welcome to hcm, I really appreciate your concern, Blockage is disease of blood vessels…Coronary Artery Disease (CAD). Bundle Branch Block is an EKG pattern – it may be the result of CAD / but not always. It can be an enlargement of Left Ventricle - from disease of muscle, valves, blood pressure and so on… Or infiltration from nearby tissues… Obviously, you don’t have any issues… Then, it must be a problem of the nerve itself! – Conduction System of the heart. It is at times a birth defect! – easy to see if we can compare with previous EKGs… Else, a defect in conduction / there are several reasons like change in electrolytes.. / occasionally a primary disease involving the conduction tissue – usually degenerative, which is most likely in your case… Generally, the ‘patient or doctor need not do anything Only a follow up is required. Please let me know if you have any further questions. Thanks. regards.