AV Block Physiology
Normally, electrical impulses in the heart stimulate the atria and ventricles to contract in a coordinated pattern. This allows the atria to contract first, forcing blood into the ventricles, and then the ventricles contract, pumping blood to the lungs and body.
Electrical impulses originate in the sinoatrial node (SA node), located within the right atrium. The SA node is the heart's pacemaker. The SA node sends an electrical impulse that is conducted to the ventricles by way of the atrioventricular node and a network of electrical pathways. These pathways are called the Bundle of HIS.
- Agarwala B, Sheikh Z, Cibils LA. Congenital complete heart block. J Natl Med Assoc. 1996 Nov;88(11):725-9. 
- Batra AS, Epstein D, Silka MJ. The clinical course of acquired complete heart block in children with acute myocarditis. Pediatr Cardiol. 2003 Sep-Oct;24(5):495-7. 
- Huang M, Krahn AD, Yee R, Klein GJ, Skanes AC. Optimal pacing for symptomatic AV block: a comparison of VDD and DDD pacing. Pacing Clin Electrophysiol. 2004 Jan;27(1):19-23. 
- MacKenzie R. Second-degree AV block. J Insur Med. 2004;36(4):327-32. 
- Ozdemir K, Altunkeser BB, Korkut B, Tokac M, Gok H. Effect of left bundle branch block on systolic and diastolic function of left ventricle in heart failure. Angiology. 2004 Jan-Feb;55(1):63-71.