Journal of Veterinary Cardiology最新文献

Feline arterial thromboembolism has been reported to be secondary to various feline cardiomyopathies; however, it has not been described in cats with transient myocardial thickening. A previously healthy, one-year-old, castrated male cat presented with acute paraparesis and congestive heart failure. Echocardiography revealed asymmetric left ventricular free wall thickening and left atrial enlargement. Antithrombotic treatment and cardiac medication resulted in reperfusion and mobility on day seven in one limb and on day 10 in the other. Different complications were managed successfully, including worsening acute kidney injury, inflammation, pleural effusion, and anemia. After three weeks, the cat was discharged and prescribed oral antithrombotic drugs (clopidogrel and rivaroxaban) and cardiac medication. Within five months, echocardiographic findings normalized, and medical treatment was gradually discontinued. To date, the cat remains healthy at 1735 days after the initial diagnosis and 1494 days after the last antithrombotic medication. To the best of our knowledge, this is the first case report on feline arterial thromboembolism combined with transient myocardial thickening, with favorable long-term survival.

Introduction/objectives

Spontaneous pulmonary vein (PV) activity triggers atrial fibrillation (AF) in humans. Although AF frequently occurs in horses, the origin remains unknown. This study investigated the structural and electro-anatomical properties of equine PVs to determine the potential presence of an arrhythmogenic substrate.

Animals, materials and methods

Endocardial three-dimensional electro-anatomical mapping (EnSite Precision) using high-density (HD) catheters was performed in 13 sedated horses in sinus rhythm. Left atrium (LA) access was obtained retrogradely through the carotid artery. Post-mortem, tissue was harvested from the LA, right atrium (RA), and PVs for histological characterization and quantification of ion channel expression using immunohistochemical analysis.

Results

Geometry, activation maps, and voltage maps of the PVs were created and a median of four ostia were identified. Areas of reduced conduction were found at the veno-atrial junction. The mean myocardial sleeve length varied from 28 ± 13 to 49 ± 22 mm. The PV voltage was 1.2 ± 1.4 mV and lower than the LA (3.4 ± 0.9 mV, P < 0.001). The fibrosis percentage was higher in PV myocardium (26.1 ± 6.6 %) than LA (14.5 ± 5.0 %, P = 0.003). L-type calcium channel (Ca_V1.2) expression was higher in PVs than LA (P = 0.001). T-type calcium channels (Ca_V3.3), connexin-43, ryanodine receptor-2, and small conductance calcium-activated potassium channel-3 was expressed in PVs.

Conclusions

The veno-atrial junction had lower voltages, increased structural heterogeneity and areas of slower conduction. Myocardial sleeves had variable lengths, and a different ion channel expression compared to the atria. Heterogeneous properties of the PVs interacting with the adjacent LA likely provide the milieu for re-entry and AF initiation.

A five-month-old male intact Goldendoodle presented for evaluation for peripheral cyanosis following exercise. Transthoracic echocardiography demonstrated severe right ventricular wall thickening and right atrial dilation secondary to pulmonary hypertension. An agitated saline contrast study demonstrated an interatrial right-to-left shunt. Cardiac-gated computed tomography confirmed a reverse patent ductus arteriosus. This case report highlights the utility of cardiac-gated computed tomography in identifying multi-level intra- and extra-cardiac shunts.

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.

A one-year-and-seven-month-old, 28 kg, male castrated crossbreed dog was presented for supraventricular tachycardia causing recurrent episodes of anorexia and lethargy. Sotalol (2.2 mg/kg q12 h) reduced the frequency of symptomatic episodes but did not provide full relief. Three-dimensional electroanatomical mapping was performed at the Ghent University Small Animal Teaching hospital using the CARTO 3. Right atrial activation mapping identified the earliest atrial activation right posteroseptal, near the tricuspid annulus. Fast retrograde ventriculoatrial conduction during tachycardia and extrastimulus testing confirmed the presence of a concealed right posteroseptal accessory pathway. Six radiofrequency catheter ablation applications were delivered, and tachycardia remained uninducible. The dog recovered well from the procedure. Sotalol was stopped three weeks later, and no more clinical signs were noted by the owner. Repeated 24-hour electrocardiography monitoring on day one and at 1, 3, and 12 months after the procedure showed no recurrence of tachycardia.

Introduction

Interventricular septal flattening, frequently present in pulmonary hypertension (PH) can be quantified by the left ventricular eccentricity index (EI) measured at end-diastole (EId), end-systole (EIs) and at maximal septal flattening (EIm). In humans, EI correlates with invasive pulmonary arterial pressure.

The aim of this study was to evaluate if EI correlates with parameters of right heart remodeling (RHR) and if EI is a quantitative marker of PH in dogs.

Materials and methods

Left ventricular eccentricity indices were retrospectively measured in four groups (no, mild, moderate and severe PH) with interpretable tricuspid and/or pulmonary regurgitation.

