Quantitation of the motion of the cardiac base in normal subjects by Doppler echocardiography

Because the motion of the base of the heart plays a central role in its filling and emptying, we developed an original method to characterize the base motion dynamics throughout each cycle by use of pulsed Doppler echocardiography. A 100 Hz wall filter and low gain settings were used to record the low-frequency, high-energy Doppler signals generated by the motion of the base. From the apical four-chamber view, the sample volume was placed at the lateral margin and at the common septal margin of the tricuspid and mitral annuli. These signals were differentiated from left and right atrioventricular flows by their opposite direction, higher energy, timing, and unique audio signal. The dynamics of the cardiac base were quantitated in 17 normal subjects (31 +/- 13 years). The time relationship between transvalvular flows and the motion of the base was studied in nine normal subjects by matching recordings at the same RR interval. The Doppler signal of the motion of the cardiac base showed a succession of positive (apically directed) and negative (atrially directed) velocity waves. Differences in the dynamics of the cardiac base were demonstrated between its left and right components, probably related to different loading conditions and different myocardial mechanical properties. The relationship between the motion of the base and mitral flow as shown in this study suggests that Doppler-measured mitral flow velocity underestimates relative left ventricular inflow velocity with respect to the atrium by about 17% at peak early flow and by 20% at peak late flow. The method reported in the present study allows a more informative noninvasive quantitation of the cardiac base motion derived from measurements of its velocity, excursion, and acceleration. This new method may provide unique information on the left ventricular and right ventricular performance in the meridional direction.

[Measurement of right ventricular dP/dt. A simultaneous/comparative hemodynamic and Doppler echocardiographic study]

Right ventricular systolic function is difficult to assess by Doppler echocardiography. We studied 14 patients with tricuspid regurgitation on Doppler echocardiographic examination with the object of determining an index of right ventricular contractility based on the continuous Doppler signal of the regurgitant jet. The rate of increase in right ventricular pressure was calculated between 2 points, V1 and V2, situated on the ascending limb of the velocity profile of the tricuspid regurgitation and compared with the dP/dt max measured simultaneously at right heart catheterisation. The different values of V1 and V2 were: 0 and 1 m/s, 0 and 2 m/s, 0.5 and 1.5 m/s, 1 and 2 m/s and 0.5 and 2 m/s. An excellent correlation was observed between the catheter dP/dt max and the rate of increase in pressure measured by Doppler between 0 and 2 m/s (r = 0.93; p = 0.0001) and between 0.5 and 2 m/s (r = 0.93; p = 0.0001). The correlation was not as close between 0 and 1 m/s (r = 0.69; p = 0.048) and there was no correlation with the measurements between 0.5 and 1.5 m/s and between 1 and 2 m/s. Doppler echocardiography could therefore be used for non-invasive assessment of right ventricular systolic function in clinical practice.

A theoretical model for the noninvasive assessment of the transmitral pressure-flow relation

The purpose of this paper is to formulate from the equations of fluid mechanics an equation which describes the transmitral pressure-flow relationship. According to the linear momentum equation applied to the atrioventricular coupling, the left-atrium-left-ventricle pressure difference (Pa-Pv) can be written as Pa-P v = A delta v/delta t + B v 2 + C v, where v is the transmitral blood velocity and A, B, and C are variables related to the geometry of the atrium, ventricle and mitral orifice, respectively. Based on this theory, Pa-Pv is calculated noninvasively in a patient with a nonobstructive mitral valve. Mitral flow and cardiac dimensions recorded by Doppler echocardiography are digitized and analyzed. Calculation shows that Pa-Pv reaches its peak value at the time of flow peak acceleration and has already considerably decreased at the time of peak velocity. The time course of calculated Pa-Pv is in close agreement with the published experimental catherization data. Numerical computation of early diastolic left atrium and left ventricle pressure curves based on the experimental data of others for the time constant of left ventricular relaxation, left atrial and ventricular chambers stiffness constants, combined with sine-waveform-simulated mitral flow, verifies the time course and the magnitude of Pa-Pv as predicted from flow equations. This paper provides a theoretical method for the noninvasive assessment of the transmitral pressure-flow relationship using ultrasound technique and might help to achieve a better understanding of the diastolic function as assessed by Doppler echocardiography.

