[Ultrasonographic evaluation of pulmonary to systemic flow ratio. Personal experience]

Usefulness of a noninvasive, ultrasound method for pulmonary to systemic flow ration evaluation (one of the basic parameters characterizing hemodynamic disorders in cardiac defects with a left-to-right intracardiac shunt) was assessed. For that reason 153 systemic and pulmonary flows examinations of 116 patients were performed. 4 of them due to unsatisfactory quality were excluded from the further analysis. 112 remainings were divided into three groups: I. The control group without an intracardiac shunt. II. The group with a left-to-right intracardiac shunt. III. Before and after defect repair. ASD or VSD were proved or excluded basing on 2-DE. Blood flows were simultaneously with 2cDE detected using pulsed, continuous and color doppler methods. Pulmonary and systemic flow volumes were calculated by means of a combined echocardiographic and doppler method. Those volumes ratio is equal to the parameter in question. In 12 cases due to disturbed flow in mai pulmonary artery, pulmonary blood flow was measured on the mitral valve (in 11 cases) or on the right ventricular outflow tract level (in 1 patient). Systemic blood flow volume was always measured on the aortic valve level. High concordance of noninvasive calculations of pulmonary and systemic blood flow volumes was stated with differences between them not exceeded more than 20% and with correlation ratio r = 0.94. Increased pulmonary flow and pulmonary to systemic flow ratio were stated in patients with intracardiac shunt. That ratio became normal after surgical correction. There were studied changes in pulmonary and systemic flow volumes before and after a defect closure. Obtained results proved usefulness of noninvasive, ultrasound assessment of pulmonary to systemic flow ratio in a left-to-right intracardiac shunt. Some potentially encountered difficulties of the method, when its applied, was also discussed.