Results

Ninety-seven dogs were included, with no (n = 29), mild (n = 13), moderate (n = 25) and severe (n = 30) PH. The intra- and inter-observer variability for EI measurements ranged from 2 % to 11 %. All EI were significantly elevated in severe compared to no, mild and moderate PH (P < 0.0005). In the moderate group, EIs and EIm were higher compared to the no PH group (P < 0.01). Tricuspid and pulmonary regurgitation pressure gradients and RHR parameters correlated with EId, EIs and EIm in all groups. Optimal cut-off values discriminating moderate and severe PH from no and mild PH were 1.24 (Sensitivity (Se) 60 %; Specificity (Sp) 90 %) for EId, 1.34 (Se 67 %; Sp 95 %) for EIs and 1.37 (Se 76 %; Sp 83 %) for EIm.

Conclusions

Left ventricular eccentricity indices are reproducible echocardiographic variables increasing with severity of PH. Dogs with moderate and severe PH can be discriminated from dogs with no or mild PH using EIs and EIm.

Three-dimensional (3D) modeling and printing is an emerging technology in veterinary cardiovascular medicine allowing the fabrication of anatomically correct patient-specific models. These patient-specific models can be used for a wide range of purposes including medical teaching, assessment of cardiac function and movement of valve leaflets, design and assessment of devices created for interventional procedures, and pre-surgical planning [1–3]. Additionally, these 3D models can facilitate communication between the clinical team and the patient's owner. The process of creating 3D models starts with acquiring volumetric imaging data sets of the area of interest. Three-dimensional modeling and printing are reliable when high-quality volumetric imaging data are used to create these models. Currently, only ungated- and electrocardiogram (ECG)-gated computed tomography (CT), cardiac magnetic resonance imaging (CMRI), and 3D echocardiography provide the volumetric data sets needed to create these 3D models. These imaging data sets are imported into a software or open-source freeware platform and then segmented to create a virtual 3D model. This virtual 3D model can be further refined using computer-aided design (CAD) software and then be printed to create a physical 3D model. Cardiovascular 3D modeling and printing is a new medical tool which allows us to expand the way we plan interventional procedures, practice interventional skills, communicate with the medical team and owner, and teach future veterinarians.

Introduction/Objectives

Juvenile ventricular arrhythmias in the absence of structural heart disease have been characterized in a small number of canine breeds with limited long-term follow up. The objective of this study was to describe the clinical outcome of dogs with JVA presenting to a university teaching hospital.

Animals, materials, methods

25 dogs, less than two years old with idiopathic ventricular arrhythmias were retrospectively identified via a medical record search. Young dogs with ventricular arrhythmias were excluded if they had structural heart disease, systemic illness, or an abnormal troponin (if performed). Electrocardiographic and Holter monitor data was evaluated for arrhythmia frequency and complexity at the time of diagnosis and over time. Long-term follow up was achieved through client and primary veterinarian contact.

Results

Breeds included German Shepherd (8), Boxer (4), Great Dane (3), mixed breed (2) and one each of the following: Anatolian Shepherd, French Bulldog, Golden Retriever, Great Pyrenees, Labrador Retriever, Shiloh Shepherd, Miniature Poodle and Siberian Husky. The average age at diagnosis was 7.9 months (range, 2–22 months). The overall median survival was 10.96 years (range, 1.75–15.66 years). There was an average reduction in the number of ventricular beats by 86.7 % per year (P value −0.0257) based on Holter data.

Conclusion

In most cases, idiopathic juvenile ventricular arrhythmias had a favorable long-term prognosis with reduced ectopy over time in this case series. Juvenile ventricular arrhythmias remains a diagnosis of exclusion but can be considered in a broader range of dog breeds than previously described.

Objectives

To investigate the clinical and echocardiographic presentation of dogs with persistent atrial standstill (PAS), identify variables measured at first presentation that could predict their survival, and document the progression of the disease after pacing.

Materials and methods

Retrospective study of medical records of dogs diagnosed with PAS at three referral hospitals of the United Kingdom over seven years.

Results

Twenty-six dogs were diagnosed with PAS during the study period. Median age of the population was three years (range: 7 months–12.5 years). The most common clinical sign was syncope (14/26). Twenty-four dogs received artificial pacemakers (PM). Major complications after PM implantation were observed in four dogs (4/24). Serial echocardiographic examinations showed that cardiac dimensions of PAS dogs with left atrial or left ventricular dilation at first presentation did not return to reference range after pacing. Further dilation of the cardiac chambers, recurrence of congestive heart failure (CHF), or development of new episodes of CHF were documented in 7, 4, and 10 PAS dogs, respectively, despite pacing. Median survival time for cardiac-related deaths after PM implantation was 1512 days (18–3207). Neither CHF nor echocardiographic variables at presentation predicted survival after PM implantation in PAS dogs.

Conclusions

PAS is an uncommon bradyarrhythmia, occurring in young adult dogs. Affected dogs were often presented with syncope. Whilst syncope resolved, cardiac remodeling persisted after PM implantation. Long-term survival was favorable after PM implantation and was not predicted by congestive status or cardiac chamber size at first presentation.