The ECG Rhythms content is currently under development and is being updated by medical professionals.
Atrial flutter is a type of supraventricular tachycardia characterized by a rapid and regular atrial rhythm.150 This rhythm is caused by a re-entrant electrical circuit within the atria, most commonly in the right atrium involving the cavotricuspid isthmus.151
Analogy: “A rapid, repetitive musical phrase played in the upper section of the orchestra.”
The hallmark of atrial flutter on an ECG is a rapid atrial rate, typically between 250 and 350 beats per minute.151 This rapid atrial activity often manifests as characteristic sawtooth flutter waves (F waves), which are particularly prominent in the inferior leads (II, III, and aVF) where they appear as inverted deflections in typical atrial flutter.151 In leads I and aVL, the flutter waves may be of low amplitude and biphasic, while in precordial lead V1, they are often upright.152 The ventricular rate is usually slower than the atrial rate and is determined by the conduction ratio through the AV node, which may be fixed (e.g., 2:1, 3:1 conduction) or variable.151 Due to the continuous rapid cycling of the electrical activity in the atria, there is typically no isoelectric baseline visible between the flutter waves.151 The QRS complexes are usually narrow, as the ventricular depolarization typically occurs via the normal conduction pathways.151
Individuals with atrial flutter may experience symptoms such as palpitations, often described as a rapid or pounding heartbeat.150 Other potential symptoms include chest pain 150, shortness of breath 150, fatigue 150, lightheadedness 152, and in some cases, fainting.150 Atrial flutter carries an increased risk of blood clot formation in the atria, which can lead to stroke or other embolic events.150 Risk factors for atrial flutter include conditions such as heart failure, chronic obstructive pulmonary disease (COPD), and prior cardiac surgery.152
“Like a stuck record skipping rapidly and rhythmically, the atria are caught in a fast, repeating electrical loop.”