Longitudinal analysis of echocardiographic and cardiac biomarker variables in dogs with atrial fibrillation: The optimal rate control in dogs with atrial fibrillation II study.

BACKGROUND: Rate control (RC; meanHRHolter ≤ 125 bpm) increases survival in dogs with atrial fibrillation (AF). The mechanisms remain unclear. HYPOTHESIS/OBJECTIVES: Investigate echocardiographic and biomarker differences between RC and non-RC (NRC) dogs. Determine if changes post-anti-arrhythmic drugs (AAD) predict successful RC in subsequent Holter monitoring. Evaluate if early vs late RC affects survival. ANIMALS: Fifty-two dogs with AF. METHODS: Holter-derived mean heart rate, echocardiographic and biomarker variables from dogs receiving AAD were analyzed prospectively at each re-evaluation and grouped into RC or NRC. The primary endpoint was successful RC. Between group comparisons of absolute values, magnitude of change from admission to re-evaluations and end of study were performed using Mann-Whitney tests or unpaired t-tests. Logistic regression explored variables associated with inability to achieve RC at subsequent visits. Kaplan-Meier survival analysis was used to compare survival time of early vs late RC. RESULTS: At visit 2, 11/52 dogs were RC; at visit 3, 14/52 were RC; and at visit 4, 4/52 were RC. At the end of study, 25/52 remained NRC. At visit 2, both groups had increased cardiac dimensions, but NRC dogs had larger dimensions; biomarkers did not differ. At the end of study, RC showed decreased cardiac dimensions and end-terminal pro-brain natriuretic peptide (NT-proBNP) compared with NRC. No variables were useful at predicting RC success in subsequent visits. Survival analysis found no differences between early vs late RC. CONCLUSIONS AND CLINICAL IMPORTANCE: The RC dogs had decreased cardiac dimensions and NT-proBNP, suggesting HR-mediated reverse-remodeling might benefit survival, even with delayed RC achievement. Pursuit of RC is crucial despite initial failures.

Retrospective evaluation of a right heart parameter score in the assessment of precapillary pulmonary hypertension in dogs (2017-2021): 135 cases.

OBJECTIVE: To determine if emergency and critical care residents can identify moderate to severe precapillary pulmonary hypertension on cardiologist-obtained cineloops using a pulmonary hypertension score (PHS) and report the interobserver variability of the PHS. DESIGN: Multicenter, retrospective, case-control study from 2017 to 2021. SETTING: Private referral center and veterinary teaching hospital. ANIMALS: One hundred and thirty-five client-owned dogs that underwent diagnostic echocardiography. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Medical records of dogs with stage B1 myxomatous mitral valve disease (MMVD) and dogs diagnosed with precapillary pulmonary hypertension (PCPH) via echocardiograms were reviewed. Dogs were categorized by a cardiologist into 5 groups (normal, B1 MMVD, mild, moderate, and severe PCPH) based on Doppler pulmonary pressure gradients and right heart morphology. Cineloops from each case were subjectively evaluated by emergency and critical care residents for the presence of right atrial and ventricular enlargement, right ventricular hypertrophy, interventricular septal flattening, and pulmonary artery and trunk enlargement to form a composite pulmonary hypertension score out of 8 (PHS8). When available, signs of peritoneal effusion and distention of the caudal vena cava were subjectively assessed to generate a pulmonary hypertension score out of 10 (PHS10). There was excellent discrimination of moderate to severe PCPH versus grouped absent to mild PCPH using PHS8 (area under the receiver operator curve [AUC] [95% confidence interval, CI] = 0.90 [0.84-0.95], P < 0.0001) and PHS10 (AUC [95% CI] = 0.89 [0.81-0.97], P < 0.0001). PHS8 ≥3 was 64% sensitive and 98% specific for moderate to severe PCPH (positive likelihood ratio [LR+] 32, negative likelihood ration [LR-] 0.37). PHS10 ≥ 3.3 was 64% sensitive and 92% specific for moderate to severe PCPH (LR+ 8, LR- 0.39). Interobserver agreement was good to excellent (intraclass correlation coefficient [ICC] = 0.74 [95% CI: 0.66-0.80], n = 135). CONCLUSIONS: Residents identified moderate to severe PCPH in dogs using PHS on cineloops previously obtained by a cardiologist. The interrater agreement was good to excellent with limited training. Prospective studies to determine if residents can obtain diagnostic images for PHS are warranted.

