Hemodynamic effect of pimobendan following intramuscular and intravenous administration in healthy dogs: A pilot study.

Background: Pimobendan is widely used for the treatment of dogs with heart failure via the oral route. A new injectable form of pimobendan is now available and its potential usefulness via intravenous route has been recently demonstrated in dogs. However, the cardiovascular effects of intramuscular (IM) administration of injectable pimobendan have not been investigated yet. Hypothesis: IM administration of pimobendan may have the same hemodynamic effect as the IV route. Methods: Six healthy Beagle dogs underwent a placebo-controlled double-blind crossover study. The early cardiovascular effects after a single dose of IM and IV injections of pimobendan (0.2 ml/kg; Pimo IM and Pimo IV, respectively) were compared to the same volume of IM placebo (Saline IM) in anesthetized dogs. Clinical [heart rate (HR) and blood pressure (BP)] and echocardiographic hemodynamic parameters [left ventricular (LV) inflow waveforms of diastolic early wave (eV), atrial systolic wave (aV), diastolic early mitral ring velocity (e'), peak velocity (pV), stroke volume (SV), cardiac output (CO), and systemic vascular resistance (SVR)] were monitored with 15 min intervals for 120 min. Results: Diastolic BP decreased significantly at 30 min in Pimo IM compared to Saline IM. Mean eV and CO values significantly increased from 75 min, e' from 60 min, pV from 75 min, and SV from 15 to 120 min, whereas SVR significantly decreased at 30-60 min in Pimo IM compared to those of Saline IM (P < 0.05). Compared with the Pimo IV, eV and pV were significantly lower at 30-60 min (P < 0.05) while SV was significantly higher at 90-105 min in Pimo IM (P < 0.05). Other hemodynamic parameters (BP, HR, SVR, CO, e', and E/e') did not significantly change between Pimo IM and IV. Conclusions: The hemodynamic effect of pimobendan following IM and IV injection was described. Our results suggested that IM administration of pimobendan is equally comparable and possibly interchangeable with IV administration. This warrant further studies to investigate the clinical effectiveness of IM pimobendan in treating dogs with congestive heart failure or in heart failure cases unable to receive IV or oral administration.

Color M-Mode Echocardiography for Non-Invasive Assessment of the Intraventricular Pressure in Dogs Before and After Ductus Arteriosus Occlusion: A Retrospective Study.

Background: Novel non-invasive evaluation of the intraventricular pressure differences and gradients (IVPD and IVPG) by color M-mode echocardiography (CMME) is a promising method in diastolic function evaluation. Patent ductus arteriosus (PDA) is a congenital heart defect which is associated with increased preload. The present work provides a clinical trial for the assessment of IVPD and IVPG changes in dogs before and after surgical occlusion of PDA. Materials and Methods: A total of 12 client-owned dogs were enrolled in this study. PDA was confirmed using echocardiography, and all dogs underwent PDA occlusion. Conventional echocardiography and CMME were conducted on each patient on the operation day (Pre-PDA) and 48 h after its occlusion (Post-PDA). The total IVPD and total IVPG, as well as segmental intraventricular pressure (basal, mid-to-apical, mid, and apical) were measured from Euler's equation using specific software (MATLAB). Data were analyzed for variability and for the difference between pre- and post-PDA. The effect of PDA occlusion on the measured variables was calculated using biserial ranked correlation (rc). Results: There was a significant reduction in end-diastolic volume, fraction shortening, stroke volume, and mitral inflow velocities (early and late) after PDA closure. CMME was feasible in all dogs, and the CMME indices showed moderate variability, except for the apical segment of IVPD and IVPG. After PDA closure, in comparison with the pre-PDA occlusion, there was a significant reduction in total IVPD (2.285 ± 0.374 vs. 1.748 ± 0.436 mmHg; P = 0.014), basal IVPD (1.177 ± 0.538 vs. 0.696 ± 0.144 mmHg; P = 0.012), total IVPG (1.141 ± 0.246 vs. 0.933 ± 0.208 mmHg; P = 0.032), and basal IVPG (0.578 ± 0.199 vs. 0.377 ± 0.113 mmHg; P = 0.001); meanwhile, mid, mid-to-apical, and apical segments of both IVPD and IVPG showed non-significant difference. The magnitude of PDA occlusion on the measured variables was clinically relevant and associated with a large effect size on total and basal IVPD and IVPG (rc > 0.6). Conclusion: The current clinical study revealed matched response of IVPD and IVPG to the reduced preload rather than left ventricular relaxation. This result is an initial step in the clinical utility of CMME-derived IVPD and IVPG measurements in the diastolic function evaluation in dogs with PDA that warrants further clinical studies.

