Tachycardias can be caused by:

• Altered impulse formation
• Altered impulse conduction

They can be divided by the anatomical site of origin:

• Supra-ventricular tachycardias - arising above the ventricles, in the atria
• Ventricular tachycardias - Arising in the ventricles

Underlying causes for tachycardias:

Drugs, alcohol, anxiety, hyperthyroidism, ischaemia, fibrosis, cardiomyopathy, hypoxaemia, infection, electrolyte abnormalities

Supraventricular Tachycardias (SVT)

Sinus Tachycardia

Paroxysmal re-entrant SVTs

Atrial flutter

Atrial fibrillation

Atrial fibrillation: Cardioversion

Atrial fibrillation: post stroke

Ventricular Tachycardias (VTs)

Ventricular Tachycardias