isthmus-dependent flutter
A type of atrial flutter where the reentrant circuit travels around the tricuspid annulus through the cavotricuspid isthmus.
Full Definition
Isthmus-dependent atrial flutter, also known as typical atrial flutter, is characterized by a large macroreentrant circuit in the right atrium that travels around the tricuspid valve annulus. The circuit typically proceeds counterclockwise (when viewed from the atrial septum) through the cavotricuspid isthmus, a narrow band of tissue between the tricuspid valve and inferior vena cava. This creates the classic sawtooth flutter waves on ECG with a cycle length of approximately 200-250 milliseconds. The arrhythmia can be curatively treated by creating a line of conduction block across the cavotricuspid isthmus using radiofrequency ablation.
Usage
Usage note: Hyphenate 'isthmus-dependent'; CTI (cavotricuspid isthmus) abbreviation acceptable in technical contexts.
In Context
- "Successful cavotricuspid isthmus ablation terminated the patient's isthmus-dependent flutter." — Ablation procedure report
- "The diagnosis of isthmus-dependent flutter was confirmed by entrainment mapping from the cavotricuspid isthmus." — EP study findings