Transcatheter Atrial Septal Defect Closure with the AMPLATZER®Atrial Septal Occluder in 13 Dogs: Short- and Mid-Term Outcome

Surgical Correction of a Sinus Venosus Atrial Septal Defect with Partial Anomalous Pulmonary Venous Connections Using Cardiac Computed Tomography Imaging and a 3D-Printed Model

Sinus venosus atrial septal defects (SVASDs), concurrent with partial anomalous pulmonary venous connections (PAPVCs), are a rare congenital heart disease in dogs. Surgical correction is essential when clinical signs or significant hemodynamic changes are present. We aimed to report on the successful surgical correction of an SVASD with PAPVCs, using a computed tomography (CT)-based customized 3D cardiac model. A 10-month-old male poodle was referred for corrective surgery for an ASD. Echocardiography confirmed a hemodynamically significant left-to-right shunting flow through an interatrial septal defect and severe right-sided heart volume overload. For a comprehensive diagnosis, a CT scan was performed, which confirmed an SVASD with PAPVCs. A customized 3D cardiac model was used for preoperative decision-making and surgical rehearsal. The defect was repaired using an autologous pericardial patch under a cardiopulmonary bypass (CPB). Temporary pacing was applied for sinus bradycardia and third-degree atrioventricular block. The patient recovered from the anesthesia without further complications. The pacemaker was removed during hospitalization and the patient was discharged without complications 2 weeks post-surgery. At the three-month follow-up, there was no shunting flow in the interatrial septum and the right-sided volume overload had been resolved. The cardiac medications were discontinued, and there were no complications. This report indicates the validity of surgical correction under CPB for an SVASD with PAPVCs, and the advantages of utilizing a CT-based 3D cardiac model for preoperative planning to increase the surgical success rate.

Large Secundum Atrial Septal Defect Managed Conservatively in an Adult Dog

•ASDs can be medically managed in dogs if interventional options are not selected. •3D modeling can be used for canine congenital heart disease. •3D imaging helps with preprocedural planning for ASD.

Information Provided by Breeders and Referring Veterinarians about the Presence and Meaning of a Murmur to Owners of Newly Purchased Puppies with a Later Confirmed Congenital Heart Disease

Background: A recent study revealed that only 10% of puppies diagnosed with a congenital heart disease were referred for murmur investigation to a veterinary cardiology specialist while the puppies were in the breeders' possession. Whether the new owners had been informed about the presence of a murmur before purchasing a puppy was not investigated. Methods: New owners whose dogs were diagnosed with a congenital heart disease at the authors' institution in a 1-year period received a questionnaire during the consult after cardiac auscultation but before performing an echocardiogram. The main study aims were to reveal whether the breeders had informed the new owners about the presence of a murmur before purchasing the puppy, and whether the owners would have still chosen to buy that specific puppy if they had known about a potentially present congenital heart disease. Results: Of the 60 interviewed owners, 72% would have refrained from buying the puppy if they had known about the presence of a congenital heart disease. However, only 23% of them were informed about the presence of a cardiac murmur before purchase. Conclusions: Most owners would have chosen to buy a healthy puppy without a heart disease if they had been informed.

Effect of preoperative administration of atenolol to dogs with pulmonic stenosis undergoing interventional procedures

Background

Beta‐blockade is sometimes used in dogs with pulmonic stenosis with the intent of reducing frequency of ventricular arrhythmias during right heart catheterization.

Objectives

To evaluate if pretreatment with atenolol reduces frequency of ventricular arrhythmias, anesthetist interventions, or shortens procedure time.

Animals

Thirty dogs with pulmonic stenosis scheduled for interventional procedures.

Methods

Single center, prospective, randomized, open‐label study. Dogs were randomized to treatment with atenolol or no treatment preoperatively for a minimum of 10 days. Variables recorded included heart rate, arrhythmias and complexity, total procedure time and administration of antiarrhythmic treatment, vasopressors, positive chronotropes, or fluid boluses.

Results

Fifteen dogs were enrolled in each group. Dogs receiving atenolol had lower mean heart rates during the procedure (atenolol 100 ± 11 bpm vs untreated 115 ± 19 bpm, P = .01). There were no significant differences between the atenolol and untreated groups in the frequency of ventricular ectopic complexes (535 [6‐5296] vs 553 [79‐2863], P = .9), ventricular couplets (46 [0‐481] vs 29 [3‐121], P = .59), ventricular triplets (20 [0‐265] vs 16 [1‐82], P = .67), ventricular tachycardia (8 [0‐224] vs 8 [1‐118], P = .99), proportion exhibiting R‐on‐T phenomenon (11/15 vs 14/15, P = .33), proportion receiving intraoperative lidocaine (1/15 vs 3/15, P = .6), vasopressors/positive chronotropes (11/15 vs 5/15, P = .06), or fluid boluses (12/15 vs 7/15, P = .13). The procedure time was similar (atenolol 41 [23‐68] min vs untreated 35 [18‐98] min, P = .91).

