Successful transcatheter retrieval of embolized Amplatz Canine Duct Occluders in two dogs.

Transcatheter occlusion of patent ductus arteriosus (PDA) using an Amplatz® Canine Duct Occluder (ACDO) is routinely performed in dogs. Pulmonary embolization of the device is a rarely reported complication of this procedure. We report here the first two cases of successful transcatheter retrieval of an embolized ACDO. An 8-month-old, 21-kg, German shepherd (case 1) was referred for pulmonary edema secondary to a large PDA with left-to-right shunting. After medical stabilization, an emergency procedure for PDA closure was recommended. An 8-mm ACDO was deployed under general anesthesia. The device was released after confirming its stability with a gentle tug test but migrated into the pulmonary trunk. A 10-mm ACDO was subsequently successfully deployed and released. Vascular access was then obtained from the right jugular vein so that a vascular snare could be used to capture the ACDO waist and pull it back toward the right ventricle and then the right atrium. It was then removed through the jugular vein. The dog recovered uneventfully and was discharged after confirmation of complete ductal occlusion. The same complication occurred in a second case (case 2, asymptomatic 6-month-old, 7.9-kg, cocker spaniel), and a similar procedure was used to successfully retrieve the embolized device. Both dogs are still doing well 9 and 21 months, respectively, after the procedure. These cases illustrate that transcatheter retrieval of ACDO devices embolized in the pulmonary artery using vascular snares is technically feasible in the dog.

Interbreed variation in serum serotonin (5-hydroxytryptamine) concentration in healthy dogs.

INTRODUCTION: Serotonin (5-hydroxytryptamine [5-HT]) has several biological functions. In different species, excessive 5-HT has been linked to valvular lesions, similar to those seen in dogs with myxomatous mitral valve disease. Previous studies suggest higher 5-HT in healthy Cavalier King Charles Spaniels (CKCSs), a breed highly affected by myxomatous mitral valve disease, compared to other breeds. OBJECTIVE: To investigate potential interbreed variation in serum 5-HT in healthy dogs. ANIMALS: 483 healthy dogs of nine breeds aged 1-7 years. METHODS: Dogs were examined at five European centers. Absence of cardiovascular, organ-related, or systemic diseases was ensured by thorough clinical investigations including echocardiography. Serum was frozen and later analyzed by enzyme-linked immunosorbent assay (ELISA). RESULTS: Median 5-HT concentration was 252.5 (interquartile range = 145.5-390.6) ng/mL. Overall breed difference was found (p<0.0001), and 42% of pairwise breed comparisons were significant. Univariate regression analysis showed association between serum 5-HT concentration and breed, center of examination, storage time, and sex, with higher 5-HT in females. In multiple regression analysis, the final model had an adjusted R2 of 0.27 with breed (p<0.0001), center (p<0.0001), and storage time (p=0.014) remaining significant. Within centers, overall breed differences were found at 3/5 centers (p≤0.028), and pairwise comparisons within those centers showed breed differences in 42% of comparisons. Among the included breeds, Newfoundlands, Belgian Shepherds and CKCSs had highest 5-HT concentrations. CONCLUSIONS: Interbreed variation in serum 5-HT concentration was found in healthy dogs aged 1-7 years. These differences should be taken into account when designing clinical studies.

Aortic dissecting aneurysm associated with systemic arterial hypertension in a cat.

INTRODUCTION: Aortic dissection is characterized by a tear in the aortic wall resulting in blood from the aortic lumen penetrating into the media, which causes dissection. When aortic dissection does not cause rupture, it provokes localized dilation of the aorta or aneurism, also called dissecting aortic aneurism (DAA). This case report describes a DAA in a cat associated with systemic arterial hypertension (SAHT). A 10-year-old male Domestic shorthair cat was presented for cardiac evaluation. Anamnestic clinical complaints were a syncope associated with paraparesis and weak femoral pules. Cardiomegaly had been found radiographically, and cardiogenic arterial thromboembolism had been suspected. Upon presentation physical abnormalities were tachycardia and a heart murmur. Measurement of systolic systemic arterial blood pressure (SABP) revealed severe SAHT. Echocardiographic images showed severe DAA, and marked aortic valve insufficiency. Palliative antihypertensive treatment resulted in fast clinical improvement and significant decrease in blood pressure. Four months later, acute severe respiratory distress due to cardiogenic pulmonary edema led to the cat's euthanasia. In human medicine, DAA is a well-reported complication of SAHT. This is the second case of DAA with congestive heart failure reported in a hypertensive cat.

