Inside Iowa State

Dec. 09, 2005

Matters of the heart

by Teddi Barron

Dr. Wendy Ware leans over and speaks softly into Lilly's ear.

"Just relax, sweetheart," she says, while gently attaching tiny alligator clamps onto the little dog's legs.

"I'm putting ECG (electro-cardiogram) electrodes on Lilly so we can watch her heart rate and rhythm while we do the ultrasound exam of her heart," she explains.

The lights in the exam room are dimmed, and Ware settles in at the controls of the Veterinary Teaching Hospital's new cardiac ultrasound equipment.

Lilly, a 15-month-old Jack Russell Terrier with a malformed heart valve, belongs to Tracy Raef, communication specialist in the College of Veterinary Medicine. Last spring, when a radiograph showed that Lilly had an enlarged heart, Raef turned to Ware, the only board-certified veterinary cardiologist in Iowa.

"When I first examined Lilly, she had massive heart enlargement caused by dilation of her left atrium and left ventricle," Ware said. "She also had an abnormal, incredibly rapid heart rhythm -- 300 beats per minute -- that was just incessant."

Over time, such a rapid, persistent rhythm leads to deterioration in heart muscle function, further dilation and heart failure. Without a meticulous diagnosis and specialized treatment, Lilly would have died.

Ware has prescribed drug therapy to control the rhythm disturbance. The ultrasound exam on this day is to assess Lilly's progress.

Ware sets the controls on the ultrasound machine -- officially known as echocardiography -- to begin the exam. The $204,000 noninvasive tool images the heart, using pulsed, high-frequency sound waves that reflect or echo back from cardiac and surrounding tissues to tell how the heart is functioning.

"We can see that Lilly's heart has gotten smaller and that rhythm control and the amount of valve leakage have improved significantly," she said, looking at the ultrasound's monitor. "Here is a little regurgitation. But most of what I'm seeing today is good, compared to her initial exam."

Veterinary medicine, by way of music

Lilly's case is one of the more interesting Ware has encountered in her 19 years at ISU, where she splits her time between veterinary clinical sciences and biomedical sciences, between seeing patients and teaching students, between writing textbooks and assuming national professional leadership.

Ware has attained a high level of success in her field -- she is president-elect of the esteemed American College of Veterinary Internal Medicine. Yet, she almost didn't become a veterinarian at all.

"My high school guidance counselor in the early 1970s strongly dissuaded me from pursuing veterinary medicine," she recalled. "Essentially, he said that girls don't do that. He recommended I go into teaching or music, which I was involved in at the time."

Although Ware earned a bachelor's degree in music, she still wanted to be a veterinarian. She went to work as a veterinarian's receptionist and kennel cleaner and enrolled in pre-veterinary medicine courses at Rutgers University in New Jersey.

In 1978, Ware set her sights on The Ohio State University's College of Veterinary Medicine. At that time, women were a substantial minority in veterinary medicine. Even eight years later, after Ware had completed her Doctor of Veterinary Medicine, a master's in veterinary clinical sciences, a medical/surgical internship and a residency in cardiology, few women practiced veterinary medicine specialties.

Ware was one of the first. In 1986, she was the fourth woman in North America to become board certified as a veterinary cardiologist. Today, 50 of the 126 boarded veterinary cardiologists are women.

And Ware is one of the most respected. It seems that just about anyone writing a textbook on small animal internal medicine asks Ware to pen the chapter on cardiology. She has authored 26 such chapters. Now, she's writing her own book, The Color Handbook of Small Animal Cardiology, which draws from a huge collection of radiographic, ECG, echocardiographic and other images amassed during 20 years of treating cardiac cases.

Changing the treatment of heart failure

More than 11 percent of dogs and cats have cardiac disease, Ware said. There is a wide range in occurrence rates of specific cardiac diseases across different species, breeds and ages. For example, less than 1 percent of all dogs and cats have congenital heart diseases. More than 30 percent of dogs older than 10 develop valvular disease.

Ware, who sees or consults on several hundred cases each year, is drawn to the processes associated with chronic heart failure and congestive heart failure.

"I'm especially interested in how and what goes wrong in the body when the heart isn't doing what it's supposed to be doing," she said.

"There's been a huge paradigm shift in the management of heart failure during the last 20 years," she said. "In the old way of thinking, the pump was failing, not pumping strongly enough. Treatment was aimed at using drugs to make the heart pump more strongly or to dilate the blood vessels so blood could move out more easily."

Today, cardiologists have a better understanding although there's still much more to be learned, she said.

"Heart failure isn't only that the heart doesn't pump strongly enough. There are various changes in the body -- neural, hormonal and inflammatory, for example -- that affect the heart's functions and structure," Ware said. "Now the approach is to modify neurohormonal changes, block some of those pathways, and protect the heart from being driven so hard."

As cardiologists learn more, new opportunities for treatment and new drug therapies emerge. Several can help slow down -- perhaps even reverse -- the process of heart deterioration and help maintain the heart's function.

"The heart is incredibly complex, and very fascinating," Ware said. "Just look at Lilly."

Lilly's case is especially interesting because the extreme, persistent rhythm abnormality like hers is not very common in dogs. Although it has been resistant to several anti-arrhythmic drugs, Ware has arrived at a combination that is suppressing it fairly well.

"There's some focus in her atrium that wants to incessantly fire. It creates an electrical signal that gets transmitted to the rest of the heart. But, because Lilly is too small for electrophysiological treatment, where they essentially zap and kill that portion of the heart muscle, our best option is drug therapy. That's not the greatest, because there's some potential of side effects from long-term use," Ware said.

"But for now, we have it under control and she's doing very well."

Wendy Ware is one of the most respected certified veterinary cardiologists in the country. It seems that just about anyone writing a textbook on small animal internal medicine asks Ware to pen the chapter on cardiology.