Complete Heart Block

Complete Heart Block

Complete heart block, also known as Third Degree Atrioventricular Block, is a type of heart block that results in a complete interruption of the electrical signal between the atria and ventricles of the heart. The atria and ventricles do not contract at the same time, and the delay in this electrical signal and its communication can lead to more serious health problems, such as arrhythmia and sudden cardiac arrest.

Complete heart block typically causes the heart rate to drop to a dangerously low level, to as low as 30 beats per minute. Further, it can lead to low blood pressure, chest pain, difficulty breathing, dizziness, and fainting. As such, it is usually identified with an electrocardiogram (ECG) or echocardiogram and is treated with a pacemaker implanted surgically to help coordinate the heart’s electrical signals.

Symptoms of Complete Heart Block

  • Lightheadedness or dizziness
  • Shortness of breath
  • Extreme fatigue
  • Fainting
  • Slow or irregular pulse
  • Chest pain

Causes of Complete Heart Block

Complete heart block is usually caused by anatomical defects in the heart muscle, such as certain congenital heart defects or cardiovascular disease. Electrical malfunctions or damage caused by heart attack or viral infection can also lead to complete heart block. Aging can also contribute to the risk of developing complete heart block. Doctors may also recommend completing a stress test to measure the heart’s response to physical stress.

Diagnosis and Treatment

Complete heart block is typically diagnosed using an electrocardiogram (ECG), echocardiogram, exercise stress test, and Holter monitoring. Treatment may include medications such as beta blockers and calcium channel blockers. However, if the underlying electrical problem is severe enough, a pacemaker may be recommended. Pacemakers are small devices that can be implanted under the skin, and use electrical signals to regulate the heart’s rhythm. There are also implantable cardiac defibrillators, which can detect abnormal heart rhythms and provide a jolt of electricity to restore the heart's normal rhythm.