Second-degree heart block may be caused by:

• Natural aging process

• Damage to the heart from surgery

• Damage to the heart muscle from a heart attack

• Other types of heart disease that damage the heart muscle

• Low thyroid levels

• Electrolyte abnormalities

• Inflammatory or infectious heart conditions

• Other diseases, including rheumatic fever and sarcoidosis

• Some medicines

In addition, some babies are born with heart block. Heart block may also run in families.

Second-degree heart block may not have symptoms, but often it does. Symptoms may include:

• Lightheadedness, faintness, or dizziness

• Feeling tired

• Shortness of breath

Second-degree heart block without symptoms may not need treatment. Your healthcare provider is likely to ask you to have regular follow-up visits. You may also be asked to take your own pulse and be alert to changes in your heart rate.

Treatments for second-degree heart block with symptoms include:

• Taking medicines to increase your heart rate in the short-term (acutely) to relieve symptoms

• Stopping medicines, if they are causing the heart block

• Getting a pacemaker

Most people who have the second type of second-degree heart block will need a pacemaker even if they have no symptoms. This type of heart block often can progress to more serious type of heart block that can be potentially dangerous.

Second-degree heart block may develop into a more serious type of heart block. It may cause a sudden loss of consciousness or it may cause the heart to suddenly stop beating.

Call your healthcare provider right away if you have any of these:

• Unusual tiredness

• Shortness of breath

• Chest pain

• Weakness, dizziness, or fainting

• Unusual drowsiness or confusion

• Pain that gets worse

• Symptoms that don’t get better with treatment, or symptoms that get worse

• New symptoms