Evaluation of a near-zero fluoroscopic approach for catheter ablation in patients with congenital heart disease

Utilising electroanatomic mapping during ablation in patients with CHD to reduce radiation exposure

BACKGROUND

Patients with CHD can be exposed to high levels of cumulative ionising radiation. Utilisation of electroanatomic mapping during catheter ablation leads to reduced radiation exposure in the general population but has not been well studied in patients with CHD. This study evaluated the radiation sparing benefit of using three-dimensional mapping in patients with CHD.

METHODS

Data were retrospectively collected from the Catheter Ablation with Reduction or Elimination of Fluoroscopy multi-institutional registry. Patients with CHD were selected. Those with previous ablations, concurrent diagnostic or interventional catheterisation and unknown arrhythmogenic foci were excluded. The control cohort was matched for operating physician, arrhythmia mechanism, arrhythmia location, weight and age. The procedure time, rate of fluoroscopy use, fluoroscopy time, procedural success, complications, and distribution of procedures per year were compared between the two groups.

RESULTS

Fifty-six patients with congenital heart disease and 56 matched patients without CHD were included. The mean total procedure time was significantly higher in patients with CHD (212.6 versus 169.5 minutes, p = 0.003). Their median total fluoroscopy time was 4.4 minutes (compared to 1.8 minutes), and their rate of fluoroscopy use was 23% (compared to 13%). The acute success and minor complication rates were similar and no major complications occurred.

CONCLUSIONS

With the use of electroanatomic mapping during catheter ablation, fluoroscopy use can be reduced in patients with CHD. The majority of patients with CHD received zero fluoroscopy.

Fluoroscopy-free ablation in congenital heart disease of moderate or great complexity

BACKGROUND

Fluoroscopy-free (FF) ablation has been demonstrated to be safe and successful in patients with structurally normal hearts, but has not been systematically evaluated in patients with congenital heart disease (CHD) of moderate or great (M/G) complexity. This study aimed to evaluate and compare feasibility, safety, and outcomes of FF ablation in patients with or without M/G-CHD.

METHODS

Consecutive patients undergoing electrophysiologic study and intended catheter ablation over a 24-month period were included. Subgroups were created based on presence and complexity of CHD-M/G-CHD or simple complexity/no CHD (S/N-CHD). Cases with total radiation dose of zero qualified as FF. Demographic and peri-procedural variables and outcome data were analyzed.

RESULTS

A total of 89 procedures were included with 62 comprising the S/N-CHD group and 27 comprising the M/G-CHD group. Of the M/G-CHD patients, 13 had CHD of great complexity (including 6 single ventricle/Fontan and 2 atrial switch patients). Patients with M/G-CHD were older, had higher BMI, had higher incidence of ventricular dysfunction, and greater incidence of complex arrhythmias. Fluoroscopy-free ablation was achieved in 59% of M/G-CHD and 69% of S/N-CHD patients. Both groups had similar rates of acute procedural success, recurrence, and complications. Fluoroscopy was primarily used to visualize pre-existing transvenous leads and peripheral venous anomalies or to guide transbaffle/transseptal puncture.

CONCLUSIONS

A fluoroscopy-free ablation approach is feasible, safe, and successful even in patients with M/G-CHD with comparable outcomes to those with S/N-CHD.

Minielectrode catheter technology for near zero-fluoroscopy substrate-guided ablation of typical atrial flutter

Background

MicroFidelity catheter technology may facilitate voltage-guided ablation by high-resolution electroanatomic mapping (HR-EAM) and precisely targeted energy application.

Objective

To evaluate the performance of minielectrode (ME) technology for zero-fluoroscopy substrate-guided cavotricuspid isthmus (CTI) ablation.

Methods

Eighty-two patients underwent near zero-fluoroscopy substrate-guided CTI ablation using a nonirrigated large-tip catheter with 3 MEs. The CTI was subdivided into 15 electroanatomic segments. Bipolar voltage maps were compared with ME signals. The outcome was compared with a historic cohort of 92 patients who underwent linear ablation.

Results

Compared with linear ablation, the substrate-guided approach was associated with an almost halved ablation duration (336 ± 228 vs 649 ± 409 seconds, P < .001), halved radiofrequency energy applied (14.2 ± 10.6 vs 28.6 ± 19.6 kJ, P < .001), and shorter procedure duration (60.8 ± 33.8 vs 76.3 ± 40.9 minutes, P = .008) limiting the extent of energy delivery to 22.7% of the CTI area. HR-EAM visualized 2.03 ± 0.88 conductive pathways with a diameter of 5.35 ± 1.98 mm. A higher number of ME-detected bundles and a larger channel diameter correlated with increased ablation requirements. In 97.6% of the voltage-guided and 88.0% of the linear procedures, fluoroscopy was not used.

Conclusion

HR-EAM-based substrate-guided CTI ablation may improve procedural outcome compared with the linear approach. Enhanced identification of discrete conductive pathways correlates with ablation efficacy. The electroanatomic subdivision of the CTI into 15 segments was feasible and may improve the understanding and comparability of anatomic variants and ablation results. Independent of the ablation strategy, modern EAM technology enables safe zero-fluoroscopy procedures in the majority of cases.

Utility and feasibility of the CartoUnivu™ system for atrial flutter ablation in patients with mechanical prosthetic valves

Ablation of macroreentrant atrial tachycardia in patients with mechanical prosthetic valves represents a challenge for electrophysiologists, because of the complexity of the procedure and the potential complications. Moreover, the need for fluoroscopy in this type of procedure is greater, due to the risk of interference between the prosthetic valve and the ablation or mapping catheter. We present two cases of patients with mechanical prosthetic valves and atrial flutter who underwent successful ablation with no complications using the CartoUnivu™ tool, which integrates the electroanatomical map and the fluoroscopy image.