Cardiac action potential wavefront tracking using optical mapping

Abstract

A wealth of knowledge is available about the effect of diabetes on the heart but very little has been done to quantify the conduction velocity of the diabetic heart. This study intends to develop a technique for tracking the cardiac wavefront across the heart in order to achieve the total activation time as well as the conduction velocity of the heart at any point during its activation, to compare the newly determined activation times with previously determined activation times, and to also compute the average conduction velocity of the heart from diabetic and control rats. The technique developed for tracking the action potential wavefront across the heart extracts the wavefront and provides the activation time as well as the conduction velocity - both instantaneous and average - successfully. The method reproduces previously measured activation times well, with a correlation of R(2) = 0.875, which suggests that this technique is reliable and that its determination of conduction velocity will allow for the examination of healthy and diseased hearts using a new criterion. In addition, the method for determining the conduction velocity of the heart allows direct comparison of the baseline conduction velocity in control and diabetic hearts. The results of this comparison indicated that conduction velocity in the diabetic hearts is slower (0.47 +/- 0.02 m/s) than in control hearts (0.55 +/- 0.02 m/s) (p = 0.001).