OBJECTIVE: To determine the echocardiographic changes in the heart at 3 months and 1 year after pulmonary thromboendarterectomy (PTE) in patients with chronic thromboembolic pulmonary hypertension (CTEPH). PATIENTS AND METHODS: Thirty-two adult patients who underwent PTE for CTEPH at the Mayo Clinic in Rochester, Minn, from 1997 to 2003 were included in the study. All underwent transthoracic echocardiography before surgery. Follow-up echocardiography was performed within 3 months of surgery in 28 patients and 1 year postoperatively in 17 patients. The results were compared with baseline data. RESULTS: Within 3 months after PTE, the right ventricular end-diastolic area decreased from 38.4±12.8 cm2 to 32.5±10.4 cm2 (mean difference, 5.8±10.4 cm2; P=.02). The right ventricular end-systolic area decreased from 30.4±12.1 cm2 to 24.1±8.6 cm2 (mean difference, 6.3±10.1 cm2; P=.008). The right ventricular systolic pressure decreased significantly from 92.6±22.0 mm Hg to 55.0±19.8 mm Hg (mean difference, 40.0±24.8 mm Hg; P<.001). Tricuspid regurgitation (TR) Improved from a mean grade of 2.5±1.2 to 1.2±1.1 (mean difference, 1.5±1.0; P<.001). At 12 months, the right ventricular end-diastolic area, right ventricular end-systolic area, right ventricular systolic pressure, and TR also were significantly lower than baseline values. CONCLUSION: In patients with CTEPH who undergo PTE, echocardiographic measurements of right ventricular size, systolic pressure, and TR show significant improvement immediately after surgery, which is sustained for up to 1 year after surgery. © 2006 Mayo Foundation for Medical Education and Research.