Introduction Endothelial-to-mesenchymal transformation is a complex process previously reported in canine myxomatous mitral valve disease (MMVD) but not in congenital mitral valve dysplasia (MD) in dogs.The aim of the current study was to evaluate the endothelial-to-mesenchymal transformation in canine MD as compared to valves affected with MMVD. Animals The study was conducted on histopathological specimens obtained from 19 dogs divided into three groups: MMVD group (n=7), MD group (n=6) and control group (n=6). Materials and Methods The paraffin blocks were retrieved from the archives of the Unit of Veterinary Cardiopathology and underwent histological and immunohistochemical stainings. Hematoxylin-eosin and Movat’s stains served to evaluate the histopathological changes within the valves. Immunohistochemical analysis involved antibodies against: vimentin, alpha-smooth muscle actin, fibronectin, platelet endothelial cell adhesion molecule-1, and transgelin. Scoring of the immunoreaction was performed according to the intensity and extent of staining. Results Remodelling of both valvular interstitial and endothelial cells was noted with similar extent in both examined diseases, despite differences in animals’ age, body weight, heart weight and cause of mitral valve changes. Limitations Study limitations included: relatively small number of animals in each group, a difference in the animals’ age, heart weight, and body weight between the groups, lack of detailed echocardiographic measurements, and EndMT evaluated basing on a single time point. Conclusions Despite different pathogenesis and disease course, endothelial and interstitial changes occur in both MMVD and MD. Further studies are required to evaluate the exact relationship between changes occurring in valvular endothelial and interstitial cells.
Tricuspid valve dysplasia is a congenital cardiac malformation in dogs characterised by abnormal tricuspid valve morphology, leaflet tethering, impaired leaflet coaptation, and right atrial and ventricular remodelling. This report describes cone reconstruction (CR) for severe tricuspid valve dysplasia in a dog. A three-year-and-10-month-old female Labrador Retriever presented with a grade IV/VI systolic murmur and exercise intolerance. Echocardiography revealed severe tricuspid regurgitation, a right atrial-to-left atrial (RA:LA) ratio of 1.57, malformed and tethered tricuspid valve leaflets, impaired leaflet coaptation, and marked right-sided cardiac enlargement, consistent with severe tricuspid valve dysplasia. Surgery involved tricuspid valve leaflet mobilisation, delamination of adherent leaflet tissue and abnormal subvalvular attachments, annular reduction, and reconstruction of the available leaflet tissue into a cone-like valve with leaflet rotation and reattachment. A small, thin, dysplastic portion of the right ventricular free wall was also excluded from the functional right ventricular cavity by longitudinal plication. The dog was discharged on postoperative day seven without other major complications. On postoperative day 294, echocardiography showed a reduction in the colour Doppler tricuspid regurgitant jet, a decrease in the RA:LA ratio to 0.50, and a reduction in right atrial size. Exercise intolerance resolved, although a grade III/VI systolic murmur persisted. Cone reconstruction, adapted from the technique used in human patients with Ebstein’s anomaly, may improve tricuspid valve function and clinical signs in selected dogs with severe tricuspid valve dysplasia. However, its indications, reproducibility, and long-term durability in dogs remain unestablished. Further studies are needed to evaluate patient selection, long-term benefits, and potential complications.
A four-year-old female neutered Labrador retriever was referred for investigation of paroxysmal tachycardia. On physical examination, a heart rate of 220 beats/min with no heart murmurs was noticed. Cardiac troponin I was significantly increased. A six-lead electrocardiography revealed phases of narrow QRS complexes tachycardia with regular RR intervals and a QP'/P'Q of 0.80, compatible with orthodromic atrioventricular reciprocating tachycardia (OAVRT), alternating with sinus rhythm. On ambulatory electrocardiography, initial phases of OAVRT were followed by sinus rhythm. The sinus beats were interrupted by occasional wide QRS complexes with reduced PR interval and noticeable delta (δ) waves, which confirmed the presence of an accessory pathway. The diagnosis was of OAVRT with intermittent ventricular pre-excitation, and laddergrams were included to illustrate the underlying conduction patterns.
