When cardiac rhythm goes awry, ablation may help restore the beat, lowering your risk of stroke
An irregular heartbeat, or cardiac arrhythmia, is a frequent threat to vigor and good health in the senior years, and atrial fibrillation, or “A-fib,” is the most common cardiac arrhythmia. Some people have A-fib without knowing it, and while the condition by itself is usually not immediately life threatening, it can increase the risk of stroke as much as fivefold, according to the National Stroke Association.
In A-fib, the electrical impulse of the heart is not regular. In effect, the atria may quiver rapidly instead of beating efficiently. A-fib affects 2.5 million to 3 million people in the S.S., says Sei Iwai, M.D., Director of Cardiac electrophysiology at Westchester Medical Center, and that number is expected to grow in coming years as the average age of the population rises. “Over time, A-fib can weaken the heart, and the death rate for people who have it is twice that of those who don’t,” says the doctor. But A-fib often can be relieved by a remarkable treatment called A-fib ablation, and Dr. Iwai and his team are the only ones who perform this procedure in the lower Hudson Valley.
Normally, the four chambers of the heart contract in a very organized way. The electrical impulse that signals the heart to contract begins in an area called the sinoatrial node (also called the sinus node or the SA node) in the top portion of the right atrium, or upper-right chamber. “In A-fib, the parts of the heart cannot contract in a coordinated pattern,” Dr. Iwai explains. “This causes a rapid heartbeat in the upper chambers, which can go to 300-plus beats per minute in an irregular pattern.” (The normal heart rate, by comparison, is about 70 beats per minute.) As a result, the heart may have difficulty pumping enough blood to meet the body’s needs.
Until the late 1990s, the only recourse was medication, and medication remains a common treatment. For some patients today, however, Dr. Iwai uses a minimally invasive procedure to ablate, or destroy, the tissues that trigger or maintain the disruptive rhythms. The procedure involves introducing a guide wire into the vascular system, usually at the groin, and threading it to the desired location in the heart. “Tissues that trigger A-fib are found in very specific places, especially at the junction of the heart and the pulmonary veins,” the doctor explains. He then threads a catheter to the same area, locating it with sophisticated 3-D computer mapping that combines different technologies, including ultra-sound and X-ray fluoroscopy, along with magnetic sensors in the catheter that work with a computer model.
Once the catheter reaches its destination, Dr. Iwai delivers either radio-frequency energy or cryoablation (freezing) with nitrous oxide to destroy or isolate the troublemaking tissue. This steps the arrhythmia at its source but does not affect the sinus node, which keeps the heart’s regular rhythm.
“Ablation isn’t a perfect remedy; however, it usually offers a better chance at symptom improvement than do medications,” says Dr. Iwai. “We can use it to achieve success in about 75 percent of patients. And if the arrhythmia returns, the treatment can be repeated.”
Dr. Iwai sees more advances on the horizon in treating arrhythmia. “We are partnering with cardiac surgeons in a hybrid approach, in which they perform part of a more extensive ablation with surgery, and we complete it with catheters,” he says. “That method has shown promising results for patients with longstanding A-fib that is difficult to reverse with catheter ablation alone.”
It’s good news for Westchester County and the lower Hudson Valley that A-fib ablation is available locally. “This area needs this complex ablation program, so that instead of traveling 30 to 60 miles or more into the city, people can be treated here,” says Dr. Iwai. “That’s especially important because this condition requires follow-up care every three to six months.”
What causes A-fib?
These factors may help produce the common heart-rhythm irregularity known as atrial fibrillation, or “A-fib”:
- alcohol use (especially binge drinking)
- coronary artery disease
- heart attack or heart-bypass surgery
- heart failure or an enlarged heart heart-valve disease (most often the mitral valve)
- overactive thyroid gland (hyperthyroidism)
- pericarditis (inflammation of the fibrous sac surrounding the heart)
- sick sinus syndrome (a group of abnormal heart rhythms presumed to be caused by a malfunction of the sinus node)
Source: National Institutes of Health
When to see your doctor
The symptoms below have many possible causes—atrial fibrillation (A-fib) is just one of them. But you should consult your physician if you experience:
- pulse that feels rapid, racing, pounding, fluttering, irregular or too slow
- heart palpitations—periods of especially rapid, intense heartbeat
- dizziness, lightheadedness
- loss of ability to exercise
- shortness of breath