Right ventricular wall mechanics in normals and patients with pulmonary hypertension using magnetic resonance tissue tagging

Right ventricular hypertrophy (RVH) and RV dysfunction are difficult to evaluate due to the complex shape of the RV and prognostic limitations of conventional global function parameters. We used MRI with magnetization tagging to measure 2-D systolic motion and deformation of the right ventricular free wall (RVFW) and septum (SEPT) in 5 patients with RVH secondary to pulmonary hypertension, and 12 normal volunteers (NL). Regional displacement (D) and 2-D principal strains in the short-axis plane were averaged at basal, midventricular and apical levels. SEPT D was severely decreased at all levels in RVH vs. NL (P<0.005). In RVH, RVFW D was higher than SEPT D (P<0.02). The 2-D strains were reduced in SEPT at all levels in RVH vs. NL (P<0.05). This technique may permit the study of progression and regression of RVH in various disease states.