Abstract 16452: Safety and Diagnostic Yield of Cardiac MRI in Patients with ICD
Background: An increasing number of patients with ICD would benefit from cardiac MRI. However, MRI in general, and especially cardiac MRI is still considered contra-indicated and the artifacts can severely limit the imaging quality.
Methods: 24 consecutive patients (30 screened patients) with ICD underwent cardiac MRI to assess left ventricular scar including anatomic-dynamic (Cine Turbo Flash), perfusion (dynamic gradient echo) and delayed enhancement (DE) imaging (specific absorption rate of <2W/kg). Devices included single (n=9), dual (n=12) and biventricular devices (n=3) from all three major vendors (wireless telemetry: n=5). ICDs were interrogated immediately before and after as well as at follow-clinic visit and diagnostic yield assessed by experienced radiologist.
Results: Six screened patients were excluded due to epicardial lead (n=1), capped endocardial lead (n=3), renal dysfunction (n=2). MRI protocols were completed in 21 patients, with only partial scanning due to claustrophobia (n=3). Three pacemaker-dependent patients were programmed to VOO/DOO during MRI. Pre-MRI battery voltage (2.97±0.21V), atrial/ventricular sensing (3.3±2.1mV/9.7±5.1mV), atrial/ventricular impedance (484±79Ω/451±89Ω), shock impedance (45±8 Ω), atrial/ventricular capture (1.6±0.9V/1.4±0.9V) were unchanged at immediate and 72±23 days follow-up (p>0.05). Two patients underwent two cardiac MRIs (8/18days apart) and one patient three cardiac MRIs (2/24days apart) without change in ICD parameters. No complications were observed. Anatomic-dynamic and first-pass perfusion MRI demonstrated limited artifacts and allowed assessment of the septal/inferior/lateral/anterior wall regarding anatomic-dynamic (100%/100%/100%/82%) and perfusion (100%/100%/100%/91%) characteristics. Artifact was more pronounced especially in the anterior wall in DE sequences allowing full and partial assessment in 9±4 and 12±3 segments (17-segment model). MRI quality determined the presence, location and extent of LV scar in 91% of patients.
Conclusions: In this series cardiac MRI could be safely performed in selected ICD patients. MRI was able provide clinical helpful information in >90%.
- © 2010 by American Heart Association, Inc.