Adjunct ambrisentan therapy had clinical benefits in 5 dogs with sildenafil-refractory pulmonary hypertension.

Although sildenafil is used in dogs with severe pulmonary hypertension, they sometimes become resistant and clinical signs deteriorate over time. The objective of this study was to determine the benefits of adjunct ambrisentan therapy in dogs with sildenafil-refractory pulmonary hypertension. In 5 dogs with severe pulmonary hypertension with deteriorating clinical signs despite ongoing sildenafil treatment, adding ambrisentan improved appetite, activity, and respiratory functions. Although peak tricuspid valve regurgitation velocity, as measured by Doppler echocardiography, did not necessarily decrease after ambrisentan administration, there was improved partial pressure of arterial oxygen and the alveolar-arterial oxygen gradient, with no apparent side effects. We concluded that ambrisentan has potential as an adjunct treatment in dogs with pulmonary hypertension that are refractory to sildenafil therapy. Key clinical message: Ambrisentan improved clinical signs in dogs with sildenafil-refractory pulmonary hypertension.

Le traitement d'appoint à l'ambrisentan a eu des avantages cliniques chez cinq chiens atteints d'hypertension pulmonaire réfractaire au sildénafil. Bien que le sildénafil soit utilisé chez les chiens souffrant d'hypertension pulmonaire sévère, ils deviennent parfois résistants et les signes cliniques s'aggravent avec le temps. L'objectif de cette étude était de déterminer les avantages d'un traitement d'appoint à l'ambrisentan chez les chiens souffrant d'hypertension pulmonaire réfractaire au sildénafil. Chez cinq chiens souffrant d'hypertension pulmonaire sévère avec détérioration des signes cliniques malgré un traitement continu au sildénafil, l'ajout d'ambrisentan a amélioré l'appétit, l'activité et les fonctions respiratoires. Bien que la vitesse maximale de régurgitation de la valve tricuspide, mesurée par échocardiographie Doppler, n'ait pas nécessairement diminué après l'administration d'ambrisentan, la pression partielle d'oxygène artériel et le gradient alvéolo-artériel d'oxygène ont été améliorés, sans effets secondaires apparents. Nous avons conclu que l'ambrisentan a un potentiel en tant que traitement d'appoint chez les chiens souffrant d'hypertension pulmonaire qui sont réfractaires au traitement par le sildénafil.Message clinique clé:L'ambrisentan a amélioré les signes cliniques chez les chiens souffrant d'hypertension pulmonaire réfractaire au sildénafil.(Traduit par Dr Serge Messier).

Successful ligation of the left and right gastric vein in a dog with congenital portosystemic shunts type Aii.

The type Aii shunt is a congenital extrahepatic portosystemic shunt (ePSS) involving the left and right gastric vein and the caudal vena cava (CVC). This report describes the case of a 6-month-old Italian greyhound diagnosed with a type Aii large-diameter ePSS. Staged surgeries were employed to completely ligate the 2 gastric veins and to avoid the risk of traumatizing the shunt vessel, CVC, and celiac artery. Clinical signs improved postoperatively, and after 3 years, ultrasonography demonstrated no evidence of reoccurrence. This procedure provides an alternative surgical option for correction of ePSS type Aii. Key clinical message: This case report demonstrates congenital PSS involving the left and right gastric vein and the caudal vena could be treated with both ligation of left and right gastric vein. This technique could decrease the risk of traumatizing the shunt vessel, CVC, and celiac artery.

