Interatrial shunt flow profiles in newborn infants: a colour flow and pulsed Doppler echocardiographic study.

Interatrial shunt flow profiles in 36 normal term infants were examined serially by colour flow and pulsed Doppler echocardiographic techniques from within an hour of birth to four or five days after birth. Shunt flow across the foramen ovale was detected in 33 normal infants (92%) within an hour of birth (mean 40 minutes). The occurrence of interatrial shunting decreased with age, but a shunt signal was still detected in 17 infants (47%) on the fourth or fifth day of life, by then the ductus arteriosus had already closed in all the normal infants. The direction of interatrial shunt flow was predominantly left-to-right, but in 64% there was a coexistent small right-to-left shunt in diastole within an hour of birth; by four to five days it was found in 19%. In the six patients with persistent fetal circulation the direction of the interatrial shunt flow was predominantly right-to-left with biphasic peaks in diastole and systole at the early stage of the disease, and the period of right-to-left shunt flow during each cardiac cycle was significantly longer than that in normal infants examined within 1 hour of birth. In all patients the ductus closed before the foramen ovale. At the time of ductal closure in all patients with persistent fetal circulation right-to-left shunt flow was seen during diastole and its period was still prolonged. These findings suggest that interatrial shunting, predominantly left-to-right, is common in normal newborn infants. Evaluation of the characteristics of the interatrial shunt by Doppler echocardiography may be useful for predicting the progress of or improvement in neonates with persistent fetal circulation.     

A pulsed Doppler echocardiographic study of the postnatal changes in pulmonary artery and ascending aortic flow in normal term newborn infants

Postnatal circulatory adaptations were studied with Doppler echocardiographic measures of flow velocity in the main pulmonary artery (PA) and ascending aorta (Ao) in 45 normal full-term neonates at 5 hours and at 27 hours after birth. PA flow velocity integral (FVI) was measured as the area under the systolic flow velocity curve and reflected total systemic flow in the presence of a left-to-right shunt through the ductus arteriosus. This index increased from 5 and 27 hours age, while Ao FVI, reflecting total pulmonary flow, remained unchanged. Evidence of a left-to-right ductal shunt demonstrated as diastolic retrograde flow in the main PA was detected in 42 neonates at 5 hours and in only four subjects after 27 hours of age, indicating a patent ductus arteriosus at 5 hours of age and its subsequent closure. In the PA, acceleration time (AT) increased while pre-ejection period to ejection time ratio (PEP/ET) decreased from 5 to 27 hours of age, reflecting the physiologic fall in PA pressure. In the Ao, FVI, AT, and PEP/ET remained unchanged, suggesting little change in left ventricular function.     

Pre-ejection flow in the left ventricular outflow tract: a pulsed Doppler echocardiographic study]

Pre-ejection flow (PEF) has been recognized as the flow of short duration toward the cardiac base in the left ventricular outflow tract. In the present study, PEF was analyzed by pulsed Doppler echocardiography to determine the contribution of left ventricular contraction to the genesis of PEF. The study subjects consisted of 20 patients with lone atrial fibrillation (Af) and 30 patients with premature ventricular contractions (PVC) without other cardiovascular diseases. Phonocardiogram and electrocardiogram were simultaneously recorded with Doppler signal of PEF. PEF was clearly detected in only 18 patients with PVC; in the remaining 12, it was not recorded or could not be differentiated from the signals of the preceding left ventricular diastolic filling. Results were as follows: 1. PEF in the cases with sinus rhythm appeared before the Q wave; whereas, it appeared after the Q wave in the cases with Af or PVC, and the peak of PEF coincided with the first heart sound on the phonocardiogram. 2. The duration of PEF was 93.6 +/- 15.4 msec in sinus rhythm, 60.6 +/- 14.2 msec in Af, and 87.5 +/- 19.4 msec in PVC. 3. Peak velocities of PEF in Af and PVC were significantly less than peak velocity of PEF in sinus rhythm. 4. Peak velocity of PEF in PVC with left bundle branch block tended to be less than that in PVC with right bundle branch block.(ABSTRACT TRUNCATED AT 250 WORDS)     

