Optimizing the Reconstruction of Cardiac Potentials Using a Novel High Resolution Pericardiac Cage

Jake Bergquist, Wilson Good, Brian Zenger, Jess Tate, Rob MacLeod
University of Utah


Introduction: Experimental preparations in which cardiac and torso recordings are made simultaneously typically do not have uniform sampling around the entire surface of the heart. To fill in the resulting gaps in coverage, signals captured from the sampled region are extended to the unsampled region of the heart before being utilized in computational models. The resulting errors have never been evaluated systematically. We explored this relationship using a novel experimental preparation, and compared the resulting measurements against a set of interpolation and optimization methods.

  Methods: Measurements came from a modified Langendorff preparation in
  which we placed a rigid, heart shaped pericardiac cage electrode array
  around an isolated canine heart within an electrolytic
  torso-tank. Using the measured cage potentials we optimized a
  reconstruction from the subset of the cage below the base of the heart
  (ventricular) to the subset above it (atrial). This optimization
  minimized the difference between the reconstructed and measured
  signals. We then compared the reconstruction to a spatial Laplacian
  interpolation of the same potentials.

  Results: Qualitative results show a high degree of agreement between
  optimized reconstructed potentials and measured potentials whereas the
  Laplacian interpolation resulted in poorer reconstructions in most
  cases. Calculated mean and maximum error were lower for optimization
  based approaches than spatial Laplacian interpolation.

  Discussion: In this study we aimed to utilize novel pericardiac cage
  recordings to investigate interpolation strategies from sampled signals
  to unsampled signals. We demonstrate that the sampled ventricular
  subset of signals is sufficient to reconstruct the atrial subset but
  that Laplacian interpolation does not achieve the level of accuracy
  that is possible.