Transesophageal echocardiography using a microprobe for determination of transcatheter procedural candidacy, device selection, and procedural monitoring in small dogs with patent ductus arteriosus.

INTRODUCTION: Small dogs with patent ductus arteriosus (PDA) may be unable to undergo transesophageal echocardiography (TEE) with traditional probes. OBJECTIVES: To report the utility of TEE using a microprobe in dogs weighing less than 4 kg diagnosed with PDA for determination of transcatheter procedural candidacy, device selection, and intraoperative procedural guidance. ANIMALS: Eight dogs weighing less than 4 kg diagnosed with PDA. MATERIALS AND METHODS: All dogs had standard transthoracic echocardiography and microprobe TEE imaging. The quality of TEE images was graded as optimal, adequate, or poor. The ability of TEE to assess PDA anatomy, determine procedural candidacy, provide procedural guidance, detect deployed devices, and assess residual flow was recorded. RESULTS: The median age of included dogs was 6.4 months (range: 3.2-15.7 months) and the median body weight was 2.2 kg (range: 1.4-3.8 kg). Microprobe TEE images were adequate or optimal in all dogs and were integral for guiding procedural candidacy decisions. Transcatheter procedures were not pursued in two dogs based on TEE images. In the other six dogs, TEE procedural guidance was useful during transvenous (n = 5) and transarterial (n = 1) PDA occlusion attempts. Each deployed device (n = 4) was easily detected with the TEE microprobe. Real-time confirmation of adequate device sizing and placement was possible prior to release and residual flow could be monitored after release. CONCLUSIONS: Transesophageal echocardiography using a microprobe in dogs weighing less than 4 kg diagnosed with PDA allowed for characterization of PDA anatomy and determination of transcatheter procedural candidacy. Microprobe TEE images were integral for PDA device selection and offered valuable intraoperative procedural guidance.

Two- and three-dimensional transesophageal echocardiographic assessment and successful occlusion of a window-like patent ductus arteriosus in two dogs.

A 16-month-old Labrador-Poodle cross (case 1) and a 3-month-old German shorthaired pointer (case 2) were referred for patent ductus arteriosus (PDA) occlusion. Two-dimensional transthoracic and two- and three-dimensional transesophageal echocardiography revealed a window-like PDA characterized by a wide and short ductus. Due to the atypical PDA morphology with no ampulla in case 1, ductal occlusion was attempted with non-canine-specific Amplatzer occluder devices. However, these were too small and failed to remain stable. Amplatz Canine Duct Occluder (ACDO) devices were used with success in both cases. Due to the defects' morphology, the proximal ACDO disc protruded into the aorta but there were no signs of obstruction to aortic blood flow 16 months (case 1) and 1 month (case 2) post-occlusion. We describe two cases of a window-like type PDA that were successfully occluded with an ACDO.

Transseptal puncture in the dog utilizing three-dimensional transesophageal echocardiographic guidance.

Transseptal puncture is necessary to access the left atrium and mitral valve from a transvenous approach but is poorly described in veterinary medicine. The procedure is generally regarded as difficult and dangerous, particularly given the size of most small animal patients. Precise imaging is paramount to the procedure to ensure that puncture occurs within the desired location and to monitor for potential complications. Transesophageal echocardiography, including biplanar two-dimensional and particularly three-dimensional modalities, has great potential to improve the success and safety of transseptal puncture due to superior visualization of the fossa ovalis and other intracardiac structures. Here, we describe the use of transesophageal echocardiography to guide transseptal puncture based on our experience in 159 dogs, with an emphasis on three-dimensional echocardiography. We also detail how to perform transseptal puncture from a jugular approach, which we consider preferable in most patients. Complications from transseptal puncture are discussed, along with ways to limit those complications.

Current use of transesophageal echocardiography in animals.