Left ventricular diastolic flow dynamics in dilated cardiomyopathy: a color flow imaging and pulsed Doppler echocardiographic study

Left ventricular filling flow was evaluated at the mitral orifice and in the left ventricle (LV) using color flow imaging and pulsed Doppler echocardiography in seven patients with dilated cardiomyopathy (DCM) and 10 normal subjects. Using the apical approach, filling flow in early and late diastole was observed by two-dimensional color and M-mode color flow imaging, and flow velocity patterns at the mitral orifice and in the LV, 3 cm below the orifice, were analyzed by pulsed Doppler echocardiography. Color flow imaging disclosed slower movement of the inflow signals toward the apex in DCM than in the normal. With pulsed Doppler echocardiography, the delay in timing of peak velocity in the LV was distinctly greater in DCM than in the normal, although the mitral inflow velocity did not differ between DCM and the normal. The width of the filling flow, the rate of velocity reduction and the flow velocity in the LV did not differ between DCM and the normal. Thus, in DCM, the timing of filling flow in the LV is clearly delayed compared to the timing at the mitral orifice, and this cannot be explained solely by the mitral flow velocity pattern.     

Venous hum and innominate vein flow velocity in chronic anemia: a pulsed Doppler echocardiographic study

To assess the hemodynamic correlates of the cervical venous hum in patients with chronic anemia, 14 patients (mean age; 49 years, mean hemoglobin (Hb); 7.3 g/dl) and 14 control subjects (mean age; 50 years, mean Hb; 14 g/dl) without cardiac disease were studied by auscultation, phonocardiography and Doppler echocardiography in two positions (supine and sitting). Venous hum was detected in the sitting position in 11 of the 14 anemic patients whose Hb was less than 9 g/dl, and in six anemic patients in the supine position, while venous hum was absent in the control subjects in both positions. Pulsed Doppler echocardiography with the transducer in the supraclavicular fossa revealed significantly (p less than 0.01) higher peak velocity in the innominate vein in the 11 anemic patients with venous hum (supine; 71 +/- 12, sitting; 111 +/- 24 cm/sec, mean +/- SD) than in the control subjects (supine; 46 +/- 15 sitting; 76 +/- 27 cm/sec) in both positions. Intensity of venous hum increased concomitantly with increased innominate vein flow velocity when the body position was changed from supine to sitting. Peak velocity in the innominate vein correlated significantly with Hb in all study subjects (r = 0.65, p less than 0.01). In conclusion, the cervical venous hum in patients with chronic anemia is related to the hemoglobin concentration and flow velocity in the innominate vein.     

Subclinical cardiotoxicity by doxorubicin: a pulsed Doppler echocardiographic study

In order to detect subclinical levels of Doxorubicin (D) cardiotoxicity, 21 patients aged 42 +/- 8 years with malignancies and treated with D as a part of a multiple regimen, were evaluated. The mean cumulative dose of D was 242 +/- 112 mg.m-2 (150 to 520 mg.m-2). Patients with systemic hypertension, valvular diseases, suspected coronary artery disease, ejection fraction less than 55% as assessed by radionuclide angiography, and aged more than 50 years were excluded from the study. A Doppler echocardiographic examination was performed before and after the course of D therapy with a mean interval of 142 days. The following variables were assessed: fractional shortening (FS), ejection fraction (EF), stroke volume (SV), isovolumic relaxation time (IVRT), maximal early diastolic flow velocity (Emax), maximal late diastolic flow velocity (Amax), and mitral deceleration time (Mdt). Indices derived from 19 aged-matched normal subjects were compared to those of the patients before the course of therapy. Doppler echocardiographic measurements did not differ significantly between the control group and patients before the course of therapy. While there were no significant changes in FS, EF, and SV in the study group before and after therapy, indices of diastolic filling showed striking differences: IVRT changed from 72 +/- 11 to 87 +/- 19 ms (P less than 0.001), Emax from 81 +/- 12 to 65 +/- 17 cm.s-1 (P less than 0.001), Mdt from 174 +/- 25 to 183 +/- 34 ms (P less than 0.05), Amax from 44 +/- 17 to 52 +/- 16 cm.s-1 (P less than 0.01). These data demonstrate impaired diastolic filling after doxorubicin therapy at conventional dosages.     