INTRODUCTION/OBJECTIVES:Chihuahuas are affected by myxomatous mitral valve disease (MMVD). The aim of this study was to investigate MMVD in Chihuahuas, specifically clinical and echocardiographic characteristics including probability of pulmonary hypertension (PH), disease progression, and survival. ANIMALS, MATERIALS AND METHODS:A retrospective study of privately owned Chihuahuas with an echocardiographic study compatible with MMVD from four cardiology centers across three countries (2020-2025) was conducted. Differences between signalment, centers, and American College of Veterinary Internal Medicine (ACVIM) stages were assessed; disease progression and survival analysis were calculated. RESULTS:In total, 390 Chihuahuas of both coat types, with median age of 11 years, were included. A total of 181 out of 390 dogs (46%) were classified as ACVIM stage B1, 85 of 390 (22%) as stage B2, 114 of 390 (29%) as stage C, and 10 of 390 (3%) as stage D. Females were more numerous in ACVIM stage B1 and males in combined stages C and D; however, sex did not influence survival or disease progression. Among 122 dogs for which follow-up was available (median: 488 days), 47% (57/390) progressed in stage, while 53% (65/122) remained stable. The population median survival time was 783 days; survival differed among ACVIM stages (survival for ACVIM stage B1 was 1,164 days, ACVIM stage B2: 794 days, and ACVIM stages C and D: 345 days, log-rank test P<0.001). A multivariable survival analysis identified ACVIM staging and PH probability as risk factors for all-cause mortality and left atrium-to-aorta ratio and PH probability for cardiac-related death. STUDY LIMITATIONS:Study limitations included the retrospective design and uneven center contribution. CONCLUSIONS:Left atrial enlargement, ACVIM staging, and PH probability were prognostic factors for cardiac and non-cardiac death in Chihuahuas with MMVD.
Introduction/Objectives Echocardiographic calculation of mitral regurgitant fraction (MR%) may complement variables used to assess myxomatous mitral valve disease (MMVD) severity. The geometric technique of calculating MR% uses four component variable measurements. Calculations using multiple measurements necessarily influence variability. The influence of disease severity on component measurements and MR% variability has not been explored. This study explored the contribution of component measurement variability and the markers of disease severity: left atrial-to-aortic ratio, R-R interval (RR) variability and heart rate on MR% variability. Animals, Materials and Methods Echocardiographic studies from 109 dogs with MMVD were analysed. The co-efficient of variation (COV) was calculated from three measurements of each echocardiographic variable and calculated MR%. A multivariable linear regression model was devised modelling COV MR% as the outcome variable. Results The COV of MR% correlated negatively with MR% severity and decreased with increasing American College of Veterinary Internal Medicine stages. Component variables of MR% generally had variability <10% in all American College of Veterinary Internal Medicine stages. In a multivariable model, of the component variables, only COV aortic diameter measured between the open aortic leaflets at mid-systole in a right parasternal long-axis view showed positive correlation with MR% variability (2.17, P=0.010). However, MR% variability showed clearest association with left atrial-to-aortic ratio (−16.89, P=0.001) and variation in R-R interval (COV RR: 1.47, P=0.002, COV RR2 = −0.04, P=0.013). Study Limitations Modelling of retrospective data is a limitation of the present study. Conclusions Variability of MR% is associated with disease severity. We propose beat-to-beat variation in component variables attributable to sinus arrhythmia is associated with variability of mitral regurgitation and echocardiographic calculation of MR% in dogs. These results provide insights into echocardiographic measurement variability in MMVD and assist interpretation of MR% at different disease stages.
