I have a client that wishes to start training with me, but she has a left bundle branch block that has caused her to pass out once. She has had clearance to exercise, but I have been unable to find any information about this condition. Will fitness improve this condition and prevent further episodes? What will be the benefits to exercise for this client?
Before we get into your client’s condition, there needs to be a few questions asked. How old is your client? Does she have any other diseases, like diabetes or thyroid problems? Who did the diagnosis? You mention she has been cleared to exercise, but by whom? A cardiologist would be the top pick and a VERY good person for you to speak with directly. Was there an exercise stress test? If so, you need to find out what her heart rate response was like. Was she able to elevate her heart rate? How about blood pressure changes? You mention your client has passed out from the Left Bundle Branch Block (LBBB). How long ago did that occur and how long was she out for? You see we have quite a few questions here.
At this point, the concern is if you should train her and if exercise will improve her cardiac function. These are excellent questions. Let’s review what your client’s condition is about. The heart has it’s own electrical system. This system starts at the top of the heart and "weaves" through the muscle down to the bottom portion. The bottom half of the heart is referred to as the ventricles. There is a right and left ventricle, which is responsible for pumping blood throughout the lungs and the body. Each ventricle has it’s own electrical conduit that sends pulses of electricity down into the ventricular muscle and contraction happens (i.e., a heart beat).
Your client’s problem is in the electrical conduit in left ventricle. This electrical "branch" is blocked somewhere. This blockage slows the impulse down and throws the rhythm off between the right and left sides of the heart. This sometimes manifests itself in people passing out, like your client. What happens with this conduction delay is that asynchronous heart activity can cause remodeling of the ventricles. This then can effect how the heart functions and impairs blood pressure responses and blunts heart rates. This is why you need the results of the exercise test. You should never train the client above the heart rate they were tested at. This assures no unusual consequences.
Between right and left bundle branch blocks, LBBB is the most sensitive. LBBB is associated with other heart diseases, like heart valve problems, cardiomyopathy and other conduction problems that may result in a bradycardial event (i.e., passing out). The problem with a sudden event of bradycardia is the heart may stop all together: 911, CPR and ABCs. Sounds scary, but it is something to think about. Remember exercise is like a medicine. People have different responses to exercise, especially people with special circumstances.
The question still exists about whether you should train her. My answer is, I don’t know. I believe you need to ask more questions before beginning her program. Speak with whoever has given her the “O.K.” and get their view on training. If this is not possible, keep her training intensity light and check her heart rate and blood pressure during training. Keep notes so you can see any changes, good or bad, that take place from the training. I would suggest she purchase a heart rate monitor. Last on the list of suggestions is quarterly EKG check ups. This will be one of the best ways to keep tabs on her changes. This way, her health care provider is in touch a few times a year.
I hope this helps you with your decision.
- Littman, L and J. Symanski. (2000) Hemodynamic implications of left bundle branch block. Journal of Electrocardiology suppl.33, pp115-21
- Wenger, N. (1978) Exercise and the heart. Pp81-92, Davis Company, Philidelphia
- Bove, A. (1983) Exercise Medicine; physiological principles and clinical applications. Chapter 11. Acedemic press. San Diego