Echocardiographic findings in apparently healthy Czechoslovakian wolfdogs.

INTRODUCTION: To echocardiographically evaluate a large number of apparently healthy Czechoslovakian wolfdogs (CWDs) to identify possible subclinical cardiac abnormalities and to generate reference intervals. ANIMALS: One-hundred and seventeen apparently healthy client-owned CWDs. MATERIALS AND METHODS: Standard two-dimensional, M-mode, and Doppler echocardiographic measurements were obtained on non-sedated, manually restrained standing dogs. Animals with no relevant echocardiographic abnormalities were used to generate reference intervals. Echocardiographic variables were compared between males and females and between dogs with and without mitral regurgitation (MR). RESULTS AND DISCUSSION: Among the 117 CWDs, 103 dogs were used to generate reference intervals. The 14 dogs with abnormalities had more than trivial MR (12 dogs), subaortic stenosis (one dog), and equivocal subaortic stenosis (one dog). The 44 males were heavier than 59 females (P<0.001) and had a larger maximum left atrial dimension (P=0.015), left ventricular internal dimension at end-diastole (P<0.001) and systole (P<0.001), and thicker interventricular septum thickness at end-diastole (P=0.016). A positive linear correlation was identified between bodyweight and aortic root and left atrial diameters and left ventricular dimensions and between age and aortic root and left atrial diameter and peak late transmitral flow velocity. A negative linear correlation was identified between age and peak early transmitral flow velocity and the ratio between peak early and late transmitral flow velocities. No differences in echocardiographic-derived cardiac dimensions were detected between healthy dogs and dogs with more than trivial MR. CONCLUSIONS: In this population of CWDs, subclinical cardiac abnormalities were uncommon, and they were mainly classified as MR.

Outcome of serial cardiac evaluations during doxorubicin-based chemotherapy in small- to medium-sized dogs with multicentric lymphoma.

Doxorubicin is an anthracycline antitumor antibiotic with dose-dependent and cumulative cardiotoxicity. However, the necessity for serial cardiac evaluation is unknown in dogs without risk factors for dilated cardiomyopathy (DCM). This study aimed to investigate serial changes in echocardiographic and electrocardiographic measures in small- and medium-sized dogs after four doxorubicin doses. We included 17 dogs, weighting < 20 kg, with multicentric lymphoma. All dogs received doxorubicin over 30 min every 4 weeks as part of a multi-drug chemotherapy protocol. The average doxorubicin dose was 3.8 times per dog. Clinical cardiotoxicity was not observed during the monitoring period. The incidence of developing arrhythmia was not significantly associated with the number of doxorubicin doses received (P = 0.600). The development of valvular regurgitations and mitral regurgitation in these dogs was not significantly associated with the number of doxorubicin doses (P = 0.363 and P = 0.779, respectively). The other echocardiographic results were not significantly different between each evaluation. In conclusion, our results showed no significant cardiotoxicity under echocardiogram and electrocardiogram in small- and medium-sized dogs without risk factors for DCM after four doses of doxorubicin in a 30-minute infusion method.

Detection of Anaplasma phagocytophilum in an inflammatory pericardial effusion of a dog.

An 11-year-old female spayed German Wirehaired Pointer with a 1-week history of lethargy, hyporexia, diarrhea, and coughing presented with pericardial effusion causing cardiac tamponade. An echocardiogram revealed no structural cause for pericardial effusion. The pericardial effusion was an exudate with mixed macrophagic and neutrophilic inflammation. Morulae occasionally were found within neutrophils. The pericardial fluid and blood were qPCR and cPCR positive for Anaplasma phagocytophilum (NC State University, Vector-borne Disease Diagnostic Laboratory, Raleigh, NC). The dog's blood was negative by ELISA (Vetscan Flex4 Rapid Test, Zoetis, Parsippany, NJ) for A. phagocytophilum antibodies at initial presentation and subsequently positive (SNAP4DxPlus, IDEXX, Westbrook, ME) 7 days later. After pericardiocentesis and administration of doxycycline (5 mg/kg PO q12h for 14 days), a repeat echocardiogram performed 1 month later showed no recurrence of pericardial effusion.

