Congenital heart diseaseResearch article
Electrophysiological Mechanisms of Typical Atrial Flutter After Atrial Switch Operation: Critical Role of the Septal Corridor
- Twenty consecutive patients with prior atrial switch surgery referred for atrial flutter ablation
- transbaffle puncture and high-density mapping
Authors' conclusion
In patients with dextro-transposition of the great arteries corrected by atrial switch, surgical incisions define posterior boundaries and create a narrow septal corridor, or baffle-tricuspid isthmus, characterized by slow conduction and a propensity for functional block. These anatomic and electrophysiological features likely underlie the high prevalence of peritricuspid reentry in this population, representing a ubiquitous critical substrate for arrhythmia initiation and maintenance. Systematic cavotricuspid isthmus ablation should, therefore, be considered in these patients.
Study context
- Population
- Patients with dextro-transposition of the great arteries and prior atrial switch surgery referred for atrial flutter ablation
- Participants
- Twenty consecutive patients
Main finding
As reported in the abstract
- In all cases of peritricuspid atrial flutter, surgical incisions defined the posterior boundary of the circuit
- Narrowest segment of the reentry consistently located within a septal corridor bounded posteriorly by the baffle incision and anteriorly by the tricuspid annulus
Further findings
Slow conduction (<30 cm/s) in the septal corridor
- of peritricuspid flutters
- 92%
- of patients during sinus or paced rhythm
- 85%
Low-voltage areas
- Low-voltage areas were limited and frequently colocalized with regions of slow conduction
- No patient exhibited slow conduction or low voltage at the cavotricuspid isthmus
Septal corridor involvement in nonperitricuspid reentrant atrial tachycardias
- of nonperitricuspid reentrant atrial tachycardias
- 60%
Programmed atrial stimulation with S2 mapping
- Accentuated conduction delay in this region, with demonstration of functional block and induction of atrial flutter
Original publication
Summarised from the published abstract; every number is checked against it