Download Premature Ventricular Contractions

Premature Ventricular Contractions
Premature ventricular contractions (PVCs) are a type of arrhythmia (irregular heartbeat). They are common
and can affect people of all ages. PVCs are often not dangerous. But if other heart problems are present,
PVCs can cause serious health issues. This sheet tells you more
about PVCs and how they are treated.
Understanding Your Heart’s Electrical
SystemTo understand how PVCs occur, it helps to first
understand how your heart works. Your heart is a muscle that
pumps blood throughout the body. It is made up of four chambers:
two atria and two ventricles. Electrical signals are sent to these
chambers, making them contract (squeeze) in a certain rhythm.
This rhythm, which pumps blood through and out of your heart, is
your heartbeat. The process begins in the sinoatrial (SA) or sinus
node:
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The SA node: This group of cells in the right atrium
sends a signal to both atria, telling them to contract. This
pumps blood into the ventricles.
•
The AV node: This is another group of cells in the right
atrium. It receives the signal from the SA node after it
passes through the atria. The AV node channels the signal
through the bundle branches and into the ventricles.
•
The bundle branches: These pathways of cells carry the
signal through the ventricle walls. As the signal moves through the ventricles, the ventricles
squeeze. This pumps blood out of the heart and into the body.
During a normal heartbeat,
electrical signals start at the SA
node and are sent through the
walls of the heart’s chambers.
What Happens During a PVC?
During a PVC, an abnormal signal disrupts the normal heartbeat. This signal is sent from a group of cells
(an ectopic focus) in the ventricles. The signal causes the ventricles to contract too soon, and the heart skips
the next normal beat. This results in an irregular heartbeat.
What Are the Symptoms of PVCs?
Sometimes PVCs cause no symptoms at all. Other times, a patient may feel palpitations (irregular
heartbeats). These can feel like “skipped” beats, or “flopping” in the chest. If PVCs are frequent, other
symptoms can occur. These include tiredness, feeling faint, or shortness of breath. They also include
fullness or pressure in the neck, and chest pain. These symptoms occur because less oxygen is delivered to
the body. This is because PVCs make the heart pump blood less effectively.
What Causes PVCs?
In some cases, no cause of PVCs is found. When a cause is found, it is either chemical or structural.
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Chemical. Changes in the body’s chemistry can prompt PVCs. For instance, raised levels of
certain hormones, such as adrenaline or thyroid, can cause PVCs. Consuming substances such as
alcohol and caffeine can also cause them.
•
Structural. This involves existing problems in the heart and/or cardiovascular system. Coronary
artery disease (CAD) is one type of problem that can be related to PVCs. Others are heart failure
and heart valve problems. How Are PVCs Diagnosed?
The doctor will take your medical history and ask you to describe your symptoms. You’ll also have a
physical exam. And certain tests may be done. These include:
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Electrocardiogram (ECG or EKG). This test records the electrical activity of your heart. During
an ECG, small pads (electrodes) are placed on your chest, arms, and legs. Wires connect the pads
to a machine, which records your heart’s electrical signals.
•
Echocardiogram (echo). This test creates a moving picture of the heart. During an echo, a probe
moved over the chest emits harmless sound waves. The resulting picture shows the size and shape
of the heart. It also shows how well heart chambers and valves are working.
•
Heart monitor. There are two types of external heart monitors:
o
Holter monitor. This monitor can be worn for 1 to 7 days. It provides a constant
recording of heart activity. After the test is done, your healthcare provider analyzes the
recording.
o
Event monitors. These monitors can be used for 3 to 4 weeks. One kind is a memory
loop recorder. This monitor records constantly, but stores the recording only when you
press a button. The other kind is a credit card-sized recorder. This monitor is turned on
only during an episode. With both types, you send the recordings of symptoms to your
healthcare provider over the phone.
How Are PVCs Treated?
Treatment depends upon whether structural heart problems are present. It is also determined by the severity
of symptoms.
•
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If you have no other heart problems and your symptoms are not bothersome, treatment may not
be needed. If it is needed, treatment can involve:
o
Lifestyle changes. Your doctor may suggest that you exercise and limit caffeine and
alcohol. If you smoke, you’ll be advised to quit.
o
Medications. Two types of medication can help with PVCs. Beta-blockers and calcium
channel blockers both can lower the heart rate and reduce blood pressure.
If you have structural heart problems, you’ll likely be referred to a doctor who specializes in
heart rhythm problems. This may be a cardiologist or an electrophysiologist. This is because for
you, PVCs can be a bigger threat to your health. They can lead to problems such as a more
dangerous heart rhythm, or even death. In severe cases, an ICD (implantable cardioverter
defibrillator) may be implanted. This can help normalize the heart rhythm.
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information is not intended as a substitute for professional medical care. Always follow your healthcare
professional's instructions.