Atrial flutter most commonly occurs in a reentrant circuit around the tricuspid valve — typical atrial flutter or type I. Ablation for this rhythm is easy since it requires only venous access to get to the right heart. A CTI line — or cavo-tricuspid isthmus line — is placed to interrupt the reentrant circuit. Success rate is high and complication risk is low.
Atrial flutter ablation can be utilized as an initial rhythm control strategy instead of antiarrhythmic drugs since this procedure is low risk with a high success rate, unlike that of atrial fibrillation where success rates vary and there is a higher complication risk. See the comparison chart below:
Atrial Fibrillation Ablation
Atrial Flutter Ablation
Originates from pulmonary veins*
Transseptal puncture required
Higher complication risk
Variable success rates**
Antiarrhythmic drugs used first
Originates from tricuspid annulus*
No transseptal puncture required
Lower complication risk
Consistently high success rate
Ablation commonly used first
*Less commonly, atrial fibrillation originates from the right atrium including the superior vena cava or coronary sinus. Atypical atrial flutter may originate from left atrium on occasion; however, it is less common.
**Duration of atrial fibrillation and left atrial volume is main determinant of success rates