Ligature réussie des veines gastriques gauche et droite chez un chien avec des shunts portosystémiques congénitaux de type Aii. Le shunt de type Aii est un shunt porto-systémique extrahépatique congénital (ePSS) impliquant la veine gastrique gauche et droite et la veine cave caudale (CVC). Ce rapport décrit le cas d'un lévrier italien de 6 mois diagnostiqué avec un ePSS de grand diamètre de type Aii. Des chirurgies par étapes ont été effectuées pour ligaturer complètement les deux veines gastriques et pour éviter le risque de traumatiser le vaisseau avec shunt, la CVC et l'artère coeliaque. Les signes cliniques se sont améliorés après l'opération et après trois ans, l'échographie n'a montré aucun signe de récidive. Cette procédure offre une option chirurgicale alternative pour la correction de l'ePSS de type Aii.Message clinique clé :Ce rapport de cas démontre un ePSS congénital impliquant la veine gastrique gauche et droite et la veine caudale pouvant être traité par la ligature de la veine gastrique gauche et droite. Cette technique pourrait diminuer le risque de traumatiser le vaisseau avec shunt, le CVC et l'artère coeliaque.(Traduit par Dr Serge Messier).

Autologous tunica vaginalis communis flap for repairing an abdominal wall hernia in a dog.

An 8-year-old, intact male miniature dachshund dog, weighing 8.6 kg, was presented with a soft swelling in the caudal abdominal region, including both sides of the groin area. Laparotomy revealed a severe caudal abdominal wall hernia with atrophy of the rectus abdominal muscle. The defect was repaired using a tunica vaginalis communis flap following a standard open prescrotal castration. There were no complications or recurrence of the hernia at 11 months after surgery. This surgical technique involves autogenous reconstruction, is easy to perform, and requires minimal dissection. The tunica vaginalis communis flap has potential clinical applications for repairing caudal abdominal wall hernias in male dogs.

Lambeau de tunique vaginale autologue pour la réparation d'une hernie de la paroi abdominale chez un chien. Un teckel miniature mâle intact de 8 ans, pesant 8,6 kg, a présenté une enflure molle dans la région abdominale caudale, y compris des deux côtés de la région de l'aine. La laparotomie a révélé une hernie sévère de la paroi abdominale caudale avec atrophie du muscle abdominal droit. Le défaut a été réparé à l'aide d'un lambeau de la tunique vaginale après une castration préscrotale ouverte standard. Il n'y a eu aucune complication ni récidive de la hernie 11 mois après la chirurgie. Cette technique chirurgicale implique une reconstruction autogène, est facile à réaliser et nécessite une dissection minimale. Le lambeau de tunique vaginale a des applications cliniques potentielles pour la réparation des hernies de la paroi abdominale caudale chez les chiens mâles.(Traduit par Dr Serge Messier).

The Utility of Intraventricular Pressure Gradient for Early Detection of Chemotherapy-Induced Subclinical Cardiac Dysfunction in Dogs.