Demonstration of postvalvuloplasty hemodynamic improvement in aortic stenosis based on Doppler measurement of valvular resistance

It was recently suggested that valvular resistance, defined as the pressure gradient/flow rate ratio, may better depict the hemodynamic impairment in aortic stenosis than does valve area. The relation between aortic valve resistance and left ventricular mechanics was studied with Doppler echocardiography in 13 patients (mean age 85 years) with severe aortic stenosis who underwent percutaneous balloon valvuloplasty. The Doppler-estimated peak valvular resistance, defined as the ratio of peak transvalvular pressure gradient to peak valvular flow rate, decreased from 510 +/- 190 dynes.s.cm-5 before valvuloplasty to 300 +/- 110 dynes.s.cm-5 after the procedure (p = 0.0001). There was a close linear relation between valvular resistance measured at catheterization and Doppler-derived peak valvular resistance (r = 0.91). After valvuloplasty, left ventricular ejection fraction increased from 53 +/- 13% to 62 +/- 11% (p = 0.0001). The percent increase in ejection fraction was linearly related to the percent decrease in end-systolic wall stress (r = 0.56), which was in turn related to the percent decrease in peak valvular resistance (r = 0.75). No such linear relation existed between the percent changes in valve area and those in end-systolic wall stress. In conclusion, hemodynamic improvement after valvuloplasty is more closely related to changes in valvular resistance than to changes in valvular area. It is suggested that valvular resistance can be estimated accurately by Doppler echocardiography with use of a simple method and should be a primary consideration in assessing the hemodynamics of aortic stenosis.

Relative importance of activation sequence compared to atrioventricular synchrony in left ventricular function

This study evaluated the relative hemodynamic importance of a normal left ventricular (LV) activation sequence compared to atrioventricular (AV) synchrony with respect to systolic and diastolic function. Twelve patients with intact AV conduction and AV sequential pacemakers underwent radionuclide studies at rest and Doppler echocardiographic studies at rest and during submaximal exercise, comparing atrial demand pacing (AAI) to sequential AV sensing pacing (DDD) and ventricular demand pacing (VVI). Studies at rest were performed at a constant heart rate between pacing modes, and the exercise study was performed at a constant heart rate and work load. Cardiac output was higher during AAI than during both DDD and VVI (6.2 +/- 1 vs 5.6 +/- 1 and 5.3 +/- 1 liters/min, p less than 0.05). LV ejection fraction was likewise higher during AAI (55 +/- 12 vs 49 +/- 11 vs 51 +/- 13, p less than 0.05). VVI with or without AV synchrony was associated with a paradoxical septal motion pattern, resulting in a 25% impairment of regional septal ejection fraction. In addition, LV contraction duration was more homogenous during AAI. Peak filling rate during AAI and VVI was higher than during DDD (2.86 +/- 1 and 2.95 +/- 1 vs 2.25 +/- 1 end-diastolic volume/s; p less than 0.05). During VVI, the time to peak filling was significantly shorter than during both AAI and DDD (165 +/- 34 vs 239 +/- 99 and 224 +/- 99 ms; p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Noninvasive assessment of intrinsic ventricular load dynamics in dilated cardiomyopathy

On the basis of hemodynamic theory, a new noninvasive method is developed to provide improved insights into the significance of depressed Doppler left ventricular ejection variables in patients with dilated cardiomyopathy. The net force (F) associated with intraventricular flow throughout ejection can be written as: F = A.dv/dt + B.v2, where v is the ejection velocity and A and B are variables related to the geometry of the ventricle and its outflow tract. Instantaneous levels of this force were calculated in 9 normal subjects and 10 patients with dilated cardiomyopathy using Doppler, M-mode and two-dimensional echocardiography. The maximal ejection force (Fmax) was 47.5 +/- 8.5 kdyn in normal subjects and 25.5 +/- 6.2 kdyn in those with dilated cardiomyopathy (p = 0.0001). Peak local acceleration and outflow velocity were severely depressed in those with cardiomyopathy compared with normal subjects (1,260 +/- 129 versus 2,671 +/- 430 cm/s2 and 71 +/- 14 versus 109 +/- 7 cm/s, respectively; p = 0.0001). Maximal ejection force was attained very early in ejection. A significant linear correlation was found between peak outflow acceleration and maximal ejection force (n = 19; r = 0.91, p = 0.0001). At the time of peak ejection velocity, the net force had decreased to 64% of its peak value in those with cardiomyopathy, whereas in normal subjects, it had decreased to only 84% of its peak value (p = 0.008). In normal subjects, the ejection force was positive during the first 75% of ejection, but in those with cardiomyopathy, it was positive only during the first 54% (p = 0.0003). Once its peak value was attained, total left ventricular systolic wall stress declined rapidly during ejection in normal subjects (to 33% of its peak value by end-ejection), whereas it remained elevated throughout ejection in patients with cardiomyopathy (at 60% of its peak value by end-ejection, p = 0.0001 versus normal). The maximal ejection force corresponded to a calculated intraventricular peak pressure gradient of 9.8 +/- 1.6 mm Hg in normal subjects and 6 +/- 1.2 mm Hg in those with cardiomyopathy (p = 0.0001). The average contribution of the intrinsic component of the left ventricular systolic load (that is, wall stress associated with the ventricular to aortic pressure gradient) to the total myocardial load was 9.1% (range 7.3% to 11.2%) in normal subjects and 6.2% (range 3.9% to 7.5%) in those with cardiomyopathy (p = 0.0001).(ABSTRACT TRUNCATED AT 400 WORDS)