The unique imaging capabilities of transesophageal echocardiography (TEE) make it a valuable tool for characterizing the structure and function of the heart and for providing procedural monitoring. With the creation of new devices and expansion of procedural options with increased applications, multiplanar and three-dimensional imaging with TEE can be essential for clinical decision making. A description of the indications and clinical application of TEE in animals while highlighting probe characteristics, limitations and patient safety are the focus of this review. The increased availability of three-dimensional imaging in smaller probes, advanced applications including photorealistic and fusion imaging, and the development of recommended standards for performing a comprehensive TEE imaging study including training guidelines may facilitate the use of TEE in the veterinary field.

A proposed rescue transesophageal echocardiographic protocol for anesthetized dogs.

OBJECTIVE: To describe the acquisition and pitfalls of a 3-view transesophageal echocardiography (TEE) protocol in anesthetized, dorsally recumbent dogs. ANIMALS: 8 beagles, 1 to 2 years old, 7.4 to 11.2 kg. METHODS: Dogs were anesthetized, mechanically ventilated, and placed in dorsal recumbency. A TEE probe was advanced, and 3 views were performed: midesophageal 4-chamber and long axis (ME 4C and ME LAX) and caudal esophageal short axis (CE SAX) at the level of the papillary muscles. Probe insertion depth, flexion, omniplane angle, and image acquisition time were recorded. Two observers assessed 24 video clips each and identified anatomical structures. RESULTS: The ME 4C and ME LAX were obtained at 35 (30 to 40) cm insertion depth, omniplane at 0° and 103° (90 to 116), respectively. Views were obtained in ≤30 seconds once the TEE was in the cervical esophagus. Left-sided structures were identified in all cases, whereas right-sided structures were not always simultaneously obtained in the ME 4C, requiring further probe manipulation. All structures were identified on ME LAX. CE SAX was obtained at 40 (35 to 45) cm, omniplane at 0°, and in 15 (10 to 90) seconds. A true SAX view (circular left ventricle at the level of papillary muscles) could not be obtained in all dogs. CLINICAL RELEVANCE: A 3-view TEE protocol using core views as those described in humans may be applicable to dogs under general anesthesia and in dorsal recumbency. The CE SAX view at the level of the papillary muscles appears more difficult to obtain with consistency than midesophageal views.

Agreement of cardiac output measurements by esophageal Doppler and transesophageal echocardiography with intermittent pulmonary artery thermodilution during pharmacologic manipulation of hemodynamics in anesthetized dogs.

OBJECTIVE: To compare cardiac output (CO) measurements by transesophageal echocardiography (TEECO) and esophageal Doppler monitor (EDMCO) with pulmonary artery thermodilution (PATDCO) in anesthetized dogs subjected to pharmacological interventions. The effect of treatments on EDM-derived indexes was also investigated. ANIMALS: 6 healthy male dogs (10.8 ± 0.7 kg). METHODS: Dogs were anesthetized with propofol and isoflurane, mechanically ventilated, and monitored with invasive mean arterial pressure (MAP), end-tidal isoflurane concentration (ETISO), PATDCO, TEECO, EDMCO, and EDM-derived indexes. Four treatments were administered to all dogs by randomization. Baseline data were collected before each treatment: (1) dobutamine infusion; (2) esmolol infusion; (3) phenylephrine infusion; and (4) ETISO > 3%. Data were collected after 10-minute stabilization and after 30 minutes of washout between treatments. Statistical tests were pairwise t test, Bland-Altman analysis, Lin's concordance correlation (ρc), and polar plot analysis with P < .05 set as significance. RESULTS: The mean ± SD relative bias (limits of agreement) for TEECO was 0.35 ± 25.2% (-49.1% to 49.8%) and for EDMCO was -27.2 ± 22.5% (-71.4% to 17%) versus PATDCO. The percent error for TEECO and EDMCO was 27.6% and 44.1%, respectively. The ρc value was 0.82 for TEECO and 0.66 for EDMCO. TEECO and EDMCO showed good trending ability. EDM-derived indexes displayed significant changes specific to the drug administered (P < .001). CLINICAL RELEVANCE: For minimally invasive CO monitoring, TEE may provide more favorable performance than EDM in clinical settings; however, EDM-derived indexes yield valuable hemodynamic information that reliably follows trends in CO, thus supporting critical decision-making in canine patients.

