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

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

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 (SA) node — or sinus node — an area of specialized cells 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 to your lungs and body.

PVCs 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 the atria first, then the ventricles.

The following can increase your risk of PVCs:

• Caffeine , tobacco, alcohol and illicit drugs
• Exercise — if you have certain types of PVCs
• High blood pressure (hypertension)
• Anxiety
• Heart disease, including congenital heart disease, coronary artery disease, heart attack, heart failure and a weakened heart muscle (cardiomyopathy)

Having frequent PVCs or certain patterns of them might increase your risk of developing heart rhythm problems (arrhythmias) or weakening of the heart muscle (cardiomyopathy).

Rarely, when accompanied by heart disease, frequent premature contractions can lead to chaotic, dangerous heart rhythms and possibly sudden cardiac death.