Conclusions and Clinical Importance

No benefit of preoperative atenolol treatment was identified in this small group of dogs.

Surgical Management of Three Dogs with an Interatrial Communication and Atrioventricular Valve Abnormalities

• Large interatrial communications in dogs are rare. • When indicated, surgical closure of an interatrial communication is possible. • When indicated, surgical repair of the atrioventricular valve is possible. • Multimodal imaging aids surgical planning in cardiac surgeries of dogs.

Key considerations in the approach to congenital heart disease in dogs and cats

Congenital heart disease is an important subset of all cardiovascular disease in dogs and cats that is present at birth and most often detected in young animals but can be diagnosed in adulthood. The range of abnormalities that can occur during development of the heart is vast incorporating simple and complex defects, varying degrees of severity and clinical presentations that include heart failure and cyanosis. While some defects do not result in morbidity in an individual animal, others cause severe clinical signs and death at a young age. Advances in imaging and expanding treatment options offer increasingly more possibilities in the diagnosis and management of congenital heart disease which is the focus of this review. The objective is to provide a broad overview of current practice and highlight key aspects to guide practitioners in their approach to congenital heart disease diagnosis and knowledge of available treatment options.

Real-time three-dimensional (3D) echocardiographic characterisation of an atrial septal defect in a horse

Atrial septal defects have been well reported in humans and dogs and the principles of intervention have been well established. In contrast, there is very little information published about these congenital anomalies in horses. True ASDs are regarded as rare and little is known about the clinical significance of these defects in horses. An 11‐year‐old Thoroughbred gelding with a history of poor performance was diagnosed with an atrial septal defect, measuring approximately 2 cm in diameter, on 2D transthoracic echocardiography. Real‐time three‐dimensional (3D) echocardiography was used to map the structure of the defect and was useful in fully characterising the ASD in this case.

Atrial septal defect closure in a midget toy poodle

Background

Atrial septal defect (ASD) is a rare congenital cardiac disease, and there have been no reports about the treatment of ASD in midget breed dogs.

Case Description

A 7-month-old female toy poodle weighing 1.4 kg presented with cardiac enlargement. Echocardiography revealed a secundum-type ASD, right ventricular and atrial enlargement, and pulmonary hypertension. Blood flow through the ASD exhibited left-to-right shunting. The dog underwent ASD closure through a hybrid approach, in conjunction with catheter techniques and thoracotomy. Ten months after treatment, cardiac enlargement and pulmonary hypertension were improved.

Conclusion

Even in midget dog breeds, ASD can be corrected through a hybrid approach.

Prevalence of major complications and procedural mortality in 336 dogs undergoing interventional cardiology procedures in a single academic center

INTRODUCTION

Overall complication rates associated with a wide range of diagnostic and therapeutic interventional cardiac procedures in a contemporary academic setting have not been reported.

ANIMALS, MATERIALS AND METHODS

Consecutive interventional procedures performed for client-owned dogs were retrospectively analyzed to characterize procedural complications and mortality.

RESULTS

Three hundred sixty-four procedures were performed on 336 dogs. Interventions included attempted or completed transvenous pacemaker (PM) implantation (n = 134) with subsequent pacing system revision (n = 8), pulmonic balloon valvuloplasty (BVP) (n = 117) with a subset of patients undergoing an additional BVP (n = 14), transarterial closure of left-to-right shunting patent ductus arteriosus (PDA) (n = 66), diagnostic angiography and/or cardiovascular pressure measurement (n = 9), transvenous temporary pacing (n = 7), septal defect occlusion (n = 5), heartworm extraction (n = 3), and BVP catheter fragment retrieval (n = 1). The prevalence of major perioperative and postoperative complications for all procedures was 5% and 6%, respectively, and the procedural mortality rate was 2%. The overall rate of major complications was 12% for the PM group, 11% for the BVP group, and 2% for the PDA occlusion group. Both PM implantation and BVP have higher rates of major complications overall compared with PDA occlusion (p=0.0151).

CONCLUSIONS

The results of this study indicate that the prevalence of major complications and mortality associated with interventional cardiac procedures is low; however, significant differences exist in complication rates between procedures.

Surgery for partial atrioventricular septal defect with pulmonary hypertension in an adult dog

A 4-year-old, 5.9-kg female Japanese Spitz presented with syncope and exercise intolerance. Echocardiography revealed an ostium primum atrial septal defect (ASD), a cleft mitral valve, mitral valve regurgitation (MR), and tricuspid regurgitation (TR) (velocity: 3.6 m/sec, pressure gradient: 52 mmHg), leading to a diagnosis of partial atrioventricular septal defect (AVSD) with moderate pulmonary hypertension (PH). Open-heart surgery using cardiopulmonary bypass was performed through right atriotomy. The cleft of the mitral valve was sutured with polypropylene and the AVSD was closed using an autologous pericardial patch fixed with glutaraldehyde. No postoperative pulmonary hypertensive crisis occurred. Shunting flow through the ASD, TR and PH had completely disappeared 2 months postoperatively; however, moderate MR persisted. The dog is still alive 5 years postoperatively without clinical signs.

