Pacemaker study seeks better ways to help dogs with complete heart block

Untitled DocumentGAINESVILLE, FLA. - 9/12/2006 - A University of Florida study aimed at discoveringbetter ways to place pacemakers in dogs with complete heart block has receiveda $100,000 boost through a grant from the Morris Animal Foundation. The study,under way at UF's Veterinary Medical Center (VMC), already has six dogs enrolled.

Complete heart block occurs when normal rhythms between cells within the heartare blocked so that normal impulses are not delivered. Other cells overcompensateto “rescue” the heart and keep it beating, but work ineffectively,leading to clinical signs of fatigue, exercise intolerance and even congestiveheart failure

“In traditional treatment, one lead is placed within the right-sided ventricleto electrically control the heart rhythm,” said Amara Estrada, DVM, anassistant professor of veterinary cardiology at UF's veterinary college. “Occasionally,an additional lead will also be placed within the right atrium as well. Lookingback over the last 20 years of pacing therapy, we now realize that this approachis less than ideal and in fact can lead to worsening heart disease in about 10percent of the dogs and people treated in this way.”

The new study will focus on the relative effectiveness of placing pacemakerswithin the right and the left ventricles as well as from both ventricles simultaneously.

“We're trying to get as close to natural cardiac physiology as possible,” Estradasays. “Pacing equipment has gotten so advanced that we can get very closeto imitating what happens normally in the heart.”

Estrada said UF's study will be “slightly ahead” of what's currentlybeing performed clinically in human cardiology to treat complete block in peopleand will hopefully provide information that will be crucial not just for veterinarypatients but also for human patients requiring pacing therapy.

For more information about the study, contact the cardiology service at 352-392-4700,ext. 4700. Referring veterinarians should contact Megan Van Rysdam at ext. 4875for an appointment or ask to speak to any member of the cardiology service formore information.