A Novel In Vitro Testing Approach for the Next Generation of Transvenous Cardiac Leads: Buckling Behavior

Abstract

Manufacturers are constantly seeking to design new, better performing transvenous cardiac leads to prevent perforation of the heart by the lead tip. Currently, there is no standardized test method to measure the buckling load of leads, a major factor in the propensity of the lead to perforate the heart. This study further investigates the effect of boundary conditions on buckling loads at the lead tip of different transvenous cardiac leads achieved using different variations of our initial physiologically relevant test method. The goals of the test are to create the maximum buckling load with high repeatability and the simplest possible design. A buckling test was performed to capture maximum buckling load using three leads of each model (five currently available cardiac lead models) and were tested in each of six test setups. The buckling test methodology had a substantial effect on the load-displacement profiles, regardless of whether the lead was a pacemaker or defibrillator lead. By adding the right ventricular (RV) constraint, the buckling load more than doubled for most leads. The use of a lubricant reduced friction between the lead body and the RV surface, and thereby subsequently lowered the buckling load in those setups that used the RV constraint. In addition, the use of the lubricant reduced the variability in the results. The addition of both the RV constraint and the lubricant substantially influences the mechanical behavior of transvenous cardiac leads and is recommended for buckling testing of transvenous cardiac leads.