Ectopic atrial tachycardia (EAT) is one of the most common forms of persistent supraventricular tachycardia in children. • EAT is due to increased automaticity of a non-sinus atrial focus, and when leIt untreated can cause tachycardia-induced cardiomyopathy, also known as tachycardiomyopathy (TCMP). • EAT can be difficult to distinguish from sinus tachycardia depending on the location of the ectopic focus.