Reviewed by Bruce Lindsay, MD
Premature ventricular contractions (PVCs) are the most common cause of irregular heart rhythms.
The heartbeat is created by an electrical signal that originates in an area of specialized cells in the heart’s upper right chamber, the right atrium. The electrical signal moves down through the heart to the atrioventricular (AV) node, a cluster of specialized cells in the center of the heart. From the AV node the signal passes along special fibers embedded in the heart walls to the ventricles, the lower chambers. When the electrical current arrives in the ventricles, it causes them to contract and pump oxygen-rich blood out to the body.
What are premature ventricular contractions?
A premature ventricular contraction (PVC) is a too-early heartbeat that originates in the ventricles and disrupts the heart’s normal rhythm. The pattern is a normal beat, an extra beat (the PVC), a slight pause, then a stronger-than-normal beat. The heart fills with more blood during the pause following the PVC, giving the next beat extra force. This pattern may occur randomly or at definite intervals.
What are the symptoms of PVCS?
When a PVC occurs as a single premature beat, patients may describe the feeling as a "palpitation" or "skipped beat." The beat following the PVC can be strong enough to cause pain or discomfort in the chest.
Individuals who have frequent PVCs or a series of them may experience a fluttering sensation in the chest or neck. If PVCs are frequent enough to reduce the heart’s pumping ability, the individual may experience weakness, dizziness or fainting.
Who is at risk for PVCs?
Almost everyone has PVCs at some time, from childhood through adulthood. In a study of healthy members of the military, the incidence of PVCs was 0.5% among those under the age of 20 and 2.2% in those over the age of 50. This study shows the rise in PVCs – as in all types of abnormal heart rhythms – that occurs with age. PVCs occur more commonly in older people and in individuals with underlying heart disease, including a history of heart attack. People with a family history of cardiac arrhythmias (abnormal heart rhythm) also have a higher risk for PVCs.
What causes PVCs?
Healthy people of any age can experience PVCs. In most cases of occasional PVCs the underlying cause cannot be identified.
PVCs that occur frequently or for longer periods of time are more likely to be related to heart disease, an injury to the heart or other, non-cardiac conditions such as a chemical imbalance in the body. Certain medications, alcohol, illegal drugs and high levels of adrenaline due to stress, exercise or caffeine also can cause PVCs.
How are PVCs diagnosed?
PVCs can be difficult to diagnose because they occur at unpredictable intervals. In most cases, PVCs are difficult for the physician to detect during a routine physical unless the patient has one during the exam or has other signs of structural heart problems. In individuals without any known heart disease, PVCs often are discovered incidentally during a routine echocardiogram (ECG). In patients with known heart disease, PVCs may be detected during other diagnostic testing for that condition.
A patient with symptoms of PVCs who consults a heart specialist will undergo an ECG, the standard test for diagnosing PVCs. It is relatively inexpensive, non-invasive and accurate. A Holter monitor, a portable ECG that provides 24 or 48 hours of continuous recording, may be used for patients who experience PVCs at least once a day. The information from a Holter monitor is very useful in determining the frequency of PVCs and correlating symptoms such as faintness or dizziness with the arrhythmia.
The American College of Cardiology recommends exercise testing – measuring the heart rate while the patient walks on a treadmill – for some patients with PVCs diagnosed by ECG.
Major heart centers like Cleveland Clinic also have other, higher level, specialized tests available for patients with PVCs who are unable to undergo exercise testing or who are at high risk for more complex heart problems. These tests may include cardiac MRI, cardiac CT, myocardial perfusion SPECT, coronary angiography or electrophysiology testing. Cleveland Clinic electrophysiologists perform more than 4000 diagnostic tests for arrhythmias each year, one of the highest patient volumes in the country.
What are the risks associated with PVCs?
Most PVCs occur infrequently and are benign. Frequent PVCs may increase the risk of developing other, more serious cardiac arrhythmias. Individuals with frequent PVCs who have underlying heart disease, structural abnormalities in the heart or have had a previous heart attack have a higher risk of death.
When should I seek medical advice about PVCs?
For most people, PVCs occur infrequently and are benign. You should consult a heart specialist if you experience frequent, regular or prolonged (duration of several minutes) PVCs, pr are experiencing PVCs and have a structural heart problem or heart disease or have had a heart attack
How are PVCs treated?
For individuals who experience occasional PVCs with no other symptoms and no underlying heart disease or structural problems, no treatment is necessary. You can help control your PVCs by reducing or eliminating your caffeine, tobacco and alcohol intake and reducing stress and anxiety. If medication you take routinely is causing your PVCs, discuss a possible change in medication with your physician. When PVCs are due to some form or heart disease or structural abnormality, treating that problem often causes the PVCs to go away.
A beta blocker medication may be prescribed for patients with PVCs who have heart failure or who have had a heart attack. Beta blockers are safe and effective drugs that are often used to treat heart arrhythmias. Other drugs that may be used to treat frequent PVCs include calcium channel blockers and other more potent heart rhythm medications.
Ablation is another treatment option for some patients with frequent or prolonged PVCs. In ablation therapy, radiofrequency waves are used to vaporize tiny amounts of tissue in the area of the heart where the extra beat originates. This is a minimally invasive procedure that is reserved for patients who cannot tolerate beat blockers, in whom medication is ineffective or who cannot comply with long-term drug therapy. Cleveland Clinic interventional cardiologists are experts in radiofrequency ablation, performing more than 1200 ablations annually to treat a variety of arrhythmias.
For patients with heart disease who have frequent PVCs or increased PVCs during exercise, angioplasty or bypass surgery may be appropriate.
Where can I learn more about PVCs?
For more information about PVCs or to make an appointment with a Cleveland Clinic heart specialist, please call 800.659.7822 toll-free to talk with a Resource Nurse in the Sydell and Arnold Miller Family Heart & Vascular Institute.
- Zipes, Douglas et al. Developed in Collaboration With the European Heart Rhythm Association and the Heart Rhythm Society. ACC/AHA/ESC 2006 Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death: A Report of the American College of Cardiology/American Heart Association Task Force and the European Society of Cardiology Committee for Practice Guidelines, J Am Coll Cardiol 2006 48: e247-346.
- American Heart Association. "Premature Contractions." Retrieved on March 1, 2011, from AHA website: www.heart.org/HEARTORG/Conditions/Arrhythmia/AboutArrhythmia/Premature-Contractions_UCM_302043_Article.jsp
- Heart Rhythm Society. "Heart Rhythm Disorders." Retrieved on March 1, 2011, from HRS website: www.hrsonline.org/PatientInfo/HeartRhythmDisorders/index.cfm
- Heart Rhythm Society. "Skipped Heartbeats." Retrieved on March 1, 2011, from HRS website: www.hrsonline.org/patientinfo/symptomsdiagnosis/skipped/
- The Merck Manuals Online Medical Library. "Ventricular Premature Beats (VPB)." Retrieved on March 1, 2011, from Merck Manuals website: www.merckmanuals.com/professional/sec07/ch075/ch075j.html