Introduction

The image shows ectopic focus in the left atrium leading to atrial tachycardia.

Atrial tachycardia is a tachycardia (rate over 100; usually 150-250) arising from atrial tissue other than the sinoatrial node an ectopic pacemaker, or rarely, multiple pacemaker sites. Atrial flutter is technically a form of atrial tachycardia, but will be described separately later.

P waves are present on the ECG but their shape is abnormal, depending on the site of origin of the ectopic pacemaker.

Most commonly, this is a benign and short-lived paroxysmal condition of the elderly.

A more prolonged form may occur in children and young adults called Incessant Ectopic Atrial Tachycardia: undiagnosed, it may progress to a dilated cardiomyopathy.