A six-year-old neutered male cat was presented for acute respiratory distress. Transthoracic echocardiography identified a left atrial membrane consistent with cor triatriatum sinister (CTS) and turbulent flow across a single fenestration. Additionally, it was suspected that the distal chamber may receive at least one pulmonary vein. Because respiratory signs improved with corticosteroids but not with a short diuretic trial, and because echocardiography suggested that the distal chamber might receive at least one pulmonary vein, cardiac computed tomography angiography was performed to further characterize the pulmonary venous anatomy and to differentiate CTS from pulmonary vein stenosis and other congenital vascular malformations. Cardiac computed tomography angiography confirmed left atrial subdivision with one interchamber orifice (5.33 mm) and demonstrated a pulmonary venous connection pattern in which three pulmonary veins connected to the proximal chamber, whereas the left cranial pulmonary vein connected to the distal chamber, which was continuous with the mitral valve. Adapting the human Lucas classification scheme, the anatomic configuration most closely resembled Lucas type C1a, and no congestive heart failure attributable to CTS was identified.
INTRODUCTION/OBJECTIVES:Pulmonary stenosis (PS) is a common congenital heart disease in dogs, often associated with poststenotic dilation of the pulmonary trunk or main pulmonary artery (MPA). We hypothesized that vertebrae-based radiographic measurement of the MPA might identify dogs with PS and potentially assess its severity. ANIMALS, MATERIALS, AND METHODS:A retrospective cohort study of 29 dogs with PS, 30 normal dogs, and 30 dogs with myxomatous mitral valve disease was conducted. Vertebral main pulmonary artery size (VMPS) was measured using dorsoventral (vertebral main pulmonary artery size measured using the dorsoventral radiograph [VMPS-DV] type 1, type 2) and right lateral (vertebral main pulmonary artery size measured using the right lateral radiograph [VMPS-LATE]) thoracic radiographs. Group differences were analyzed using the Kruskal-Wallis test. Correlation between VMPS and maximal instantaneous pressure gradient (continuous wave Doppler) was assessed using Spearman's correlation. Diagnostic performance was evaluated using receiver-operator characteristic analysis with Youden's index. RESULTS:Vertebral main pulmonary artery size measured using the dorsoventral radiograph type 1 and VMPS-LATE were significantly greater in the PS group than in the normal group (P<0.001) but not significantly different from the myxomatous mitral valve disease group. After excluding French bulldogs, these indices remained significantly elevated. A VMPS-DV type 1 > 1.06 and a VMPS-LATE >3.6 were identified as optimal cutoffs for distinguishing dogs with PS from normal. No significant correlations between VMPS and pressure gradient were identified. STUDY LIMITATIONS:small sample size limited statistical power. Due to the absence of echocardiographic data, a comparison of MPA size between radiographic and echocardiographic modalities was not possible. CONCLUSIONS:Although VMPS did not reflect PS severity, a VMPS-DV type 1 > 1.06 and a VMPS-LATE >3.60 support the diagnosis of PS in dogs with compatible clinical findings.
Left-sided congestive heart failure was diagnosed in a 2.6-kg 13-year-old neutered male Yorkshire terrier by compatible clinical signs and findings on thoracic radiographs. Echocardiography revealed left atrium enlargement, left ventricular concentric hypertrophy, and thickening and stenosis of the mitral and aortic valves (AVs). A hypercoagulable state, chronic kidney disease, and a portal vein thrombus were identified. Medical management and balloon valvuloplasty of the AV provided good quality of life for nine months since diagnosis, but ultimately, recurrent episodes of pulmonary oedema and acute kidney injury led to attempted mitral balloon valvuloplasty which resulted in cardiac arrest and death. Postmortem examination revealed thickening of the mitral and aortic leaflets with loss of normal stratification and the presence of large areas of fibroelastic tissue and accumulation of myxoid tissue. Hypertrophy of cardiomyocytes was also observed and was considered secondary to aortic stenosis and not due to primary myocardial disease. Histopathological examination revealed fibroelastic changes affecting both the mitral valve and AV leaflets. These findings were considered atypical for more common forms of acquired valvular disease. This case report describes the clinical presentation, diagnostic approach, interventional management, and pathological features of an unusual case of acquired combined aortic and mitral stenosis in a dog and discusses similarities and differences with other conditions associated with comparable valvular abnormalities.
