Transvenous pacemaker placement in a dog with atrioventricular block and persistent left cranial vena cava

Persistent left cranial vena cava and right cranial vena cava aplasia in a French bulldog and a Cavalier King Charles spaniel with severe pulmonic stenosis

One French bulldog and one Cavalier King Charles spaniel were referred for pulmonary balloon valvuloplasty (PBV) after being diagnosed with severe pulmonic stenosis. In both patients, a dilated coronary sinus was noted on transthoracic echocardiography, suggesting persistent left cranial vena cava. Despite complete preoperative workup being performed, persistent left cranial vena cava with right cranial vena cava aplasia was not identified until after right jugular catheterization. This case study highlights vascular anomalies that hinder traditional approaches to PBV and diagnostic considerations for preoperative workup as recognition of these venous anomalies would have changed the approach to catheterization for PBV, minimizing the risk for complications, saving resources, and decreasing anesthetic time in these patients.

Abnormalities of External Jugular Veins in Bulldogs with Pulmonary Valve Stenosis

Simple Summary

This case series is about two French bulldogs and one English bulldog affected by pulmonary valve stenosis that were diagnosed with different abnormalities of the external jugular veins (EJV) before a pulmonary balloon valvuloplasty. The EJV abnormalities encountered were severe hypoplasia of both external jugular veins and right external jugular vein absence, associated with persistent left cranial vena cava. All cases were diagnosed through computed tomography and vascular ultrasound. The aim of this case series is to describe external jugular veins abnormalities that can affect the decision-making process regarding central venous catheterization needed to perform procedures such as pulmonary balloon valvuloplasty or central catheter placement. Based on the results of the present case series, anomalies of the external jugular veins should be considered in French and English bulldogs when the external jugular veins cannot be clinically identified or when echocardiography shows coronary sinus dilation. Vascular ultrasound or computed tomography may help identify jugular venous anomalies and should be considered in the preoperative evaluation of bulldogs that need to undergo interventional procedures requiring transjugular catheterization.

Abstract

Two French bulldogs and one English bulldog affected by pulmonary valve stenosis and referred for pulmonary balloon valvuloplasty were diagnosed with different abnormalities of the external jugular veins. The diagnosis included unilateral absence of the right external jugular vein and bilateral hypoplasia of the external jugular veins, associated with persistent left cranial vena cava. Vascular ultrasound and computed tomography were used for the diagnosis. Jugular vein anomalies can affect decision-making regarding the central venous catheterization needed to perform procedures such as pulmonary balloon valvuloplasty or central catheter placement. Based on the results of the present case series, anomalies of external jugular veins should be considered in French and English bulldogs when the external jugular veins cannot be palpated or when echocardiography shows coronary sinus dilation. Vascular ultrasound or computed tomography may help identify jugular venous anomalies and should be considered in the preoperative evaluation of bulldogs that need to undergo interventional procedures requiring transjugular catheterization.

2022 Update of the Consensus on the Rational Use of Antithrombotics and Thrombolytics in Veterinary Critical Care (CURATIVE) Domain 1- Defining populations at risk

OBJECTIVES

To expand the number of conditions and interventions explored for their associations with thrombosis in the veterinary literature and to provide the basis for prescribing recommendations.

DESIGN

A population exposure comparison outcome format was used to represent patient, exposure, comparison, and outcome. Population Exposure Comparison Outcome questions were distributed to worksheet authors who performed comprehensive searches, summarized the evidence, and created guideline recommendations that were reviewed by domain chairs. The revised guidelines then underwent the Delphi survey process to reach consensus on the final guidelines. Diseases evaluated in this iteration included heartworm disease (dogs and cats), immune-mediated hemolytic anemia (cats), protein-losing nephropathy (cats), protein-losing enteropathy (dogs and cats), sepsis (cats), hyperadrenocorticism (cats), liver disease (dogs), congenital portosystemic shunts (dogs and cats) and the following interventions: IV catheters (dogs and cats), arterial catheters (dogs and cats), vascular access ports (dogs and cats), extracorporeal circuits (dogs and cats) and transvenous pacemakers (dogs and cats).

