Hepatic vein velocities in children with right ventricular hypertension

Can Doppler systemic venous flow indices predict central venous pressure in children?

Tricuspid valve, superior vena cava (SVC), and hepatic vein Doppler patterns may be abnormal in right heart anomalies and have been used to predict high central venous pressure (CVP) in adults. The purpose of this study was to evaluate the relationship of these systemic venous flow indices to CVP in children. Children undergoing cardiac catheterization were studied prospectively using simultaneous recordings of mean CVP with pulsed-Doppler tracings of SVC, hepatic vein, and tricuspid valve flow. Systemic venous Doppler measurements included peak velocities and velocity time integrals for ventricular systole (S), ventricular diastole (D), and ventricular systole (B), and atrial systole (A). Tricuspid inflow Doppler E and A waves were recorded also. Patients with significant tricuspid stenosis or regurgitation, systemic venous obstruction, and nonsinus rhythm were excluded. The 42 patients ranged in age from 0.2 to 21.0 years and in weight from 3.0 to 68.0 kg. Mean CVPs ranged from 1 to 17 mmHg. Catheterization indications included hemodynamic evaluation (25 patients), transplant biopsy, (11 patients), and interventional procedures (6 patients). No SVC or tricuspid valve Doppler measurement correlated with CVP. Hepatic vein peak D, peak B, and peak A significantly correlated with CVP (r = 0.34 - 0.55; P < 0.05, linear regression). For all correlations, the r values were low with significant overlap among patients. Thus, in children, only hepatic vein peak velocities correlate with CVP. Because of the low r values and significant overlap among patients, the currently used Doppler indices have a low sensitivity for predicting CVP in this age group.

Pulsed Doppler echocardiographic assessment of patterns of venous flow after the modified Fontan operation: potential clinical implications

To assess the effect of a modified Fontan operation on systemic venous blood flow and the hepatic circulation, we compared 11 patients having an atriopulmonary connection and 35 with total cavopulmonary anastomosis. The Doppler echocardiographic study of the caval venous, hepatic venous and portal venous flow was performed so as to calculate the pulsatility ratio and the variation of flow with respiration. All patients had undergone cardiac catheterization. In addition, we included specific laboratory investigations to assess function of various organs. Significantly lower maximum velocities of flow at inspiration (0.31+/-0.12 m/sec vs 0.45+/-0.14 m/sec) and expiration (0.23+/-0.09 m/sec vs 0.32+/-0.11 m/sec), less pulsatility (0.43 vs 0.16) and a lower ratio of systolic to diastolic velocity (1.22 vs 1.85) were found in the patients having a cavopulmonary as compared to an atriopulmonary anastomosis. Peak velocities of hepatic venous flow during inspiration and expiration were significantly lower in those with a cavopulmonary anastomosis (p = 0.001 and p < 0.001, respectively). In these patients, forward flow was extremely dependent on respiration, with decrease or cessation of antegrade flow during expiration in 22 patients. The velocity of portal venous flow was also significantly lower in these patients, although the pulsatility ratio did not differ significantly between the groups (0.5+/-0.21 and 0.57+/-0.23, respectively). The ratio of inspiratory and expiratory velocities showed no significant difference between the groups, nor was there any correlation between the pulsatility ratio of the venous vessels or the ratio of peak flow velocities during expiration and the mean systemic venous/right atrial pressure on postoperative cardiac catheterization. Hypoproteinemia was found in 8 patients after total cavopulmonary anastomosis; 9 of 10 patients with protein C deficiency belonged to this group. The dependence of hepatic venous flow on respiration in the presence of a chronically elevated systemic venous pressure in patients after the total cavopulmonary anastomosis may influence hepatic function in the postoperative period.

Doppler systemic venous flow patterns: changes in children with mild/moderate pulmonic stenosis

To determine the usefulness of systemic venous flow patterns in patients with mild/moderate right ventricular hypertension, 17 patients with isolated mild/moderate pulmonic stenosis and 17 age-matched normal children were evaluated with pulsed Doppler echocardiography. Tricuspid valve, superior vena caval, and hepatic vein pulsed Doppler recordings were obtained with simultaneous respirometry and electrocardiography. Peak velocities and velocity-time integrals were measured for Doppler signals corresponding with ventricular systole, ventricular diastole, ventricular end systole, and atrial systole. The groups were similar in weight, heart rate, tricuspid inflow Doppler echocardiograms, and cardiac indexes. Compared with normal subjects, patients showed changes in respiratory variation for some superior vena caval and hepatic vein indexes. In addition, hepatic vein measurements made at ventricular end systole were significantly lower and measurements made at atrial systole were significantly higher in patients than in normal subjects. These changes in systemic venous flow patterns may provide a sensitive indicator of early right-sided heart dysfunction.