Noninvasive Doppler echocardiographic evaluation of shunt flow dynamics of the ductus arteriosus.

Abstract

The pulsed Doppler technique was used to record the flow velocity patterns in the ductus arteriosus and the pulmonary artery in 26 patients with either isolated or complicated patent ductus arteriosus (PDA). In all patients, abnormal Doppler signals indicating left-to-right (L-R) or right-to-left shunt flow or both could be obtained at the site of the ductus arteriosus. These Doppler flow patterns determined within the ductus coincided with the direction of ductal flow seen on the contrast two-dimensional echocardiogram. No Doppler signals of shunt flow were demonstrated in any of 42 control subjects. The peak, mean, and diastolic velocities of the L-R shunt flow within the ductus were measured from the ductal flow velocity profiles. With the Doppler-derived measurements of the mean and diastolic velocities, patients with normal pulmonary arterial pressure and those with evidence of pulmonary hypertension could be correctly identified. In addition, the mean velocity of the diastolic antegrade flow portion obtained from the proximal left pulmonary artery, which was related to ductal L-R shunting, was measured in 16 patients with isolated PDA. This Doppler flow determinant showed a good linear correlation with the L-R shunt ratio determined by Fick's method (r = .88, p < .01). Our technique permits the noninvasive evaluation of shunt flow dynamics in patients with PDA. Circulation 75, No. 6, 1146-1153, 1987 ALTERATION of Doppler flow patterns in the pulmonary artery and descending aorta has been useful in the diagnosis of patent ductus arteriosus (PDA).1 Twodimensional echocardiography has allowed visualization of the ductus from the parasternal, suprasternal, and subxyphoid windows.6'7 Recent reports8'9 have demonstrated that two-dimensional/Doppler echocardiography is a highly sensitive technique for detection of ductal patency. However, few studies have been reported concerning the assessment of shunt flow within the ductus.°l We therefore designed the present study to (1) evaluate the ability of two-dimensional/ Doppler echocardiography to determine the direction of shunt flow in the ductus and (2) assess the pulmonary-to-systemic peak pressure ratio and the degree of left-to-right (L-R) shunting with Doppler-derived indexes of the flow velocity.

Correlation of Patent Ductus Arteriosus Shunting with Plasma Atrial Natriuretic Factor Concentration in Preterm Infants with Respiratory Distress Syndrome

“…Recently, quantitative data have been obtained using pulsed Doppler echocardiography by measuring the mean velocity of diastolic antegrade flow in the proximal left pulmonary artery (12). In small, severely distressed infants, pulsed Doppler echocardiography can be used, but quantitative data are difficult to obtain.…”

Doppler Echocardiographic Evaluation of Left Ventricular Output and Left Ventricular Diastolic Filling Changes in the First Day of Life

“…The inner diameter was measured at the narrowest portion of the ductal lumen in the parasternal long-axis plane. As suggestedby Hiraishi et al (9,10), we also judged that the ductus arteriosus was closing when the narrowest diameter was less than 2 mm or non phasic continuous low-velocity flow was recorded upstream of the narrowing portion of the ductus arteriosus. It was considered closed when the color image and shunt flow were no longer detectable .…”

Variation in the diagnosis and management of patent ductus arteriosus in premature infants

“…Trivial PDAs can now be successfully detected by colour Doppler flow mapping (32)(33)(34), and shunt size can be quantitated by M-mode echocardiography (35)(36)(37). However, given the medical complexity of these patients, it is unlikely that echocardiography alone will accurately identify patients with PDA for whom the benefits of therapy outweigh the risks.…”