About premature ventricular contractions (pvcs)
What is premature ventricular contractions (pvcs)?
What are premature ventricular contractions (PVCs)?
Premature ventricular contractions (PVCs) are premature heartbeats originating from the ventricles of the heart. Premature ventricular contractions are premature because they occur before the regular heartbeat.
Normal function of the heart
The heart has four chambers. The upper two chambers are the atria, and the lower two chambers are the ventricles.
- The atria deliver blood to the ventricles, and the ventricles deliver blood to the lungs and to the rest of the body.
- The right ventricle delivers blood to the lungs while the left ventricle delivers blood to the rest of the body.
- The heartbeat (pulse) that we feel is caused by the contraction of the ventricles.
The heartbeat is normally controlled by the electrical system of the heart. The electrical system of the heart consists of the sinoatrial (SA) node, the atrioventricular (AV) node and special tissues in the ventricles that conduct electricity.
The SA node is the heart's electrical pacemaker. It is a small patch of cells located in the wall of the right atrium; the frequency with which the SA node discharges electricity determines the rate at which the heart normally beats. The SA node keeps the heart beating in a regular manner. At rest, the frequency of the electrical discharges originating from the SA node is low, and the heart beats at the lower range of normal (60 to 80 beats/minute). During exercise or excitement, the frequency of discharges from the SA node increases, increasing the rate at which the heart beats. In people who exercise regularly, the resting heart rate may be below 50 to 60 and is not of concern.
The electrical discharges pass from the SA node through the special tissues of the atria into the AV node and through the AV node to the special conduction tissues of the ventricles, causing them to contract.
What are the symptoms for premature ventricular contractions (pvcs)?
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
When to see a doctor
If you feel fluttering, 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, whether it's PVCs, other heart rhythm problems, serious heart problems, Anxiety, anemia or infections.
What are the causes for premature ventricular contractions (pvcs)?
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.
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. Heart disease or scarring may also cause electrical impulses to be misrouted.
Premature ventricular contractions can be associated with:
- Certain medications, including decongestants and antihistamines
- 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
What are the treatments for premature ventricular contractions (pvcs)?
For most people, PVCs with an otherwise normal heart won't need treatment. However, if you have frequent PVCs, your doctor might recommend treatment.
In some cases, if you have heart disease that could lead to more-serious rhythm problems, you might need the following:
- Lifestyle changes. Eliminating common PVC triggers — such as caffeine or tobacco — can decrease the frequency and severity of your symptoms.
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Medications. Beta blockers — which are often used to treat high blood pressure and heart disease — can suppress premature contractions.
Other medications, such as calcium channel blockers, or anti-arrhythmic drugs, such as amiodarone (Pacerone) or flecainide (Tambocor), also might be used if you have ventricular tachycardia or frequent PVCs that interfere with your heart's function.
- Radiofrequency catheter ablation. For PVCs that don't respond to lifestyle changes or medications, your doctor might recommend ablation therapy. This procedure uses radiofrequency energy to destroy the area of heart tissue that is causing your irregular contractions.
What are the risk factors for premature ventricular contractions (pvcs)?
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)