Intracardiac echocardiography: use during transcatheter device closure of a patent ductus arteriosus in a dog.

Intracardiac echocardiography (ICE) is used in humans for percutaneous interventional procedures, such as transcatheter device closures. Intracardiac echocardiography provides high-resolution imaging of cardiac structures with two-dimensional, M-mode, Doppler, and also three-dimensional modalities. The present report describes application of ICE during transcatheter occlusion of patent ductus arteriosus using a canine ductal occluder in a dog for which transesophageal echocardiography could not provide an optimal acoustic window.

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.

Effect of Breed on Plasma Endothelin-1 Concentration, Plasma Renin Activity, and Serum Cortisol Concentration in Healthy Dogs.

BACKGROUND: There are breed differences in several blood variables in healthy dogs. OBJECTIVE: Investigate breed variation in plasma endothelin-1 (ET-1) concentration, plasma renin activity, and serum cortisol concentration. ANIMALS: Five-hundred and thirty-one healthy dogs of 9 breeds examined at 5 centers (2-4 breeds/center). METHODS: Prospective observational study. Circulating concentrations of ET-1 and cortisol, and renin activity, were measured using commercially available assays. Absence of organ-related or systemic disease was ensured by thorough clinical investigations, including blood pressure measurement, echocardiography, ECG, blood and urine analysis. RESULTS: Median ET-1 concentration was 1.29 (interquartile range [IQR], 0.97-1.82) pg/mL, median cortisol concentration 46.0 (IQR, 29.0-80.8) nmol/L, and median renin activity 0.73 (IQR, 0.48-1.10) ng/mL/h in all dogs. Overall, breed differences were found in ET-1 and cortisol concentrations, and renin activity (P < .0001 for all). Pair-wise comparisons between breeds differed in 67% of comparisons for ET-1, 22% for cortisol, and 19% for renin activity, respectively. Within centers, breed differences were found at 5/5 centers for ET-1, 4/5 centers for cortisol, and 2/5 centers for renin activity. Newfoundlands had highest median ET-1 concentration, 3 times higher than Cavalier King Charles Spaniels, Doberman Pinschers, and Dachshunds. Median renin activity was highest in Dachshunds, twice the median value in Newfoundlands and Boxers. Median cortisol concentration was highest in Finnish Lapphunds, almost 3 times higher than in Boxers. CONCLUSIONS AND CLINICAL IMPORTANCE: Breed variation might be important to take into consideration when interpreting test results in clinical studies.

Breed differences in natriuretic peptides in healthy dogs.

BACKGROUND: Measurement of plasma concentration of natriuretic peptides (NPs) is suggested to be of value in diagnosis of cardiac disease in dogs, but many factors other than cardiac status may influence their concentrations. Dog breed potentially is 1 such factor. OBJECTIVE: To investigate breed variation in plasma concentrations of pro-atrial natriuretic peptide 31-67 (proANP 31-67) and N-terminal B-type natriuretic peptide (NT-proBNP) in healthy dogs. ANIMALS: 535 healthy, privately owned dogs of 9 breeds were examined at 5 centers as part of the European Union (EU) LUPA project. METHODS: Absence of cardiovascular disease or other clinically relevant organ-related or systemic disease was ensured by thorough clinical investigation. Plasma concentrations of proANP 31-67 and NT-proBNP were measured by commercially available ELISA assays. RESULTS: Overall significant breed differences were found in proANP 31-67 (P < .0001) and NT-proBNP (P < .0001) concentrations. Pair-wise comparisons between breeds differed in approximately 50% of comparisons for proANP 31-67 as well as NT-proBNP concentrations, both when including all centers and within each center. Interquartile range was large for many breeds, especially for NT-proBNP. Among included breeds, Labrador Retrievers and Newfoundlands had highest median NT-proBNP concentrations with concentrations 3 times as high as those of Dachshunds. German Shepherds and Cavalier King Charles Spaniels had the highest median proANP 31-67 concentrations, twice the median concentration in Doberman Pinschers. CONCLUSIONS AND CLINICAL IMPORTANCE: Considerable interbreed variation in plasma NP concentrations was found in healthy dogs. Intrabreed variation was large in several breeds, especially for NT-proBNP. Additional studies are needed to establish breed-specific reference ranges.

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.

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.

Association of plasma N-terminal pro-B-type natriuretic peptide concentration with mitral regurgitation severity and outcome in dogs with asymptomatic degenerative mitral valve disease.

