Introduction
Atrial flutter is a type of supraventricular tachycardia which originates from a macro-re-entrant circuit in the atria. The atrial rate is typically between 250-350 beats/min with 2:1 conduction ratio the ventricular rate is 150 beats/min.
Conduction to ventricles:
Atrial flutter usually starts with trigger beats that initiate the arrhythmia.
Classification
Types of atrial flutter depend on anatomical position and direction of the macro-re-entrant circuit.
Typical atrial flutter involves counterclockwise, or less commonly clockwise, conduction in the right atrium in a circuit around the cavotricuspid isthmus (tissue that lies between the tricuspid valve annulus and the inferior vena cava).
Counter-clockwise typical flutter (Common typical flutter)
Clockwise typical flutter (Reverse typical flutter)
ECG findings:
Picture 1 Mechanism and electrocardiographic pattern of typical atrial flutter (left) and reverse typical atrial flutter (right)
ECG 1 Typical counter-clockwise atrial flutter
Typical atrial flutter with variable AV-block
ECG 2 Typical clockwise atrial flutter
ECG 3 Typical counter-clockwise atrial flutter
Typical atrial flutter with 4:1 conduction
ECG 4 Adenosine demasking typical atrial flutter
Typical atrial flutter with conduction 1:1 and ventricular rate at 250 bpm
Causes
Management
- Decreasing atrioventricular (AV) nodal conduction physiologically with a vagotonic maneuver (such as the Valsalva maneuver or carotid sinus massage) or with a rapidly acting drug (such as verapamil, or metoprolol/esmolol) will increase the AV nodal block and reveal the atrial F waves.
Acute therapy
Adenosine
- is useful for diagnostic purposes, - by decreasing atrioventricular (AV) nodal conduction with a vagotonic maneuver or with adenosine the atrial F waves are revealed
- AV node is not involved in the flutter circuit = adenosine does not terminate the rhythm
Pharmacological termination
- i.v. ibutilide or i.v. or oral dofetilide (in-hospital) are recommended for conversion to sinus rhythm
Synchronized cardioversion
- Low-energy (75 J)
High-rate atrial pacing
- might be considered for termination of atrial flutter in the presence of an implanted pacemaker or defibrillator
Rate control therapy (not often successful)
- Beta blockers - i.v. esmolol, i. v. metoprolol
- Calcium channel blockers (verapamil/diltiazem i.v.)
Chronic therapy
- Catheter ablation – recommended for all symptomatic or recurrent atrial flutters
- Beta-blockers or non-dihydropyridine calcium channel blockers (verapamil/diltiazem or beta blocker) should be considered if ablation is not desirable or feasible
Anticoagulation
Picture 2 Treatment of atrial flutter as per ESC guidelines
References
Introduction
Atrial flutter is a type of supraventricular tachycardia which originates from a macro-re-entrant circuit in the atria. The atrial rate is typically between 250-350 beats/min with 2:1 conduction ratio the ventricular rate is 150 beats/min.
Conduction to ventricles:
Atrial flutter usually starts with trigger beats that initiate the arrhythmia.
Classification
Types of atrial flutter depend on anatomical position and direction of the macro-re-entrant circuit.
Typical atrial flutter involves counterclockwise, or less commonly clockwise, conduction in the right atrium in a circuit around the cavotricuspid isthmus (tissue that lies between the tricuspid valve annulus and the inferior vena cava).
Counter-clockwise typical flutter (Common typical flutter)
Clockwise typical flutter (Reverse typical flutter)
ECG findings:
Picture 1 Mechanism and electrocardiographic pattern of typical atrial flutter (left) and reverse typical atrial flutter (right)
ECG 1 Typical counter-clockwise atrial flutter
Typical atrial flutter with variable AV-block
ECG 2 Typical clockwise atrial flutter
ECG 3 Typical counter-clockwise atrial flutter
Typical atrial flutter with 4:1 conduction
ECG 4 Adenosine demasking typical atrial flutter
Typical atrial flutter with conduction 1:1 and ventricular rate at 250 bpm
Causes
Management
- Decreasing atrioventricular (AV) nodal conduction physiologically with a vagotonic maneuver (such as the Valsalva maneuver or carotid sinus massage) or with a rapidly acting drug (such as verapamil, or metoprolol/esmolol) will increase the AV nodal block and reveal the atrial F waves.
Acute therapy
Adenosine
- is useful for diagnostic purposes, - by decreasing atrioventricular (AV) nodal conduction with a vagotonic maneuver or with adenosine the atrial F waves are revealed
- AV node is not involved in the flutter circuit = adenosine does not terminate the rhythm
Pharmacological termination
- i.v. ibutilide or i.v. or oral dofetilide (in-hospital) are recommended for conversion to sinus rhythm
Synchronized cardioversion
- Low-energy (75 J)
High-rate atrial pacing
- might be considered for termination of atrial flutter in the presence of an implanted pacemaker or defibrillator
Rate control therapy (not often successful)
- Beta blockers - i.v. esmolol, i. v. metoprolol
- Calcium channel blockers (verapamil/diltiazem i.v.)
Chronic therapy
- Catheter ablation – recommended for all symptomatic or recurrent atrial flutters
- Beta-blockers or non-dihydropyridine calcium channel blockers (verapamil/diltiazem or beta blocker) should be considered if ablation is not desirable or feasible
Anticoagulation
Picture 2 Treatment of atrial flutter as per ESC guidelines
References