Pulmonary vein isolation without fluoroscopy: results evaluation

Introduction

From the outset, the use of Xray (XR) has been a critical component in both the guidance and development of arrhythmia ablation procedures. At present however, due to the complex nature of electrophysiology procedures, the use of XR in isolation is not sufficient to ensure procedural success. Subsequently, the use of non-fluoroscopic virtual mapping systems is essential. Currently, given the evolution of this technology and its essential nature for procedural guidance, it is worth asking whether the use of XR is indeed still necessary in the modern era. The objective of this study was to demonstrate that “zero-XR” ablation of complex arrhythmias such as atrial fibrillation is both possible and safe.

Methods

Between 2020 and 2021, a total of 116 patients admitted for pulmonary vein ablation were included in the study. Amongst these, 41 patients were prospectively included at our centre, in a protocol for point-by-point ablation of pulmonary veins without fluoroscopy, “zero-XR”. In addition to the non-fluoroscopic mapping system, the transseptal puncture was monitored by intracardiac ultrasound in all cases. The objective of the ablation was the complete isolation of the pulmonary veins. In some patients, at the discretion of the operator, the ablation of other substrates was added. For the remaining 75 patients in the study, the ablation was performed using conventional techniques without the limitation of the use of XR. The mean follow up was 12 months.

Results

The baseline characteristics of the patients, as well as the description of the procedure, are shown in the Table. There were no differences in the acute success rate or procedure time between the two groups. There was only one complication related to the procedure in the non-XR group consisting of pericardial effusion without cardiac tamponade. Regarding the recurrence rate at 12 months, it was higher in the group with fluoroscopy, without reaching statistical significance [n=0 in the group without fluoroscopy, n=2 (2.7%) in the group with fluoroscopy, p=0.15].

Conclusion

In our series, point-by-point ablation of atrial fibrillation without fluoroscopy proved to be a safe and feasible technique, with similar success rates when compared to conventional procedures using XR.

Funding Acknowledgement

Type of funding sources: None.

Usefulness of unipolar electrograms to detect isthmus block after radiofrequency ablation of typical atrial flutter

BACKGROUND

RS morphology of the unipolar electrogram is associated with propagation of the wave front through the exploring electrode, whereas positive uniphasic (R) unipolar electrograms are characteristic of the end of activation.

METHODS AND RESULTS

Unipolar electrograms were recorded in 45 consecutive patients with atrial flutter who were undergoing radiofrequency ablation (RFA). Bidirectional cavotricuspid isthmus (CTI) block was achieved in 44 patients. The unipolar electrogram obtained before RFA at the low anterolateral right atrium during coronary sinus pacing changed from RS, rS, or QS to R or Rs in all patients after clockwise CTI block was obtained. The morphology of unipolar electrograms recorded close to the coronary sinus during pacing from the low anterolateral right atrium changed from RS or rS to R or Rs in all but 4 patients after counterclockwise CTI block. In the patient in whom CTI block was not achieved, the RS morphology of the unipolar electrogram remained unchanged. In 18 patients, the results of the RFA were assessed with only the unipolar electrogram. The unipolar electrogram correctly predicted 100% and 89% of the cases of clockwise and counterclockwise CTI block, respectively.

CONCLUSIONS

The creation of CTI block is associated with an easily detectable loss of negative components and development of an R or Rs pattern of the unipolar electrogram recorded close to the ablation line while pacing at the opposite side of the CTI.