In vivo acoustoelectric imaging for high-resolution visualization of cardiac electric spatiotemporal dynamics

Acoustoelectric cardiac imaging (ACI) is a hybrid modality that exploits the interaction of an ultrasonic pressure wave and the resistivity of tissue to map current densities in the heart. This study demonstrates for the first time in vivo ACI in a swine model. ACI measured beat-to-beat variability (n=20) of the peak of the cardiac activation wave at one location of the left ventricle as 5.32±0.74µV, 3.26±0.54mm below the epicardial surface, and 2.67±0.56ms before the peak of the local electrogram. Cross-sectional ACI images exhibited propagation velocities of 0.192±0.061m/s along the epicardial-endocardial axis with an SNR of 24.9 dB. This study demonstrates beat-to-beat and multidimensional ACI, which might reveal important information to help guide electroanatomic mapping procedures during ablation therapy.