Imaging Study of Allocation of Pacing Targets in Cardiac Resynchronization Therapy

MRI Allocation of Pacing Targets in Cardiac Resynchronization Therapy

This randomized controlled trial will assess a cardiac MRI derived 4D digital cardiac model to optimized left and right ventricular lead delivery to improve response to cardiac resynchronization therapy.

Regional mechanical delay, myocardial scar, and inter-lead distance have each been demonstrated to be relevant variables for the realization of optimal response to cardiac resynchronization therapy (CRT). Pilot study results have suggested clinical feasibility and potential value from LV and RV lead navigation aimed at optimizing these combined variables. A computer software program has been developed to deliver an interactive, 4D digital heart model of mechanical dyssynchrony and myocardial scar to guide LV and RV CRT lead delivery to optimal targets. This multi-center randomized clinical trial has been designed to assess the feasibility, safety and clinical impact of LV-RV lead navigation using a web-deployed 4D cardiac model.

Inclusion Criteria:

1. Age ≥ 18 years.
2. Ejection fraction ≤ 35 %.
3. LBBB with QRS duration ≥ 120 msec.
4. NYHA class II-IV.
5. On maximum tolerated heart failure medication therapy ≥ 6 weeks.
6. Clinically accepted for CRT device implantation.

Exclusion Criteria:

1. Failure to provide consent.
2. CCS class III-IV angina.
3. Recent Q-wave myocardial infarction or revascularization procedure ( ≤ 3 months).
4. Atrial fibrillation at time of randomization >6 weeks in duration
5. Standard contra-indications to MRI.
6. Documented severe allergy to intravenous contrast dye ( iodinated CT contrast or Gadolinium MRI contrast).
7. Estimated Glomerular Filtration Rate (eGFR) ≤ 45 ml/min/m2.
8. Patient is pregnant.