The newborn transitional circulation: a two-dimensional Doppler echocardiographic study

To characterize changes in circulation after birth, 11 normal full-term infants were examined with two-dimensional and pulsed Doppler echocardiography. The initial examination was performed within 10 hours after delivery and serially for 3 days. Retrograde diastolic pulmonary artery velocities, which are evidence for a patent ductus arteriosus, were detected in 10 infants (91%) on day 1, in 2 (18%) on day 2 and in none on day 3. Retrograde systolic descending aortic velocities, which are evidence of flow from the aorta into the ductus arteriosus, were observed in 10 infants (91%) on day 1, 9 (81%) on day 2 and 7 (64%) on day 3. Persistence of the retrograde systolic velocity in the descending aorta in the absence of retrograde diastolic velocity in the pulmonary artery is consistent with physiologic ductal closure beginning near the pulmonary artery end of the ductus arteriosus. Localized turbulent retrograde systolic flow, proximal to the septal leaflet of the tricuspid valve and consistent with tricuspid insufficiency, was detected in six patients (55%) on day 1, in eight (73%) on day 2 and in seven (64%) on day 3. Thus, tricuspid insufficiency appears to be a frequent observation in healthy newborns. Normal Doppler velocities in the great arteries and across the tricuspid and mitral valves of newborns up to 3 days of age are presented. These normal measures of intracardiac flow velocities may be used for comparison to identify abnormal flow profiles in newborns with congenital heart defects.     

Intracardiac blood flow velocities and cardiac output in normal fetuses: a prospective pulsed Doppler echocardiographic study.

Two dimensional and pulsed Doppler echocardiographic studies were performed in human fetuses with the aim to establish normal values for blood flow velocities and cardiac output in Indian subjects. Thirteen pregnant mothers were prospectively followed up at 4 weeks interval from 19 to 40 weeks of gestation. Blood flow velocity spectra across aortic, pulmonary, mitral and tricuspid valves were analyzed to obtain peak flow velocity (cm/sec) and velocity time integral. Aortic and pulmonary diameters were measured at the valve level from two dimensional echocardiographic images and ventricular stroke volume calculated. The values were plotted against fetal age (weeks) and fetal weight (gms). Our results showed that there is a linear increase of the measured Doppler data, with increasing gestational age and weight. These values may be used as a reference for the Indian population.     

Left ventricular filling in hypertrophic cardiomyopathy: a pulsed Doppler echocardiographic study

Abnormal left ventricular diastolic properties have been described in patients with hypertrophic cardiomyopathy. To evaluate the diastolic filling characteristics of the left ventricle in patients with this disease, pulsed Doppler echocardiography was used to study mitral flow velocity in 17 patients with hypertrophic cardiomyopathy (11 with and 6 without systolic anterior motion of the mitral valve) and 16 age-matched normal subjects. There were no statistically significant differences between patients with hypertrophic cardiomyopathy with and without systolic anterior motion with regard to ventricular septal thickness, left ventricular posterior wall thickness, left ventricular internal dimensions or the extent of hypertrophy evaluated by two-dimensional echocardiography. Mitral regurgitation was detected by Doppler echocardiography in all 11 patients with and in 2 (33%) of the 6 patients without systolic anterior motion of the mitral valve. Early and late diastolic peak flow velocity, the ratio of late to early diastolic peak flow velocity and deceleration of early diastolic flow were measured from Doppler mitral flow velocity recordings. There were no statistically significant differences in these four indexes between the patients with systolic anterior motion and normal subjects. In contrast, the patients with hypertrophic cardiomyopathy without systolic anterior motion showed lower early diastolic peak flow velocity, higher ratio of late to early diastolic peak flow velocity and lower deceleration of early diastolic flow compared with the patients with systolic anterior motion and normal subjects, suggesting impaired left ventricular diastolic filling.(ABSTRACT TRUNCATED AT 250 WORDS)     

