[Two-chambered right ventricle--a comparison of the methods of releasing stenosis in the right ventricle].

Twenty-four patients who underwent radical correction for two-chambered right ventricle from 1973 to 1990 were classified into 3 groups according to the method used for releasing the stenosis in the right ventricle; Group A (n = 7): resection of thickened fibrous tissue; Group B (n = 13): resection of the fibrous tissue and abnormal muscular bundles; and Group C (n = 4): resection of the fibrous tissue and abnormal muscular bundles with patch-enlargement of the right ventricular outflow tract. Postoperative cardiac catheterization was performed in the 22 patients. The pressure gradient between the right ventricle and pulmonary artery (RV-PA) at rest was 10 mmHg or less in 5 out of 7 cases in Group A, 7 out of 11 cases in Group B and all 4 cases in Group C. Isoproterenol stress test was performed in patients in whom the RV-PA pressure gradient at rest was low; the right ventricular inflow pressure increased above 50 mmHg in 3 out of 3 cases in Group A and 3 out of 4 in Group B, although it remained below 30 mmHg in 4 out of 4 cases in Group C. In conclusion, patch enlargement of the right ventricular outflow tract is the method of choice for releasing stenosis in the two-chambered right ventricle.