Comparative assessment of right ventricular volumes and ejection fraction by thermodilution and magnetic resonance imaging in dilated cardiomyopathy.

Measurements of right ventricular (RV) ejection fraction (EF) and volumes using a new thermodilution technique were compared to serially performed magnetic resonance imaging (MRI) in 21 patients with dilated cardiomyopathy. For RVEF (%) and RV volume indices (ml/m2) the following correlation coefficients were found: RVEF r = 0.82; end-diastolic volume index (EDVI) r = 0.45; end-systolic volume index (ESVI) r = 0.65; stroke volume index (SVI) r = 0.61; all p < 0.05. However, RVEF by thermodilution was significantly lower (RVEF thermo = 31 +/- 14 vs. RVEF MRI = 50 +/- 14, p < 0.01) and RV EDV and ESVI were significantly higher compared to MRI, while SVI showed no significant difference. Exclusion of patients with atrial fibrillation (n = 8) improved the correlations (RVEF r = 0.94, EDVI r = 0.77, ESVI r = 0.87, SVI r = 0.65, all p < 0.05), but did not reduce the mean difference between both methods.