Cardiac MR (CMR) in Cardiac Resynchronization Therapy Non-responders

Cardiac MR (CMR) in Cardiac Resynchronization Therapy (CRT) Non-responders: Therapy Optimization by Means of Tissue Characterization, Hemodynamic Analysis and Analysis of Myocardial Activation

Cardiac MR (CMR) will be used to assess myocardial activation and hemodynamics in patients with CRT.

Goals are to demonstrate that

• differences in Left ventricle (LV)- right ventricle (RV) pacing delays cause differences in myocardial activation
• differences in LV-RV pacing delays cause differences in LV/RV hemodynamics

and to use these data to optimize CRT.

CMR will be performed in patients under CRT who are currently not responding to CRT. Different LV-RV delays will be programmed during CMR and LV function and different dyssynchrony parameters will be assessed. Results will be used to determine the optimal LV-RV delay, and CRT-devices will be reprogrammed accordingly. Improvement in NYHA-class/conversion to therapy responder will be determined clinically after 3 months.

Inclusion Criteria:

• presence of CRT device
• CRT non responder

Exclusion Criteria:

• pregnancy
• end-stage renal failure