Early detection of doxorubicin (DXR)-induced cardiomyopathy (DXR-ICM) is crucial to improve cancer patient outcomes and survival. In recent years, the intraventricular pressure gradient (IVPG) has been a breakthrough as a sensitive index to assess cardiac function. This study aimed to evaluate the usefulness of IVPG for the early detection of chemotherapy-related cardiac dysfunction. For this purpose, six dogs underwent conventional, speckle tracking, and color M-mode echocardiography concomitantly with pressure-and-volume analysis by conductance catheter. The cardiac function measurements were assessed before DXR administration (baseline, Pre), at the end of treatment protocol (Post), and at 1.5 years follow-up (Post2). The result showed a significant reduction in the left ventricular end-systolic pressure-volume (Emax: 4.4 ± 0.7, 6.1 ± 1.6 vs. 8.4 ± 0.8 mmHg/mL), total-IVPG (0.59 ± 0.12, 0.62 ± 0.15 vs. 0.86 ± 0.12 mmHg), and mid-IVPG (0.28 ± 0.12, 0.31 ± 0.11 vs. 0.48 ± 0.08 mmHg), respectively in Post2 and Post compared with the baseline (p < 0.05). Mid-to-apical IVPG was also reduced in Post2 compared with the baseline (0.29 ± 0.13 vs. 0.51 ± 0.11). Meanwhile, the fraction shortening, ejection fraction, and longitudinal strain revealed no change between groups. Total and mid-IVPG were significantly correlated with Emax (R = 0.49; p < 0.05, both) but only mid-IVPG was a predictor for Emax (R2 = 0.238, p = 0.040). In conclusion, this study revealed that impairment of contractility was the initial changes observed with DXR-ICM in dogs and only IVPG could noninvasively detect subclinical alterations in cardiac function. Color M-mode echocardiography-derived IVPG could be a potential marker for the early detection of doxorubicin cardiomyopathy.

Effects of Individual and Coexisting Diabetes and Cardiomyopathy on Diastolic Function in Rats (Rattus norvegicus domestica).

The goal of this study was to evaluate diastolic intraventricular pressure gradients (IVPG) and 2-dimensional tissue tracking (2DTT) patterns during diabetes and cardiomyopathy. Rats (n = 60) were induced to become diabetic (DM group, n = 15) by using streptozotocin, to become cardiomyopathic (CM group, n = 15) by using isoproterenol, and to become both diabetic and cardiomyopathic (DMCM group, n = 15); control rats (CT group, n = 15) were injected with saline. Two months after induction, all rats underwent conventional echocardiography, IVPG, and 2DTT and then were euthanized for microscopic examination of cardiac fibrosis. Compared with the controls, all 3 treated groups showed diastolic dysfunction and delayed cardiac relaxation. DMCM rats showed the most pronounced cardiac abnormalities. In addition, CM and DMCM groups had showed decreased middle IVPG, whereas DMCM rats had decreased midapical IVPG. Although the overall IVPG of the CM group was normal, the middle segment was significantly decreased. 2DTT results showed that the DMCM group had a delay in relaxation compared with other groups. IVPG and 2DTT can be used to overcome the limitation of conventional echocardiographic methods and reveal diastolic dysfunction. DM worsened diastolic function during cardiac disease.

Metformin prevents the development of monocrotaline-induced pulmonary hypertension by decreasing serum levels of big endothelin-1.

Pulmonary hypertension (PH) is a disease with poor prognosis, and it is characterized by the progressive elevation of pulmonary vascular resistance and pressure. Various factors are associated with the pathology of PH, including AMP-activated protein kinase (AMPK) deficiency. The present study aimed to evaluate the therapeutic effect of metformin, an AMPK activator, in a monocrotaline (MCT)-induced PH rat model. Rats were randomly divided into the following three groups: i) Saline-injected group (sham group); ii) monocrotaline (MCT)-injected group (PH group); iii) MCT-injected and metformin-treated group (MT group). Four weeks following MCT injection, cardiac ultrasonography, invasive hemodynamic measurements, measurement of serum levels of big endothelin-1 (big ET-1) and histological analysis were performed to evaluate the effect of metformin treatment in PH. Pulmonary arterial pressure and serum big ET-1 concentrations were reduced in the MT group compared with the PH group. Medial wall thickness and wall area of the pulmonary arterioles in the MT group were decreased compared with the PH group. Comparing the right heart functional parameters among groups revealed that the acceleration time/ejection time ratio improved in the MT group compared with the PH group. Thus, the present study demonstrated the efficacy of metformin in an MCT-induced PH rat model and suggested that metformin may be a valuable, potential novel therapeutic for the treatment of PH.

Key factors of diastolic dysfunction and abnormal left ventricular relaxation in diabetic rats.

