| RHYTHM II |
|---|
| Comparison |
| Echo-optimized VV timing vs nominal VV settings |
| Results |
| No difference in QOL, NYHA or 6MW |
| DECREASE-HF |
| Comparison |
| Simultaneous VV pacing vs EGM optimized VV timing |
| Results |
| No difference in LV volumes or EF |
| FREEDOM |
| Comparison |
| Clinically optimized AV and VV timing vs serial EGM optimized AV and VV timing |
| Results |
| No difference in clinical outcomes or functional measures |
| CLEAR |
| Comparison |
| Echo optimized AV and VV timing vs automatic adjustment of AV delays via contractility sensor |
| Results |
| Improved clinical response with the contractility sensor |
| SMART AV |
| Comparison |
| Echo optimized AV and VV timing vs EGM optimized AV and VV timing vs fixed AV (120 ms) and VV (0 ms) |
| Results |
| No difference in LV volumes, EF, or functional measures |
AV, atrioventricular; CLEAR, Clinical Evaluation on Advanced Resynchronization; DECREASE-HF, Device Evaluation of CONTAK RENEWAL 2 and EASYTRAK 2: Assessment of Safety and Effectiveness in Heart Failure; EF, ejection fraction; EGM, electrogram; FREEDOM, Frequent Optimization Study Using the QuickOpt Method; LV, left ventricular; 6MW, 6-minute walk; NYHA, New York Heart Association; QOL, quality of life; RHYTHM II, Resynchronization for Hemodynamic Treatment for Heart Failure Management II; SMART-AV, SmartDelay Determined AV Optimization: A Comparison of AV Optimization Methods Used in Cardiac Resynchronization Therapy; VV, interventricular.
Modified from Exner et al. with permission from Elsevier