Ion channels -- Action potentials -- Wide complex tachycardia in the emergency room -- Long QT syndrome -- Propagation -- Arrhythmia mechanisms -- Automaticity -- Triggered firing -- Reentry -- Atrial fibrillation : a case study in reentry -- Anatomy for electrophysiologists -- Deducing anatomy -- Electrical activity, electrodes and electrograms -- Electrogram analysis : understanding electrogram morphology -- Differential diagnostic pacing maneuvers -- Electro-anatomic mapping.