Evaluation of two probes for transesophageal echocardiography in small dogs: imaging capabilities, image quality, and usability.

INTRODUCTIONS: Patient size is a limiting factor for transesophageal echocardiography (TEE) in small dogs. The objective of this study was to describe imaging capabilities of two probes for TEE in small dogs. ANIMALS, MATERIALS, AND METHODS: Prospective study in 10 client-owned dogs weighing <4 kg with congenital heart disease (CHD). Dogs had TEE performed with a microprobe (10T-D, GE Medical) and intracardiac echocardiography (ICE) catheter-based probe (AcuNav™, Biosense Webster) in the esophagus in alternating order. Ease of placement, ability to acquire images of the CHD, image quality, and probe limitations were recorded. RESULTS: Median weight was 2.4 kg (range, 1.0-3.2). Congenital abnormalities included patent ductus arteriosus (n = 9) and pulmonary valve stenosis (n = 1). The 10T-D microprobe was easy to place (n = 8) or achievable with gentle manipulation (n = 2), and image quality of the CHD was optimal (n = 8), adequate (n = 1), or poor (n = 1). The ICE probe was difficult to place in the esophagus even with an external support system (n = 9) or could not be placed (n = 1), and image quality of the CHD was optimal (n = 2), adequate (n = 3), or poor (n = 5). Both probes provided images in a 1.0-kg dog. Probe limitations included lack of lateral motion (microprobe), the need for an external support system (ICE probe) and inability to consistently maintain contact with the esophagus (ICE probe). CONCLUSION: The 10T-D microprobe provided high-quality TEE images more consistently than the ICE probe in the majority of dogs in this study; however, the lack of lateral motion can diminish its utility in some dogs.

Hybrid balloon valvuloplasty for management of severe mitral stenosis in four symptomatic, adult dogs.

Four adult dogs weighing <10 kg presented for the evaluation of severe mitral valve stenosis with clinical signs. Owing to the size of the dogs, a hybrid surgical and interventional approach was utilized for balloon valvuloplasty. A left lateral thoracotomy was performed to allow direct entry through the left atrial wall. Transesophageal echocardiography was utilized for the entirety of the procedure in all dogs, and fluoroscopy was additionally used in two dogs. One dog had mild to moderate intra-operative bleeding from the left atrial wall during the procedure, but no other intra-operative complications were observed. No dogs developed a clinically relevant amount of worsened mitral regurgitation. Based on mitral leaflet mobility and transmitral flow profiles, there was perceived improvement in all four dogs. One dog died 6 h after extubation due to respiratory arrest. The remaining dogs survived to discharge and had resolution of clinical signs at home and discontinuation of heart failure medications. One dog died of an unknown cause at five months and another developed atrial fibrillation, and the owners elected to euthanize at ten months after the procedure. One dog continues to do well six months after the procedure as of the time of this writing. Hybrid balloon valvuloplasty can be a viable management option for small breed dogs with severe mitral stenosis exhibiting clinical signs, and both transesophageal echocardiography and fluoroscopy can be used intra-operatively to assist in successful procedural outcomes.

Prospective evaluation of complications associated with transesophageal echocardiography in dogs with congenital heart disease.

BACKGROUND: Transesophageal echocardiography (TEE) is useful in the assessment and procedural monitoring of congenital heart disease (CHD) with a relatively low complication rate in humans. OBJECTIVES: To evaluate the safety of TEE and report complications in dogs. ANIMALS: Forty client-owned dogs with CHD. METHODS: Prospective observational study including gastroesophagoscopy before and after TEE imaging. TEE was planned with a GE 6VT-D adult probe in dogs weighing ≥4 kg and a GE 10T-D microprobe alternating with an intracardiac echocardiography probe placed in the esophagus in dogs <4 kg. Difficulties with probe placement, probe interference and TEE probe imaging times were recorded. Dogs were monitored in the recovery period after TEE using an established nausea scoring system. RESULTS: New gastroesophageal abnormalities were identified after TEE in 4 dogs including 4 areas of mucosal damage involving <25% of the lower esophageal sphincter (n = 4) and 1 lesion at the heart base (n = 1) and were not attributed to longer imaging times or a specific probe. Lesions identified before TEE in 4 dogs remained unchanged after TEE. The 6VT-D probe could not be placed in 1 dog with enlarged tonsils, and it obstructed fluoroscopic views in 3 dogs. The probes did not compress any structures in dogs in which fluoroscopy was performed (n = 20). Four dogs had evidence to suggest nausea after the procedure. CONCLUSIONS AND CLINICAL IMPORTANCE: While major complications remain possible, complications in this study were mild and few in number. Dog size and probe characteristics are factors to consider when performing TEE.

