Radionuclide stroke count ratios for assessment of right and left ventricular volume overload in children

The ratio of left ventricular to right ventricular stroke counts measured by radionuclide angiography has been used in adults to estimate the severity of left-sided valvular regurgitation. The validation of this technique in children for assessment of right and left ventricular volume overload is reported herein. Radionuclide stroke count ratios in 60 children aged 0.5 to 19 years (mean 11) were determined. Based on their diagnoses, the patients were divided into 3 groups: (1) normal-40 patients with no shunts or valvular regurgitation, (2) left ventricular volume overload-13 patients with mitral or aortic regurgitation, or both, and (3) right ventricular volume overload-7 patients, 2 with severe tricuspid regurgitation, 3 with atrial septal defects, and 2 with total anomalous pulmonary venous drainage. The radionuclide stroke count ratio clearly differentiated these groups (p <0.05): normal patients had a stroke count ratio of 1.04 ± 0.17 (mean ± 1 standard deviation), the left ventricular volume overload group had a stroke count ratio of 2.43 ± 0.86, and the right ventricular volume overload group had a stroke count ratio of 0.44 ± 0.17. In 22 of our 60 patients, radionuclide stroke count ratios were compared with cineangiographic stroke volume ratios, resulting in a correlation coefficient of 0.88. It is concluded that radionuclide ventriculography is an excellent tool for qualitative and quantitative assessment of valvular regurgitation in children.