Dr. M.J. Bazos, MD Patient Handout


About Your Diagnosis

Bundle branch block is a delay of conduction of electrical signals from the atrium. These signals go through branches of the bundle of His (the electrical wiring of the heart). This bundle carries the electrical signals that tell the ventricles to contract. The block can affect either the left or the right side of the heart. It is generically referred to as heart block. There are many different types of blocks of electrical signals in the heart. The atria contract normally, but because the ventricles do not receive the proper signal, they may not contract as often as they are supposed to.

Living With Your Diagnosis
Symptoms of heart block are related to insufficient pumping of blood from the heart. If a block is mild, it may produce no symptoms. Severe blocks can cause dizziness, fainting, angina (chest pain), or stroke (not enough blood flow to the brain). Heart block is relatively common. About one half of persons with heart block have no known cause. Most of those with heart block have some form of heart disease. They may have had damage to the heart from a heart attack (myocardial infarction), myocarditis (inflammation of the heart muscle), or rheumatic fever (from previous infection with streptococcal bacteria. Heart block also may be caused by overdosing of digitalis (digoxin) or a congenital heart abnormality (one that is present at birth). Heart block is detected with an electrocardiogram (ECG). The patient usually has a slower than normal heart rate.

If you have no symptoms and no heart disease, no treatment is required. If you have symptoms because the ventricle not beating fast enough to meet blood demands, a pacemaker may be inserted. A pacemaker is an electrical device with a wire connected to the heart muscle to signal the ventricles to contract more regularly (fixed-rate pacers) or to contract faster in response to increased activity (demand pacers). Pacemakers are battery operated, and the batteries have a long life. Pacemakers can be external with the wire entering through a vein, or they can be implanted inside the patient with a minor operation. Older pacemakers were susceptible to damage from microwaves and strong electronic equipment. Newer pacemakers are safe and reliable. Caution remains to avoid strong magnetic or ultrasonic forces such as those used in some physical therapy settings or in airport security screens. Patients who need a pacemaker are given instructions by a cardiologist regarding maintenance and care of the pacemaker. Persons with bundle branch block or pacemakers may take medications to manage the heart disease or other medical conditions.

The DOs
•If you are on medications, take them as directed.
•Lower the fat and cholesterol in your diet
•Lose weight
•Stop smoking.
•Exercise as directed by your physician if you have a demand pacer.
•Exercise as tolerated and adopt a healthy-heart lifestyle if you have bundle branch block and no symptoms.

The DON’Ts
•Do not ignore worsening symptoms.

When to Call Your Doctor
•If you have dizziness, fainting, chest pain, or shortness of breath.