Welcome to Healthcare Magic Yes. Septum is important to transmit the electrical impulses from the Right atrium SA node to the rest of the heart via AV node conductive tissue. The AF has less chance of causing clots since the Atrial appendage is ligated. AF is known to cause complications like sending clots into the brain and other parts of the body causing stroke and end organ damage. How was your response to Propranolol. It is frequently prescribed as drug of choice for AF reduction. You could be having multiple points of electrical activity in your left atrium which is causing the AF despite catheter ablation. Do you have any other problems like PVCs or WPW syndrome for which other drugs may be needed.