Hi! Great question. Atrial fibrillation and heart block are two different types of irregular heart rhythms. With complete heart block, the electrical signals between the upper and lower chambers (atria and ventricles) don’t transmit properly, so a pacemaker is used to keep a steady heart rate. Atrial fibrillation, on the other hand, happens when different areas of the atria become overly excited, causing an irregular heart rhythm. AFib is actually quite common and can usually be managed with medications or other treatments. Does this help? Are these both conditions that you’re dealing with?John. community moderator.