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Ventricular Contraction  
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A beat (contraction) of the lower chambers of the heart.

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Definition  

A premature ventricular beat (PVB) is an extra heartbeat caused by abnormal electrical activity. It starts in the ventricles (the lower chambers of the heart) before a normal heartbeat occurs. PVB interferes with the heart’s normal rhythm and causes a pause before the next heartbeat. It may feel like a heartbeat is skipped.

PVBs are common, especially among the elderly. They can occur in people who are healthy, in which case they are harmless. However, when they occur after a heart attack or heart surgery they can lead to dangerous heart rhythms. In some cases, these rhythms can cause sudden death. You should contact your doctor right away if you suspect you have PVBs after a heart attack or heart surgery.

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Causes  

The causes of PVBs include:

  • Physical or emotional stress
  • Physical exercise
  • Caffeine, alcohol, tobacco, and other drugs (eg, cocaine, amphetamines)
  • Certain medications, especially those that stimulate the heart
  • Heart disease:
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Risk Factors  

A risk factor is something that increases your chance of getting a disease or condition.

The following factors increase your chance of developing PVBs:

  • Age: frequency increases with age, PVBs are most common in the elderly
  • Sex: more common in men than women
  • Race: African Americans have a much higher risk than Caucasian
  • Heart disease
  • Use of caffeine, alcohol, tobacco, or other drugs
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Symptoms  

In many cases, there are no symptoms. When symptoms do occur they can include:

  • Feeling the heart beating (palpitations)
  • Feeling of a skipped or missed heart beat

In people with heart disease, PVBs can cause decreased blood flow from the heart to other parts of the body. This can produce dizziness and fainting.

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Diagnosis  

Your doctor will ask about your symptoms and medical history, and perform a physical exam. If you have heart disease, you should see a cardiologist.

Tests may include:

  • Lab Tests
    • Electrolyte levels, especially potassium and magnesium
    • For medicat