Premature ventricular contractions (PVCs) are extra, abnormal heartbeats that begin in one of your heart’s two lower pumping chambers (ventricles). These extra beats disrupt your regular heart rhythm, sometimes causing you to feel a flip-flop or skipped beat in your chest. Premature ventricular contractions are very common — they occur in most people at some point.

Premature ventricular contractions are also called:

• Premature ventricular complexes
• PVCs
• Ventricular premature beats
• Extrasystoles

If you have occasional premature ventricular contractions, but you’re an otherwise healthy person, there’s generally no reason for concern, and no treatment is needed. If you have frequent premature ventricular contractions or underlying heart disease, you may need treatment to help you feel better and treat underlying heart problems.

Premature ventricular contractions often cause no symptoms. But you may feel an odd sensation in your chest, such as:

• Flip-flops
• Fluttering
• Pounding or jumping
• Skipped beats or missed beats
• Increased awareness of your heartbeat

When to see a doctor

If you feel flip-flops, a sensation of skipped heartbeats or odd feelings in your chest, talk to your doctor. You’ll want to identify the source of these symptoms. Premature ventricular contractions may be the problem, but other conditions also may be to blame, including other rhythm problems, serious heart problems, anxiety, anemia or infections.

Causes:

Your heart is made up of four chambers — two upper chambers (atria) and two lower chambers (ventricles). The rhythm of your heart is normally controlled by the sinoatrial node (SA node) — or sinus node — an area of specialized cells located in the right atrium.

This natural pacemaker produces the electrical impulses that trigger the normal heartbeat. From the sinus node, electrical impulses travel across the atria to the ventricles, causing them to contract and pump blood out to your lungs and body.

Premature ventricular contractions are abnormal contractions that begin in the ventricles. These extra contractions usually beat sooner than the next expected regular heartbeat. And they often interrupt the normal order of pumping, which is atria first, then ventricles. As a result, the extra, out-of-sync beats are usually less effective in pumping blood throughout the body.

Why do extra beats occur?

The reasons aren’t always clear. Certain triggers, heart diseases or changes in the body can make cells in the ventricles electrically unstable. Underlying heart disease or scarring may also cause electrical impulses to be misrouted.

Premature ventricular contractions may be associated with:

• Chemical changes or imbalances in the body
• Certain medications, including common asthma medications
• Alcohol or illegal drugs
• Increased levels of adrenaline in the body that may be caused by caffeine, tobacco, exercise or anxiety
• Injury to the heart muscle from coronary artery disease, congenital heart disease, high blood pressure or heart failure

Risk factors:

The following stimulants, conditions and triggers may increase your risk of premature ventricular contractions:

• Caffeine, tobacco and alcohol
• Exercise
• High blood pressure (hypertension)
• Anxiety
• Underlying heart disease, including congenital heart disease, coronary artery disease, heart attack, heart failure and a weakened heart muscle (cardiomyopathy)