Minimally Invasive Cardiac InterventionsApril 25, 2018

Cardiology Notes

Minimally Invasive Cardiac Interventions

Written by Ivan Sosa Samper, DVM, DACVIM (Cardiology)

Heart disease is common in dogs and cats. In addition to diagnostic tests such as radiography, echo cardiograms, and drugs to manage congestive heart failure, some patients need advanced intervention to be properly treated. At Mass Vet, our board-certified specialists are able to perform minimally-invasive surgical treatments that provide management of heart conditions with a significant reduction in post-operative pain and recovery time.



Patent Ductus Arteriosus (PDA) is a defect where a large blood vessel fails to close after birth. This vessel connects the aorta to the pulmonary artery, bypassing the lungs during the development of the fetus. If left uncorrected, a PDA will lead to cardiac enlargement and congestive heart failure. Pets with an uncorrected PDA have a mortality rate of greater than 60% by one year of age.

Coils have traditionally been used to close PDAs, however in the last decade, a new device called the Amplatz Canine Ductal Occluder (ACDO) has become available.  When used, the ACDO significantly decreases the risk of complications. This procedure is usually curative. Patients go home within 24 hours of the intervention and have excellent long-term prognosis.

Pulmonic Stenosis

newsletter-stent-xrayPulmonic stenosis is a narrowing in the dog’s pulmonic valve, causing blood flow obstruction between the right side of the heart and the lungs. Although patients with mild or moderate obstruction may live a normal life, dogs with severe pulmonic stenosis have a reduced life span due to the development of congestive heart failure or life-threatening arrhythmias.

To relieve the obstruction, we perform a procedure called balloon valvuloplasty. A catheter is used to access the vein that runs down the neck. Multiple wires and catheters are placed across the obstruction using fluoroscopy (live X-rays) as a guide. Contrast is also used to visualize the anatomy and choose the appropriate catheters. A balloon catheter is placed at the narrowing. When we inflate this balloon the fused valve leaflets separate, relieving the obstruction and improving blood flow to the lungs. The balloon is then deflated and removed. A small bandage covers the small incision; dogs usually go home within 24 hours.

Some patients with severe pulmonic stenosis cannot have the obstruction relieved using this procedure and may require more advanced intervention. At Mass Vet, we offer the use of stents as a way of maintaining the pulmonary artery free of obstruction.

Pacemakers in Dogs

newsletter-pace-maker-xrayIn the same way that people may need to have a pacemaker placed for certain heart diseases, dogs also benefit from this amazing technology. Pacemakers are used to treat different conditions. Sometimes, the electrical system of the heart, which is generated in the upper chambers of the heart, does not reach the bottom chambers, leading to an abnormally low heart rate. This is called third AV block. Patients with this condition can have fainting episodes and lethargy. The only effective treatment is placing a pacemaker. The pacemaker maintains a more appropriate heart rate which prevents the patients from collapsing.

A small incision is made in the vein that runs down the neck, the pacemaker lead is introduced in the right side of the heart with fluoroscopy. One tip of the lead is anchored to the muscle of the heart, and the other tip is connected to the pacemaker generator. This small computer is programmed to track the dog’s heart rate, when it is too low, the pacemaker delivers an electrical stimulus to the heart to increase the heart rate. The generator is buried under the skin and the patient goes home within 24 hours. Routine rechecks are necessary to ensure appropriate pacemaker settings and assess the pacemaker’s battery life.

More information on each of these conditions and our cardiology team is available at

About the Author

Ivan Sosa Samper, DVM, DACVIM (Cardiology)


Dr. Sosa received his DVM at the University of Zaragoza in Spain, in 2007. He then went on to complete a small animal rotating internship in medicine and surgery at the University of Bristol in the United Kingdom. After working as a general practitioner for four years, in 2012 Dr. Sosa moved to the United States for a residency in Cardiology at the University of Florida. He became a board certified cardiologist by the American College of Veterinary Internal Medicine in 2016, the same year he joined the Massachusetts Veterinary Referral Hospital.

Although Dr. Sosa enjoys challenging cardiology cases in both dogs and cats, he has a special interest in interventional cardiology procedures such as balloon valvuloplasty, PDA occlusion and pacemaker implantation. When not at work, Dr. Sosa and his wife enjoy sailing with his Golden Retriever.

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