It's often called the 'silent threat' that can lead to strokes. Here's what to know about AFib.

Atrial fibrillation, or A-fib, is the most common type of arrhythmia, affecting at least 2.7 million people in the United States. This number is expected to grow to more than 12 million by 2030, which makes understanding the risks extremely important as A-fib can be life-threatening.

Dr. Michael Bernard called A-fib a "silent threat" because symptoms can go unnoticed for months or years.

Bernard is the section head of cardiac electrophysiology at Ochsner Health.

A-fib, the basics

A-fib is when the atrium of the heart, or the upper chambers of the heart, start to beat erratically and rapidly. Instead of the heart pumping together, chambers of the heart pump out of sync.

"It's all chaos," Bernard said. "The heart shakes."

A-fib treats people differently. Some people are very symptomati