[Abnormal tricuspid flow in carcinoid heart disease. A case report]

A case of the carcinoid syndrome with right heart involvement is reported. Echocardiography showed diffuse right ventricular disease with a pathological tricuspid valve. Doppler recordings of forward tricuspid blood flow showed changes suggesting abnormal right ventricular filling, the mechanisms of which are discussed.

A simplified normalized ejection phase index measured by Doppler echocardiography for the assessment of left ventricular performance

Although useful for the assessment of directional changes in contractility in individual patients, resting peak aortic blood velocity is of limited value for differentiating among patients with different levels of basal cardiac function. A dimensional analysis based on fluid dynamics shows that peak aortic blood velocity is not only generated by the contracting myocardium but also reflects the convective acceleration of blood from the left ventricle to the aorta. The reduction of cross-sectional area from the midleft ventricle to the aorta at the time of peak aortic blood velocity generates the convective acceleration. Accordingly, a higher convective acceleration due to left ventricular (LV) enlargement as observed in cardiomyopathy may explain why peak aortic blood velocity can be maintained as normal although myocardial contractility is depressed. This study tested the hypothesis that peak aortic blood velocity normalized by the ratio of midleft ventricle to aortic cross-sectional areas might provide a reliable index of LV performance. Nine normal control subjects and 25 patients undergoing catheterization were studied by M-mode, 2-dimensional and Doppler echocardiography. The normalized peak velocity measured noninvasively showed a high correlation with angiographic ejection fraction (r = 0.90, p less than 0.0001). Peak aortic blood velocity and the ratio of midleft ventricle to aortic cross-sectional areas alone correlated less well with ejection fraction (r = 0.76 and r = 0.75, p less than 0.0001, respectively). Furthermore, peak aortic blood velocity showed a significant overlap between patients with normal and those with abnormal LV function, whereas normalized peak aortic blood velocity was a better discriminator.(ABSTRACT TRUNCATED AT 250 WORDS)

Accuracy of the simplified Bernoulli relationship in measuring pressure gradients across stenosis

In order to test the validity of the modified Bernoulli equation in predicting pressure gradients across stenotic regions, we have constructed an in-vitro model and studied the influence of the length and of the severity of the stenosis. Under physiological conditions, simultaneous pressure gradients are estimated by both Doppler and direct pressure manometer techniques. Measurements of the pressure gradients (in the range 10-150 mmHg) by the two techniques show that the Doppler estimation using the modified Bernoulli equation underestimated the pressure transducer gradient measurements for every length of stenosis, this underestimation being greater than 45% for very severe stenosis.

The tall R wave in lead V1 in posterior myocardial infarction: a reciprocal sign or a His-Purkinje conduction disturbance?