PURPOSE: To study the diastolic functions using color Doppler M-mode (CDMM) for noninvasive analysis of the intraventricular pressure difference (IVPD) in diabetic rats. METHODS: Two equal groups of rats were included: control and streptozotocin-induced DM (n = 15). The cardiac functions were examined monthly using conventional echocardiography and CDMM with a specific MATLAB software. Echocardiography was performed under 2% isoflurane mask inhalation. Five months thereafter, all rats were killed for macroscopic and microscopic examinations of the cardiac fibrosis. RESULTS: DM rats showed higher systolic blood pressure and diastolic dysfunction, i.e., decreases in several parameters such as E, E/A, TDIs, and IVPDs, compared to the controls. Moreover, obvious cardiac fibrosis was seen in perivascular and interstitial tissues, but there were no notable differences in terms of gross lesions. CONCLUSIONS: Because of the noninvasive nature of CDMM, IVPD and other conventional echocardiographic parameters can be used as reliable indicators generally for evaluating cardiac function and particularly the change in intraventricular pressure.

Changes in left ventricular blood flow during diastole due to differences in chamber size in healthy dogs.

Vorticity is a novel index that reflects diastolic function of left ventricle. The size of the ventricle can influence the ventricular diastolic blood flow. We evaluated effect of ventricular size on diastolic function and diastolic intracardiac blood flow using a particular species of dogs, which has a wide range of body size. Vector flow mapping was used for evaluation of intracardiac blood flow, and intraventricular pressure gradient (IVPG) was used for evaluation of diastolic function. 58 dogs weighing 1.3-42.3 kg were included in this study. Vorticity was found to be inversely proportional to the length of the ventricular chamber. Intraventricular pressure difference was positively correlated with the length of the left ventricle, whereas IVPG was not. This study showed that the vorticity is influenced by the size of the left ventricle independently of other factors. To evaluate the hemodynamic state of each individual appropriately by using vorticity and IVPD, ventricular size should be taken into account especially in the field of veterinary medicine and human pediatric and adolescent cardiology.

Effects of high-dose alacepril on left atrial pressure and central aortic pressure in awake dogs with mitral valve regurgitation.

The purpose of this study was to clarify how alacepril in amounts greater than those recommended on the product labeling approved by drug regulatory agencies affects left atrial pressure (LAP) and central aortic pressure in dogs with experimentally induced mitral valve regurgitation (MR). Six healthy Beagle dogs were surgically induced for MR and received alacepril at either 1.5mg/kg/12-h (3.0mg/kg/day) or 3.0mg/kg/12-h (6.0mg/kg/day) per one administration for seven days. After a four-week washout period, another dosage was administrated as a crossover study. Dogs were randomised to receive 3.0mg/kg/day or 6.0mg/kg/day first. LAP and central systolic (SAP), mean (MAP), and diastolic (DAP) aortic pressure were measured for 24-h before and during the administration of alacepril. The earliest decreases in SAP, MAP, and DAP with 6.0mg/kg/day were observed on days 4, 4, and 5, respectively. With 3.0mg/kg/day, the earliest decrease in DAP was observed on day 7. The maximum LAP was decreased on days 5 and 7 with 6.0mg/kg/day. The mean LAP was decreased on day 7 with 6.0mg/kg/day. In conclusion, the administration of alacepril at 6.0mg/kg/day reduced the LAP and central aortic pressure within several days.

Left ventricular vortex and intraventricular pressure difference in dogs under various loading conditions.

