Journal of Veterinary Cardiology最新文献

A four-year-old spayed female Shiba Inu dog weighing 6.1 kg presented with ascites. Cor triatriatum dexter (CTD) without any other concurrent cardiovascular anomalies was diagnosed using echocardiography. The ostium of the abnormal membrane dividing the right atrium into two abnormal chambers was surgically excised under cardiopulmonary bypass. All clinical abnormalities were resolved after surgery. However, seven months later, ascites and CTD recurred. A balloon-expandable stent was placed at the site of recurrence, which improved caudal venous return to the right ventricle. After the second procedure, ascites were resolved, and the dog remained asymptomatic for 18 months without complications. There are previous reports of successful surgical resection of the CTD and of stenting in recurrent CTD following balloon dilation in dogs. However, to the authors’ knowledge, no previous reports have described recurrent CTD in dogs after surgical resection of the CTD. In this case, as with recurrent CTD following balloon dilation, stent placement at the site of the CTD can be a viable treatment option when the abnormal membrane recurs.

Introduction/Objectives

Dogs with severe pulmonary stenosis (PS) are routinely treated with balloon valvuloplasty. Success and safety of these procedures require an accurate assessment of the pulmonary valve annulus (PVA) diameter for proper balloon catheter selection. PVA diameter is assessed with angiography (PVA-Ang) and transthoracic echocardiography (PVA-TTE), and both may impact procedural planning for balloon valvuloplasty. The objective of this study was to describe the relationship between PVA-Ang and PVA-TTE in dogs with PS.

Animals, materials and methods

Observational, retrospective study of 59 client-owned dogs. Medical records of dogs diagnosed with PS were reviewed. Images from selective right ventricular angiography and transthoracic echocardiography were reviewed. The PVA diameters were measured at the time of angiography (PVA-Ang) and by a single operator for this study (PVA-TTE). Image quality scores were assigned to echocardiographic images of the PVA based on visualization of PVA margins and valve leaflet hinge points.

Results

In 41/59 (70%) dogs, the diameter of the PVA-Ang was larger than the PVA-TTE, and the median absolute difference between measurements was 1.9 mm (range 0.1–8.4). With worse echocardiographic image quality, the difference in measurement between modalities increased. Dogs with poor echocardiographic image quality had greater differences (range −7.7 to 8.4 mm) between PVA-Ang and PVA-TTE compared to those with excellent image quality (range −2.2 to 3.8 mm), and the absolute differences between poor (median 2.8 mm, range 1.5–8.4 mm) and excellent (median 1.4 mm, 0.2–3.8 mm) image quality were significant (P=0.005).

Conclusions

Diameters of PVA-Ang are greater than PVA-TTE in most dogs, and these differences are most apparent with worse echocardiographic image quality. These differences may be clinically relevant to interventional procedure planning.

Introduction/objectives

In clinical practice, dogs are screened for subaortic stenosis (SAS) using two-dimensional (2DE) and Doppler echocardiography. There is no accepted antemortem diagnostic criterion to distinguish between mild SAS and unaffected, therefore additional means of evaluating the left ventricular outflow tract (LVOT) and aorta may be desirable. This study sought to determine and compare LVOT and aortic orifice areas using 2DE and three-dimensional echocardiography (3DE) in apparently healthy dogs of various breeds and somatotypes.

Animals, materials, and methods

Sixty-nine healthy, privately-owned dogs. The LVOT and aortic orifice areas were determined using 2DE aortic valve (AV) diameter-derived area; the continuity equation (CE); and 3DE planimetry of the LVOT, AV, sinus of Valsalva, and sinotubular junction. Orifice areas were indexed to body surface area (BSA).

Results

Obtaining 3DE images and performing planimetry were feasible in all dogs. The mean indexed area measured using the 2DE AV diameter (2.85 cm²/m²) was significantly lower than that derived from 3DE AV planimetry (3.85 cm²/m²; mean difference, 1.00 cm²/m²; P<0.001). There was poor agreement between the effective area calculated using the CE and the anatomic areas calculated using 2DE AV diameter and 3DE planimetry. The area calculated using the CE was less than all other calculations of area. Interobserver and intraobserver repeatability and reproducibility for 3DE planimetry were excellent.

Conclusions

Methods for determining aortic orifice areas in dogs are not interchangeable, and this must be taken into account if these methods are investigated in the evaluation of dogs with SAS in the future.

A 7-year-old male neutered domestic shorthaired cat underwent surgical placement of a permanent epicardial pacemaker following diagnosis of intermittent second and third degree atrioventricular block, which was responsible for ‘seizure-like’ episodes. Although the pacemaker implant was successful, the cat started experiencing near-syncopal episodes approximately one year after surgery. Ambulatory Holter recording showed periods of loss of capture. Therefore, the pacemaker was interrogated using incremental energy output, which did not evoke any capture, even at the highest possible pulse voltage and duration. Thoracic radiographs showed that the pulse generator had rotated compared to the original radiographic assessment and the lead appeared entangled and shortened, resembling the findings described as ‘twiddler syndrome’ in humans and dogs, which is characterised by twisting of the lead caused by rotation of the pulse generator around its long axis and subsequent lead migration. To the best of the authors’ knowledge, this is the first report of twiddler syndrome in a cat.