INTRODUCTION/OBJECTIVES:Mitral valve regurgitation (MR) is frequently detected in horses, but its classification and prognostication remain challenging. This study investigated whether auscultatory findings and left atrial function are associated with MR severity. ANIMALS, MATERIALS AND METHODS:Fifty controls (no/trivial MR) and 101 MR horses (58 mild, 36 moderate, seven severe) were retrospectively evaluated. All were in sinus rhythm and underwent auscultation and echocardiography. Mitral regurgitation severity was graded using a scoring system. Systolic murmur characteristics (duration, type and grade) were recorded. Left atrial function was quantified measuring left atrial fractional area change and left atrial and ventricular tissue Doppler indices. Statistics included analysis of variance, Kruskal-Wallis, chi-square, Spearman's rho and Cohen's weighted kappa tests. RESULTS:A positive association was found between MR severity and left-sided systolic murmur intensity (P < 0.001) and duration (P < 0.001), and between left-sided systolic murmur duration and largest jet duration on ultrasound (P < 0.001). Left atrial fractional area change decreased with increasing MR severity (P < 0.001). Myocardial velocity of the left atrial and ventricular free wall during atrial contraction showed non-significant differences between groups [P = 0.573 and P = 0.039 (within F-test; P ≥ 0.073 after Bonferroni correction for multiple comparisons)]. STUDY LIMITATIONS:Study limitations included the absence of a gold standard for equine MR classification and few severe MR horses. CONCLUSIONS:Although auscultation gives an indication about MR severity, echocardiography remains necessary to accurately diagnose MR and determine jet characteristics. Except for left atrial fractional area change, left atrial functional variables did not seem to be associated with MR severity in horses.
A three-month-old male intact domestic shorthair cat was presented to Michigan State University for evaluation of a heart murmur and was diagnosed with a left-to-right shunting patent ductus arteriosus (PDA) via transthoracic echocardiography. The patient returned at eight months of age, and the PDA was successfully occluded with the Amplatzer™ Vascular Plug II using a transjugular approach. There are limited reports regarding non-surgical closure of a PDA in cats, including a single report describing closure of a PDA in a cat with this specific device. This case report highlights a feasible transjugular option for interventional closure of a PDA in cats.
A thoracic aortic aneurysm (TAA) is a relatively common cardiovascular disorder in humans. However, it is rarely reported in dogs. To date, several reported canine cases are associated with clinical signs and severe complications, such as aortic dissection and rupture. Herein, we report an incidentally diagnosed TAA in an asymptomatic elderly dog with suspected aortic valve abnormality. A 12-year-old spayed female Shiba Inu was referred for the evaluation of anorexia and vomiting. It was subsequently diagnosed with gallbladder mucocele. Thoracic radiography revealed cranial mediastinal widening, and transthoracic echocardiography showed marked dilation of the thoracic aorta distal to the sinus of Valsalva, with a maximal diameter of 30.2 mm. Echocardiographic findings revealed an abnormal aortic valve morphology characterized by asymmetric cusp motion and eccentric systolic opening, accompanied by aortic regurgitation. Severe circumferential dilation of the aortic root, ascending thoracic aorta, and aortic arch, without evidence of dissection or rupture, was confirmed on computed tomography angiography and intra-operative transesophageal echocardiography. Hence, a diagnosis of a non-dissecting fusiform TAA was made. The clinical signs resolved completely after cholecystectomy, and the dog remained clinically stable for >200 days without specific treatment for the aortopathy. This is a rare case of an incidentally diagnosed TAA in a dog with aortic valve abnormality. This case indicates that canine TAA may be under-recognized and emphasizes the importance of advanced imaging modalities for identifying TAA in dogs.