Restrictions on the conventional evaluation of diastolic function have been recognized, especially under various loading conditions. Recently, new noninvasive ventricular vortex indexes have been introduced and are expected to reflect the cardiac function. Physiologically, there is a hypothesis that the intraventricular pressure difference (IVPD) is related to the formation of vortexes. IVPD and vortex indexes were simultaneously measured, and the relationship between the two was investigated. To verify the possibility of diastolic vorticity as an index of diastolic relaxation, a correlation between diastolic vorticity and the load dependency of vorticity [time constant (τ)] was examined. Six healthy dogs were studied using transthoracic echocardiography, pressure, and a conductance catheter. Vorticity was analyzed using vector flow mapping (VFM). IVPD was determined using Euler's equation with color M-mode Doppler images. Data were obtained at baseline, at balloon dilatation in the thoracic aorta to alter afterload, at hydroxyethyl starch infusion to alter preload, and at milrinone administration to alter ventricular relaxation. Peak vorticity at early diastole (E-Vor) and IVPD of the midventricle (MIVPD) decreased under pressure loading, were unchanged under volume loading, and increased during milrinone administration. In multivariate analysis, the independent predictors of τ were global longitudinal strain, strain rate at early diastole, and E-Vor. MIVPD was strongly correlated with E-Vor ( r = 0.84). VFM-derived peak E vorticity was strongly related to IVPD, especially MIVPD, under various loading conditions. Both of these novel indexes are promising as reliable indexes of ventricular relaxation, independent from preload. NEW & NOTEWORTHY We showed the close relationship of vortex and intraventricular pressure difference and showed that both of them can become new markers of the left ventricular relaxation property. Our present study creates a paradigm for future studies in the field of intraventircular flow physiology and clinical diastology.

Combined cutting balloon and conventional balloon angioplasty in a dog with supravalvular pulmonary stenosis.

A 7-year-old Miniature Schnauzer presented with exercise intolerance and easy fatigability. Echocardiography revealed the presence of supravalvular pulmonary stenosis. The peak velocity through the stenosis was 6.4 m/sec, and the interventricular septum was flattened. Cutting balloon angioplasty was designed for the treatment of coronary artery stenosis, which was resistant to conventional balloon angioplasty. Accordingly, the dog underwent cutting balloon angioplasty and conventional balloon dilation. One month after treatment, it showed neither exercise intolerance nor easy fatigability. The ventricular septum flattening disappeared. Five months later, the dog showed an increase in activity. Two years later, the peak velocity through the stenosis decreased to 4.4 m/sec. Neither clinical symptoms nor restenosis was observed. Thus, supravalvular pulmonary stenosis was successfully treated using this combination method. The present case showed that combined cutting balloon and conventional balloon angioplasty is a useful and minimally invasive treatment for supravalvular pulmonary stenosis.

Dose-dependent effects of isoflurane and dobutamine on cardiovascular function in dogs with experimental mitral regurgitation.

OBJECTIVE: To investigate the dose-dependent effects of isoflurane and dobutamine on haemodynamics in dogs with experimentally induced mitral valve insufficiency (MI). STUDY DESIGN: Experimental, dose-response study. ANIMALS: Six healthy Beagle dogs. METHODS: Dogs with surgically induced MI were anaesthetized once. First, anaesthesia was maintained at an end-tidal isoflurane concentration (Fe'Iso) 1.0% (ISO1.0) for 20 minutes. Then, dobutamine was infused successively at 2, 4, 8 and 12 µg kg-1 minute-1 (DOB2-12) for 10 minutes at each dose rate. Measurements were recorded at each stage. Dobutamine was discontinued and Fe'Iso was increased to 1.5% (ISO1.5) for 20 minutes. Dobutamine was administered similarly to ISO1.0, and cardiovascular variables were recorded. The same sequence was repeated for Fe'Iso 2.0% (ISO2.0). Aortic pressure (AoP) and left atrial pressure (LAP) were recorded by radiotelemetry. The combination method of the pressure-volume loop analysis and transoesophageal echocardiography was used to measure cardiovascular variables: end-systolic elastance (Ees), effective arterial elastance (Ea), Ea/Ees, forward stroke volume (FSV), heart rate (HR), and cardiac output (CO). RESULTS: High isoflurane concentration resulted in reduced Ees and increased Ea/Ees, which indicated low arterial pressure. High-dose dobutamine administration resulted in increased Ees and FSV at all isoflurane concentrations. In ISO1.5 and ISO2.0, HR was lower at DOB4 than baseline (BL) but increased at DOB12 compared with DOB4. CO increased at ≥ DOB8 compared with BL. In ISO1.5 and ISO2.0, systolic and mean AoP increased at ≥ DOB4 and ≥ DOB8, respectively. LAP did not change under all conditions. CONCLUSIONS AND CLINICAL RELEVANCE: The dose-dependent hypotensive effect of isoflurane in MI dogs was mainly derived from the decrease in contractility. Dobutamine increased AoP without increasing LAP by increasing the contractility attenuated by isoflurane. Our findings may improve the cardiovascular management of dogs with MI undergoing general anaesthesia with isoflurane.