Unilateral absence of an external jugular vein in two English bulldogs with pulmonary valve stenosis

Two English bulldogs referred for interventional palliation of severe pulmonary valve stenosis were incidentally diagnosed with unilateral absence of an external jugular vein (left in one case, right in the other) by computed tomography and Doppler ultrasound. The right internal jugular vein also could not be visualized in the dog with absence of the left external jugular vein. Cervical venous anomalies can impact diagnostic or interventional venous catheterization procedures such as balloon pulmonary valvuloplasty. Additionally, absence of an external jugular vein may impact central venous catheter placement. Absence of an external jugular vein should be considered in dogs when the external jugular vein cannot be easily palpated. Ultrasound or computed tomography may help identify jugular venous anatomy and confirm anomalies.

Sequential segmental classification of feline congenital heart disease

Feline congenital heart disease is less commonly encountered in veterinary medicine than acquired feline heart diseases such as cardiomyopathy. Understanding the wide spectrum of congenital cardiovascular disease demands a familiarity with a variety of lesions, occurring both in isolation and in combination, along with an appreciation of complex nomenclature and variable classification schemes. This review begins with an overview of congenital heart disease in the cat, including proposed etiologies and prevalence, examination approaches, and principles of therapy. Specific congenital defects are presented and organized by a sequential segmental classification with respect to their morphologic lesions. Highlights of diagnosis, treatment options, and prognosis are offered. It is hoped that this review will provide a framework for approaching congenital heart disease in the cat, and more broadly in other animal species based on the sequential segmental approach, which represents an adaptation of the common methodology used in children and adults with congenital heart disease.

Iatrogenic embolization and transcatheter retrieval of a ventricular septal defect occluder in a dog

A 7-month-old Irish Setter underwent transcatheter therapy of a muscular ventricular septal defect (VSD) and pulmonary valve stenosis. Standard devices for muscular VSD closure could not span the interventricular septum due to right ventricular hypertrophy, and an Amplatzer post-infarction muscular VSD occluder with a wider waist was successfully implanted. Following VSD closure, inflation of the balloon dilation catheter during balloon pulmonary valvuloplasty resulted in iatrogenic embolization of the VSD occluder to the left ventricular outflow tract. Retrieval and reimplantation of the device was achieved using a snare catheter. This report describes a potential complication and management during intracardiac device implantation in a dog. Additionally, the case illustrates that the Amplatzer post-infarction muscular VSD occluder holds potential value in animals with a hypertrophied interventricular septum that cannot be spanned using a conventional device.

Transoesophageal echocardiography in the dog

Transoesophageal echocardiography (TEE) allows imaging of the heart through the oesophagus using a special transducer mounted on a modified endoscope. The proximity to the heart and minimal intervening structures enables the acquisition of high-resolution images that are consistently superior to routine transthoracic echocardiography and optimal imaging of the heart base anatomy and related structures. TEE provides high-quality real-time imaging free of ionizing radiation, making it an ideal instrument not only for diagnostic purposes, but also for monitoring surgical or minimally invasive cardiac procedures, non-cardiac procedures and critical cases in the intensive care unit. In human medicine, TEE is routinely used in these settings. In veterinary medicine, TEE is increasingly used in referral centres, especially for perioperative assessment and guidance of catheter-based cardiovascular procedures, such as patent ductus arteriosus, balloon valvuloplasty, and atrial and ventricular septal defect occlusion with vascular devices. TEE can also aid in heartworm retrieval procedures. The purpose of this paper is to review the current uses of TEE in veterinary medicine, focusing on technique, indications and complications.

Gerbode defect associated with blunt trauma in a dog

A 6 year-old Labrador retriever was presented after being struck by a car. A ventricular arrhythmia, attributed to myocardial trauma, developed 12 h post-trauma. Echocardiography revealed lesions consistent with a subaortic paramembranous ventricular septal defect (VSD) with shunting of blood from the left ventricle to the right atrium (Gerbode defect). A right-to-left shunting atrial septal defect (ASD) was visualised. Pleural and peritoneal effusions developed within 48 h. Fifteen days post-trauma flow across the ASD was left-to-right while left-to-right shunting across the VSD persisted. No cavitary effusions were detected at 15 days post-trauma or subsequently.

Minimally invasive per-catheter occlusion and dilation procedures for congenital cardiovascular abnormalities in dogs

With ever-increasing sophistication of veterinary cardiology, minimally invasive per-catheter occlusion and dilation procedures for the treatment of various congenital cardiovascular abnormalities in dogs have become not only available, but mainstream. Much new information about minimally invasive per-catheter patent ductus arteriosus occlusion has been published and presented during the past few years. Consequently, patent ductus arteriosus occlusion is the primary focus of this article. Occlusion of other less common congenital cardiac defects is also briefly reviewed. Balloon dilation of pulmonic stenosis, as well as other congenital obstructive cardiovascular abnormalities is discussed in the latter part of the article.