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From the Fall 2005 Issue

Cardiovascular News

Newest Treatment for Heart Failure: CRT Device

When Brainard Walker first noticed that he couldn't finish his 6-mile runs, he wondered if his age was catching up to him. Within 2 years, 35-year-old Brainard could barely walk from one room to another. He couldn't keep up with his job, and he had to sleep propped up on pillows just to breathe. He had developed heart failure.

Today, Brainard is one of many people who has fewer symptoms because of a new treatment for heart failure. The treatment, delivered by an implantable cardiac device, is called cardiac resynchronization therapy (CRT). (To learn more about Brainard, see Feeling Better, Living Better With a CRT Device.)

When used along with medications, CRT can help relieve symptoms of heart failure. A CRT device delivers tiny amounts of electrical energy to the heart like a pacemaker does. A typical pacemaker treats slow heartbeats by sending signals to — or "pacing" — one side of the heart. A CRT device paces both of the heart's lower chambers (ventricles). So CRT is sometimes called biventricular pacing, or bi-V pacing. (You might also hear a CRT device called a device with three wires or leads.)

The Effects of Heart Failure

Heart failure is a condition in which the heart muscle weakens over time. This condition also weakens the pumping of the heart's ventricles, which pump blood to the entire body.

In a healthy heart, both ventricles pump or beat at exactly the same time in a coordinated way. But for many people with heart failure, the ventricles do not pump at the same time. For these people, the pumping is uncoordinated.

Video

Coordinated vs.
Uncoordinated Pumping

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(30 seconds)

 

 

 

Common symptoms of heart failure include shortness of breath, weakness, and fatigue. Fluid can also build up in the body, causing swelling in the legs and feet.

CRT Can Improve Heart Failure Symptoms

"CRT has the ability to improve the lives of many patients," explained Richard Fogoros, MD, medical advisor for research and development at Guidant. "Normally the ventricles contract at the same time. It's like making a fist — all of the fingers squeeze in unison."

What if the ventricles don't pump at the same time? "It's like making a fist just one finger at a time," said Dr. Fogoros.

CRT helps restore the normal timing of the heartbeats, causing both ventricles to pump together again. "CRT helps both sides of your heart work together. It's like a fist closing normally again," explained Dr. Fogoros.

"Most people who receive the device notice that they can function better," he continued. "They may not be in the hospital as often. And they have fewer symptoms.

"The results from CRT may be dramatic," Dr. Fogoros noted. "Some very ill patients who are nearly bedridden can return to their daily activities. Altogether, those are significant benefits."

How CRT Works

The CRT device is implanted near the shoulder just under the skin. CRT works by sending tiny amounts of electrical energy from the device to the heart through thin, coated wires called leads (Figure 1).

Figure 1. Cardiac Resynchronization Therapy Device

Click to enlarge

The CRT device sends electrical energy — which you can't feel — to re-coordinate, or resynchronize, the pumping of both ventricles. "With CRT, the heart's energy is used much more efficiently," said Dr. Fogoros. "So the heart does a better job of pumping the blood."

Prior to CRT, doctors prescribed medications to treat heart failure. Even with CRT, medications remain important. "There's no question that good drug therapy is absolutely necessary in treating heart failure. That's true whether or not a person gets a CRT device," said Dr. Fogoros. Heart failure medications include beta blockers, ACE inhibitors, and diuretics (water pills).

CRT Can Change Lives

One medical study recently found that people treated with a CRT-D device (see CRT With a Defibrillator box above) and medication lived longer than those treated with medications only.1 The study also found that people who received CRT had fewer symptoms and reported a better quality of life. So CRT may be a good treatment option for some heart failure patients.

Real-life experiences often reflect the study findings. "One gentleman in his 70s comes to mind," said Dr. Fogoros. "He was virtually bedridden, with severe symptoms even at rest. He could barely walk across the room. After receiving his device he was again able to drive, do errands, and go fishing with his grandson. He said he felt 10 years younger."

When used over a period of months, CRT can, for many people, "reverse some of the heart muscle weakness," Dr. Fogoros said. "The heart failure isn't cured. But some people's heart muscles actually get stronger.

"People with heart failure may want to talk to their doctor to make sure they're on the best medications — and to find out if they might benefit from CRT," said Dr. Fogoros.

1. Bristow MR, Saxon LA, Boehmer J, et al. Cardiac resynchronization therapy with or without an implantable defibrillator in advanced chronic heart failure. N Engl J Med. 2004;350:2140-2150.

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