Surgery for partial atrioventricular septal defect with pulmonary hypertension in an adult dog.

A 4-year-old, 5.9-kg female Japanese Spitz presented with syncope and exercise intolerance. Echocardiography revealed an ostium primum atrial septal defect (ASD), a cleft mitral valve, mitral valve regurgitation (MR), and tricuspid regurgitation (TR) (velocity: 3.6 m/sec, pressure gradient: 52 mmHg), leading to a diagnosis of partial atrioventricular septal defect (AVSD) with moderate pulmonary hypertension (PH). Open-heart surgery using cardiopulmonary bypass was performed through right atriotomy. The cleft of the mitral valve was sutured with polypropylene and the AVSD was closed using an autologous pericardial patch fixed with glutaraldehyde. No postoperative pulmonary hypertensive crisis occurred. Shunting flow through the ASD, TR and PH had completely disappeared 2 months postoperatively; however, moderate MR persisted. The dog is still alive 5 years postoperatively without clinical signs.

Canine case of swallowing syncope that improved after pacemaker implantation.

A 14-year-old intact male West Highland White Terrier weighing 6.9 kg was admitted to the Tokyo University of Agriculture and Technology Animal Medical Center with the complaint of syncope after showing signs of nausea during feeding. Sinus arrest induced by deglutition was confirmed using a Holter electrocardiography test. However, the clinical symptoms significantly improved after implantation of a permanent pacemaker. Seven months after implantation, the dog died from acute pancreatitis, a cause unrelated to the syncope. Immediately after its death, the heart, lungs, gastrointestinal tract, and other organs were dissected and examined histopathologically. The brain was also examined using magnetic resonance imaging. Examination results led to the diagnosis of swallowing-induced situational syncope.

The relationship between systolic vector flow mapping parameters and left ventricular cardiac function in healthy dogs.

Vector flow mapping (VFM) is a novel echocardiographic technology that shows blood flow vectors and vortexes, enabled the hydrokinetic evaluation of hemodynamics within the left ventricle. VFM provides several unique parameters: circulation, vorticity, vortex area, and energy loss. The present study aims to reveal a relationship between VFM parameters and cardiac function. Five healthy Beagle dogs were anesthetized and administered with dobutamine (0, 2, 4, 8, 12 µg/kg/min). Pressure-volume diagrams were acquired to assess cardiac function using pressure-volume conductance catheter. Systolic maximum circulation, vorticity, vortex area, and energy loss were measured using VFM. The systolic maximum circulation, systolic vorticity, systolic vortex area, and systolic energy loss were increased by dobutamine administration. There was a strongly significant correlation between the systolic maximum circulation and ejection fraction (r = 0.76), maximal positive left ventricular (LV) pressure derivatives (dP/dt max) (r = 0.80), and end-systolic LV elastance (r = 0.73). Systolic vorticity and systolic vortex area were strongly correlated with ejection fraction (r = 0.76, 0.68) and dP/dt max (r = 0.76, 0.69), and end-systolic LV elastance (r = 0.62, 0.74), respectively. Systolic energy loss was strongly correlated with dP/dt max (r = 0.78), systolic maximum circulation (r = 0.81), and systolic vorticity (r = 0.82). The present study revealed that systolic VFM parameters are associated with the LV contractility. Furthermore, systolic energy loss was susceptible to the systolic vortex parameters such as systolic vorticity and systolic maximum circulation. Systolic VFM parameters are new hydrokinetic indices reflecting LV contractility.

Effective new membrane for preventing postthoracotomy pleural adhesion by surface water induction technology.

