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A PVC is a premature ventricular contraction. According to the American Heart Association (AHA), a PVC feels like your heart is skipping a beat but it’s really not. A PVC is an early heartbeat, meaning there is a longer pause till the next heartbeat. It is a pause, not a skip. Also, the beat after the pause is stronger than usual to make up for the pause, and that is what you feel This sensation is called a palpitation.
How Common Are PVCs?
Isolated PVCs are very common, and they tend to increase with old age. If you record a person’s heartbeat for 48 hours on an electrocardiogram (ECG), about 75 percent of people will have at least one PVC. PVCs usually come as a single PVC. Two PVCs in succession is called a doublet PVC. Three PVCs in succession is called a triplet, and more than three in a row is called ventricular tachycardia. PVCs are considered occasional if they occur less than 30 times per hour and frequent if they occur more than 30 times per hour. A PVC that occurs on every other beat is called bigeminy and a PVC that occurs on every third beat is called trigeminy.
Are PVCs Dangerous?
PVCs are not dangerous to your heart unless you have over 1000 PVCs per day. This amount of PVCs can lead to a type of heart muscle damage called cardiomyopathy, which can lead to heart failure. PVCs can be a sign of danger if they are caused by heart disease, another disease, or any condition that is stressing your heart. These types of PVCs may cause symptoms and they tend to occur frequently. Causes of these PVCs include:
- Many types of heart disease, including decreased blood supply to the heart
- Heart valve abnormalities
- High blood pressure
- Abnormal levels of blood minerals (electrolytes) including low magnesium or potassium and high calcium
Less dangerous causes of PVC include stress, anxiety, too much caffeine or nicotine, not getting enough sleep, legal or illegal stimulant drugs, and abuse of alcohol.
What Happens During a PVC?
Your heart depends on a regular and coordinated rhythm to pump blood out to your body. Stimulation for a normal heartbeat begins in an area of an upper heart chamber, called the atrium. The area where it starts is called the sinoatrial (SA) node. The signal to beat travels to another area located between the atria and the lower chambers of the heart called the ventricles. This is the atrioventricular (AV) node. The AV node sends signals through fibers in the ventricles called Purkinje fibers. A PVC occurs when Purkinje fibers initiate the ventricular beat before the SA node.
Diagnosis and Treatment of PVCs
Most PVCs are never diagnosed or treated because they are not noticed or occur infrequently. PVCs usually occur without causing palpitations. In the vast majority of cases, the cause of these PVCs is unknown. PVCs may be diagnosed when they are frequent and cause frequent symptoms. You should let your health care provider know if you have frequent palpitations or palpitations that cause:
- Lightheadedness or dizziness
- Brief shortness of breath or a sensation of almost passing out (syncope)
- A feeling of pounding pulse in your chest or neck
Your healthcare provider may diagnose PVCs based on your symptoms and physical exam. Testing may include:
- An ECG
- A 24-to-48-hour ECG, also called a Holter monitor
- Blood testing for anemia and electrolytes
- An imaging study of the heart
Treatment of PVCs depends on the cause. This might include avoiding causes like stress or lack of sleep, avoiding stimulants like caffeine or nicotine, treating an underlying disease like high blood pressure or hyperthyroidism, or treating heart disease. PVCs without a known cause rarely need to be treated.
You may be able to reduce your risk of PVCs by maintaining a healthy weight, getting regular physical activity, eating a heart healthy diet, getting at least eight hours of sleep, and avoiding nicotine or too much caffeine or alcohol.
When to Get Help Right Away
An occasional PVC is not an emergency, but if you have palpitations along with persistent dizziness, confusion, passing out, chest pain, or difficulty breathing, call 911.