Transoesophageal echocardiography-guided hybrid balloon valvuloplasty for severe pulmonic stenosis in small dogs.

Pulmonic stenosis (PS) is the most common congenital heart disease in dogs and is commonly seen in small breeds, such as Chihuahuas. Conventional treatments have limitations specific to small dogs, including the invasive nature of open-heart surgery and size limitations in percutaneous balloon valvuloplasty. Here, transoesophageal echocardiography (TEE)-guided balloon valvuloplasty via thoracotomy was performed for three small dogs with PS. The procedure was feasible in all cases, including those for which percutaneous treatment was not an option. Although the procedure is invasive, because of the need for thoracotomy, it is one of the treatment options that may be effective for PS, especially in small dogs, as it allows visualisation of the pulmonary artery lesion without relying on the experience of the surgeon.

Analysis of mitral valve morphology in dogs undergoing mitral valve repair with three-dimensional transesophageal echocardiography.

INTRODUCTION: Information about real-time three-dimensional (3D) transesophageal echocardiography (TEE) for the evaluation of canine mitral valve morphology is lacking in veterinary medicine. OBJECTIVES: To evaluate the feasibility of 3D TEE for the evaluation of canine mitral valves and whether there was a difference in mitral valve morphology between American College of Veterinary Internal Medicine (ACVIM) stages. ANIMALS: Thirty-one dogs were evaluated, including nine dogs classified as ACVIM stage B2, 15 as stage C, and seven as stage D. MATERIALS AND METHODS: Three-dimensional TEE was performed after anesthetic induction for mitral valve surgery, and the 3D geometry of the mitral valve apparatus was measured. RESULTS: The intraclass correlation coefficient was good in both inter- and intraobserver analyses of the 3D measurements of mitral valve annulus geometry and excellent in both inter- and intraobserver analyses in the 3D measurements of mitral valve annular and leaflet sizes. Annulus height to commissural width ratio of stage D dogs showed significantly lower values than B2 dogs (B2: 14.2% [9.1-20.5%]; C: 10.6% [6.5-24.1%]; D: 9.5% [4.7-13.8%]). The aortic-mitral angle of stages C and D were significantly flatter than stage B2 (B2: 122.32 ± 9.39; C: 133.66 ± 8.43; D: 140.70 ± 10.70). CONCLUSIONS: Real-time 3D echocardiography using TEE is a feasible method to evaluate the morphology of the mitral valve in dogs. The saddle shape of the mitral annulus and aortic-mitral angle were flatter in stage D. Further studies are required to understand the pathology of mitral valve disease in dogs.

Quantitative assessment of left ventricular volume and function by transthoracic and transesophageal echocardiography, ultrasound velocity dilution, and gated magnetic resonance imaging in healthy foals.

