Noninvasive Imaging of Three-dimensional Ventricular Activation Sequence in a Rabbit Model

Noninvasive imaging of ventricular activation is of great importance in cardiovascular research and clinical diagnosis of cardiac diseases. Three-dimensional (3-D) cardiac activation imaging (3-DCAI) is a biophysical model based approach that aims at imaging the activation sequence throughout the entire myocardium. In the present study, the performance of 3-DCAI was evaluated through in vivo pacing experiments in a rabbit model. The distributed cardiac equivalent current density (ECD) was estimated and the local activation time within myocardium was determined as the latency with the peak amplitude of local ECD estimates. To allow for a rigorous evaluation, intramural bipolar recordings were measured simultaneously with the body surface potentials in a closed-chest situation. The encouraging results suggest that 3-DCAI can non-invasively image the activation sequence and localize the origin of activation with good accuracy.