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Welcome to North Suburban Cardiology Associates

Heart block is a problem in the electrical signals of the heart. It occurs when the electrical signal is slowed down or does not reach the bottom chambers of the heart. Your heart may beat slowly, or it may skip beats. Heart block may go away on its own, or it may be permanent and require treatment.

There are three degrees of heart block. First-degree heart block is the mildest type.

First-degree heart block

  • Rarely has symptoms

Second-degree heart block

  • The electrical impulse may not reach the lower chambers of the heart.
  • The heart may miss a beat or beats and may be slow and irregular.

Third-degree heart block:

  • The electrical signal does not move to the lower chambers of the heart. In this case, the lower chambers beat at a much slower rhythm, and the upper and lower chambers do not beat at the same rate.
  • The heart fails to pump enough blood to the body. This can lead to fainting and shortness of breath.
  • This is an emergency that needs medical help right away.


Heart block may be caused by:

  • Side effects from medicines, such as digitalis and beta-blockers
  • A heart attack that damages the heart’s electrical system
  • Heart diseases, such as heart valve disease and cardiac sarcoidosis
  • Some infections, such as Lyme disease
  • Heart surgery

You may have heart block because you were born with it. You are more at risk for the condition if:

  • You have a heart defect.
  • Your mother has an autoimmune disease, such as lupus.


The symptoms are different for first, second and third-degree heart block.

You may not have any symptoms for first-degree heart block. You may not know you have heart block until it shows up on an electrocardiogram (ECG).

If you have second-degree or third-degree heart block, symptoms may include:

  • Chest pain
  • Dizziness
  • Feeling faint
  • Tiredness
  • Heart palpitations

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