OBJECTIVE: To compare measurements of left ventricular volume and function derived from 2-D transthoracic echocardiography (2DE), transesophageal echocardiography (TEE), and the ultrasound velocity dilution cardiac output method (UDCO) with those derived from cardiac MRI (cMRI) in healthy neonatal foals. ANIMALS: 6 healthy 1-week-old Standardbred foals. PROCEDURES: Foals were anesthetized and underwent 2DE, TEE, and cMRI; UDCO was performed simultaneously with 2DE. Images acquired by 2DE included the right parasternal 4-chamber (R4CH), left apical 4- and 2-chamber (biplane), and right parasternal short-axis M-mode (M-mode) views. The longitudinal 4-chamber view was obtained by TEE. Measurements assessed included left ventricular end-diastolic volume (LVEDV), end-systolic volume (LVESV), ejection fraction, stroke volume (LVSV), cardiac output (CO), and cardiac index (CI). Bland-Altman analyses were used to compare measurements derived from biplane, R4CH, and M-mode images and UDCO with cMRI-derived measurements. Repeatability of measurements calculated by 3 independent reviewers was assessed by the intraclass correlation coefficient. RESULTS: Compared with cMRI, all 2DE and TEE modalities underestimated LVEDV and LVESV and overestimated ejection fraction, CO, and CI. The LVSV was underestimated by the biplane, R4CH, and TEE modalities and overestimated by UDCO and M-mode methods. However, the R4CH-derived LVSV, CO, and CI were clinically comparable to cMRI-derived measures. Repeatability was good to excellent for measures derived from the biplane, R4CH, M-mode, UDCO, and cMRI methods and poor for TEE-derived measures. CONCLUSIONS AND CLINICAL RELEVANCE: All assessed modalities yielded clinically acceptable measurements of LVEDV, LVESV, and function, but those measurements should not be used interchangeably when monitoring patient progress.

Double-outlet right ventricle in a Vietnamese potbellied pig.

A 6-month-old, neutered male, Vietnamese potbellied pig presented for evaluation of exercise intolerance and intermittent episodes of exertional cyanosis. Initial diagnostic evaluation revealed arterial hypoxemia. Transthoracic echocardiogram revealed double-outlet right ventricle (DORV) and a subaortic ventricular septal defect. Agitated saline contrast study confirmed the entry of saline contrast from the right ventricle into both pulmonary artery and aorta. Due to deterioration of clinical status, the patient was euthanized 3 months later. Gross necropsy examination was performed confirming the congenital cardiac defects noted on the echocardiogram. To the authors knowledge, this is the first case report of DORV in a Vietnamese potbellied pig.

Comparison of pulse pressure variation versus echocardiography-derived stroke volume variation for prediction of fluid responsiveness in mechanically ventilated anesthetized dogs.

OBJECTIVE: To evaluate the ability and accuracy of aortic flow velocity-time integral variation (ΔVTI) and peak aortic velocity variation (ΔVpeak) compared with pulse pressure variation (PPV) to predict fluid responsiveness in mechanically ventilated dogs. STUDY DESIGN: Prospective clinical study. ANIMALS: A group of 50 mechanically ventilated dogs with spontaneous hypotension during orthopedic or oncologic surgery. METHODS: Investigations were performed in the surgery room. When mean arterial pressure (MAP) decreased to <65 mmHg, measurements were performed before and after a fluid challenge (lactated Ringer's solution 5 mL kg-1 over 15 minutes). Responders were defined as a change in stroke volume (SV; transesophageal Doppler) ≥15%. Data were analyzed using paired/unpaired t test or Mann-Whitney/Wilcoxon test when appropriate and receiver operating characteristics (ROC) curves; a p value <0.05 was considered statistically significant. RESULTS: After the fluid challenge, 35 (70%) of 50 dogs were responders with significant increases in SV and decreases in PPV; 15 dogs were nonresponders. ΔVTI and ΔVpeak correlated with a 15% increase in SV. The optimum cut-off value for PPV was 15.6% (sensitivity, 88%; specificity, 100%), for ΔVTI was 10.65% (sensitivity, 65%; specificity, 100%) and for ΔVpeak was 10.15% (sensitivity, 80%; specificity, 100%). The area under the ROC curve for PPV was (0.93 ± 0.08) and for ΔVpeak was (0.89 ± 0.09), before fluid challenge. The gray zone area spread from 6.15% to 15.6% for PPV (18 dogs), 2.45% to 10.65% for ΔVTI (22 dogs) and 0.6% to 10.15% for ΔVpeak (25 dogs). CONCLUSIONS: When using mechanical ventilation, ΔVTI and ΔVpeak predicted fluid responsiveness with the same ability as PPV, based on the area under the ROC curve analysis. However, PPV showed great accuracy demonstrated by a narrower gray zone that included fewer individuals. CLINICAL RELEVANCE: ΔVTI and ΔVpeak can be used as indices of fluid responsiveness in anesthetized dogs.

