Atrial flutter 2 to 1 vs 4 to 11/16/2024 Ī variety of underlying conditions can predispose to the development of atrial flutter. (See "Focal atrial tachycardia".)ĮTIOLOGY AND RISK FACTORS - Atrial flutter is uncommon in the structurally normal heart. ![]() In atypical atrial flutters, the flutter waves in the inferior leads and lead V1 are often concordant. Focal atrial tachycardias with atrioventricular block may also mimic atypical atrial flutter by ECG appearance, but by electrophysiologic study the focal mechanism can be differentiated from the macroreentry seen in atrial flutter. Incomplete ablation lines created in attempts to cure atrial fibrillation with ablation can promote atypical atrial flutter circuits in the left atrium (mitral isthmus flutter, etc). Left atrial flutters that arise after AF ablation procedures constitute a large fraction of atypical flutters. These circuits are usually right atrial, related to anatomic obstacles and surgical scars (cavotricuspid isthmus, right atriotomy scar, atrial septal defect repair, etc). Surgical repair of congenital heart disease may lead to macroreentrant atrial flutter circuits, both typical (cavotricuspid isthmus dependent) and atypical. This type of flutter can involve any region of the right or left atria, around areas of scar tissue due to intrinsic heart disease or surgical/ablated scar tissue (see "Electrocardiographic and electrophysiologic features of atrial flutter"). These ECG rules are generally less reliable after atrial ablation or surgery.Ītypical atrial flutter - If the CTI is not involved in the underlying mechanism, then it is called "atypical" atrial flutter. In clockwise circuits, the opposite is true. In counterclockwise circuits, flutter waves are directly negative in the inferior leads but are positive in lead V1. The ECG hallmark of typical atrial flutter is discordance in flutter wave "direction" between the inferior leads and lead V1. The clockwise circuit occurs far less frequently than the counterclockwise circuit rare patients exhibit both circuits at different times. If the circuit is clockwise, it is called "reverse" or "clockwise" typical flutter, exhibiting positive flutter waves in the inferior ECG leads ( image 1C). ![]() The circuit is usually a counterclockwise rotation around the tricuspid valve ( figure 2), exhibiting a classic sawtooth appearance in the inferior electrocardiogram (ECG) leads (II, III, aVF) ( image 1B). If this isthmus is involved, it is called "typical" atrial flutter or CTI-dependent atrial flutter. This isthmus is the region of right atrial tissue between the orifice of the inferior vena cava and the tricuspid valve annulus ( figure 2). Typical atrial flutter - The designation of "typical" atrial flutter involves a macroreentrant circuit traversing the cavo-tricuspid isthmus (CTI) ( figure 1). (See "Restoration of sinus rhythm in atrial flutter" and "Control of ventricular rate in atrial flutter" and "Atrial flutter: Maintenance of sinus rhythm" and "Embolic risk and the role of anticoagulation in atrial flutter".)ĮLECTROPHYSIOLOGIC CLASSIFICATION - Atrial flutter was previously classified as either type I or type II. ![]() Other topics discuss management issues in detail. This topic will summarize key points regarding the causes, clinical presentation, diagnosis, and management approach to patients with atrial flutter. (See "Epidemiology, risk factors, and prevention of atrial fibrillation".) It may also be associated with a variety of other supraventricular arrhythmias. Atrial flutter may be a stable rhythm or a bridge arrhythmia between sinus rhythm and atrial fibrillation, or an organized rhythm in atrial fibrillation patients treated with antiarrhythmic drugs. It can lead to symptoms of palpitations, shortness of breath, fatigue, or lightheadedness, as well as an increased risk of atrial thrombus formation that may cause cerebral and/or systemic embolization.Ītrial flutter occurs in many of the same situations as atrial fibrillation, which is much more common. INTRODUCTION - Atrial flutter is an abnormal cardiac rhythm characterized by rapid, regular atrial depolarizations at a characteristic rate of approximately 300 beats/min and a regular ventricular rate of about 150 beats/min in patients not taking atrioventricular (AV) nodal blockers.
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