Exit vs. entrance block testing for cardiac lesion assessment.

Cardiac lesions are created to act as barriers which prohibit the transmission of cardiac myocyte contractile activity from one side of the lesion to the other. Testing for conduction block is the main way to acutely confirm the effectiveness of this therapy. There are two general methods used to test for conduction block. These methods are called: 1) "exit block testing" and 2) "entrance block testing." In this study, two different devices were used on n = 5 swine to determine if the method of lesion assessment (exit vs. entrance block testing) affected the ability to correctly identify if acute conduction block was achieved. No significant difference was found between conclusions drawn from either method of lesion assessment. However, the most robust lesion assessment will occur when both methods are employed so that the physician has the most information available for analysis.