A fibrillation is an abnormal heartbeat. Healthy hearts contract in a synchronized way. Electrical signals in the heart cause each of its parts to work together. Atrial fibrillation interrupts the electrical signals in the heart and causes a chaotic delivery.

When the parts of the heart no longer work together, signs and symptoms of a problem may become evident. The heart’s rhythm and beat rate will become irregular; the heart will no longer pump blood as it should, and the risk of life-threatening problems will increase.

What Are the Atria and Ventricles?

The heart is one large organ comprised of these four chambers. The parts of the heart where the fibrillation occurs determine the exact condition’s name. For example, atrial fibrillation (AFib) occurs in the heart’s upper two chambers, also known as the atria. Ventricular fibrillation (VFib) occurs in the heart’s lower two chambers, known as the ventricles.

If an irregular heartbeat (arrhythmia) occurs in the atria, the word “atrial” will precede the type of arrhythmia. If an arrhythmia occurs in the ventricles, the word “ventricular” will precede the type of arrhythmia.

Though they have similar names and both occur in the heart, AFib and VFib affect the body in different ways. VFib is an emergency: When it occurs, a person experiencing it needs immediate medical attention. AFib, although serious, can often occur for years without causing any noticeable signs or symptoms. Learn more in the following sections about how each condition affects the heart.

How Does AFib Affect the Body?

In a healthy heart, blood flows from the upper chamber into the lower chamber in a single heartbeat. Another beat sweeps the blood out of the lower chamber and into the body. However, when AFib affects a heart, the heart stops beating in sync. With AFib, blood in the atria may not completely empty.

AFib typically is not life threatening. However, it’s a serious medical condition that can lead to life-threatening complications if it goes untreated. The most serious complication is stroke. When blood doesn’t completely empty from the atria, it can begin to pool. Pooled blood can clot, and blood clots that block entire blood vessels or arteries can cause a stroke.

How Does VFib Affect the Body?

Ventricular fibrillation is disorderly and irregular electrical activity in the heart’s ventricles. A heart affected by VFib “flutters.” These rapid beats prevent the heart from pumping adequate amounts of blood into the body.

VFib is an emergency situation. If you develop VFib, your body will not receive the blood it needs because your heart is no longer pumping enough. This dramatically reduces the blood flow throughout your body, and your blood pressure will sink quickly. You may faint, pass out, or experience sudden cardiac arrest.

The only way to correct a heart that is experiencing VFib is to give it an electrical shock with a defibrillator. A defibrillator can revert the heart back to a normal, healthy pattern if the shock is administered in time.

If VFib is a chronic problem, your doctor may suggest you get an implantable cardioverter defibrillator (ICD). An ICD is implanted in your chest wall and connected to your heart. From there, it constantly monitors your heart’s electrical activities. If it detects an irregular heart rate or rhythm, it sends out a quick shock in order to return the heart to a normal pattern.

In most cases, not treating VFib is not an option. In fact, the long-term survival rate for people who live through a VFib attack outside the hospital ranges from 2 to 25 percent. If not treated properly and immediately, people who survive AFib may suffer long-term damage or even enter a coma.

Preventing AFib and VFib

A heart-healthy lifestyle can help reduce your likelihood of both AFib and VFib. Regular physical activity and a diet rich in heart-healthy fats and limited in saturated and trans fats is key to keeping your heart strong for a lifetime. Here are some other heart-healthy strategies that can reduce your risk for AFib and VFib:

  • Quit smoking.
  • Avoid alcohol and excessive caffeine.
  • Reach and maintain a healthy weight.
  • Control your cholesterol.
  • Monitor and manage your blood pressure.
  • Treat conditions that can lead to cardiac issues, including obesity, sleep apnea, and diabetes.

If you have been diagnosed with either AFib or VFib, work closely with your doctor to develop a treatment and lifestyle program that address your risk factors, history of arrhythmia, and health history. Together, you can treat both of these conditions before they become deadly.