[Evaluation of aortic to pulmonary blood flow ratio by Doppler echocardiography in septal defects]. / Estimation du rapport des débits aortique et pulmonaire par l'échographie-Doppler dans les défauts septaux.

Pulsed Doppler-echocardiography was used to measure systemic and pulmonary blood flows in 22 patients aged from 3 months to 62 years presenting with interatrial (n = 13) or interventricular (n = 9) septal defect. Calculations were based on echographic measurements of aortic and pulmonary orifice areas and on the integral of maximal aortic and pulmonary Doppler velocity curves. Section areas or the arteries, taken as being circular, were deduced from arterial diameter measurements effected above Valsalva's sinus. Doppler velocity curves were recorded at that level, looking for maximal velocities and assuming a flat velocity profile. Blood flow ratios evaluated from Doppler-echocardiography data were compared with data provided by oximetry and showed good correlations (r = 0.92; Y = 0.71x + 0.53; SEE = 0.24). Calculations by categories of lesions showed better results in patients with interatrial septal defect (r = 0.94; Y = 0.73x + 0.507; SEE = 0.22) than in patients with interventricular septal defect (r = 0.83; Y = 0.547x + 0.75; SEE = 0.25). The main difficulties encountered in measuring Doppler-echocardiography blood flow ratios concerned accurate measurement of pulmonary artery diameter, due to problems of lateral resolution, and accurate measurement of turbulent Doppler velocimetry curves. However, this new, non-invasive technique may be useful to determine the best indications for catheterization or even surgery.

[Recurrent thrombosis of an aortic valve prosthesis in a pregnant woman. Treatment with urokinase]. / Thrombose récidivante d'une prothèse valvulaire aortique chez une femme enceinte. Traitement par urokinase.

A 36 year old woman developed two thromboses on aortic valve prosthesis. The first thrombus at the 14th week of pregnancy was treated with urokinase (2,000 U/kg/h) plus heparin (700-1,000 U/h) over 24 hours and normal wing kinetics were obtained. The second thrombus developed at the 36 th week of pregnancy when the patient was receiving calciparin, and only transient improvement was obtained with similar doses of urokinase hourly over 72 hours. Progressive worsening resulted in higher doses (4,000 U/kg/h) being given without heparin and the thrombus then resolved. The use of urokinase for the first time in this indication allowed therefore, on two occasions and without hemorrhagic complications the cure of this recurrent thrombosis on aortic prosthesis, and the birth, by caesarean, of a healthy baby.

[Calculation of the pulmonary to systemic flow ratio using echo-Doppler in septal defects--correlation with oximetry]. / Cálculo da relação dos débitos pelo eco-Doppler nos defeitos septais--correlação com a oximetria.

OBJECTIVE: 1. local validation of a protocol of measurement of pulmonary to systemic flow ratio (QP/QS) by echo-Doppler in children with septal defects; 2. to assess continuous wave Doppler efficacy mainly in those patients where peak pulmonary flow velocity was beyond the Nyquist limit of pulsed Doppler. DESIGN: To correlate QP/QS ratio determined by echo-Doppler with that obtained by cardiac catheterization (oximetric method) performed within 48 hours, in children with isolated septal defects. MATERIAL AND METHODS: The QP/QS ratio was evaluated by pulsed and or continuous wave echo-Doppler in 50 children who were submitted within 48 hours to cardiac catheterization. All children had an intracardiac shunt (12 atrial septal defects--ASD; 26 ventricular septal defects--VSD and 12 atrio ventricular septal defects--AVDS). Identical measurements were performed in a group of 20 children without cardiac malformation--control group. To test inter-observer variability, all the measurement in 31 patients were repeated by a second observer. Pulmonary and aortic flow was calculated as: Q = A x V x ET x CF where, A is the valvular orifice area (cm2), V the mean flow velocity (cm/sec), ET the ejection time (sec) and CF the cardiac frequency (cycles/min). The Doppler beam-flow direction angle in the pulmonary (P) artery and ascending aorta (Ao) was less than 20 degrees. Results were correlated with those obtained by catheterization (oximetric method). RESULTS: We obtained a fairly good correlation with both pulsed wave Doppler (n = 43; r = 0.88; p less than 0.001; y = 0.84x + 0.40) and continuous wave Doppler (n = 50; r = 0.91; p less than 0.001; y = 0.86x + 0.35) or with pulsed wave Doppler in the P artery and continuous wave Doppler in the Ao (n = 43; r = 0.92; p less than 0.001; y = 0.86x + 0.27). In the control group, QP/QS ratio was evaluated by echo-Doppler: pulsed wave Doppler at 1.05 +/- 0.15 (mean +/- DS); continuous wave Doppler at 1.05 +/- 0.12 and, pulsed wave Doppler in the P artery and continuous wave Doppler in the Ao at 1.03 +/- 0.12. There was no significant difference in all three groups to the normal range of 1.00 (p less than 0.01). Inter-observer variability was less than 5.5% (p less than 0.001). CONCLUSION: Pulsed and/or continuous wave echo-Doppler measurements are a reliable noninvasive method in evaluating QP/QS ratio in children with isolated septal defects.