Cor triatriatum sinister in a dog.

This report describes the transthoracic and transesophageal echocardiographic features of cor triatriatum sinister in an asymptomatic 6-year-old male French bulldog. Although cor triatriatum sinister represents a well-known and widely described cardiac malformation in humans, its description in the canine population is rare. In this clinical case, non-invasive echocardiographic techniques were helpful in visualizing and characterizing the lesion, allowing a valuable assessment of the malformation, and its hemodynamic consequences.

Balloon valvuloplasty in a dog with congenital bicuspid aortic valve and supravalvar aortic stenosis (atypical Shone's complex).

An 8-month-old intact female pug was presented for evaluation and possible balloon valvuloplasty (BV) for severe aortic stenosis. A bicuspid, severely stenotic aortic valve of type 3 morphology with a supravalvar stenosis component was diagnosed, consistent with the diagnosis of atypical Shone's complex. There was severe concentric hypertrophy of the left ventricle, with increased echogenicity of the myocardium nearest to the endocardial border. Mild left atrial enlargement was observed. Selective angiography and transesophageal echocardiography revealed an enlarged and relatively tortuous ascending aorta. The changes to the ascending aorta and the anatomy of the lesion made retrograde access to the left ventricle challenging. Ultimately, BV was successful using a pediatric valvuloplasty balloon catheter and rapid right ventricular pacing, and the pressure gradient across the aortic valve was decreased by more than 50% compared with preoperative measurements. Although valvar aortic stenosis is rare in veterinary medicine, this report highlights the potential challenges and feasibility of BV for this disease.

Transesophageal Echocardiography Examination in Ailuropoda melanoleuca.

OBJECTIVE: Cardiac function analysis for Ailuropoda melanoleuca, also called giant panda, with transthoracic echocardiography has several limitations, such as limited probe position area and poor echo window. We want to determine the feasibility of transesophageal echocardiography (TEE) for cardiac examination in Ailuropoda melanoleuca. METHODS: Eight-year-old male Ailuropoda melanoleuca was anesthetized by intramuscular ketamine and followed by inhalation isofl urane with spontaneous respiration. TEE probe was inserted through mouth. Comprehensive examinations were done by two-dimensional (2D), Doppler method, 3D zoom and 3D full volume mode for their cardiac evaluation. RESULTS: The structure of heart was similar to human. We found mild mitral regurgitation. Right ventricle and pulmonary artery were free of any organic lesions. We did comprehensive multiplane examination by American Society of Echocardiography/Society of Cardiovascular Anesthesia guideline, but transgastric (TG) and deep TG view were not approachable. 3D reconstruction offered high quality image and quantitative calculations. Complete examinations took less than 30 minutes. There was no significant hemodynamic change during probe insertion, and no oropharyngeal trauma certifi ed by dentist. CONCLUSIONS: TEE is a reasonable semi-invasive tool for cardiac function evaluation. Though some anatomical limitations prohibited comprehensive 2D views, improvements such as 3D images help to give detailed cardiac examination.

Quantitative assessment of two- and three-dimensional transthoracic and two-dimensional transesophageal echocardiography, computed tomography, and magnetic resonance imaging in normal canine hearts.

