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Understanding Heart Failure
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This article is the second in a series of four focusing on advances in the treatment of cardioelectric disorders. The latest treatment of complex cardioelectric disorders will be available at John Muir Health's new Cardiac Rhythm Center, located at John Muir Medical Center, Walnut Creek Campus.
Heart Failure Increasing in Older Population
Heart failure is a common and serious medical condition that develops slowly as the heart muscle gradually weakens, usually caused by an underlying problem such as clogged arteries, high blood pressure, or a defect in its muscular walls or valves. The "failure" refers to the heart's inability to pump enough blood to meet the body's needs.
According to the American Heart Association, about five million Americans are living with this condition, and about 550,000 new cases are diagnosed each year. Although heart failure affects people of all ages, it's more common among older people. It's expected that as the older population grows even larger over the next few decades, so will the number of people living with heart failure or caring for a loved one who has it.
People with heart failure have a problem circulating enough blood through the body. As a result, they tend to feel weak, fatigued or short of breath. Everyday activities such as walking, climbing stairs, carrying groceries and doing yard work can become quite difficult. Secondary physiological problems caused by heart failure can include: inadequate blood flow to body tissues including the kidneys, and the release of stress hormones. All of these can cause the heart to work harder to maintain its function. In turn, this can lead to a higher risk of lethal arrhythmias, termed "sudden cardiac death"(SCD).
Early Detection Essential to Outcomes
Early testing is important because early treatment can sometimes prevent heart failure from worsening or even reverse its progress. If your doctor suspects you may have heart failure, blood tests, X-rays, an ECG, an echocardiogram, or other tests may be performed to determine a diagnosis. One of the ways to help reverse and prevent heart failure is through healthy lifestyle choices. Obesity, smoking and high blood pressure are all significant contributors to heart failure.
According to Michael Lee, M.D., cardiac electrophysiologist on staff at John Muir Health, one critical measurement in determining the patient's risk for heart failure is the heart's ejection fraction (EF). "Most patients know their blood pressure and cholesterol numbers. National guidelines have clearly shown that they also need to know what their ejection fraction number is, and most people haven't heard of it."
An ejection fraction is the measurement of what percentage of blood is pumped by the ventricles with each heartbeat. A healthy heart pumps 55 percent or more of its blood with each beat, but those people with an ejection fraction lower than 40 percent are at particular risk. Most cases of a low ejection fraction result from a major heart attack that is associated with coronary artery disease (a condition in which the arteries that supply blood to the heart are narrowed or blocked). Other cases of low ejection fraction can be caused by a viral infection or through genetic predisposition. Dr. Lee added that patients who have a low EF can be put on medications that will help increase their EF number. If doctors are able to catch a problem at the early stage, it's possible their patients can avoid the need for an implantable device by lowering their risk of heart failure and sudden cardiac death.
Implantable Devices Serve Double-Duty
Those with mild heart failure will first take medication to help reduce symptoms. There are some for whom the medication doesn't help enough, and other therapies also must be used. One such therapy is an implantable device called a Cardiac Resynchronization Therapy Defibrillator (CRT-D). Heart failure can cause problems with the coordination of the heart's contractions, especially in the ventricles. A CRT-D device can help restore proper coordination so that the heart pumps more efficiently. In the case of an arrhythmia (irregular heartbeat) occurring, the CRT-D delivers small electrical impulses to help ventricles contract at the same time. If and when necessary, it also can send a life-saving shock when dangerously fast heart rhythms are detected, preventing sudden cardiac death (SCD).
"The beauty of this device is that it helps our patients with heart failure and can reverse it. The CRT-D also improves heart failure conditions to improve quality of life and offers protection from sudden cardiac death," said Paul Ludmer, M.D., cardiac electrophysiologist at John Muir Health, who performs more than 300 implant surgeries each year. He stated that patients at risk for SCD can experience heart failure and need this type of implant device.
Slightly larger than a pager, the device is implanted under the skin near the collarbone through a small incision made in the chest. It's then connected to leads, which are threaded through blood vessels and placed in the heart. A CRT-D will last about five years in a patient, who would then get a new device surgically implanted.
Responding quickly to symptoms of heart failure is key to controlling or possibly even reversing the disease, according to Drs. Ludmer and Lee. They suggested that those who think they have symptoms of heart failure or low EF should consult with their physician immediately.