Paroxysmal AV block overview

• Paroxysmal AV block is defined as a delayed escape rhythm which repetitively blocks conduction from the atria to the ventricles, thereby causing syncope, conduction defects such as asystole and sudden cardiac death.
• It may or may not be associated with Phase 3 or Phase 4 conduction defects.
• It may be due to an increased vagal tone, innately low adenosine levels or an intrinsic conduction defect, all of which lead to different ECG presentations.
• Insufficient data is available regarding the exact etiology, diagnostic study of choice and treatment of paroxysmal AV blocks.
• It can be thought of more as a disease of exclusion. However,efforts must be made to have a standardized approach to such patients.