for later retrieval and documentation. For the Doppler measurements, pulsed wave (PW) and continuous wave (CW) capabilities are required. Color flow Doppler (CFD) is a useful option and allows the rapid documentation and localization of turbulent blood flow, thereby facilitating the placement of the PWD- and CWD- cursors for spectral display and peak velocity measurements. It is however a costly option and not essential for the documentation of neither SAS or PS. SEDATION: The authors highly recommend against tranquilization of the patients, as blood flow velocities are affected by most sedatives. Even if the blood pressure measured under sedation is in the normal range, this does not warrant truly non-influenced blood flow velocity values.

Cardiomyopathy in dystrophin-deficient hypertrophic feline muscular dystrophy.

A colony of cats affected with hypertrophic feline muscular dystrophy was used to study the occurrence of cardiomyopathy associated with dystrophin deficiency. Affected male and female cats, obligate carrier females, and unaffected healthy littermates were followed from 12 weeks of age into adulthood. Thoracic radiography, 2-D echocardiography, and 2-D-derived M-mode echocardiography were performed at 3-month intervals until 12 months of age and regularly thereafter. From 9 months of age, all affected cats had larger hearts than normal and carrier animals. Left ventricular wall thickness in systole and in diastole and interventricular septal thickness in systole were greater in affected cats 12 months and older when compared with normal or heterozygous animals (P < .05). The myocardium of affected cats was diffusely hypoechoic and thickened. Multiple hyperechoic foci were in the myocardium and papillary musculature. Shortening fraction was normal in all cats. Changes seen in carrier females included enlargement and hyperechogenicity of the papillary musculature after the age of 2 years. Gross and light microscopic examination revealed left ventricular wall thickening with multiple foci of mineralization in 2 of 5 hearts from dystrophin-deficient cats. Although approximately 10% of the normal dystrophin amount was present in the skeletal muscle, dystrophin could not be detected in the myocardium. Early onset concentric myocardial hypertrophy was present in all adult cats. Lesions were mainly localized in the myocardium of the left ventricular free wall and interventricular septum, papillary musculature, and the endocardium. Clinical signs of heart failure developed only infrequently in cats with hypertrophic feline muscular dystrophy.

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).

[Palliative treatment of tetralogy of Fallot using a PTFE (polytetrafluoroethylene) vascular graft]. / Palliative Behandlung von Fallotscher Tetralogie mit einer PTFE-(Polytetrafluorethylene-) Gefässprothese.

The application of a PTFE (polytetrafluorethylene) vascular graft for palliative surgical treatment in a case of tetralogy of Fallot in a dog is described. The surgical procedure took place after an attempt to perform a Blalock anastomosis failed. The surgical technique, the postoperative care and the outcome are presented. The technique and its indications are discussed.

Recommendations for standards in transthoracic two-dimensional echocardiography in the dog and cat. Echocardiography Committee of the Specialty of Cardiology, American College of Veterinary Internal Medicine.

Recommendations are presented for standardized imaging planes and display conventions for two-dimensional echocardiography in the dog and cat. Three transducer locations ("windows") provide access to consistent imaging planes: the right parasternal location, the left caudal (apical) parasternal location, and the left cranial parasternal location. Recommendations for image display orientations are very similar to those for comparable human cardiac images, with the heart base or cranial aspect of the heart displayed to the examiner's right on the video display. From the right parasternal location, standard views include a long-axis four-chamber view and a long-axis left ventricular outflow view, and short-axis views at the levels of the left ventricular apex, papillary muscles, chordae tendineae, mitral valve, aortic valve, and pulmonary arteries. From the left caudal (apical) location, standard views include long-axis two-chamber and four-chamber views. From the left cranial parasternal location, standard views include a long-axis view of the left ventricular outflow tract and ascending aorta (with variations to image the right atrium and tricuspid valve, and the pulmonary valve and pulmonary artery), and a short-axis view of the aortic root encircled by the right heart. These images are presented by means of idealized line drawings. Adoption of these standards should facilitate consistent performance, recording, teaching, and communicating results of studies obtained by two-dimensional echocardiography.

Results of continuous ambulatory electrocardiography in a cat with hypertrophic cardiomyopathy.

An 8-year-old neutered male cat with a history of intermittent collapse and dyspnea was evaluated. Hypertrophic cardiomyopathy was diagnosed on the basis of findings from physical examination, radiography, and echocardiography. Cardiac arrhythmias were not recorded during routine electrocardiography. Continuous ambulatory electrocardiography documented severe ventricular arrhythmias (ventricular premature complexes, ventricular bigeminy, and paroxysmal ventricular tachycardia). Continuous ambulatory electrocardiography can detect intermittent and potentially life-threatening cardiac arrhythmias.