Construction of a multipolar needle electrode for activation study of the heart

The study of transmural activation of the intact heart requires placement of multipolar needle electrodes through the wall of the beating heart. This report describes a method developed for constructing lightweight multipolar needles with 10-30 leads mounted 1 mm apart. The electrodes are constructed from readily available materials and no special equipment is required. The electrodes are well suited to the intraoperative mapping studies required to surgically correct arrhythmias.