Cardiac computed tomography (cCT) has emerged as a valuable imaging modality in veterinary cardiology and can be used to visualize and understand diseases that affect the mitral and tricuspid valves of dogs. While echocardiography remains the primary diagnostic tool for atrioventricular valve disease, cCT offers excellent spatial and temporal resolution, at the same time overcoming the limitations posed by acoustic windows. This review article describes the technical aspects of cCT in dogs emphasizing administration of contrast medium, electrocardiographic gating, and scan timing. Specific recommendations and protocols for imaging the atrioventricular valves in dogs are discussed. Clinical applications for cCT of the atrioventricular valves include evaluation of congenital malformations, such as dysplasia and stenosis, and assessment of acquired conditions like degenerative valve disease and neoplasia. Cardiac CT enables precise visualization of valve anatomy, chamber volumes, and may assist in postprocedural evaluations for transcatheter device placement and surgical implant integrity. Advanced postprocessing techniques - such as volume rendering, virtual reality, and three-dimensional printing - enhance anatomical understanding and procedural planning. Cardiac CT is a transformative tool in veterinary cardiology, offering unparalleled anatomical and functional insights. As mechanical therapies for atrioventricular valve disease become more common in veterinary practice, cCT is likely to become a required tool for pre procedural planning as it has been in human medicine.
A 12-year-old, 20-kg, Cocker spaniel was evaluated for the recent onset of marked weakness. Cardiologic assessment revealed myxomatous degeneration of the atrioventricular valves, moderate left atrial dilation, and a sustained narrow QRS complex tachycardia primarily consistent with focal atrial tachycardia. Moreover, two-dimensional imaging of the interatrial septum showed a hyperechoic, multifocal thickening (maximum thickness: 10 mm). Differential diagnoses included neoplastic infiltration, intracardiac thrombosis, and mural endocarditis. Despite prompt hospitalization in the intensive care unit and combination antiarrhythmic therapy, adequate control of the tachyarrhythmia was not achieved, and euthanasia was ultimately elected. Necropsy confirmed myxomatous mitral valve degeneration and excluded cardiac neoplasia, thrombosis, and mural endocarditis. Histologic examination of the interatrial septum revealed abnormal infiltration by mature adipose tissue, causing full-thickness separation and dissociation of septal myofibers. Based on antemortem and postmortem findings, the diagnosis was lipomatous hypertrophy of the interatrial septum, a condition not previously reported in dogs but well recognized in human cardiology.
INTRODUCTION/OBJECTIVES:Restrictive cardiomyopathy (RCM), the second most common cardiomyopathy in cats, is known to induce primary diastolic dysfunction. Little is known about systolic function in cats with RCM. The aim of this study was to evaluate systolic function using two-dimensional speckle-tracking echocardiography-derived endocardial global longitudinal strain (GLS) in a population of cats with RCM. ANIMALS, MATERIALS AND METHODS:Twenty-five adult cats diagnosed with RCM as well as 25 healthy control cats were included in the present study. Left apical two-, three-, and four-chamber views were obtained retrospectively for endocardial GLS analysis derived by two-dimensional speckle tracking. Comparison of cats with RCM with a matched control group was performed. RESULTS:Cats with RCM had significantly larger left ventricular internal diameters in both, systole (P < 0.0001) and diastole (P = 0.0015), than controls. In systole, cats with RCM had values of 11.05 mm ± 2.24, in contrast to those of 8.48 mm ± 1.35 in healthy controls. In diastole, these values were 16.10 mm (range: 10.50-20.60 mm) in cats with RCM, higher than 14.90 mm (range: 10.00-17.50 mm) in the control group. Global longitudinal strain values were significantly lower in cats diagnosed with RCM than in control cats (P < 0.0001), with a mean value of -17.68% ± 4.78 vs. -28.35% ± 3.72, respectively. STUDY LIMITATIONS:Limitations mainly comprised the retrospective character of the study, leading to lack of treatment standardization and histopathology, as well as a limited population of felines. CONCLUSIONS:Endocardial GLS is reduced in cats with RCM, indicating that cats with RCM not only have a diastolic but also systolic dysfunction.