INTRODUCTION: The objective of the study was to evaluate the accuracy of two- and three-dimensional (2D, 3D) transthoracic echocardiography (TTE), 2D transesophageal echocardiography, and computed tomography angiography (CTA) compared with cardiac magnetic resonance imaging (CMR) in normal dogs and to assess repeatability of 2D and 3D TTE for the assessment of left ventricular (LV) and left atrial (LA) dimensions. ANIMALS: The study was performed on six healthy dogs. MATERIALS AND METHODS: Transthoracic echocardiography, transesophageal echocardiography, CTA, and CMR were performed on each dog. Right ventricular (RV) and LV volumes (in systole and diastole), ejection fraction (EF), and LA and right atrial (RA) volumes were assessed. Repeatability and intrarater and interrater measurements of variability were quantified by average coefficient of variation (CV) for 2D and 3D TTE. RESULTS: No clinically relevant differences in LV volume were detected between CMR and all modalities. Importantly, 3D TTE had the lowest CV (6.45%), correlated with (rs = 0.62, p = 0.01), and had the highest overlap in distribution with CMR (OVL >80%). Left ventricular EF and LA size via CTA compared best with CMR and RV and RA volumes were best estimated by 3D TTE. Assessment of LV and LA volumes via 3D TTE had moderate repeatability (15-21%) compared with LV M-mode measurements and 2D LA-to-aortic ratio (<10%), respectively. For LV size, interrater CV for 3D TTE (19.4%) was lower than 2D TTE (23.1%). CONCLUSIONS: Measurements of LV, RV, and RA volumes via 3D TTE and LA volume and LV EF assessed by CTA compared best with CMR. Three-dimensional echocardiography had lower interrater and intrarater CV compared with 2D TTE.

Clinical, echocardiographic and advanced imaging characteristics of 13 dogs with systemic-to-pulmonary arteriovenous fistulas.

OBJECTIVES: The objective is to describe the clinical, radiographic, echocardiographic and angiographic findings in dogs with systemic-to-pulmonary arteriovenous fistula (SPAVF). ANIMALS: Thirteen medical records of client-owned dogs with a diagnosis of SPAVF were reviewed/analysed. METHODS: This is a retrospective study of case records. Thoracic radiography, transthoracic echocardiography (TTE), transesophageal echocardiography (TEE), three-dimensional TEE, intracardiac echocardiography, fluoroscopy-guided or computed tomography (CT) angiography were carried out. RESULTS: Based on the TTE, SPAVF was identified in seven of the included dogs. In eight cases, TEE and angiography were both performed and confirmed the diagnosis. Computed tomography angiography was performed in three dogs. A case was diagnosed by TEE alone, another one by three-dimensional TEE and the latter by intracardiac echocardiography. CONCLUSIONS: Transthoracic echocardiography identified seven cases of SPAVF, while definitive diagnosis in the remaining dogs required selective angiography or computed tomography angiography.

Comparative, multidimensional imaging of patent ductus arteriosus and a proposed update to the morphology classification system for dogs.

BACKGROUND: Accurately assessing the morphology and shape of the patent ductus arteriosus (PDA) and obtaining measurements are important to avoid procedural complications. OBJECTIVES: To characterize and compare PDA morphology, shape, and dimensions with angiography and echocardiography. ANIMALS: 25 client-owned dogs with echocardiographically confirmed PDA. METHODS: Prospective case series. Imaging consisted of single plane angiography, transthoracic echocardiography from the right (TTE-R) and left (TTE-L), and two-dimensional, biplane, and three-dimensional transesophageal echocardiography (TEE-2D and TEE-3D). Measurements included angiographic minimal ductal diameter (MDD), echocardiographic pulmonary ostium in a single dimension (TTE-R, TTE-L, and TEE-2D) and in perpendicular dimensions (TEE-3D) with similar measurements of the ampulla 3 mm above the MDD or pulmonary ostium. The morphology and shape of the PDA were characterized. RESULTS: Catheter-based occlusion (N = 20) and surgical ligation (N = 5) were performed without complication. Angiographic morphology was classified as type II (N = 19), type III (N = 1), and other (N = 1). Angiographic MDD and TEE-2D pulmonary ostium measurements were significantly (P = .008) but weakly correlated (r = .56); similar relationships were found for ampulla diameter measurements (P < .0001; r = .75). In general, TEE-2D did not correlate with other imaging modalities measurements. Based on TEE-3D measurements, the majority of pulmonary ostium (17/24; 71%) and ampulla (19/24; 79%) were oval. CONCLUSIONS AND CLINICAL IMPORTANCE: Measurements using different imaging modalities are not interchangeable. TEE-3D provided an en face view of the PDA that cannot be replicated with other echocardiographic techniques and demonstrated an oval shape in the majority of dogs. We propose an update to the current classification system to include additional PDA morphologies.