Two-dimensional strain echocardiography is a new method for the assessment of regional contractility. Thirty-seven patients with pulmonary arterial hypertension (mean age 56.4 +/- 11 years) and 38 normal subjects (mean age 58.3 +/- 12 years) underwent 2-dimensional echocardiography and tissue Doppler echocardiographic evaluation of right ventricular (RV) global function and regional contractility. Patients with pulmonary arterial hypertension additionally underwent 6-minute walking distance tests and right-sided cardiac catheterization before and after (8 +/- 3 months) vasodilator therapy. Moderate or severe RV dysfunction was present in all patients (2-dimensional strain of the basal segment of the RV free wall: -8.8 +/- 4.1% systolic longitudinal deformation) compared with normal subjects (-24.3 +/- 4.7% systolic longitudinal deformation, p < 0.001) and was improved with vasodilator therapy after 6 to 11 months (-13.3 +/- 6.2% systolic longitudinal deformation, p < 0.001).