Integrated analysis of diastolic, systolic and pulmonary vascular function using MRI guided catheterization

The EDPVR was determined by synchronizing invasive ventricular pressures with cine and real-time MRI derived ventricular volumes and pulmonary/aortic blood flow measurements. In 7 pigs the MRI and conductance-catheter method (gold standard) were compared for measuring the EDPVR at rest and during dobutamine. Parameters of global function, myocontractility (ESPVR), vascular resistance and EDPVR were measured with MRI at rest and under dobutamine in 14 patients with Fontan circulation. Bland-Altman test showed agreement between the conductance-catheter and MRI method. In the pigs, there was in both ventricles during dobutamine a right/bottom shift of the EDPVR, the stiffness co efficient decreased slightly (p < 0.051). In the patients during dobutamine we noted failure to increase stroke volumes despite increased contractility and evidenced diastolic dysfunction. Active relaxation was inconspicuous but the EDPVR shifted towards the left/top, the stiffness constant remained unchanged. Pulmonary resistance decreased slightly (p = 0.058) and thus showed adequate response to augmented cardiac outputs. This novel MRI method provides differential information about diastolic, systolic and vascular function. The method evidenced that in Fontan patients diastolic dysfunction is an important pathophysiologic cause of heart failure.