Here's what you need to know about the symptoms and risks of A

Jan 05, 2024

Atrial fibrillation, or A-fib in short, is one of the most common heart conditions, characterized by an irregular and often rapid heart rate. An estimated 5 million Americans live with A-fib. About one in four adults will develop A-fib in their lifetime.

The heart has four chambers: atria on the top and ventricles on the bottom. Blood flows from the veins into the right atrium, passing through the tricuspid valve into the right ventricle, which squeezes it out into the lungs. Oxygen-rich blood from the lungs then comes back to the left atrium, through the mitral valve into the left ventricle to be pumped to the arteries and delivered to the rest of the body. Normally, an electrical signal starts out in the right atrium and spreads to the left atrium and the ventricles in a coordinated manner so that the chambers contract sequentially. This is the "tick-tock" of the heartbeat.

In A-fib, the electrical signal is disorganized. The atria trembles like a plastic bag in wind instead of squeezing like a bellow. Some, but not all, of the signal from the atria passes to the ventricles, so the heartbeat is irregular and can be as fast as 100-150 beats per minute.

The risk of A-fib increases with age. The majority of patients with A-fib are older than 65. Other risk factors for include obesity, high blood pressure, diabetes, tobacco and alcohol, thyroid disease, kidney disease, obstructive sleep apnea, and a history of other heart diseases. Specifically, those who’ve suffered injury to the heart from previous heart attacks or have leaky valves inside the heart, tend to develop A-fib.

Some people have A-fib that comes and goes while others experience it continuously. Stress or infection can trigger A-fib. That's why we see it a lot in hospitalized and surgical patients. People often feel palpitations, or that their heart is racing, beating fast, or skipping beats. They may also feel light-headed, have shortness of breath, or are generally fatigued and low in energy. Some faint or even have chest pain that mimics a heart attack. Many have no symptoms and can't tell when their heart is in A-fib. I’ve met several patients who realized that they have A-fib because of the alarms going off on their smartwatches.

Unfortunately, for some people, stroke is the first presentation of A-fib. Because the atria don't contract properly, blood pools inside the chambers and forms clots. The clots can travel up to the brain and cause a stroke. A fast heartbeat decreases the efficiency of contraction. The heart doesn't have enough time to fill and pump, leading to heart failure. Even if they don't subjectively feel any symptoms, people with A-fib are still at risk of these serious consequences.

A-fib is diagnosed by an electrocardiogram, a simple test in the office. The patient is usually referred to a cardiologist for management. The first strategy is rate control. Drugs are prescribed to slow down the heart so it can fill properly and squeeze more effectively. Alternatively, the doctor can try rhythm control. An electrical current can be applied to shock the heart out of A-fib and restore regular rhythm. Medications can also help the heart convert and stay in a regular rhythm. If A-fib recurs or persists, then catheter ablations can be useful. This is a minimally invasive procedure under anesthesia. The cardiologist uses a long, thin catheter to go inside the heart and burn (or freeze) the abnormal electrical pathways that trigger A-fib. Stroke prevention is important for every A-fib patient. The doctor calculates the individual risks and starts the patient on either aspirin or a stronger blood thinner. Warfarin used to be the standard choice, but it's being replaced by newer and easier to manage agents, like apixaban.

The prevalence of A-fib will increase even more as the population ages. With the advent of technology, it's easy to check heart rhythms at home. If you experience any of the symptoms above or notice an irregular heartbeat, don't ignore it because A-fib may be the culprit.

Qing Yang and Kevin Parker are a married couple living in Springfield. Dr. Yang is an anesthesiologist. She received her medical degree from Yale School of Medicine and completed residency training at Massachusetts General Hospital. Parker has helped formulate and administer public policy at various city, state, and federal government entities, including the Illinois Department of Innovation and Technology and the Illinois Emergency Management Agency. This column is not intended to substitute for professional medical advice, diagnosis or treatment. The opinions are those of the writers and do not represent the views of their employers.