The echocardiographic pulmonary to left atrial ratio: A noninvasive variable for the hemodynamic classification of pulmonary hypertension in dogs.

BACKGROUND: Hemodynamic classification of pulmonary hypertension (PH) has important clinical implications. However, only a few echocardiographic variables have been used to hemodynamically classify PH in dogs. OBJECTIVE: To evaluate the echocardiographic pulmonary to left atrial ratio index (ePLAR) in dogs with PH. ANIMALS: Forty-six dogs with intermediate to high probability of PH. METHODS: Cross-sectional study. Variables were compared between dogs with precapillary PH [PrePH (n = 24)] vs postcapillary PH [PostPH (n = 22)], and with combined PH [CombPH (n = 14)] vs isolated PH [IsoPH (n = 8)] using the t-, Mann-Whitney, Pearson's Chi, or Fisher's exact test. The receiver operating characteristic curve and Youden index were used to identify the optimal ePLAR cutoff value to differentiate among the groups, intraclass correlation coefficients (ICC) were used to determine the reliability of measurements. RESULTS: The mean (SD) ePLAR of the PrePH was higher than that of the PostPH group [0.36 (0.13) vs 0.26 (0.09), respectively; P = .005]. The median (interquartile range) ePLAR of the CombPH was higher than that of the IsoPH subgroup [0.29 (0.24-0.38), vs 0.20 (0.16-0.23), respectively; P = .001]. The best cutoff value of ePLAR for identifying IsoPH was <0.245 [AUC at cutoff point = 0.86; sensitivity (95% confidence interval [CI]) = 0.71 (0.47-0.95); specificity (95% CI) = 1 (0.76-1)]. The ICC analysis indicated a high degree of reliability. CONCLUSIONS AND CLINICAL IMPORTANCE: ePLAR can be considered a valid noninvasive variable to hemodynamically classify PH in dogs with an intermediate to high probability of PH. Assessment of ePLAR can be useful in the therapeutic management of PH in dogs.

Platelet hyperresponsiveness and increased platelet-neutrophil aggregates in dogs with myxomatous mitral valve disease and pulmonary hypertension.

BACKGROUND: Pulmonary hypertension (PH) in dogs with myxomatous mitral valve disease (MMVD) is caused by increased pulmonary venous pressure. Thrombosis, vascular remodeling, and vasoconstriction mediated by platelets could exacerbate PH. HYPOTHESIS: Dogs with PH will exhibit a hypercoagulable state, characterized by increased platelet activation, platelet-leukocyte, and platelet-neutrophil aggregate formation. ANIMALS: Eleven dogs (≥3.5 kg) diagnosed with MMVD and PH and 10 dogs with MMVD lacking PH. METHODS: Prospective cohort ex vivo study. All dogs underwent echocardiographic examination, CBC, 3-view thoracic radiographs, and heartworm antigen testing. Severity of PH and MMVD were assessed by echocardiography. Viscoelastic monitoring of coagulation was assessed using thromboelastography (TEG). Platelet activation and platelet-leukocyte/platelet-neutrophil interactions were assessed using flow cytometry. Plasma serotonin concentrations were measured by ELISA. RESULTS: Unstimulated platelets from dogs with MMVD and PH expressed more surface P-selectin than MMVD controls (P = .03). Platelets from dogs with MMVD and PH had persistent activation in response to agonists. The number of platelet-leukocyte aggregates was higher in dogs with MMVD and PH compared with MMVD controls (P = .01). Ex vivo stimulation of whole blood resulted in higher numbers of platelet-neutrophil aggregates in dogs with MMVD and PH (P = .01). Assessment of hypercoagulability based on TEG or plasma serotonin concentrations did not differ between groups. CONCLUSION AND CLINICAL IMPORTANCE: Platelet hyperresponsiveness and increased platelet-neutrophil interaction occur in dogs with MMVD and PH, suggesting that platelets play a role of in the pathogenesis of PH. Clinical benefits of antiplatelet drugs in dogs with MMVD and PH require further investigation.