BACKGROUND: The clinical outcome of dogs affected by degenerative mitral valve disease (MVD) without overt clinical signs is still poorly defined, and criteria for identification of animals that are at a higher risk of early decompensation have not yet been determined. HYPOTHESIS: N-terminal pro-B-type natriuretic peptide plasma concentration (NT-proBNP) is correlated with mitral regurgitation (MR) severity and can predict disease progression in dogs with asymptomatic MVD. ANIMALS: Seventy-two dogs with asymptomatic MVD, with or without heart enlargement (International Small Animal Cardiac Health Council: ISACHC classes 1a and 1b), and a control group of 22 dogs were prospectively recruited. METHODS: Severity of MR was quantitatively assessed from the regurgitation fraction (RF) by the proximal isovelocity surface area method. Consequences of MR were evaluated from measurements of the left atrium/aorta ratio (LA/Ao), fractional shortening (FS), end-diastolic and end-systolic left ventricular volumes indexed to body surface area (EDVI and ESVI). The relevance of these echo-Doppler indices and NT-proBNP for prediction of outcome at 12 months was studied. RESULTS: A significant correlation was found between NT-proBNP and RF, LA/Ao, FS, and EDVI (P < .05). NT-proBNP was higher in dogs with MVD (ISACHC classes 1a and 1b) compared with the control group (P= .025 and < .001, respectively). The difference was not significant when only dogs from ISACHC class 1a with RF < 30% were considered. Lastly, NT-proBNP was higher in dogs that underwent MVD decompensation at 12 months (P < .05). CONCLUSIONS AND CLINICAL IMPORTANCE: NT-proBNP is correlated with MVD severity and prognosis in dogs with asymptomatic MVD.

Prospective echocardiographic and tissue Doppler imaging screening of a population of Maine Coon cats tested for the A31P mutation in the myosin-binding protein C gene: a specific analysis of the heterozygous status.

BACKGROUND: A mutation in the sarcomeric gene coding for the myosin-binding protein C gene has been identified in a colony of Maine Coon cats with hypertrophic cardiomyopathy (MyBPC3-A31P mutation). However, the close correlation between genotype and phenotype (left ventricular hypertrophy [LVH] and dysfunction) has never been assessed in a large population, particularly in heterozygous (Hetero) cats. OBJECTIVES: To investigate LV morphology and function with echocardiography and tissue Doppler imaging (TDI) in a population of Maine Coon cats tested for the MyBPC3-A31P mutation with focus on Hetero animals. ANIMALS: Ninety-six Maine Coon cats. METHODS: Prospective observational study. Cats were screened for the MyBPC3-A31P mutation and examined with both echocardiography and 2-dimensional color TDI. RESULTS: Fifty-two out of 96 cats did not have the mutation (wild-type genotype, Homo WT), 38/96 and 6/96 were Hetero- and homozygous-mutated (Homo M) cats, respectively. Only 11% of Hetero cats (4/38) had LVH and 29% (10/34) of Hetero cats without LVH were >4 years old (4.1-11.5 years). LVH was also detected in 2 Homo WT cats (4%). A significantly decreased (P < .05) longitudinal E/A (ratio between early and late diastolic myocardial velocities) in the basal segment of the interventricular septum was observed in Hetero cats without LVH (n = 34) compared with Homo WT cats without LVH (n = 50), thus confirming that the Hetero status is associated with regional diastolic dysfunction (P < .05). CONCLUSIONS: The heterozygous status is not consistently associated with LVH and major myocardial dysfunction. Moreover, Homo WT cats can also develop LVH, suggesting that other genetic causes might be implicated.

Effect of benazepril on survival and cardiac events in dogs with asymptomatic mitral valve disease: a retrospective study of 141 cases.

