Ultrasound Current Source Density Imaging using a clinical intracardiac catheter

Radiofrequency catheter ablation for treatment of cardiac arrhythmia requires pre-surgical mapping of the heart´s activation wave. However, modern cardiac mapping systems continue to suffer from significant limitations. We have proposed Ultrasound Current Source Density Imaging (UCSDI) as a new modality to map reentry currents in the heart. In this study, we focus on interfacing UCSDI with a clinical intra-cardiac catheter - a key step towards translating UCSDI to the clinic for guiding cardiac ablation therapy. Sensitivity of UCSDI combined with the catheter was tested in a tissue mimicking phantom and fresh excised porcine hear tissue. Effect of the recoding distance on the detection of UCSDI was also investigated. Sensitivity of UCSDI with catheter was 4.7 μV/mA (R² = 0.999) in cylindrical gel (0.9% NaCl), and 3.2 μV/mA (R² = 0.92) in porcine heart tissue. The AE signal was detectable more than 25 mm away from the source in cylindrical gel (0.9% NaCl).