Aims: Ventricular fibrillation (VF) is a life-threatening arrhythmia treated by defibrillation. However, conventional protocols may cause myocardial injury due to high electric field (E) intensities. A promising alternative is multidirectional stimulation (applying stimuli in multiple directions in sequence), which can reduce E while preserving efficacy, but often requires one electrode pair per direction—limiting practicality. This study explores whether monodirectional stimuli in multiple directions can be generated using only two electrode pairs, as a step toward future multidirectional protocols.
Methods: Simulations were performed using COMSOL Multiphysics (v5.4) on an isolated rat heart model. We applied monodirectional electric fields of 3 V/cm—sufficient to stimulate the heart—in five different directions (0°, 30°, 45°, 60°, and 90°) by varying the value of the stimulus applied to each axis, using only two electrode pairs, based on the superposition principle.
Results: The simulations showed that E could be oriented accurately in all intended directions (0°, 30°,45°, 60°, and 90°) using only two electrode pairs and the superposition principle. The maximum E magnitude in the heart was approximately 5.5 V/cm when applying E = 3 V/cm —enough to stimulate cardiac cells without causing damage.
Conclusion: These results demonstrate that monodirectional stimulation in various directions can be achieved with a minimal electrode setup. This approach may serve as a building block for future multidirectional defibrillation strategies, offering a way to reduce the number of electrodes and minimize tissue injury while maintaining effectiveness.