[Diagnosis and treatment of feline persistent ductus arteriosus: a retrospective evaluation of 17 cats]. / Diagnose und Therapie eines persistierenden Ductus arteriosus: Eine retrospektive Evaluation bei 17 Katzen.

OBJECTIVE: The objective of this study was to evaluate the signalement, clinical features, and echocardiographic findings of cats diagnosed with patent ductus arteriosus (PDA) as well as short- and medium-term outcome after successful ligation of the PDA. MATERIAL AND METHODS: Over a 10-year period 17 cats were diagnosed with PDA by transthoracic echocardiography. Thirteen cats were surgically treated by thoracotomy and ligation of the PDA. RESULTS: In all cats, a heart murmur was detected. In 88.2% of the cases, this presented as grade 4 out of 6 murmur (15/17 cats). A continuous murmur was more common (10/17 cats; 58.9%) than a systolic murmur (7/17 cats; 41.1%). Echocardiography showed that left ventricular internal diameter end diastole (LVIDd) and left ventricular internal diameter end systole (LVIDs) were significantly above reference values in the majority of cats. Mean diameter of the PDA measured at the widest point of the vessel was 3.4 mm (± 1.08 mm) and mean maximum flow velocity amounted to 5,06 m/sec (2,6m/sec-6,4m/sec). Surgery was successfully performed in all cats treated by surgical ligation and all of these patients were discharged after postoperative inpatient therapy. One cat experienced perioperative bleeding from the PDA, which was stopped efficaciously. This cat exhibited a residual shunt directly postoperatively; this could no longer be visualized in a re-check echocardiography 3 months later. Six cats were followed over a longer period of time. CONCLUSIONS: The surgical prognosis in this case study is very good with a postoperative survival rate of 100%. CLINICAL RELEVANCE: Surgical treatment of PDA is curative in animals not displaying advanced cardiac lesions. The auscultation of a heart murmur can provide initial findings indicative of PDA. Therefore, cardiac auscultation is warranted at every first presentation of a kitten. It must however be taken into consideration that not every cat with PDA necessarily has a continuous murmur but may display a systolic heart murmur. Therefore, it is important give utmost attention to the patients' clinical signs.

Aorto-left atrial fistula secondary to aortic infective endocarditis in a dog with a bicuspid aortic valve.

An 11-year-old male neutered American bulldog was presented for evaluation of thrombocytopenia, acute onset of ataxia, and vomiting. A new murmur was auscultated on physical examination. Transthoracic echocardiographic examination revealed a bicuspid aortic valve, vegetative lesions on the aortic valve, and continuous shunting from the aortic root to the left atrium through an aorta to left atrial fistula. The dog was euthanized due to its guarded prognosis and critical condition. Pathological examination confirmed presence of a bicuspid aortic valve, aorto-left atrial fistula, and aortic infective endocarditis. Antemortem blood culture revealed two unusual organisms: Achromobacter xylosoxidans and Fusobacterium mortiferum.

Myocardial injury in dogs: a retrospective analysis on etiological, echocardiographic, electrocardiographic, therapeutic, and outcome findings in 102 cases.

