Cardiac MR-assessed hemodynamic changes in pulmonary arterial hypertension and their relation to pulmonary artery pressure

Purpose: To demonstrate the hemodynamic changes of pulmonary arterial hypertension using cardiac MRI and to determine which parameters are best representative of the pulmonary artery pressure. Patient and methods: We examined 44 patients with pulmonary arterial hypertension using cine cardiac imaging and phase-contrast velocity encoding sequence to obtain data regarding ventricular morphology, function and pulmonary artery flow. The resulting parameters were correlated to echocardiography-derived mean pulmonary artery pressure. Results: We found increased right ventricular end diastolic, end systolic volumes and mass with decreased stroke volume and ejection fraction. The left ventricular end diastolic volume and stroke volume decreased and the end systolic volume increased while the ventricular mass index has increased compared to normal populations. The mean pulmonary artery pressure had significant positive correlation with the ventricular mass index (r = 0.61; p = 0.02) and right ventricular mass (r = 0.40; p = 0.02) with significant negative correlation with right ventricular ejection fraction (r = −0.48; p = 0009). Conclusion: MR-derived ventricular mass index, right ventricular mass, and right ventricular ejection fraction had the strongest relation with the pulmonary artery pressure, and hence they could be reliable parameters on monitoring patients with pulmonary arterial hypertension.