Aortic regurgitation associated with hypertrophic cardiomyopathy: a colour Doppler echocardiographic study

The frequency, severity, and cause of aortic regurgitation were assessed by colour Doppler and cross sectional echocardiography in 87 patients (mean SD) age 57 (12) years) with hypertrophic cardiomyopathy, and 48 age matched controls (57 (8) years). Aortic regurgitant murmurs were recorded in only three of 87 patients and in none of the controls. Colour Doppler echocardiography showed an aortic regurgitant signal in 20 (23%) of the patients and three (6%) of the 48 controls. The colour Doppler signals typical of aortic regurgitation were limited to the left ventricular outflow tract. There were no significant differences between patients with hypertrophic cardiomyopathy with and without aortic regurgitation in terms of age (59 years v 56 years), blood pressure (140/84 mm Hg v 136/80 mm Hg), aortic diameter (34 mm v 33 mm), or frequency of calcification of the aortic valve (15% v 10%) and of systolic anterior motion of the mitral valve with mitral-septal contact (25% v 16%). On cross sectional echocardiograms, the degree of septal protrusion into the left ventricular outflow tract during systole was significantly more prominent (15 v 10 mm), and the portion of the basal septum that protruded most deeply into the left ventricular outflow tract was significantly closer to the aortic annulus in patients with aortic regurgitation than in those without it (11 v 14 mm). Mild aortic regurgitation was found in almost a quarter of patients with hypertrophic cardiomyopathy. The regurgitation was related to the morphological abnormality of the left ventricular outflow tract.     

Left ventricular blood flow dynamics caused by ventricular premature contraction: pulsed Doppler echocardiographic study

Cardiac function at the time of ventricular premature contractions (VPC) is influenced by the coupling interval or the site of those origin. Clinical and experimental studies of the effects of VPC on intracardiac pressure dynamics have been performed; however, little is known about left ventricular blood flow dynamics. This study was attempted to determine the characteristics of blood flow dynamics in respect to the site of origin of VPC using pulsed Doppler echocardiography. The subjects consisted of 18 cases with VPC but without apparent organic heart disease. Seven cases had VPCs with a left bundle branch block pattern suggesting possible origin in the right ventricle. The other 11 cases had VPCs with a right bundle branch block pattern indicating the left ventricular origin. With the probe in the apical position, the blood flow patterns of the left ventricular outflow, central and inflow tracts were examined. The results were as follows; 1. Except for one case with shortened coupling interval, all six cases with VPCs originated from the right ventricle showed preservation of left ventricular ejection flow. 2. In two of the three cases with VPC which originated from the left ventricle and with left axis deviation, systolic flow in the left ventricular central area showed "back flow" to the apex. Ejection flow at the outflow tract was markedly diminished or disappeared in all three cases. 3. In all eight cases with VPC which originated from the left ventricle and with right axis deviation, ejection flow was slightly disturbed both in the left ventricular outflow and in the central area. 4. Ejection flow volume assessed by velocity integral indicated similar dynamics as did the ejection flow velocity. 5. In left ventriculography, asynchrony due to dyskinetic motion of the anteroapical wall was observed at the times of VPCs with left axis deviation. In conclusion, the patterns of left ventricular ejection flow dynamics depend on the site of origin of VPCs. This disturbed flow is more apparent in VPCs originating from the left ventricle compared to the right ventricle. This is especially true in cases with left axis deviation, in which VPCs arise from the posterior site of the left ventricle.     

