Premature Ventricular Contractions
What are premature ventricular contractions (PVCs)?
Premature ventricular contractions, or PVCs, are a type of abnormal heartbeat. Your heart has 4 chambers: 2 upper atria and 2 lower ventricles. Normally, a special group of cells start the signal to start your heartbeat. These cells are in the sinoatrial (SA) node in the right atrium. The signal quickly travels down your heart’s conducting system. It travels to the left and right ventricle. As it travels, the signal triggers nearby parts of your heart to contract. This allows your heart to squeeze in a coordinated way.
In a premature ventricular contraction, the signal to start your heartbeat comes from one of the ventricles instead. This signal is premature, meaning it happens before the SA node has had a chance to fire. The signal spreads through the rest of your heart, causing a heartbeat. If this happens very soon after the previous heartbeat, your heart will push out very little blood. This causes a feeling of a pause between beats. If it happens a little later, your heart pushes out an almost normal amount of blood. This leads to a feeling of an extra heartbeat. So, the heart has a random “premature” heartbeat sandwiched between many other normal heartbeats.
Occasional PVCs are common in people of all ages, but they are a little more common in older people. They often happen in people without any heart disease. However, PVCs are somewhat more common in people with some kind of heart disease. Only rarely do PVCs cause problems on their own.
What causes PVCs?
Certain things can help set off a premature signal in the ventricles, such as:
- Reduced blood flow to your heart
- Scarring after a heart attack (myocardial infarction)
- Electrolyte abnormalities, like low sodium or potassium levels
- Increased adrenaline (such as in anxiety)
- Certain drugs, like digoxin
Who is at risk for PVCs?
Many heart conditions increase the risk for PVCs, such as:
- Mitral valve prolapse
- High blood pressure
- Heart attack
- Coronary heart disease
- Dilated cardiomyopathy
- Hypertrophic cardiomyopathy
- Congenital heart disease
- Heart failure
What are the symptoms of PVCs?
Most people with occasional PVCs do not have symptoms. When symptoms do happen, they are usually minor. Sometimes PVCs cause an unpleasant awareness of the heartbeat (palpitations). Some people may describe feeling a “skipped” or “extra” heartbeat. Dizziness, near-fainting, and a pounding sensation in the neck are other possible symptoms.
Generally, PVCs cause dangerous symptoms only if the person has another heart problem. For example, they might happen in someone whose ventricle already squeezes poorly. So if you have heart failure, you may notice increased symptoms, like shortness of breath. You are also more likely to have symptoms if you have PVCs often.
How are PVCs diagnosed?
Your healthcare provider will ask about your medical history and give you a physical exam. An electrocardiogram (ECG) is the most important test for diagnosis. This test allows your provider to study the signal of your heartbeat for a brief moment in time. Any PVCs during this time will show up on the ECG. In some cases, your healthcare provider might recommend ECG monitoring over a day or two, or up to 30 days. This can help to catch PVCs that don’t happen often.
These may be the only tests your healthcare provider will need. You may need more testing if you have PVCs often, or many in a row. Your provider may look at other causes, including potential heart problems. These tests might include:
- Echocardiography, to evaluate heart structure and function
- Cardiac stress testing, to see how your heart responds to exercise and to evaluate blood flow through your heart
- Blood tests, to check potassium and thyroid levels
How are PVCs treated?
Most people with PVCs do not need any treatment. If are treated for another problem with your heart, your PVCs may decrease. For example, you might take a medicine to lower your blood pressure. This may lower your rate of PVCs.
In some cases, specific treatment may be done to help prevent PVCs. These are used only if you have symptoms from PVCs. Options include:
- Other medicines to help prevent abnormal heart rhythms
- Catheter ablation, to destroy the part of your heart responsible for the abnormal beats
How do I manage PVCs?
Your healthcare provider may give your more instructions about how to manage your PVCs and other medical conditions, such as the following:
- Eat a heart-healthy diet
- Get enough exercise and maintaining a healthy weight
- Avoid too much alcohol and caffeine, which can trigger PVCs
- Avoid too much stress and fatigue, which can also trigger PVCs
- Get treatment for your other medical conditions, like high blood pressure
- Make sure to keep all your medical appointments
When should I call my healthcare provider?See your healthcare provider right away if you have severe symptoms like chest pain, lightheadedness, or sudden shortness of breath. If your symptoms are getting worse over time, plan to see your healthcare provider soon.
Key points about PVCs
PVCs are a kind of abnormal heart rhythm. The signal to start your heartbeat starts somewhere in the ventricles instead of in the SA node. This can feel like a skipped heartbeat or an extra heartbeat.
- PVCs are very common in people of all ages. They are a little more common if you have other heart problems.
- Most of the time, PVCs do not cause symptoms. And, most of the time, they do not need treatment.
- Medicines and surgical ablation are options if you have PVCs.
- Your healthcare provider may want to check you for other heart conditions.
- Follow all your healthcare provider’s instructions about medicine, exercise, and lifestyle.
Tips to help you get the most from a visit to your healthcare provider:
- Know the reason for your visit and what you want to happen.
- Before your visit, write down questions you want answered.
- Bring someone with you to help you ask questions and remember what your provider tells you.
- At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.
- Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are.
- Ask if your condition can be treated in other ways.
- Know why a test or procedure is recommended and what the results could mean.
- Know what to expect if you do not take the medicine or have the test or procedure.
- If you have a follow-up appointment, write down the date, time, and purpose for that visit.
- Know how you can contact your provider if you have questions.
March 22, 2017
Fetterman, Anne, RN, BSN,Kang, Steven, MD