Optimization of Cardiac Resynchronization Therapy: Echocardiographic vs Semiautomatic Device Algorithms

Large evidence supports the importance of individualized optimization of cardiac resynchronization therapy in patients with congestive heart failure. The aim of this study was to compare a recently developed intracardiac electrogram (IEGM)-based method with the Doppler echocardiographic (ECHO)-based method to calculate optimal atrioventricular (AV) and interventricular (VV) delays. Ten male patients implanted with a St Jude Medical resynchronization device received AV and VV delay assessment with both the IEGM and the ECHO-based methods. Estimates of the optimal AV and VV delays assessed by the 2 tested methods proved highly comparable. No difference emerged between the IEGM (126.8+/-22.7) and the ECHO (127.3+/-19.8) AV delay values (P=.987). The VV delay suggested by ECHO was highly significantly correlated with the delays calculated by the IEGM method (35+/-27.6 vs 21.31+/-24.31; r(2)=0.78; P<.001). These preliminary data support the evidence that an IEGM based cardiac resynchronization optimization method may be as reliable as a complete ECHO assessment.