Effect of atrial fibrillation on pulmonary venous flow patterns: transoesophageal pulsed Doppler echocardiographic study

The effect of atrial fibrillation on pulmonary venous flow patternsis still not well known. Twenty-four patients in atrial fibrillationand 21 patients in sinus rhythm were studied by transoesophagealechocardiography. In ninety-five percent (20/21) of sinus rhythmpatients, the early systolic wave due to atrial relaxation orreverse wave due to atrial contraction could be distinguishedon pulsed Doppler tracings by transoesophageal echocardiography.However, there was no early systolic wave and/or reverse atthe end of diastole in any atrial fibrillation patients. Inatrial fibrillation patients without mitral regurgitation (n= 14), the onset of systolic flow was delayed (165±38vs 50±46 ms, P < 0.05), and systolic peak velocities,time-velocity integrals and systolic fractions were reduced(31 ± 13 vs 54±17 cm.s^–1, P < 0.05; 5± 2 vs 13 ± 6 cm, P < 0.05 and 36 ±8 vs 61±15%, P < 0.05, respectively) as compared tothose in sinus rhythm. Significant mitral regurgitation (n =10) reduced systolic velocity parameters considerably in atrialfibrillation patients but the diastolic flow parameters werenot significantly different between sinus rhythm and atrialfibrillation patients. Stepwise multiple regression analysis identified atrial fibrillationas an important independent predictor for changes in systolicflow parameters. The R-R interval is also an important factorfor diastolic flow parameters. Thus, the present study demonstratesthat atrial fibrillation significantly modifies pulmonary venousflow pattern and is an important factor for systolic flow parameters.Significant mitral regurgitation can further modify systolicflow pattern in atrial fibrillation patients.     

Aortic regurgitation associated with hypertrophic cardiomyopathy: a colour Doppler echocardiographic study.

The frequency, severity, and cause of aortic regurgitation were assessed by colour Doppler and cross sectional echocardiography in 87 patients (mean SD) age 57 (12) years) with hypertrophic cardiomyopathy, and 48 age matched controls (57 (8) years). Aortic regurgitant murmurs were recorded in only three of 87 patients and in none of the controls. Colour Doppler echocardiography showed an aortic regurgitant signal in 20 (23%) of the patients and three (6%) of the 48 controls. The colour Doppler signals typical of aortic regurgitation were limited to the left ventricular outflow tract. There were no significant differences between patients with hypertrophic cardiomyopathy with and without aortic regurgitation in terms of age (59 years v 56 years), blood pressure (140/84 mm Hg v 136/80 mm Hg), aortic diameter (34 mm v 33 mm), or frequency of calcification of the aortic valve (15% v 10%) and of systolic anterior motion of the mitral valve with mitral-septal contact (25% v 16%). On cross sectional echocardiograms, the degree of septal protrusion into the left ventricular outflow tract during systole was significantly more prominent (15 v 10 mm), and the portion of the basal septum that protruded most deeply into the left ventricular outflow tract was significantly closer to the aortic annulus in patients with aortic regurgitation than in those without it (11 v 14 mm). Mild aortic regurgitation was found in almost a quarter of patients with hypertrophic cardiomyopathy. The regurgitation was related to the morphological abnormality of the left ventricular outflow tract.     

Pulmonary venous flow pattern--its relationship to cardiac dynamics. A pulsed Doppler echocardiographic study

We studied the physiology of pulmonary venous flow in 13 normal subjects and five patients with atrial rhythm disorders and atrioventricular conduction disturbances with pulsed Doppler and two-dimensional echocardiography. The left atrium, mitral valve, and pulmonary venous ostia were visualized through the apical four-chamber view. Mitral and pulmonary venous flows were obtained by placing the Doppler sample volume at the appropriate orifice. Pulmonary venous flow was biphasic: a rapid filling wave was observed during systole when the mitral valve was closed; a second wave was observed in diastole during the rapid ventricular filling phase of mitral flow, but was significantly delayed. In patients without atrial contraction (atrial fibrillation and sinoatrial standstill), the initial rapid filling was greatly diminished and only the second diastolic wave appeared to contribute to left atrial filling. In patients with high-grade atrioventricular block, each atrial contraction was followed by a surge in flow from the pulmonary veins. These results are consistent with data obtained from invasive measurements in both dogs and man, and confirm the validity of the use of pulsed Doppler echocardiography in the study of pulmonary venous flow. We suggest that pulmonary venous flow is influenced by dynamic changes in left atrial pressure created by contraction and relaxation of the atrium and ventricle. The initial peak in pulmonary venous flow occurs with atrial relaxation simultaneously with the reduction of left atrial pressure, and the second peak occurs with left ventricular relaxation and rapid transmitral filling of the ventricle.     

