Rex and his owner Karen Silverman. Photo courtesy Cornell University College of Veterinary Medicine Cornell University Hospital for Animals (CUHA) and veterinarians from three countries joined forces to save a young German shepherd’s life. At 6 months old, Rex was by far the calmest dog the Silverman family of New York had ever owned. Their other German shepherds all bounced off the walls at that age, so at first they attributed Rex’s docile behavior to temperament. Nothing in his regular checkups indicated a problem, but when Rex became violently ill, the Silvermans noticed the dog’s heart was racing and knew it was something far more serious. Gretchen Singletary, DVM, DACVIM, a veterinary cardiologist in New York, stabilized him and performed a series of tests, including an electrocardiogram that confirmed the presence of an arrhythmia. The culprit turned out to be a small bundle of muscle running inside the wall of his heart, a defect he was born with and likely caused his low energy. Dr. Singletary told Silverman that Rex was a candidate for radiofrequency catheter ablation, where small areas of the heart muscle are heated through the tip of a catheter to destroy abnormal tissue. It’s a complicated, precise procedure, and only two places in the U.S. offer it routinely—a private practice in Ohio and CUHA. “I was going to do whatever it took,” said Karen Silverman said. Collaborations in cardiology Rex before his radiofrequency catherter ablation procedure. Photo courtesy Cornell University College of Veterinary Medicine When Rex arrived at the College of Veterinary Medicine, the cardiology team quickly controlled his skyrocketing heart rate and assessed the situation. They agreed he needed the ablation, and only the right mix of medicine would keep his heart rate at normal levels until they could do the procedure. “We knew the tachycardia would come back quickly if he didn’t have those medications,” said Romain Pariaut, DVM, DACVIM, DECVIM-CA, associate professor in the Department of Clinical Sciences and section chief of cardiology at the hospital. Italian cardiologist and adjunct professor Roberto Santilli, DVM, Ph.D., is one of the few veterinarians in the world who can perform the catheterization component of the ablation, which guides the catheters through the jugular and femoral veins and delivers the heat blasts to their target in the heart. Dr. Santilli was in Italy and rushed to Ithaca five days after Rex arrived. With Pariaut, members of the cardiology section, and a lineup of CUHA residents and students, this international dream team prepped Rex for the procedure. Precision procedure Finding the exact location of the abnormal muscle bundle in Rex’s body was a challenge. “It was difficult to spot the bundle, which is also known as [an] accessory pathway, and we were coming closer and closer to the atrioventricular (AV) node, which we didn’t want to damage,” said Pariaut. Damaging the AV node would be a serious complication that could affect Rex’s long-term quality of life and mean a pacemaker, which have grim success rates for dogs his age. The Cornell team found that the bundle of tissue rested just next to this sensitive area. Karen Silverman insisted they proceed. Santilli and Pariaut managed to burn the problematic area without damaging the nearby AV node. “I knew they could do it,” said Silverman. “Six hours later [Rex] came running down the hall, and the next day he came home with me. It was the most amazing thing.” Now that a few months have passed, the risk of the tissue recreating the arrhythmia diminishes each day. Since then, the cardiologists at the hospital have re-examined his heart to confirm that it is beating normally. In honor of Rex’s successful recovery and the surgeons who made it possible, the Silvermans partnered with the cardiology team to create the Henry and Karen Silverman Initiative to Advance Treatment of Canine Arrhythmias, housed within CUHA. Their intention is to further the study, diagnosis, and treatment of arrhythmias in dogs, as well as to educate pet owners and veterinarians about these treatments for heart rhythm disorders. “Now all [Rex] does is run,” said Silverman. “He finally has the energy to play.” Originally reported by Melanie Greaver Cordova, a staff writer at the Cornell University College of Veterinary Medicine.
