PDA

Patent Ductus Arteriosus (PDA)

 Jamie was a 6 and a half week-old puppy when she was first brought to Dr. Chuck Noonan at Animal Doctors of Weston. She was acting normally and seemed to have had no issues in her first weeks of life. Dr. Noonan examined her and listened to her heart only to discover a significant heart murmur that was continuous throughout her heartbeat cycle. Dr. Noonan astutely recognized that this was likely a very significant heart defect that she was likely born with and recommended that Jamie’s mother take her to a veterinary cardiologist.

A week later, Jamie was seen by Dr. Mandi Kleman, a board-certified veterinary cardiologist at Cornell University Veterinary Specialists. Dr. Kleman performed an echocardiogram (ultrasound of the heart), which revealed a structural abnormality called a patent ductus arteriosus (PDA). A PDA is a congenital cardiac abnormality in which a connection exists between the aorta (the major systemic artery) and the pulmonary artery (the major vessel to the lungs). This abnormal connection results in the heart becoming overloaded by recirculating blood and typically results in heart failure within the first year of life. It was imperative, therefore, that we correct Jamie’s PDA.

There are 2 ways to correct PDAs. The first is via open chest surgery, to locate and ligate (tie off) the abnormal PDA vessel. This is the traditional method. The second option is to occlude (close off) the PDA vessel via an Interventional Radiology technique. Interventional Radiology is a method of surgery that uses video xrays (fluoroscopy) to allow the surgeon to see into the body and manipulate structures. This is a new technique in veterinary medicine, available at few academic and specialty institutions, including Cornell University Veterinary Specialists. The advantages of these techniques are that they are less invasive; there is no open surgery and thus, less pain and a faster recovery. For PDA correction via Interventional Radiology, an Amplatz ductal occluder or embolic coil can be inserted via a blood vessel until it is placed across the abnormal PDA vessel. The device then causes obstruction of blood flow across the PDA.

Here, at CUVS, both techniques are possible. In Jamie’s case, however, it was decided that surgery was her best option given her very small size. Dr Oli Morgan, staff surgeon at Cornell University Veterinary Specialists, performed the surgery - a left lateral thoracotomy via the 4th intercostal space. The PDA was carefully dissected and ligated, restoring normal blood flow. Jamie recovered smoothly in the Intensive Care Unit. Her heart murmur resolved. That evening she was already standing and eating! The next day, she was giving kisses and behaving like a puppy again. She was discharged to her owners care for at home recovery. After two weeks of exercise restriction she was healed. Her prognosis is excellent with a normal life expectancy.

Scottie's Pacemaker Implantation at CUVS

Scottie is a very special male 7-year-old Pembroke Welsh Corgi who has previously enjoyed Championships in multiple US and Canadian dog shows. He has also received titles for herding ducks and sheep. Unfortunately, Scottie's owner, Mari Carroll, noticed over the past few weeks that he had become exercise intolerant and less interested in playing with the other dogs in the household. Scottie was brought to his regular vet for an exam. While at the vet's office, he suffered four fainting episodes (syncope). The results of an electrocardiogram (ECG) were cause for concern and Scottie's veterinarian immediately referred him to the Emergency and Critical Care service of Cornell University Veterinary Specialists (CUVS) for a consultation with cardiologist Dr. Mandi Kleman, DVM, DACVIM (Cardiology).

Upon arriving at CUVS, Scottie experienced another episode of fainting and collapse, and he was immediately brought into the Emergency service for stabilization under the care of Dr. Sergi Serrano, LV, DVM, DACVECC. A repeat ECG showed complete heart block. After discussing all of the options with the owners, Dr. Serrano admitted Scottie for a diagnostic workup with the intention of Dr. Kleman implanting a pacemaker.

Scottie's initial diagnostic workup included bloodwork, a urinalysis and an echocardiogram. Due to the additional findings during Scottie's physical exam, an abdominal ultrasound was performed by CUVS board certified internist Dr. Forman DVM, DACVIM (Internal Medicine) prior to pacemaker implantation.

Dr. Kleman implanting Scottie's pacemaker.

At this point,  Scottie was a good candidate for emergency pacemaker implantation, and Dr. Kleman was prepared for the procedure. The 75-minute implantation procedure went smoothly and Scottie was kept overnight for post-surgical monitoring. The next day, Dr. Kleman performed a chest x-ray, another ECG, and programmed the pacemaker to optimize the settings. Programming the pacemaker, as well as periodic evaluations of the pacemaker's function, can be achieved with no sedation and absolutely no discomfort for the animal. Scottie laid down on a bed in ICU and enjoyed a head scratching (care of our technicians) as Dr. Kleman programmed the pacemaker with her laptop computer and a remote control. 

 

Scottie's x-ray (radiograph) taken the day after surgery showing the pacemaker's location.