RESULTS

Of the diseases evaluated in this iteration, a high risk for thrombosis was defined as heartworm disease or protein-losing enteropathy. Low risk for thrombosis was defined as dogs with liver disease, cats with immune-mediated hemolytic anemia, protein-losing nephropathy, sepsis, or hyperadrenocorticism.

CONCLUSIONS

Associations with thrombosis are outlined for various conditions and interventions and provide the basis for management recommendations. Numerous knowledge gaps were identified that represent opportunities for future studies.

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.

Imaging characteristics of persistent left cranial vena cava incidentally diagnosed with computed tomography in dogs

Persistent left cranial vena cava (PLCVC) is an uncommon congenital thoracic venous anomaly in dogs. This study examines the clinical and CT findings of dogs diagnosed with PLCVC incidentally. In this study, complete type of PLCVC was diagnosed in 26 dogs with CT angiography. Shih tzu (17 cases) and Pekingese dogs (3 cases) were overrepresented. There was no gender predisposition, and the average age at presentation was 10.3 years. Of 26 dogs, one dog had a bridging vein connecting right and left cranial vena cavae, and another dog showed azygos vein terminating PLCVC. On the thoracic CT images in the third dog, the right cranial vena cava was absent so that right brachiocephalic vein ended to PLCVC. However, the right costocervical vein drained another vein coursing caudally to the right atrium with azygos vein. In conclusion, CT angiography is a very useful method to diagnose PLCVC and variations of related thoracic vein anomalies in dogs.

Diagnostic imaging and pacemaker implantation in a domestic goat with persistent left cranial vena cava

Difficulty was encountered with the insertion of a right atrial pacing lead via the left jugular vein during lead and pacemaker implantation in a clinically normal goat as part of an ongoing rapid atrial pacing - induced atrial fibrillation research project. Fluoroscopic visualization of an abnormal lead advancement path prompted angiographic assessment which revealed a persistent left cranial vena cava (PLCVC) and prominent coronary sinus communicating with the right atrium. Angiography facilitated successful advancement and securing of the pacing lead into the right side of the interatrial septum. Cardiac magnetic resonance imaging/magnetic resonance angiography (MRI/MRA) allowed further characterization of this rare venous anomaly. Even though PLCVC has been reported once in a goat, to the authors' knowledge this is the first report to include MRI/MRA characterization of PLCVC and prominent coronary sinus with successful cardiac pacemaker implantation using the PLCVC.

Interventional cardiology for the criticalist

OBJECTIVE

To review indications, procedures, and prognosis for common cardiovascular emergencies requiring intervention in small animals.

ETIOLOGY

Pericardial effusion, symptomatic bradycardia, and heartworm-induced caval syndrome are examples of clinical scenarios commonly requiring intervention. Pericardial effusion in small animals occurs most frequently from cardiac neoplasia, idiopathic pericarditis, or congestive heart failure. Indications for temporary pacing include transient bradyarrhythmias, ingestions resulting in chronotropic incompetence, and emergency stabilization of critical bradyarrhythmias. Caval syndrome results from a large dirofilarial worm burden, pulmonary hypertension, and mechanical obstruction of right-sided cardiac output with resultant hemolysis and organ dysfunction.

DIAGNOSIS

The diagnosis of pericardial effusion is suspected from signalment and physical findings and confirmed with cardiac ultrasound. Symptomatic bradycardias often present for syncope and definitive diagnosis derives from an ECG. Caval syndrome is diagnosed upon clinical, hematologic, and ultrasonographic evidence of severe heartworm infestation, cardiovascular compromise, and/or mechanical hemolysis.

THERAPY

Pericardial effusion is alleviated by pericardiocentesis in the emergency setting, though may require further intervention for long-term palliation. Temporary transvenous pacing can be performed emergently to stabilize the symptomatic patient with a bradyarrhythmia. Dirofilariasis leading to caval syndrome requires urgent heartworm extraction.

PROGNOSIS

The prognosis for pericardial effusion is dependent upon the underlying etiology; the prognosis for cardiac pacing is favorable, and the prognosis for caval syndrome is grave if untreated and guarded to fair if heartworm extraction is performed.