Ablation of Human Cardiac Fibrillation Based on Models of Hierarchical Organization of Tissue Excitation

Primary outcomes

1. Mapping for the identification of stable reentrant domains with high activation frequency in persistent AF.

   Time frame: During procedure

   After performing cardiac CT, non-invasive mapping will be performed using ECGi non-invasive map system. The signals will be analyzed for real-time inverse solution calculations using proprietary spectral fingerprint identification algorithms (Calvo D et al. Sci Rep. 2025 Dec 16;15(1):43892). In particular, non-invasive mapping will provide the fibrillation signal from both atria for the implementation of the calculations necessary for the spectral fingerprint study. The instantaneous phase will be computed by two methods: (i) by Hilbert transformation of the signal; and (ii) by phase calculation on the discrete frequencies identified in the power spectrogram. On the other hand, invasive mapping will be used to process bipolar and unipolar cardiac signals in order to analyze hierarchically organized patterns.

2. Effects of ablation of DFSAI > 0.8 domains on fibrillation dynamics and sustainability

   Time frame: During procedure

   • In patients in the active group, changes in fibrillation dynamics induced by CPVI and ablation of DFASI domains will be evaluated, as suggested by our preliminary results (Calvo D et al. Sci Rep. 2025 Dec 16;15(1):43892). Therefore, an experimental protocol will be carried out in which, after CPVI, each DFASI domain will be addressed sequentially. The following will be determined: a) changes in hierarchical organization levels, b) the formation of new DFASI domains; c) if AF ends after ablation, the termination mechanisms will be described. Once all ablation sets on the identified DFASI reentrant domains have been completed, noninvasive maps will be acquired under the effect of adenosine in order to compare fibrillatory dynamics under basal adenosine vs. post-ablation.
   • In patients in the control group, once CPVI is completed new noninvasive maps will be acquired to characterize basal and adenosine-induced fibrillatory dynamics.

3. Effects of ablation of reentrat domains of human ventricular fibrillation on arrhythmia inducibility.

   Time frame: Procedure

   Adapt the model to patients with ventricular arrhythmias such as polymorphic ventricular tachycardia and/or VF. After performing a cardiac CT scan, non-invasive mapping will be performed using ECGi non-invasive map system. The signals will be analyzed for real-time inverse solution calculations using algorithms for identifying reentrant domains and their correlation with hierarchical organization patterns (Calvo D et al. Sci Rep. 2025 Dec 16;15(1):43892). To this end, VF will be induced by programmed stimulation on two occasions in order to identify the hierarchical organization of the stability of rotational activity in terms of frequency. Ablation will follow and inducibility tested as measurement of efficacy.

4. Arrhythmia burden during Follow-up

   Time frame: 3, 6 and 12 months follow-up visits

   A subcutaneous Holter monitor will be implanted one month prior to the ablation procedure to mesure arrhythmia burden (Atrial fibrillation; number of recurrences and hours per day). Patients will be monitored continuously after the ablation procedure using remote subcutaneous Holter monitoring platforms and in person at cardiology consultations at 3, 6, and 12 months, at a minimum.

   Patients with VF ablation will be followed up after the ablation procedure on an ongoing basis using implantable defibrillator remote monitoring platforms and in person at cardiology consultations at least 3, 6, and 12 months after the procedure. The arrhythmia burden will be measure as a function of number of recurrences per follow-up time.