Non-invasive determination of the activation sequence of the heart: validation by comparison with invasive human data

During cardiac surgery epicardial electrograms were recorded. From these electrograms epicardial activation maps were constructed. Prior to surgery the ECG at the body surface was measured. For each subject an individual volume conductor model was constructed based on MR images. The UDL source model was used to compute the epicardial activation times from the recorded ECGs. The compute activation times were compared to the measured ones. The overall pattern of the activation sequence found by the UDL corresponds well to the actual activation pattern. Epicardial breakthroughs and regions of late activation that were seen in the measured data, occurred at similar sites in the computed data