BACKGROUND: Angiotensin-converting enzyme inhibitors (ACEIs) improve quality of life and extend the life span of dogs with naturally acquired ISACHC class II-III congestive heart failure (CHF). However, their effects on asymptomatic heart disease remain controversial. HYPOTHESIS: Benazepril (BNZ), an ACEI, could have beneficial effects at the asymptomatic stage of degenerative mitral valve disease (MVD). ANIMALS: Dogs with ISACHC class Ia MVD and moderate-to-severe mitral regurgitation (MR) assessed by the color Doppler mapping technique at entry (Day 0) were retrospectively included. METHODS: Dogs were assigned to the treated group (BNZ group) if they received BNZ (and no other cardiac medication) from Day 0 or to the untreated group (UT group) if they did not receive any cardioactive treatment until occurrence of CHF. RESULTS: A total of 141 dogs were included in the study, 66 in the BNZ group (dosage: 0.30 +/- 0.13 mg/kg) and 75 in the UT group. In the population (n = 93) including all breeds except Cavalier (CKC) and King Charles Spaniels (KC), median survival time to all causes of death in the BNZ group (n = 34, 3.3 years) was significantly longer than in the UT group (n = 59, 1.9 years) as was time to cardiac event (P < .05). Conversely, no effect of the BNZ treatment was observed in the CKC and KC population. CONCLUSIONS AND CLINICAL RELEVANCE: BNZ had beneficial effects in asymptomatic dogs other than CKC and KC affected by MVD with moderate-to-severe MR. Breed distribution should be taken into account for interpretation of clinical trials performed in dogs with cardiac disease.

Comparison of 3 ultrasound methods for quantifying left ventricular systolic function: correlation with disease severity and prognostic value in dogs with mitral valve disease.

BACKGROUND: End-systolic volume index (ESVI) is a marker of systolic function, which can be assessed by the geometric (GM, based on Teichholz formula) or 2 planimetric methods (PM, Simpson's derived and length area methods). HYPOTHESIS: Systolic dysfunction (SyD) may be observed in dogs with mitral valve disease (MVD) and is better assessed by PM than GM, which does not take into account the longitudinal left ventricular systolic shortening. ANIMALS: Six healthy dogs were used to determine the variability of the tested variables (Study 1). These variables were then prospectively assessed (Study 2) in 101 small breed dogs: 77 dogs with MVD and 24 healthy controls (CD). METHODS: ESVI was measured by GM and PM in awake dogs. RESULTS: All within- and between-day coefficients of variation were <11% (Study 1). For Study 2, a nonlinear overestimation of ESVI was observed by GM compared with PM. PM-derived ESVI was significantly increased in ISACHC class 3 dogs compared with ISACHC class 1 dogs and exerted a significant influence on cardiac events at 5 months in dogs with MVD from ISACHC classes 2 and 3 (P < .05). CONCLUSIONS AND CLINICAL IMPORTANCE: ESVI can be calculated by GM and PM with good repeatability and reproducibility. However, GM overestimates ESVI in a nonlinear way. Therefore, PM-derived ESVI should be preferred for the detection of SyD that is present at the late stages of the disease.

Noninvasive assessment of systolic left ventricular torsion by 2-dimensional speckle tracking imaging in the awake dog: repeatability, reproducibility, and comparison with tissue Doppler imaging variables.

BACKGROUND: Left ventricular (LV) torsional deformation plays an important role in myocardial function. However, it has never been assessed in the awake dog, because magnetic resonance imaging and sonomicrometry have been the only methods available so far. HYPOTHESIS: Two dimensional speckle tracking echocardiography (STE), a new ultrasound imaging technique, provides a repeatable and reproducible noninvasive assessment of systolic LV wringing motion in the awake dog. ANIMALS: Six healthy dogs were used to determine the repeatability and reproducibility of STE variables (study 1). These variables also were prospectively assessed in a population of 35 healthy dogs (study 2). METHODS: Peak LV basal and apical systolic rotations were measured by STE from right parasternal short-axis views using automatic frame-to-frame tracking of gray-scale speckle patterns. Systolic LV torsion (LVtor, degrees ) was defined as apical rotation relative to the base. RESULTS: All within-day and between-day coefficients of variation were <20% (6.8-18.0%). Amplitude of apical systolic rotation was significantly higher (P < .001) than the basal value (5.4 +/- 3.2 degrees and -3.1 +/- 1.3 degrees , respectively). Global LVtor was significantly correlated with systolic longitudinal LV myocardial velocity gradient assessed by tissue Doppler (P < .05), but not with either systolic radial LV myocardial velocity gradient or the ratio of early mitral inflow velocity to early mitral annular velocity (Em/Ea). CONCLUSIONS AND CLINICAL IMPORTANCE: Speckle tracking echocardiography is a repeatable and reproducible method for assessing systolic LV torsional deformation. The combination of these new STE indices with tissue Doppler variables could provide a new approach for quantifying canine LV systolic function.

Congenital heart diseases in the boxer dog: A retrospective study of 105 cases (1998-2005).