Hypereosinophilic syndrome is a rare systemic disorder in cats characterized by sustained eosinophilia and eosinophil-mediated tissue injury. A three-year-old castrated male domestic shorthair cat was presented for acute onset dyspnea and was diagnosed with left-sided congestive heart failure. Echocardiography revealed concentric left ventricular hypertrophy with hyperechoic and irregular endomyocardium, large irregular oscillating lesions involving the mitral valve apparatus, and severe left atrial dilation. Complete blood count revealed a marked leukocytosis (53.33 x103/μL; reference range: 5.5-19.5 x103/μL) and marked eosinophilia (11.20 x103/μL; reference range: 0.0-0.75 × 103/μL). Despite initial stabilization and medical management for congestive heart failure, the cat experienced cardiopulmonary arrest. Prior medical records documented a chronic history of eosinophilia. Necropsy and histopathology revealed eosinophilic and granulomatous mitral valvular and mural endomyocarditis with thrombosis, myocardial necrosis, and eosinophilic infiltration of multiple organ systems. This case report highlights hypereosinophilic syndrome as a rare cause of cardiac disease in cats but a relevant differential diagnosis for an echocardiographic phenotype mimicking infective endomyocarditis and provides echocardiographic and pathologic images of this uncommon disorder.
A nine-year-old male intact Pomeranian, previously diagnosed with a patent ductus arteriosus (PDA), presented with a two-day history of anorexia and lethargy. Echocardiography confirmed a bidirectional shunting PDA and pulmonary arterial hypertension (PAH). The patient underwent transcatheter occlusion of the PDA; however, there was subsequent development of right heart failure secondary to persistent PAH postoperatively. Combination medical therapy using ambrisentan, sildenafil, pimobendan and amlodipine resulted in resolution of right-sided congestive heart failure and oxygen dependency. Follow-up echocardiography and thoracic radiographs revealed gradual cardiac reverse remodelling and ultimately a structurally normal heart. At the last follow-up, the patient remained stable without complications associated with ductal occlusion. This case highlights the success of bidirectional ductal occlusion with postoperative use of ambrisentan for management of refractory PAH.
INTRODUCTION/OBJECTIVES:In the preclinical phase of myxomatous mitral valve disease, pimobendan administration to dogs with cardiomegaly reduces cardiac dimensions and risk of congestive heart failure (CHF). Administration of pimobendan to dogs with CHF prolongs survival. Increasing proportions of dogs are administered preclinical pimobendan; however, the influence of this on CHF survival time in dogs that progress to CHF has not been explored in a multicentre study. ANIMALS, MATERIALS AND METHODS:This is a multicentre retrospective study comparing survival time from the onset of CHF in 137 dogs from five centres administered preclinical pimobendan (B2P, n = 61, 44.5%) or 'pimobendan naïve' (B2N, n = 76, 55.5%) at the onset of CHF. RESULTS:At the onset of CHF, there were no differences in patient, echocardiographic or biochemical variables between groups. Following the onset of CHF, median times to all-cause mortality and cardiac death were shorter in Group B2P than in Group B2N: 168 days (95% confidence interval: 58-227) vs. 359 days (245-473), P < 0.001 and 201 days (128-287) vs. 442 days (293-711), P < 0.001, respectively. There was no difference in proportions of dogs experiencing cardiac death between groups (P = 0.116). CONCLUSIONS:Whilst preclinical treatment of myxomatous mitral valve disease with pimobendan is anticipated to be the optimal management strategy in extending and maintaining quality of life overall, these results suggest that in dogs developing CHF, the survival times of dogs administered preclinical pimobendan might be shorter following the onset of CHF. Preclinical pimobendan administration should be considered when interpreting survival studies and when managing dogs that develop CHF. STUDY LIMITATIONS:This is an underpowered retrospective study.
