Heart finds a way around bundle branch block

DEAR DR. ROACH: I’m a female, age 70, 5 feet, 4 inches tall and 125 pounds. I have no problems with cholesterol, diabetes or blood pressure. I do not take any medications, just vitamins. I take dance exercise classes and walk often. I recently went for my checkup and found that I have a left bundle branch block. How did I get this? Is there anything I can do?

Do I continue taking exercise classes, or will it make my heart worse? At about the age of 6, I was told I had scarlatina. I had to take penicillin for a year and had a heart murmur. The murmur went away in my 40s. — Anon.

ANSWER: The bundle branches carry electrical impulses inside the heart, and in the ventricle, there are two main branches — the left bundle branch and the right. A left bundle branch block is the blockage of one of the main “wires” to the heart. Fortunately, the impulse still can be carried across the muscle cells, so usually there are no symptoms, and you need not make changes to your busy lifestyle. Your doctor will have done a careful checkup on you, since other heart issues, including blockages in the arteries and a weakened heart muscle, sometimes are associated with LBBB.

Scarlet fever (I like the delightfully old-fashioned term “scarlatina”) is a complication of strep throat and is occasionally confused with rheumatic fever, another complication. Scarlet fever causes a characteristic rash with a sandpaper quality, whereas rheumatic fever can cause permanent damage to heart valves. Scarlet fever does not affect the heart.

Most people with bundle branch block have an excellent prognosis; however, if there is further damage to your conduction system, you likely will need a permanent pacemaker. I would not stop your exercise classes.