INTRODUCTION: In dogs, myocardial injury (MI) is a poorly characterized clinical entity; therefore, this study aimed to provide a detailed description of dogs affected by this condition. ANIMALS, MATERIALS, AND METHODS: Dogs diagnosed with MI according to the concentration of cardiac troponin I (cTnI) were retrospectively searched. Signalment, diagnostic, therapeutic, and outcome data were retrieved. Dogs were divided into six echocardiographic (dilated cardiomyopathy phenotype; hypertrophic cardiomyopathy phenotype; hypertrophic cardiomyopathy phenotype with systolic dysfunction; abnormal echogenicity only; endocarditis; and no echocardiographic abnormalities suggestive of MI), four electrocardiographic (abnormalities of impulse formation; abnormalities of impulse conduction; abnormalities of ventricular repolarization; and no electrocardiographic abnormalities suggestive of MI), and nine etiological (infective; inflammatory; neoplastic; metabolic; toxic; nutritional; immune-mediated; traumatic/mechanical; and unknown) categories. Statistical analysis was performed to compare cTnI values among different categories and analyze survival. RESULTS: One hundred two dogs were included. The median cTnI value was 3.71 ng/mL (0.2-180 ng/mL). Echocardiographic and electrocardiographic abnormalities were documented in 86 of 102 and 89 of 102 dogs, respectively. Among echocardiographic and electrocardiographic categories, the dilated cardiomyopathy phenotype (n = 52) and abnormalities of impulse formation (n = 67) were overrepresented, respectively. Among dogs in which a suspected etiological trigger was identified (68/102), the infective category was overrepresented (n = 20). Among dogs belonging to different echocardiographic, electrocardiographic, and etiological categories, cTnI did not differ significantly. The median survival time was 603 days; only eight of 102 dogs died due to MI. CONCLUSIONS: Dogs with MI often have an identifiable suspected trigger, show various echocardiographic and electrocardiographic abnormalities, and frequently survive to MI-related complications.

First reported long-term two- and three-dimensional echocardiographic follow-up with histopathological analysis of a transcatheter pulmonary valve implantation in a pet dog.

Transcatheter pulmonary valve implantation (TPVI) is indicated for use in the management of failing pulmonary valves in humans. We report here the long-term follow-up of the first documented transcatheter pulmonary valve implanted in a client-owned dog. A one-year-old Beagle dog with severe congenital type A valvular pulmonic stenosis first underwent percutaneous balloon pulmonary valvuloplasty, leading two years later to severe pulmonary regurgitation. A TPVI using a Melody™ bioprosthetic valve was then successfully performed, with normalization of the right heart cavities. Repeated two- and three-dimensional transthoracic echocardiographic examinations combined with Doppler modes confirmed the appropriate position and function of the valve for four years. Mitral myxomatous valvular degeneration led to refractory left-sided congestive heart failure, and the dog was humanely euthanized. After postmortem examination, X-ray imaging and histopathological evaluation of the stent and the valve were performed. Ex-vivo imaging of the implanted valve using a Faxitron® Path radiography system and microscopic evaluation of the implanted stent and bioprosthetic leaflets did not show any relevant leaflet or stent alterations. This case provides a proof of concept in interventional veterinary cardiology, showing that TPVI can be performed in dogs with subsequent long-term maintaining normal pulmonary valve function.

Pulmonary-vein-to-pulmonary-artery ratio can be utilized to evaluate myxomatous mitral valve disease progression in dogs.

OBJECTIVE: To evaluate the diagnostic value of pulmonary-vein-to-pulmonary-artery ratio (PV:PA) in dogs with myxomatous mitral valve degeneration (MMVD), classified according to the American College of Veterinary Internal Medicine (ACVIM) consensus guidelines. ANIMALS: 80 client-owned dogs with either MMVD (n = 65) or no cardiovascular disease (control group; n = 15) between August 5, 2020, and July 19, 2023. METHODS: This is a retrospective study. Dogs with MMVD were classified according to ACVIM consensus guidelines. Echocardiograms, thoracic radiographs, and other measurements needed in this study were reviewed in all dogs. Spearman correlation was used to determine the correlation between the PV:PA and the following variables: vertebral heart size, vertebral left atrial size, left-atrium-to-aorta ratio, normalized left ventricular internal diameter, and peak transmitral early diastolic velocity. Receiver operating characteristic (ROC) curve analysis was used to evaluate the value of PV:PA in distinguishing between stages B1 and B2 and stages B2 and C. RESULTS: All conventional indices showed correlations with PV:PA. The area under the ROC curve (AUC) for stages B1 and B2 was 0.83, and the cutoff value for differentiating stage B2 was 1.52. The AUC for stages B2 and C was 0.81, and the cutoff value for differentiating stage C was 2.09. CLINICAL RELEVANCE: PV:PA was significantly different between control and the stage B1 group, stage B1 and B2 group, and stage B2 and C group. PV:PA can be an index that can be used in evaluating MMVD dogs.

Echocardiographic and electrocardiographic findings in Irish Wolfhounds eating high-pulse or low-pulse diets.