INTRODUCTION/OBJECTIVES:This study aimed to evaluate the repeatability and reproducibility (R&R) of left ventricular myocardial area (LVMA) measurements and linear left ventricular wall thickness measurements. ANIMALS, MATERIALS AND METHODS:A retrospective study was conducted; apparently normal echocardiograms from 50 cats were included. Using right parasternal two-dimensional short-axis echocardiographic images at the level of the papillary muscles, LVMA, left ventricular myocardial area including papillary muscles (LVMAP), interventricular septum thickness at end-diastole (IVSd), and left ventricular posterior wall thickness at end-diastole (LVPWd) were recorded. Ten echocardiograms were randomly selected for R&R assessment by three observers on three separate occasions each. Concordance between observers was assessed using Kendall's W, and measurement system variance was analyzed via Gage R&R, using a random-effects model. RESULTS:Median (minimum-maximum) of measurements from the 50 echocardiograms were as follows: LVMA: 2.46 cm2 (1.44-3.20 cm2), LVMAP: 2.92 cm2 (1.79-3.88 cm2), IVSd: 3.94 mm (3.11-5.21 mm), and LVPWd: 4.37 mm (2.74-5.18 mm). The LVMAP showed the highest interobserver concordance (Kendall's W, 0.85) and lowest measurement-system variability (Gage R&R, 6.57%), whereas IVSd and LVPWd had lower concordance (0.67 and 0.60, respectively) and higher Gage R&R values (17.88% and 13.22%, respectively). STUDY LIMITATIONS:Measurements were based on preselected high-quality cine loops and may not reflect variability encountered in real-world practice. All echocardiograms were acquired from a single machine and included only apparently normal echocardiograms, limiting generalizability to diseased populations or diverse imaging systems. CONCLUSIONS:The LVMAP has good R&R. Further studies are warranted to validate LVMAP's diagnostic utility.
A one-year-old neutered male Kooikerhondje dog, weighing 12 kg, was referred for evaluation of a heart murmur without clinical signs and mosaic blood flow within the main pulmonary artery detected by transthoracic echocardiography. On day 0, transthoracic echocardiography revealed left heart enlargement, continuous mosaic flow within the main pulmonary artery, and a shunt vessel entering the left pulmonary artery. Electrocardiography (ECG)-gated non-helical computed tomography angiography (CTA) using a 320-row multidetector computed tomography scanner demonstrated two anomalous vessels that converged to form a common trunk draining into the left pulmonary artery: one arising from the right costocervical artery, coursing tortuously through the thoracic cavity, and entering the origin of the left pulmonary artery (right costocervical artery-left pulmonary artery shunt) and another arising from the left coronary artery and entering the origin of the left pulmonary artery (left coronary artery-left pulmonary artery shunt). On day 47, both shunt vessels were completely ligated at their entry points into the left pulmonary artery via thoracotomy, resulting in the disappearance of shunt flow. On day 234, ECG-gated CTA confirmed the complete disappearance of both shunts and the absence of any additional abnormal vessels. To the authors' knowledge, this is the first report of concurrent right costocervical artery-left pulmonary artery and left coronary artery-left pulmonary artery shunts in a dog, diagnosed using ECG-gated CTA and successfully treated surgically.
INTRODUCTION/OBJECTIVES:Cardiac disease is the second leading cause of death in Irish wolfhound (IW) populations (15.27%). Dilated cardiomyopathy (DCM) is a common hereditary disease in IWs. No correlation between ventricular premature complexes (VPCs) and DCM has been noted in IW populations. The authors hypothesized that VPCs on a baseline electrocardiogram (ECG) do not predict the development of DCM. ANIMALS, MATERIAL AND METHODS:Twenty-four IWs of breeding age were prospectively recruited in the study. Irish wolfhounds underwent a cardiac examination, echocardiogram, laboratory testing, and 24-h Holter monitor (HM). Enrolled dogs had a normal echocardiogram, at least one VPC on a 1-min ECG, and HM placed within 90 days of echocardiogram. Irish wolfhounds were followed up for a minimum of 1 year and underwent a follow-up HM within 12 months. RESULTS:Three of 24 IWs (16.67%) developed structural changes and/or atrial fibrillation consistent with DCM during the study period. Ten of 24 dogs (41.6%) developed arrhythmias necessitating medical therapy. There was no significant association between complexity of VPCs and the development of DCM. STUDY LIMITATIONS:Limitations include the small number of dogs and lack of standardized recheck interval and treatments. CONCLUSIONS:Three of 24 IWs ultimately developed DCM at least three years after enrollment. No correlation can be made between VPCs on screening ECG and development of DCM within 12 months. Ten of 24 dogs were started on anti-arrhythmic medication, as indicated by arrhythmia complexity. An HM is recommended for all IWs with VPCs noted on surface ECG.
