TOPICS: Cardiac electrical system, sinoatrial (SA) node, atrioventricular (AV) node, Bundle of His, Purkinje fibers, right and left bundle branches, conduction velocity, action potential, Phase 0, Phase 1, Phase 2, Phase 3, Phase 4, upstroke, repolarization, depolarization, funny channels (I_f), contraction, relaxation, ryanodine receptors, sarcoplasmic reticulum (SR), troponin C, tropomyosin, actin, phospholamban, Na+/Ca2+ antiporter, inotrope, chronotrope, dromotrope