BACKGROUND: Apparently healthy dogs of various breeds eating nontraditional, high-pulse diets can have larger left ventricular diameter, lower systolic function, and more ventricular premature complexes (VPCs) compared with dogs eating traditional, low-pulse diets. It is unknown whether Irish Wolfhounds eating high-pulse diets have similar cardiac abnormalities. HYPOTHESIS/OBJECTIVES: To compare electrocardiographic and echocardiographic findings between Irish Wolfhounds eating high- or low-pulse diets. ANIMALS: Ninety-seven Irish Wolfhounds. METHODS: Retrospective study of Irish Wolfhounds that had echocardiography performed at dog shows between October 2018 and May 2021. Demographic information, echocardiographic measurements, cardiac rhythm (1-minute lead II rhythm strip), and main diet were recorded retrospectively. Diets were classified as high-pulse or low-pulse based on the presence and location of pulses (peas, lentils, chickpeas, or dry beans) on the ingredient list. RESULTS: Thirty-five of 97 Irish Wolfhounds (36%) were eating high-pulse diets and 62 of 97 (64%) were eating low-pulse diets. There were no significant differences between diet groups in echocardiographic measurements. A significantly higher percentage of dogs in the high-pulse diet group (6/35 [17%]) had VPCs compared with those in the low-pulse diet group (1/62 [2%]; effect size = 0.15 [95% confidence interval: 0.004-0.31]; P = .005). CONCLUSIONS AND CLINICAL IMPORTANCE: In this retrospective study of apparently healthy Irish Wolfhounds, high-pulse diets were associated with a higher prevalence of VPCs which could represent early cardiac abnormalities.

The effect of obesity and subsequent weight reduction on cardiac morphology and function in cats.

BACKGROUND: In people, obesity is a risk factor for cardiovascular disease, associated with systemic hypertension, cardiac remodelling and systolic and diastolic dysfunction. Weight reduction can reverse myocardial remodelling and reduce risk of subsequent cardiovascular disease. In cats, far less is known regarding the effects of obesity and subsequent weight reduction on cardiovascular morphology and function. This prospective study aimed to assess cardiac morphology and function, heart rate variability, cardiac biomarkers and body composition before and after controlled weight reduction in cats with obesity. Body composition analysis (by dual energy x-ray absorptiometry, DEXA) and cardiovascular assessment (echocardiography, systemic arterial systolic blood pressure, electrocardiography, plasma cardiac biomarkers) were performed prior to weight management in twenty cats with obesity. These investigations were repeated in eleven cats that reached target weight. RESULTS: At baseline, systemic hypertension was not documented, but the majority of cats with obesity (15 out of 19) showed echocardiographic evidence of diastolic dysfunction. Eleven of 20 cats had increased maximal end-diastolic septal or left ventricular free wall thickness (≥ 6.0 mm) at baseline. Median (interquartile range) percentage of weight lost in the cats reaching target weight was 26% (17-29%), with a median reduction in body fat mass of 45% (26-64%). Both the end-diastolic left ventricular free wall (median magnitude of change -0.85 mm, IQR -0.05 mm to -1.55 mm, P = 0.019; median percentage reduction 14.0%) and end-diastolic interventricular septum (median magnitude of change -0.5 mm, IQR -0.2 mm to -1.225 mm, P = 0.047; median percentage reduction 7.9%) thickness decreased after weight reduction. Following weight reduction, pulsed wave tissue Doppler imaging of the left ventricular free wall was consistent with improved diastolic function in 4 out of 8 cats, however there was no significant difference in overall diastolic function class. Further, there was no change in heart rate variability or cardiac biomarkers with weight reduction. CONCLUSION: An increase in left ventricular wall thickness and diastolic dysfunction were common echocardiographic features in cats with obesity within our study and may be reversible with successful weight and fat mass loss. Further studies are required to clarify the clinical consequences of these findings.

Assessment of left and right ventricular systolic function in dogs with multicentric lymphoma.

