Paul J. Wang, MD, Professor of Medicine and Bioengineering
Bryant Y. Lin, MD, MSEng, Associate Clinical Professor of Medicine
October 3, 2019
When someone has a heart condition called atrial fibrillation, they may feel an unusual heartbeat. It can feel like their heart is racing.
For some, it’s so mild they barely notice it. For others, it’s so intense they say, “It’s jumping out of my chest,” said Paul J. Wang, MD.
Atrial fibrillation can be uncomfortable or distressing. But it’s relatively common, especially for people as they age past 60.
“You’re not alone, if you have it,” said Dr. Wang in a recent lecture at the Stanford Health Library. The condition is most common in people age 60 to 85.
“With every [passing] decade of life, our likelihood of getting atrial fib is going to get greater,” said Dr. Wang, who is the director of the Stanford Arrhythmia Service that treats this condition.
What makes the heart beat
A normal heartbeat depends on the electrical signals that move rapidly in the upper chambers of the heart. Those signals are swirling or spinning around like a windstorm.
The signals go through a connector in the heart, called the AV node, which passes them from the upper to the lower chambers. “It’s the number of beats that get to the bottom chamber that determines our pulse – how fast it’s going,” Dr. Wang said.
The first step in treating atrial fibrillation is to affect the AV node connector to calm down the heart rate, Dr. Wang said.
Not everyone feels symptoms of atrial fibrillation. Those who do may feel an unusual heartbeat that can be mildly racing or severely pounding. Sometimes the symptoms come and go, and sometimes they persist.
Some people feel short of breath or unusually tired. They may feel chest pain. In severe cases, people feel dizzy or even lose consciousness.
Some factors that stress the body appear to be linked to atrial fibrillation. Patients may say they feel a little more exhausted, or dehydrated before the symptoms start. Sometimes people say they drank a lot of caffeine or alcohol before they felt symptoms.
Heavy alcohol drinking, even in young people, can be a trigger that doctors call “Saturday night heart,” Dr. Lin said.
Other factors that can also be triggers include an overactive thyroid gland, undergoing surgery, or exercise, especially after moving to a higher elevation.
For some people, there is no trigger. “Sometimes we have no answer,” said Dr. Wang.
What raises risk?
Some common medical conditions might contribute to a higher risk for getting atrial fibrillation. They include:
- High blood pressure
- Sleep apnea
- Over active thyroid
- Heart attack or cardiomyopathy (a disease of the heart muscle)
When someone younger, in their 20s or 30s, gets atrial fibrillation, that’s more likely to be tied to a genetic predisposition, Dr. Wang said.
The first step in treatment is taking medicine to slow down the heart rate in the heart’s lower chambers. “You can calm it down,” Dr. Wang said. “That’s often a simple, very safe, thing to do to make the patient feel pretty quickly better.”
Drugs for this include digoxin, beta-blockers (like metropolol or propanolol), or calcium channel blockers.
These drugs may be enough for the heartbeat to return to normal in some patients. Others may improve but still have uncomfortable symptoms, or not improve at all. Even if someone’s heart rate improves, the rhythm may not be back to normal.
Next step: Heart rhythm
The next step in treatment, for those who need it, is to get the heart rhythm back to normal. That can often be gone with a different kind of medicine, called antiarrhythmic drugs.
There are several different antiarrhythmic drugs available, and the choice depends on individual patient health status. If those drugs don’t help, there’s another option: a procedure.
This procedure, called catheter ablation, eliminates the problem cells in the heart that are causing the rhythm disturbance. A doctor inserts a tube (the catheter) in the body going to the heart and kills the “island” of problem cells.
Some patients are hesitant to get catheter ablation, Dr. Lin said. Those anxious may decide to skip it if their symptoms are mild. Others may choose it quickly because they’ve heard “it’s the best thing since sliced bread.”
Patients should think over the decision carefully because each person may have different goals for their treatment. The benefits and risks of catheter ablation differ for each individual.
Some people who still feel short of breath even after taking antiarrhythmic drugs may choose the procedure. Others may their symptoms aren’t bad enough to choose it.
Someone who has had atrial fibrillation for a long time may need an ablation more than once to stop the symptoms.
“Luckily, atrial fibrillation is not immediately life-threatening,” Dr. Wang said. That leaves time to talk to a doctor about the decision.
When drugs don’t help
There is another option for patients who seem stuck in continuous atrial fibrillation even when they take drugs.
Doctors can deliver electrical shock therapy to the heart to jar it into a normal rhythm. “This is a pretty good option,” Dr. Wang said. “It’s pretty low risk.”
Getting rid of symptoms may be the main goal of treatment for many patients. But there’s another issue to think over: preventing a higher risk of stroke.
“Patients that have atrial fibrillation are, as a group, more likely to have a stroke,” said Dr. Wang. “Stroke prevention is really important.
That risk can be lowered “tremendously” by taking medicine that prevents blood clots, Dr. Wang said. These drugs are called “anticoagulants,” which prevent blood clots.
The first anticoagulant drug developed was warfarin (Coumadin). Now there are several others.
Estimating risk for stroke
Doctors can estimate each patient’s risk for stroke with a scoring system. The patient gets points for each factor that increases their risk, including:
- High blood pressure
- Congestive heart failure
- Previous stroke
- Vascular disease
Men who score 2, and women who score 3, are recommended to take an anticoagulant drug. Most people who score 0 don’t need to take it.
People who fall in the middle range can talk to their doctors about what’s the best option for them. This can be a complicated decision, depending on each individual’s medical status.
Each person considering whether to take an anticoagulant drug has to balance different possible risks (for bleeding) and benefits.
“It’s very complex,” said Dr. Lin. “You don’t want to navigate that by yourself.”
Preventing atrial fibrillation
One of the biggest factors linked to atrial fibrillation is age. “As we age, that is probably the most important factor. We can’t change that,” Dr. Wang said. “We’ve not invented a way to turn back the clock.”
Other factors can be changed. Taking these steps can help:
- Getting treatment for high blood pressure
- Controlling diabetes
- Losing excess weight
- Getting treatment to lower high cholesterol or blood fat levels
- Treating sleep apnea
- Reducing stress
- Stopping smoking
- Reducing alcohol drinking
If people who are overweight lose 10% of their body weight, they do “vastly better” than people who don’t lose weight, Dr. Wang said.
“It gives you some hope there are certain things you can do without medications.”
Some people may be skeptical that weight loss will help, thinking “Oh, I can just get an ablation and it won’t matter if I lose weight or not,” Dr. Wang said. “But it does. Your results are going to be better, by and large.”
Dr. Lin added, “Those are all good health habits. We should all strive for that, whether or not we worry about a-fib.”
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