Heart block are category of disease which occur in electrical conduction system of heart. Video first overviews electrical conduction system. Later on, AV blocks are explained majorly. Timeline 0:00 Introduction 0:03 Electrical conduction system overview 0:38 Heart block 1:22 AV blocks 1:32 First degree AV Block 1:55 Second degree AV block 3:49 Third degree heart block