Estimation of global ventricular activation sequences by noninvasive three-dimensional electrical imaging: Validation studies in a swine model during pacing

Estimation of Global Ventricular Activation Sequences. Background: A novel noninvasive imaging technique, the heart-model-based three-dimensional cardiac electrical imaging (3DCEI) approach was previously developed and validated to estimate the initiation site (IS) of cardiac activity and the activation sequence (AS) from body surface potential maps (BSPMs) in a rabbit model. The aim of the present study was to validate the 3DCEI in an intact large mammalian model (swine) during acute ventricular pacing. Methods and Results: The heart-torso geometries were constructed from preoperative magnetic resonance (MR) images acquired from each animal. Body surface potential mapping and intracavitary noncontact mapping (NCM) were performed simultaneously during pacing from both right ventricular (RV) (intramural) and left ventricular (LV) sites (endocardial). Subsequent 3DCEI analyses were performed from the measured BSPMs. The estimated ISs were compared with the precise pacing locations and estimated ASs were compared with those recorded by the NCM system. In total, five RV and five LV sites from control and heart failure (HF) animals were paced and sequences of 100 paced beats were analyzed (10 for each site). The averaged localization error (LE) of the RV and LV sites were 7.3 ± 1.8 mm (n = 50) and 7.0 ± 2.2 mm (n = 50), respectively. The global 3D ASs throughout the ventricular myocardium were also derived. The endocardial ASs as a subset of the estimated 3D ASs were consistent with those reconstructed from the NCM system. Conclusion: The present experimental results demonstrate that the noninvasive 3DCEI approach can localize the IS and estimate AS with good accuracy in an in vivo setting under control, paced, and/or diseased conditions.