OBJECTIVE: Myocardial dysfunction in cardio-oncology is generally thought to be related to the cardiotoxicity of chemotherapy treatment. However, it is known that some tumors have direct effects on myocardial function. These effects have already been studied in man, but there are no publications of these of the effects in dogs. Novel advanced echocardiographic techniques may allow early detection of myocardial dysfunction when compared to conventional echocardiographic techniques. This study aims to assess myocardial systolic function in dogs with multicentric lymphoma prior to initiation of chemotherapy. ANIMALS: Fifteen dogs with multicentric lymphoma and nineteen healthy dogs. METHODS: Case-control study. Dogs with multicentric lymphoma and healthy control dogs underwent physical examination, electrocardiography, systolic blood pressure measurement, standard and speckle tracking echocardiography to assess biventricular systolic function. RESULTS: There were no differences between groups in terms of ejection fraction, fractional shortening, left ventricular systolic and diastolic diameter, tricuspid annular plane systolic excursion, mitral annular plane systolic excursion and fractional area change of the right ventricle (RV). However, there was a reduction in the values of global circumferential strain (p = 0.0003), RV strain (p = 0.01) and RV tissue motion annular displacement (p < 0.05) in the dogs with lymphoma when compared to the control group. CONCLUSIONS: Speckle tracking techniques appear to demonstrate early systolic dysfunction, primarily affecting the RV, in dogs with lymphoma prior to chemotherapy treatment.

Congenital right atrial diverticulum in a kitten.

A four-month-old domestic shorthair cat with no clinical signs was referred for further examination of a heart murmur. An echocardiogram revealed marked right atrial dilation, extending into the left hemithorax. Computed tomography angiography was conducted to investigate further, which revealed a balloon-shaped, contrast-filled cavity on the cranial and left side of the chest that connected to the right atrium through a narrow passage. This was diagnosed as a congenital right atrial diverticulum. Treatment included clopidogrel to reduce the risk of thrombus formation. Two months after the initial diagnosis, castration surgery was successfully performed without complications. The cat died suddenly at home 10 months after diagnosis. To the authors' knowledge, this is the first right atrial diverticulum reported in a cat.

Use of combined cutting balloon and high-pressure balloon technique for the treatment of double-chambered right ventricle or primary infundibular stenosis: a case series.

Five dogs and two cats with a diagnosis of double-chambered right ventricle or primary infundibular stenosis were referred to undergo a combined cutting balloon and high-pressure balloon technique. At admission five cases were asymptomatic, one had a history of syncope and one had signs of right-sided congestive heart failure. Each patient underwent a complete transthoracic echocardiogram, thoracic radiographs, an angiogram and the combined interventional procedure. Median diameter of the right mid-ventricular stenosis was 4 mm (range 2-8.7 mm) in dogs, and it measured 1.9 and 2 mm in cats. Under general anesthesia initial dilation with an 8-mm × 2-cm cutting balloon was performed from a left external jugular vein approach followed by dilation with a high-pressure balloon (1.5:1 balloon diameter-right outflow tract diameter ratio). In one dog and the two cats the procedure was not completed due to technical issues. In the other four dogs the median intracavitary proximal chamber pressure decreased from 100 mmHg (range 70-150 mmHg) before the procedure to 57 mmHg (range 45-70 mmHg) post-dilation. Long-term follow-up (from six months to two years) showed complete or partial reverse remodeling of the proximal chamber with a median residual pressure gradient below 80 mmHg (range 46-75 mmHg) for all four dogs. This case series shows that this procedure should be considered in dogs with right ventricular outflow tract obstruction. In cats, the procedure might be feasible, if additional guidewire inventory were available.

Reference intervals for various measurements of canine left atrial size and function obtained using two-dimensional and three-dimensional echocardiography.

