Fig. 1.

Location of implanted myocardial markers and epicardial pacing sites in the canine left ventricle. Intramyocardial gold beads were implanted at the anterolateral left ventricle, between diagonal branches of the left anterior descending (LAD) artery. Surface epicardial beads were sewn at the entrance of each transmural column and at the apex and base of the heart, defined by the bifurcation of the LAD and circumflex (CCX) arteries. Bipolar pacing electrodes were positioned at the right ventricular apex (not shown) and at five left ventricular epicardial sites: anterior apical (A), anterior basal (B), anterior midventricle (C), lateral (D), and posterior basal near the coronary sinus (E). AoV, aortic valve; MV, mitral valve.