Cavotricuspid Isthmus Dependent Atrial Flutter
Conditions
Brief summary
Pulsed field ablation (PFA) has been demonstrated to be safe and effective in achieving pulmonary vein isolation in patients with atrial fibrillation (AF). Coexisting atrial flutter is common in patients with AF. It is therefore appealing to treat the atrial futters with PFA. The use of PFA for extra-pulmonary ablation, such as linear ablation at the mitral or cavo-tricuspid isthmus (CTI) has been investigated. When PFA is applied near a coronary vessel, acute coronary spasm is a common observation, which has been reported to be reversible and largely mitigated by pre-emptive intravenous or intracoronary nitroglycerine (TNG) injection. A recent clinical study based on qualitative coronary angiogram reported no apparent coronary stenosis 6 months after PFA. However, quantitative measurements were not provided. While acute conduction block is easy to create with pulsed field ablation catheters, the long-term lesion durability is unknown. The circular array pulsed field ablation catheter was shown to be safe and effective in achieving pulmonary vein isolation. This study aims to evaluate the safety and efficacy of pulsed-field ablation for CTI flutters. This study will be a multicenter prospective cohort study involving 30 patients undergoing ablation for atrial fibrillation and CTI flutter. The decision for ablation will be a clinical decision based on existing class I and II guideline recommendations. The atrial fibrillation ablation procedure will be performed as per routine clinical practice. Procedure will be performed with a 3-D electro-anatomical system guidance. Pulmonary vein isolation (PVI) will be performed with pulsed field ablation with a circular array catheter (Pulse Select system, Medtronic). After confirming PVI, extrapulmonary ablation will be performed per clinically need. CTI ablation will be performed with PFA as planned. Patient will be managed by usual clinical care after ablation. They will come back for follow up at 3 months for a remapping procedure. During the remapping procedure, a RCA coronary angiogram will be performed to exclude late coronary damage. A multipolar catheter will be inserted via right femoral vein to check for conduction block across CTI. If there is ongoing conduction, a repeat ablation will be performed with radiofrequency ablation.
Interventions
DEVICECTI ablation
CTI ablation will be performed with PFA. Before ablation, The RA geometry will be created with a multipolar catheter. Coronary angiogram will be performed at baseline in LAO 45 degree before and after each set of ablations. After ablation, a 15-minute waiting period will be mandated. The CTI block will be rechecked with 3D mapping system and multipolar catheter. If there is persistent CTI conduction, ablation will be repeated until CTI block is achieved. This will be followed by another 15 minutes of waiting period before rechecking the block across CTI, and so on. TNG will be prepared. It will be given via intracoronary route in 100-200mcg bolus if severe spasm is observed. If CTI block cannot be achieved with repeated PFA ablation, ablation with radiofrequency will be allowed to achieve block. Patient will come back for follow up at 3 months for a remapping procedure. During the remapping procedure, a RCA coronary angiogram will be performed to exclude late coronary damage.
Sponsors
Chinese University of Hong Kong
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 80 Years
Healthy volunteers
No
Inclusion criteria
1\. Patients with atrial fibrillation who are clinically planned to undergo AF ablation and atrial flutter ablation per guideline recommendations
Exclusion criteria
1. \>80 years old or \<18 years old 2. Known severe coronary artery disease 3. Prior history of atrial flutter or atrial fibrillation ablation 4. Refusal for remapping or coronary angiogram 5. Contraindication for coronary angiogram 6. Pregnancy 7. Expected life expectancy \<1 year 8. Inability to provide informed consent
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Rate of residual conduction | In 3 months follow up | Evaluate rate of residual conduction across CTI in 3-month remapping |
| Rate of coronary artery damage | In 3 months follow up | Evaluate rate of coronary artery damage in 3-month repeat coronary angiogram |
| Rate of acute severe coronary spasm | In 3 months follow up | Evaluate rate of acute severe coronary spasm induced by PFA (\>70% diameter reduction or ST change) |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Rate of successful acute conduction block in all patients (with PFA or PFA + RFA) | In ablation procedure | Evaluate rate of successful acute conduction block in all patients (with PFA or PFA + RFA) |
| Rate of clinical recurrence of atrial arrhythmia | In 3 months follow up | Evaluate rate of clinical recurrence of atrial arrhythmia at 3 months |
| Number of mapping points in right atrium in electroanatomic system | In mapping procedure | Evaluate number of mapping points in right atrium in electroanatomic system |
| Number of PFA applications | In ablation procedure | Evaluate number of PFA applications required to achieve CTI block |
| Rate of successful acute conduction block by PFA alone | In ablation procedure | Evaluate rate of successful acute conduction block by PFA alone |
Countries
Hong Kong
Contacts
Primary ContactTsz Kin Mark Tam
Outcome results
None listed