Diagnostic criteria of interatrial defects: a single gate pulsed Doppler echocardiographic study

Functional closure of the oval foramen occurs during the first days of life. Nevertheless, range-gated pulsed Doppler echocardiography shows a transatrial flow pattern in many newborns. In this situation, cross-sectional echocardiography often fails in differentiating the valve-incompetent oval foramen from an atrial septal defect. In order to establish Dopplersonographic criteria for these diagnoses, we performed a prospective echocardiographic and pulsed Doppler study in 34 newborns with valve-incompetent oval foramen and in 30 children with atrial septal defect. We could not find any significant difference of flow pattern in either group, although a so-called "flap" signal could be demonstrated in 73.5% of the patients with an oval foramen, but in only 23% of the children with atrial septal defect. We suggest this feature reflects a distinct movement of the flap of oval foramen which passively follows the different interatrial pressure-flow dynamics. Nevertheless, this sign was insufficiently constant to prove presence of an oval foramen and not that specific to exclude an atrial septal defect. We conclude, therefore, that the precise nature of interatrial defects cannot be differentiated by single gate pulsed Doppler echocardiography.     

Bidirectional flow in congenital ventricular septal defect: a Doppler echocardiographic study

The purpose of this study was to demonstrate the value of combined two-dimensional and pulsed Doppler echocardiography (echo) in localizing and recording bidirectional flow in congenital ventricular septal defect. Eight children, aged 8 months to 16 years, with clinical signs of a ventricular septal defect, underwent two-dimensional and pulsed Doppler echo study prior to cardiac catheterization. The ventricular septal defect was documented anatomically by two-dimensional echo in all eight patients. Flow patterns in systole and diastole through the ventricular septal defect and on both sides of the defect were carefully studied. In all eight children, systolic, high velocity, pathologic, left to right flow was documented when the sampling volume was positioned on the right ventricular side of the defect. When the sampling volume was positioned inside the defect, to and fro flow, left to right in systole and right to left in diastole, was observed. In children with moderate to large defects, the diastolic flow had a peak in early diastole. Increased pressure in the right ventricle over the left ventricle during the same period was demonstrated by cardiac catheterization and coincided with the Doppler flow. The direction of flow across the defect was affected by the size of the defect and the magnitude of the net shunt. Two-dimensional and pulsed echo Doppler were shown to be useful in demonstrating the ventricular septal defect and estimating its size and hemodynamic significance noninvasively.     

Cross sectional early mitral flow velocity profiles from colour Doppler

Instantaneous cross sectional flow velocity profiles from early mitral flow in 10 healthy men were constructed by time interpolation of the velocity data from each point in sequentially delayed two dimensional digital Doppler ultrasound maps. This interpolation allows correction of the artificially produced skewness of velocities across the flow sector caused by the time taken to scan the flow sector for velocity recording of pulsatile blood flow. These results suggested that early mitral flow studied in an apical four chamber view is variably skewed both at the leaflet tips and at the annulus. The maximum flow velocity overestimated the cross sectional mean velocity at the same time by a factor of 1.2-2.2. Also the maximum time velocity integral overestimated the cross sectional mean time velocity integral to the same extent. This cross sectional skew must be taken into account when calculation of blood flow is based on recordings with pulsed wave Doppler ultrasound from a single sample volume.     

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

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 less than .01). Our technique permits the noninvasive evaluation of shunt flow dynamics in patients with PDA.