BACKGROUND: Many canine cardiac diseases are associated with left atrial (LA) remodeling and decreased function. For accurate assessment of LA indices, large-scale and prospectively determined reference intervals are necessary. OBJECTIVES: To generate reference intervals of LA size and function using two-dimensional and three-dimensional echocardiography. ANIMALS: Two hundred and one healthy adult dogs. METHODS: Left atrial volume was assessed in right parasternal long-axis, left apical four-chamber and two-chamber views using monoplane Simpson's method, two-dimensional and three-dimensional speckle tracking. Additionally, LA diameter was measured in right parasternal short-axis and long-axis views. Furthermore, LA function was determined by measuring strain and calculating LA fractional shortening and ejection fraction. All variables were tested for correlation to heart rate, age, and body weight. For LA diameter and volume, scaling exponents and prediction intervals were generated using allometric scaling. Reference intervals for LA function parameters were calculated using nonparametric methods. RESULTS: Left atrial diameter and volume showed a strong correlation with body weight. The scaling exponent for LA diameter was approximately 1/3 (0.34-0.40) and approximately one for volume measurements (0.97-1.26). Parameters of LA function showed no clinically relevant correlation with body weight, except for two variables, which showed a mild negative correlation. No clinically relevant correlations with age or heart rate were found. CONCLUSIONS: Reference intervals for linear, two-dimensional and three-dimensional measurements of LA size and function were established. The wide range of measurement methods offers the opportunity to select the appropriate reference values for LA evaluation depending on the available technical possibilities.

Positive correlation between echocardiographic tricuspid E peak velocity and central venous pressure in dogs: A preliminary study.

In the absence of vascular obstruction, central venous pressure (CVP) is a hydrostatic pressure in the cranial and caudal vena cava, providing valuable information about cardiac function and intravascular volume status. It is also a component in evaluating volume resuscitation in patients with septic shock and monitoring patients with right heart disease, pericardial disease, or volume depletion. Central venous pressure is calculated in dogs by invasive central venous catheterization, which is considered high-risk and impractical in critically ill patients. This study aimed to investigate the feasibility of using echocardiographic tricuspid E/E' as a noninvasive method to estimate CVP in anesthetized healthy dogs under controlled hypovolemic conditions. Ten male mixed-breed dogs were included in the study after a thorough health assessment. For hypovolemia induction, blood withdrawal was performed, and echocardiographic factors of the tricuspid valve, including peak E and E' velocities, were measured during CVP reduction. Repeated measures analysis of variance and Bonferroni post hoc tests were employed to compare the average difference between measured echocardiographic indices and CVP values derived from catheterization and intermittent measurement methods. Spearman's ρ correlation coefficient was used to evaluate the correlation between echocardiographic indices and CVP. E peak velocity had a significant negative correlation with venous blood pressure phases (r = -0.44, P = .001), indicating a decrease in peak E velocity with progressive CVP reduction. However, tricuspid valve E' peak velocity and E/E' did not correlate with CVP, suggesting that these parameters are not reliable for CVP estimation in dogs.

Twenty-four hour continuous transvenous temporary right ventricular pacing in healthy horses.

BACKGROUND: The ability to perform transvenous temporary cardiac pacing (TV-TP) is critical to stabilize horses with symptomatic bradyarrhythmias. Reports of successful TV-TP in horses are limited, and only briefly describe short-term pacing. OBJECTIVE: To describe temporary, medium-term (24 h) transvenous right ventricular pacing in awake horses using a bipolar torque-directed pacing catheter. ANIMALS: Six healthy adult institutional teaching horses. METHODS: Prospective experimental study with 2 immediately successive TV-TP lead placements in each horse with a target location of the RV apex. One placement was performed primarily with echocardiographic guidance and 1 primarily with fluoroscopic guidance. In all placements, corresponding images were obtained with both imaging modalities. Horses were then paced for 24 h, unrestricted in a stall with continuous telemetric ECG monitoring. Echocardiographically determined lead position, episodes of pacing failure in the preceding 6 h, and pacing thresholds were recorded every 6 h. Pacing failure was defined as a period of loss of capture longer than 20 s. RESULTS: Pacing leads were placed with both guidance methods and maintained for 24 h with no complications. Two horses with leads angled caudally in the right ventricular apex had no pacing failure, the remaining 4 horses had varying degrees of loss of capture. Leads located in the right ventricular apex had longer time to pacing failure and lower capture thresholds P < 0.05. CONCLUSIONS AND CLINICAL IMPORTANCE: Medium-term TV-TP is feasible and has potential for stabilization of horses with symptomatic bradyarrhythmias. Lead position in the right ventricular apex appears optimal. Continuous ECG monitoring is recommended to detect pacing failure.