BACKGROUND: After thoracic surgery, adhesions between the pleura can cause substantial complications. This study investigated the effectiveness of a novel membrane utilizing surface water induction technology to prevent adhesions. METHODS: Eight beagles were divided into an experimental group (five males) and a control group (three females). The experimental group underwent thoracotomy on both the left and right sides of the chest. Both sides received the membrane, and the membrane on one side was glued to the pleura using tissue adhesive. The control group underwent thoracotomy only on the left side. Two weeks postoperatively, all dogs were sacrificed and adhesions were evaluated macroscopically and microscopically. RESULTS: Severe adhesion was seen between the parietal and visceral pleura in all control dogs, whereas the experimental group showed minor adhesion in only one dog on one side. CONCLUSIONS: Our novel anti-adhesive membrane appeared highly effective in preventing postthoracotomy pleural adhesions.

Effects of postural change on transesophageal echocardiography views and parameters in healthy dogs.

The purpose of the present study is to investigate the effect of postural change on transesophageal echocardiography (TEE) views and parameters of interest anesthesia monitoring in healthy dogs. Twelve Beagle dogs were anesthetized and randomly positioned in one of four postures: right lateral-recumbency, left lateral-recumbency, supine position and prone position. After examinations in one posture, the same examination was demonstrated in another posture and repeated in all postures. In each posture, several standard TEE views were demonstrated: longitudinal cranial-esophageal aorta long-axis-view, transverse middle-esophageal mitral valve long-axis-view and transgastric middle short-axis-view. Additionally, echocardiographic parameters were attempted to measure, and direct blood pressure monitoring was performed in each view. As a result, oriented views, except for transgastric middle short-axis-view, could be obtained in all postures. Stroke volume and peak early diastolic velocity of mitral inflow were lower in supine position compared with those in right and left lateral-recumbency. Heart rate (HR) and systemic vascular resistance were higher in supine position compared with those in right and left lateral-recumbency. Left ventricular pre-ejection period/left ventricular ejection time corrected and uncorrected by HR were higher in supine position compared with those in right and left lateral-recumbency. In conclusion, longitudinal cranial-esophageal aorta long-axis-view and transverse middle-esophageal mitral valve long-axis-view provide useful information of interest anesthesia monitoring, because of their views enable to certainly obtain TEE parameters in various postures. Furthermore, TEE parameters allow to detect the changes of preload, afterload and HR that occur in supine position dogs.

Hybrid technique coil embolisation for intrahepatic arterioportal fistula in a cat: case report.

CASE SUMMARY: A 13-month-old, female, mixed breed, 4.0 kg cat was referred with a 6 month history of decreased appetite, loss of vigour and intermittent vomiting. Physical examination revealed no cyanosis or wasting, and no audible heart murmur was auscultated. Blood profile revealed mild anaemia and mildly elevated postprandial serum ammonia (109 µg/dl). Abdominal ultrasonography revealed dilation of an intrahepatic portal vein branch and an intrahepatic aneurysm, with splenomegaly and ascites. Hepatic arteriovenous fistula/hepatic artery-portal vein fistula with multiple acquired portosystemic shunts was strongly suspected. Medical control was achieved using antibiotics, liver-protecting agents, a low-protein diet and blood transfusions. However, because medical treatment proved ineffective, coil embolisation was performed on day 11, using a hybrid approach via the mesenteric vein. Subsequent follow-up showed good appetite, with no signs of diarrhoea or ascites. Abdominal ultrasonography revealed that the mosaic pattern around the site of coil placement in the portal vein branch had improved and pulsatility had disappeared. RELEVANCE AND NOVEL INFORMATION: Intrahepatic arterioportal fistula involves a circulatory shunt between the hepatic artery and the hepatic or portal vein within the liver, and may be congenital or acquired. Both forms have been reported in humans, but most cases in cats have been congenital. Few reports have described treatment methods or prognosis in cats. We report here that coil embolisation using a hybrid approach is a procedure offering easy, effective treatment by blocking hepatofugal blood flow.