I have a left bundle branch block and my doctor wants to perform a stress test. My concern is the result will not be accurate due to left bundle branch block. Is this true?
You are correct. Stress tests in the setting of complete left bundle branch block, be it echo or nuclear based, can be problematic. They are still valuable but may lead to both under and over diagnosis. The electrocardiogram portion does not help except for monitoring the heart rhythm. A treadmill stress test can be useful to monitor for symptom provocation and also for a normal vs. abnormal blood pressure response to exercise. I cannot make a recommendation as to yes or no should the pt have the stress test as I am not directly involved with their care. I do offer stress tests in patients with LBBB but make sure they are interpreted extremely carefully in the context of exercise duration, blood pressure response and presence or lack of chest discomfort.
Answered by Dr. Curtis Rimmerman, staff cardiologist in the Section of Clinical Cardiology, the Robert and Suzanne Tomsich Department of Cardiovascular Medicine.