Objectives: To test whether magnetic resonance(MR) imaging can be used to assess differential lung blood flow as accurately as isotope lung perfusion studies in patients investigated for congenital heart disease. Meth...Objectives: To test whether magnetic resonance(MR) imaging can be used to assess differential lung blood flow as accurately as isotope lung perfusion studies in patients investigated for congenital heart disease. Methods and results: Radionuclide lung perfusion and MR imaging were performed in 12 children with suspected unilateral branch pulmonary artery stenosis(mean age 12.1(5.9) years, range 3.1-17.2 years). A non-breath hold, fast gradient echo phase contrast MR sequence was used to measure flow in the pulmonary trunk and one pulmonary artery to calculate differential flow. Good agreement was shown between the two imaging methods by Bland-Altman analysis. There was excellent correlation between the radionuclide and MR phase contrast calculated total lung blood flow(r=0.98, p< 0.0001). Conclusion: MR phase contrast is an accurate method for measuring differential total right and left lung blood flow. If MR imaging is performed to assess the branch pulmonary arteries, differential lung blood flow can be also measured, avoiding the need for an additional radionuclide lung perfusion scan and reducing the overall radiation burden to this group of patients.展开更多
Background -Right ventricular outflow tract obstruction(RVOTO) is a common problem after repair of congenital heart disease. Percutaneous pulmonary valve implantation(PPVI) can treat this condition without consequent ...Background -Right ventricular outflow tract obstruction(RVOTO) is a common problem after repair of congenital heart disease. Percutaneous pulmonary valve implantation(PPVI) can treat this condition without consequent pulmonary regurgitation or cardiopulmonary bypass. Our aim was to investigate the clinical and physiological response to relieving RVOTO. Methods and Results -We studied 18 patients who underwent PPVI for RVOTO(72%male, median age 20 years) from a total of 93 who had this procedure for various indications. All had a right ventricular outflow tract(RVOT)gradient >50 mm Hg on echocardiography without important pulmonary regurgitation(less than mild or regurgitant fraction< 10%on magnetic resonance imaging[MRI]). Cardiopulmonary exercise testing, tissue Doppler echocardiography, and MRI were performed before and within 50 days of PPVI. PPVI reduced RVOT gradient(51.4 to 21.7 mm Hg, P< 0.001)and right ventricular systolic pressure(72.8 to 47.3 mm Hg, P< 0.001) at catheterization. Symptoms and aerobic(25.7 to 28.9 mL·kg-1.min-1, P=0.002) and anaerobic(14.4 to 16.2 mL·kg-1.min-1, P=0.002) exercise capacity improved. Myocardial systolic velocity improved acutely(tricuspid 4.8 to 5.3 cm/s, P=0.05; mitral 4.7 to 5.5 cm/s, P=0.01), whereas isovolumic acceleration was unchanged. The tricuspid annular velocity was not maintained on intermediate follow-up. Right ventricular end-diastolic volume(99.9 to 89.7 mL/m2, P< 0.001) fell, whereas effective stroke volume(43.7 to 48.3mL/m2, P=0.06) and ejection fraction(48.0%to 56.8%, P=0.01) increased. Left ventricular end-diastolic volume(72.5 to 77.4 mL/m2, P=0.145), stroke volume(45.3 to 50.6 mL/m2, P=0.02), and ejection fraction(62.6%to 65.8%, P=0.03) increased. Conclusions -PPVI relieves RVOTO, which leads to an early improvement in biventricular performance. Furthermore, it reduces symptoms and improves exercise tolerance. These findings have important implications for the management of this increasingly common condition.展开更多
文摘Objectives: To test whether magnetic resonance(MR) imaging can be used to assess differential lung blood flow as accurately as isotope lung perfusion studies in patients investigated for congenital heart disease. Methods and results: Radionuclide lung perfusion and MR imaging were performed in 12 children with suspected unilateral branch pulmonary artery stenosis(mean age 12.1(5.9) years, range 3.1-17.2 years). A non-breath hold, fast gradient echo phase contrast MR sequence was used to measure flow in the pulmonary trunk and one pulmonary artery to calculate differential flow. Good agreement was shown between the two imaging methods by Bland-Altman analysis. There was excellent correlation between the radionuclide and MR phase contrast calculated total lung blood flow(r=0.98, p< 0.0001). Conclusion: MR phase contrast is an accurate method for measuring differential total right and left lung blood flow. If MR imaging is performed to assess the branch pulmonary arteries, differential lung blood flow can be also measured, avoiding the need for an additional radionuclide lung perfusion scan and reducing the overall radiation burden to this group of patients.
文摘Background -Right ventricular outflow tract obstruction(RVOTO) is a common problem after repair of congenital heart disease. Percutaneous pulmonary valve implantation(PPVI) can treat this condition without consequent pulmonary regurgitation or cardiopulmonary bypass. Our aim was to investigate the clinical and physiological response to relieving RVOTO. Methods and Results -We studied 18 patients who underwent PPVI for RVOTO(72%male, median age 20 years) from a total of 93 who had this procedure for various indications. All had a right ventricular outflow tract(RVOT)gradient >50 mm Hg on echocardiography without important pulmonary regurgitation(less than mild or regurgitant fraction< 10%on magnetic resonance imaging[MRI]). Cardiopulmonary exercise testing, tissue Doppler echocardiography, and MRI were performed before and within 50 days of PPVI. PPVI reduced RVOT gradient(51.4 to 21.7 mm Hg, P< 0.001)and right ventricular systolic pressure(72.8 to 47.3 mm Hg, P< 0.001) at catheterization. Symptoms and aerobic(25.7 to 28.9 mL·kg-1.min-1, P=0.002) and anaerobic(14.4 to 16.2 mL·kg-1.min-1, P=0.002) exercise capacity improved. Myocardial systolic velocity improved acutely(tricuspid 4.8 to 5.3 cm/s, P=0.05; mitral 4.7 to 5.5 cm/s, P=0.01), whereas isovolumic acceleration was unchanged. The tricuspid annular velocity was not maintained on intermediate follow-up. Right ventricular end-diastolic volume(99.9 to 89.7 mL/m2, P< 0.001) fell, whereas effective stroke volume(43.7 to 48.3mL/m2, P=0.06) and ejection fraction(48.0%to 56.8%, P=0.01) increased. Left ventricular end-diastolic volume(72.5 to 77.4 mL/m2, P=0.145), stroke volume(45.3 to 50.6 mL/m2, P=0.02), and ejection fraction(62.6%to 65.8%, P=0.03) increased. Conclusions -PPVI relieves RVOTO, which leads to an early improvement in biventricular performance. Furthermore, it reduces symptoms and improves exercise tolerance. These findings have important implications for the management of this increasingly common condition.
