Arrhythmias & electrophysiology
High-density mapping of upper loop macroreentry surrounding the superior vena cava: Substrate-evolved ablation strategy
Authors' conclusion
A surgical incision/scar extending from the SVC to right atrium promotes the development of SVC-AFL. Substrate-based linear lesions along with prophylactic cavotricuspid isthmus ablation afford favorable clinical outcomes.
Study context
- Population
- Patients with macroreentrant atrial tachycardias with upper loop macroreentry atrial flutter surrounding the superior vena cava (SVC-AFL), June 1, 2017, to May 1, 2023patients with SVC-AFL, of 1282 patients with macroreentrant atrial tachycardias (ATs)
- Participants
- 16 patients
- Comparison
- SVC-AFLs with shorter circuits vs those with longer circuits
- Outcome
- SVC-AFL among patients with macroreentrant ATs
Methodological detailsconsecutive patients, 7 institutions, high-resolution mapping
- Consecutive patients
- 7 institutions
- High-resolution mapping
Main finding
As reported in the abstract
Patients with SVC-AFL
16 patients (1.2%
Median age
60.9 years
Male
8
Mean cycle length
281.0 ± 55.1 ms
Further findings
| Outcome | Shorter circuits | Longer circuits |
|---|---|---|
| Slow conduction areas | 3.0 (range 2.0–4.0) | 1.0 (range 1.0–1.5) |
- Slow conduction areas: more slow conduction areas with shorter circuits; P = .023
Prior cardiac surgery or catheter ablation
- Prior cardiac surgery
- 14 [87.5%]
- Catheter ablation
- 8 [50.0%]
Longitudinal surgical incision/scar extending from the superior vena cava (SVC) to the right atrium
- Observed in all patients, enabling macroreentry
AT termination
- All ATs were terminated by ablating the channel between the surgical incision/scar and anatomic barriers
- Cavotricuspid isthmus block was achieved in all patients
Freedom from atrial arrhythmias · 21-month follow-up
- Short-lived paroxysmal ATs that did not require further ablation
- 4 patients
- All other patients free of atrial arrhythmias
Original publication
High-density mapping of upper loop macroreentry surrounding the superior vena cava: Substrate-evolved ablation strategy. Heart Rhythm. Published 3 April 2025. doi:10.
Summarised from the published abstract; every number is checked against it