Body surface mapping during endocardial pacing at multiple left ventricular sites: QRS variability in patients with prior myocardial infarction

Correlations between cardiac imaging and electrophysiological studies: what is the state of the art?

Changes in ventricular activation produced by bundle branch block, pre-excitation, and ventricular tachycardia and pacing have been studied by various cardiac imaging modalities. We reviewed results of previously published and newly generated imaging data correlated with known or measured electrophysiological studies. Echocardiography has been demonstrated to grossly correlate with abnormal ventricular wall motion when activation sequence was altered. However, phase analysis of radionuclide and cine-computed tomography have provided detailed noninvasive activation data that correlated reasonably well with measured electrical activation sequence in both animals and man. Analysis of wall motion may not predict activation sequence when muscle is damaged or excessive translational movement of the heart occurs. Body surface mapping of electrical potentials has the capability to accurately but noninvasively register an electrical activation image of the heart that circumvents the problems of imaging contraction sequence. In the future, body surface potential mapping should be more widely used clinically and experimentally.