Introduction: Ablation procedures require accurate mapping of cardiac elec-trical activation to locate ectopic foci and reentrant pathways. Phase maps offer a complementary approach to conventional mapping, enabling the identification of reentry patterns in complex arrhythmia through the compu-tation of the instantaneous phase (IP) of cardiac signals. In this study, we propose the application of the Sinusoidal Recomposition (SR) method to reconstruct the IP from electrical and optical signals obtained from Langen-dorff-perfused rabbit hearts under atrial fibrillation (AF), ventricular tachy-cardia (VT), and ventricular fibrillation (VF). The resulting phase maps from SR were compared to those obtained by directly applying the Hilbert Transform (HT), focusing on the detection of rotors.
Methods: Data were obtained from isolated rabbit hearts under Langendorff perfusion. Electrical signals were recorded from three 4×4 microelectrode arrays positioned in the atria and ventricle, while optical signals were cap-tured by three high-speed cameras (500 fps) placed around the heart. Elec-trical and optical signals were filtered to remove baseline drift, noise, and powerline interference. IP was computed using both HT and SR methods. In the SR approach, signals were reconstructed using sinusoids based on the dominant frequency (3–12 Hz range), followed by phase calculation aligned with depolarization events. Phase maps were constructed in 2D (electrical) and 3D (optical) for-mats. Rotors were identified and quantified by their spatial rotation patterns and duration.
Results: In AF, HT highlighted unstable and transient rotors (n=9, average duration: 3 s). In VT, SR agreed with HT, identifying 37 rotors (average duration: 2.6 s). In VF, SR provided more segmented phase maps, improving rotor visualization (n=24, avg. 3.61 s) and highlighting better pattern organ-ization.
Conclusion: The overall similarity between the SR and HT maps in VF sup-ports previous findings that favor direct IP analysis in conditions where signals present more regular morphology.