Introduction

Right ventricular (RV) dysfunction is a significant negative prognostic indicator in human dilated cardiomyopathy (DCM). Many RV indices are weight-dependent, and there is a lack of reference values for the right heart in giant breed dogs (over 50 kg), including Great Danes (GDs). This study aimed to compare indices of RV function in echocardiographically normal GDs, those with preclinical DCM (PC-DCM), and those with DCM and congestive heart failure (DCM-CHF).

Animals

A total of 116 client-owned adult GDs: 74 normal, 31 with PC-DCM, and 11 with DCM-CHF.

Methods

A retrospective, single-center cohort study assessed RV function using free-wall RV longitudinal strain (RVLS), strain rate, fractional area change (FAC), tricuspid annular plane systolic excursion (TAPSE), and pulsed-wave tissue Doppler imaging-derived systolic myocardial velocity of the lateral tricuspid annulus (TDI S’). Relationships between DCM status and RV function indices were analyzed.

Results

RV function, measured by TAPSE (P=0.001), FAC (P<0.001), and TDI S’ (P<0.001), decreased in dogs with PC-DCM and DCM-CHF compared to healthy dogs, with FAC being lower in DCM-CHF compared to PC-DCM (P=0.048). RVLS impairment was more significant in the DCM-CHF group than in the PC-DCM group (P=0.048). RVLS had the highest area under the curve (0.899) for differentiating between normal and DCM-CHF dogs.

Conclusion

As DCM progresses, echocardiographic variables of RV function, including TAPSE, FAC, TDI S’, RVLS, and strain rate, worsen, indicating impaired RV systolic function in GDs affected by DCM.

A 4-year-old Labrador Retriever was presented for intermittent tachycardia. The electrocardiogram showed sinus rhythm conducted with ventricular pre-excitation and short runs of orthodromic atrioventricular reciprocating tachycardia. Four months later, the rhythm degenerated into a symptomatic sustained tachycardia, suspected to be pre-excited atrial fibrillation, a potentially life-threatening rhythm in the presence of an accessory pathway with a short refractory period. Two days after initiating oral diltiazem, the dog deteriorated and represented with sustained orthodromic atrioventricular reciprocating tachycardia, which was terminated by a precordial chest thump. It proceeded to sinus rhythm with ventricular pre-excitation followed by an episode of pre-excited focal atrial tachycardia. A bolus of lidocaine IV successfully restored sinus rhythm and sotalol treatment was started. The dog clinically recovered but died spontaneously 24 h later. This is the first case report that describes spontaneous pre-excited focal atrial tachycardia.

Three cats were presented for unusual collapsing episodes. Echocardiography revealed a hypertrophic cardiomyopathy (HCM) phenotype in each cat. Continuous electrocardiographic monitoring showed that the clinical signs coincided with periods of severe ST-segment elevation in each cat. The first cat was treated with amlodipine and diltiazem but did not improve and was euthanized due to poor quality of life. Postmortem examination revealed cardiac lymphoma without obstructive coronary disease. The second cat was thought to have cardiac lymphoma, based on pericardial effusion cytology, and was euthanized before starting therapy. The third cat was diagnosed with HCM and left ventricular outflow tract obstruction and was treated with atenolol and diltiazem. This treatment reduced the frequency of episodic clinical signs, but the cat subsequently developed congestive heart failure and was euthanized. This case series describes clinical signs associated with severe ST elevation in cats with an HCM phenotype, and their outcomes. Continuous electrocardiographic monitoring was necessary to detect transient ST elevation in each case.

A hybrid surgical approach was utilized to address cor triatriatum sinister in a 10-month-old castrated male domestic shorthair cat. Prior to surgery, open-mouth breathing occurred with exertion. The procedure was guided by transesophageal echocardiography and fluoroscopy. A minithoracotomy was performed, and the left atrial membrane was accessed via an introducer placed through the left ventricular apex. Sequential balloon dilations were performed, and the mean transmembrane gradient under anesthesia was reduced from 16 mmHg to 2.23 mmHg. Four months after surgery, the transmembrane mean gradient remained lower than prior to intervention. The cat tolerated surgery well and remains free of clinical signs nine months after surgery.

Double outlet right atrium is a rare congenital cardiac abnormality that has been previously reported in humans and cats, but not in dogs. A double outlet right atrium is typically characterized by the presence of a leftward deviation of the interatrial septum and atrial septal defect. Therefore, the right atrium drains into both ventricles. The unique features consistent with double outlet right atrium were identified by transthoracic echocardiography and computed tomography in a puppy. This case report describes the clinical, echocardiographic, and tomographic findings of a five-month-old Cocker Spaniel diagnosed with this rare congenital abnormality.