Background: Pressure-volume analysis is the gold standard for quantifying pump function of the right ventricle (RV); however, volume measurements based on a conductive catheter may be imprecise. The reference method for volume assessment is cardiac magnetic resonance (CMR).
Purpose: To determine the levels of agreement between RV volume measurements obtained by cine CMR, phase-contrast CMR (PC CMR), and a conductance catheter in an animal model.
Material and methods: CMR was performed in 20 sheep three months after pulmonary artery banding. Ejection fraction (EF), end-diastolic (EDV), end-systolic (ESV), and stroke volumes (SV) were obtained by cine CMR and conductance catheter.
Results: Statistically significant differences between cine CMR and conductance catheter derived volume measurements were found for EDV (P < 0.001), ESV (P < 0.05), and SV (P < 0.05). Bland-Altman analysis showed very poor agreement between the two methods: EDV, bias 36.27 mL, agreement of limits 1.96-70.57 mL; ESV, bias 15.33 mL, agreement of limits -6.89-37.55 mL; and SV, bias 20.69 mL, agreement of limits 8.01-49.10 mL. Good agreement was found for SV between cine CMR and PC CMR (bias -7.0 mL, agreement of limits -24.01-9.98 mL), while SV derived from PC CMR measurements showed poor agreement with conductance catheter (bias 27.76 mL, agreement of limits -3.84-59.26 mL).
Conclusion: Poor agreement between the conductance catheter and CMR RV volume measurements was found. PC CMR and cine CMR measurements of SV agreed well.
Keywords: Right ventricle; cardiac magnetic resonance imaging; hemodynamics; pulmonary hypertension.