Subaortic stenosis (SAS) is one of the most common congenital heart diseases (CHD) in dogs with Boxers being predominantly affected. However, the increasing availability of modern diagnostic imaging systems now allows a better assessment of cardiac morphology and function, thereby facilitating early detection of CHD in awake animals. In this context, the case records of Boxer dogs diagnosed with CHD using echocardiography combined with Doppler mode, were retrospectively reviewed (1998-2005). One hundred and five Boxers exhibiting either a single CHD (53/105, 50.5%) or association of several CHD (52/105, 49.5%) were included. The most common CHD was atrial septal defect (ASD) observed in 56.2% of these animals (59/105), followed by mitral dysplasia (58/105, 55.2%), and SAS (49/105, 46.7%). SAS was associated with one or two CHD in 29.5% of cases (31/105). Most of the dogs with a low intensity left heart base systolic murmur had an isolated ASD whereas most of the dogs with a similar but high intensity murmur had SAS, either isolated or associated with a concurrent CHD. The incidence of ASD and mitral dysplasia in Boxer dogs is higher than previously assumed, and ASD is a common cause of left heart base systolic murmur in this breed of dog. This confirms that the detection of such a murmur should not be used as the unique criterion for diagnostic confirmation of SAS.

Retrospective study of 156 atrial septal defects in dogs and cats (2001-2005).

Atrial septal defect (ASD) is a common congenital heart disease (CHD) in humans, but considered relatively rare in veterinary medicine. However, modern echocardiographic and Doppler techniques currently offer a good view of the morphology of the interatrial septum, thus facilitating earlier detection of ASD in awake animals. In this context, we carried out a retrospective study of cases of recently diagnosed ASD in dogs and cats at the Cardiology Unit of Alfort (2001-2005) using echocardiography combined with colour Doppler mode. ASD was diagnosed in 156 animals and represented 37.7% of all canine and feline CHDs (n = 414). ASD was the most common CHD after mitral dysplasia in both species. Boxer and Domestic shorthair were the most common canine and feline breeds affected. Most defects (98.7%) were secundum-type ASD, without clinical signs in 73.7% of cases. The most common clinical signs included systolic murmur heard over the left heart base (20.2%), exercise intolerance (7.0%), syncope (5.3%), dyspnoea (2.6%) and cough (2.6%). Animals that presented a systolic heart murmur over the left base had a significantly larger ASD than others (P < 0.05). These data suggest that the incidence of ASD is higher than previously assumed. ASD should be suspected, for example, in instances of left basal systolic heart murmur, although its clinical and haemodynamic consequences are usually minor.

Efficacy of oral tadalafil, a new long-acting phosphodiesterase-5 inhibitor, for the short-term treatment of pulmonary arterial hypertension in a dog.

Systolic pulmonary arterial hypertension (PAH) was diagnosed in a 15-year-old intact male Yorkshire terrier presented for progressive dyspnoea and coughing. Several examinations were performed (thoracic radiographs, faecal analysis, heartworm antigen test, tracheal fluoroscopy, abdominal ultrasound, complete blood cell count, urine and serum biochemistry) but the PAH remained of unknown origin. Despite medical treatment (diuretics and angiotensin-converting enzyme inhibitor), cardiovascular and respiratory signs dramatically worsened over a 1-month period, with several daily syncope, cyanosis and tachypnoea at rest requiring permanent oxygen therapy. Oral tadalafil (Cialis), a new long-acting phosphodiesterase-5 inhibitor, belonging to the same family as sildenafil (Viagra), was added to the background therapy. The condition of the dog improved quickly (< 24 h), and short-term follow up (7 days) showed a decrease in systolic pulmonary arterial pressure up to 26 mmHg concomitant with the disappearance of all respiratory and cardiac signs of PAH (cyanosis, syncope and tachypnoea). This case is of interest because it concerns the first reported short-term use of tadalafil in canine PAH. However, long-term studies with a large number of diseased animals are now required before prescription by general practitioners could be recommended.

Echocardiographic and Doppler diagnosis: first case of atrial septal aneurysm in a cat.

A 6-year-old female cat developed pleural and abdominal effusion. Cardiac ultrasound and 2D color tissue Doppler imaging revealed restrictive cardiomyopathy with severe biatrial dilatation and hypertension. This cardiomyopathy was associated with atrial septal aneurysm and a patent foramen ovale. The atrial septal aneurysm involved the entire atrial septum. Necropsy and histological examination confirmed all these findings. ASA is a rare malformation and, as in this cat, it generally occurs concomitantly with congenital or acquired heart disease and may be explained by greater pressure in one atrium, leading to controlateral protrusion of the atrial septum.