It should be noted that the total amount of time that elapsed between Scottie's arrival at CUVS and the end of Dr. Kleman's pacemaker implantation procedure was only about 7 hours- a testament to the speed, accuracy and flexibility that is only possible at a state-of-the-art animal hospital such as CUVS.

Dr. Kleman, DVM, DACVIM (Cardiology) and Nicole VanSant, BS, LVT, VTS (ECC) examine Scottie the day after his pacemaker implantation.

“Pacemaker implantation in dogs and cats is not uncommon. Hundreds of pacemakers are implanted in the U.S. each year by veterinary cardiologists,” says Dr. Kleman. “Pacemaker implantation in dogs and cats is also not as expensive as one might think.” The cost of the procedure is comparable to an orthopedic surgery on a dog’s knee or back. Additionally, the procedure is minimally invasive, with the pacemaker implanted through a superficial vein.

Scottie, bright, alert and happy the day after his pacemaker implantation.

The patient recovers from the procedure with instant clinical improvement. The heart rate is restored to normal and the heart can provide enough oxygen-rich blood to the pet's body. The rechecks are not difficult for the pet or the owner. It can be expected that the typical pacemaker only needs to be programmed two to three times in the first year, and once per year after that.

 Please click on the image above to see an enlarged version.

We were thrilled that we could provide the necessary care to another dog with complete heart block. Scottie was a remarkable patient and our affection for him was trumped only by the joy on Mari's face as he was discharged from CUVS the following day.

 Dr. Kleman, DVM, DACVIM (Cardiology) Nicole VanSant, BS, LVT, VTS (ECC), Scottie & Scottie's mom Mari at discharge.

 Nicole, Dr. Kleman, Scottie & Scottie's mom Mari at discharge.

To learn more about pacemakers, click here.

Sherman Gets a Pacemaker at CUVS

Sherman Tank is an 8-year-old, 66-pound male bulldog who was brought into CUVS in need of help. Sherman needed a pacemaker. Sherman’s owners brought him to their family veterinarian for an exam after noticing that sometimes he lacked his usual energy and was reluctant to climb stairs. Sherman’s veterinarian performed an electrocardiogram (diagnostic tool that measures the electrical activity of the heart) and found that Sherman had 3^rd degree atrioventricular block with a ventricular escape rhythm. In layman’s terms, this diagnosis means the normal electrical impulse which stimulates the heart to contract is blocked. Fortunately, the muscular portion of the heart has a back-up system which allows it to continue to beat in the absence of a normal electrical impulse. Unfortunately, this back-up system often fails over time, despite various medical therapies.  Previous veterinary studies have shown that dogs such as Sherman may experience episodes of collapse or even pass away suddenly at home. Sherman was then referred by his family veterinarian to Cornell University Veterinary Specialists to see our cardiologist, Dr. Mandi Kleman, for an evaluation for a pacemaker.

Upon examining Sherman, Dr. Kleman found Sherman to be bradycardic (possessing a heart rate that is too slow), consistent with his previous exam. In preparation for potential pacemaker implantation, she obtained a repeat ECG, an echocardiogram (an ultrasound of the heart), bloodwork, and a urinalysis. The ECG confirmed the continued presence of the 3^rd degree AV block and the echocardiogram showed mild volume overload of the left heart. After discussing the plan at length with the owners, Dr. Kleman scheduled a pacemaker implantation procedure for the following day.

Dr. Kleman surgically implanting Sherman's pacemaker

Sherman stayed at CUVS overnight for monitoring and at noon the following day, Dr. Kleman prepared and scrubbed for the surgery. During a short 90-minute procedure, Dr. Kleman implanted a Medtronic pacemaker device into Sherman’s heart via two small incisions in his neck.  The surgery was a complete success with no complications. The pacemaker was ideally working to control Sherman’s electrical heart rhythm. Sherman recovered in ICU overnight with attentive pain management and monitoring. 

 

Dr. Kleman evaluating Sherman's pacemaker with ECG the next day.

Dr. Kleman programming Sherman's pacemaker the next day.

The morning after the procedure, the pacemaker was functioning properly, Sherman was energetic, and he ate a can of dog food for breakfast. That day, Dr. Kleman performed a chest x-ray, another ECG, and programmed the pacemaker to optimize the settings.  To program the pacemaker, Dr. Kleman uses a specialized computer to evaluate the pacemaker’s function and if necessary, to adjust the settings of the pacemaker. Sherman was prescribed oral antibiotics and a mild tranquilizer to keep him calm and to allow him to heal properly. He was discharged to his owners at 4PM that day with a normal heart rate and a short little wagging tail.

Sherman at discharge with Dr. Kleman,DVM, DACVIM (Cardiology), Carrie Maskley BS, CVT, Sherman and his owners

–      Dr. Mandi Kleman, DVM, DACVIM (Cardiology)
–      Stephanie Phillips, BA, A.A.S, LVT                       

Learn more about pacemakers by clicking here.