title: Ultrasound current source density imaging of the cardiac activation wave using a clinical cardiac catheter.
abstract: Ultrasound current source density imaging (UCSDI), based on the acoustoelectric (AE) effect, is a noninvasive method for mapping electrical current in 4-D (space + time). This technique potentially overcomes limitations with conventional electrical mapping procedures typically used during treatment of sustained arrhythmias. However, the weak AE signal associated with the electrocardiogram is a major challenge for advancing this technology. In this study, we examined the effects of the electrode configuration and ultrasound frequency on the magnitude of the AE signal and quality of UCSDI using a rabbit Langendorff heart preparation. The AE signal was much stronger at 0.5 MHz (2.99 μV/MPa) than 1.0 MHz (0.42 μV/MPa). Also, a clinical lasso catheter placed on the epicardium exhibited excellent sensitivity without penetrating the tissue. We also present, for the first time, 3-D cardiac activation maps of the live rabbit heart using only one pair of recording electrodes. Activation maps were used to calculate the cardiac conduction velocity for atrial (1.31 m/s) and apical (0.67 m/s) pacing. This study demonstrated that UCSDI is potentially capable of real-time 3-D cardiac activation wave mapping, which would greatly facilitate ablation procedures for treatment of arrhythmias.
authors.forename: Yexian
authors.initials: Y
authors.lastname: Qin
authors.forename: Qian
authors.initials: Q
authors.lastname: Li
authors.forename: Pier
authors.initials: P
authors.lastname: Ingram
authors.forename: Christy
authors.initials: C
authors.lastname: Barber
authors.forename: Zhonglin
authors.initials: Z
authors.lastname: Liu
authors.forename: Russell S
authors.initials: RS
authors.lastname: Witte
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000465:Algorithms; D000818:Animals; D006328:Cardiac Catheterization / Q000379:methods*; D006329:Heart Conduction System / Q000000981:diagnostic imaging / Q000502:physiology*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods*; D066298:In Vitro Techniques; D009431:Neural Conduction / Q000502:physiology; D011817:Rabbits; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014463:Ultrasonography / Q000379:methods*