Acute Medicine | Cardiovascular | Causes of palpitations - atrial flutter

Causes of Palpitations - Atrial Flutter
Session Overview
Description
This session describes the underlying conditions predisposing to the development of atrial flutter and outlines how the cardiac re-entrant arrhythmia can lead to the typical 12 lead ECG, the underlying arrhythmia circuit.

Learning Objectives
By the end of this session you will be able to:

• Describe the key ECG features of typical atrial flutter and explain the abnormal re-entry circuit giving rise to the arrhythmia

Atrial flutter is a common cardiac arrhythmia with a distinctive ECG pattern. Of all the cardiac arrhythmias it is perhaps the most straightforward to relate the cardiac conduction disturbance to the surface 12 lead ECG.

Typical atrial flutter has a very specific underlying cardiac abnormality of electrical conduction, i.e. an anticlockwise re-entrant circuit around the tricuspid valve annulus (Fig 1).

The left atrium activates passively.

The re-entrant activation pattern gives rise to the saw tooth baseline seen on the 12 lead ECG.