The significance of the tall R wave in lead V1 with an R/S ratio greater than or equal to 1 in posterior myocardial infarction (PMI) was investigated in 28 patients during programmed electrical stimulation. The patients had been admitted with acute PMI documented by electrocardiogram and proven by enzymatic increase. Electrophysiological study was performed 3 weeks after acute PMI. In 17 of the 28 patients (group 1), the tall R wave in V1 disappeared during stimulation: In 13 of them a premature atrial extrastimulus was responsible for an abrupt normalization of QRS complex in V1 related to an increase in AH or HV interval. In the 4 remaining patients the disappearance of the tall R wave in V1 was related to a sinus pause. In 14 patients of group 1, a different prematurity in atrial stimulation induced a right or left bundle branch block (BBB). In 11 of the 28 patients (group 2) the tall R wave in V1 was unchanged but a premature atrial extrastimulus induced a right BBB in 5 patients and a left BBB in 6. In conclusion, the normalization of QRS complex in lead V1 during atrial stimulation or alterations in cycle length suggests that the tall R wave in V1 in PMI is not a simple reciprocal sign of leads V8 V9. Its association with different varieties of BBB and changes in AH or HV intervals could suggest a relationship with a His-Purkinje conduction disturbance in some patients.

Doppler echocardiographic measurement of low velocity motion of the left ventricular posterior wall

A new noninvasive method using pulsed Doppler echocardiography was developed to assess left ventricular (LV) posterior wall motion dynamics. Seventeen normal subjects and 23 patients undergoing cardiac catheterization were prospectively studied. The sample volume was placed within the LV posterior wall endocardium just apical to the mitral valve sulcus using a posteriorly angulated low parasternal view. The wall filter was set at 100 Hz to record the low velocities of the LV posterior wall motion. The Doppler signal was morphologically similar to the rate of change of the LV posterior wall endocardium excursion obtained by a digitized M-mode echocardiogram, and showed 3 major waves: a systolic wave (S), an early diastolic wave (E) and a late diastolic wave (A). The peak velocities of LV posterior wall endocardium excursion were also determined by M-mode echocardiographic technique. We found a significant linear correlation between peak E-wave velocity and M-mode peak diastolic endocardial velocity (r = 0.90, p less than 0.001) and between peak S-wave velocity and M-mode peak systolic endocardial velocity (r = 0.81, p less than 0.001). M-mode peak systolic endocardial velocity showed an important overlap between control subjects and patients with normal and patients with abnormal LV posterior wall motion on the angiogram. In contrast, peak S-wave velocity was a better discriminator, and a peak S-wave velocity less than 7.5 cm/s was associated with abnormal LV posterior wall motion with an 83% sensitivity, 100% specificity and 95% accuracy. In patients with coronary artery disease but normal systolic LV posterior wall motion and normal global systolic LV function, peak S-wave velocity was not different when compared to control subjects. Peak E-wave velocity and E/A were significantly lower than in control subjects (p less than 0.01) and peak A-wave velocity was greater (p less than 0.01). In conclusion, these data suggest that pulsed Doppler echocardiography can be used for the direct analysis of LV posterior wall instantaneous low velocities and appears to be more informative than M-mode technique for systolic measurements. Thus, detection of abnormal LV posterior wall diastolic motion by pulsed Doppler echocardiography may, upon additional confirmation, be used as a new noninvasive method to gain insight into global LV diastolic performance.

A new Doppler method of assessing left ventricular ejection force in chronic congestive heart failure

A noninvasive method using Doppler echocardiography was developed to determine the force exerted by the left ventricle in accelerating the blood into the aorta. The value of this new Doppler ejection index in the assessment of left ventricular (LV) performance was tested in 36 patients with chronic congestive heart disease undergoing cardiac catheterization and in 11 age-matched normal control subjects. The 36 patients were subgrouped into 3 groups based on angiographic ejection fraction (LV ejection fraction greater than 60, 41 to 60 and less than or equal to 40%). According to Newton's second law of motion (force = mass X acceleration), the LV ejection force was derived from the product of the mass of blood ejected during the acceleration time with the mean acceleration undergone during that time. In patients with LV ejection fraction less than or equal to 40%, LV ejection force, peak aortic velocity and mean acceleration were severely depressed when compared with the other groups (p less than 0.001). In patients with LV ejection fraction of 41 to 60%, LV ejection force was significantly reduced (22 +/- 3 kdynes) when compared with normal subjects (29 +/- 5 kdynes, p = 0.002) and with patients with LV ejection fraction greater than 60% (29 +/- 7 kdynes, p = 0.009); peak velocity and mean acceleration did not differ between these 3 groups. The LV ejection force showed a good linear correlation with LV ejection fraction (r = 0.86) and a better power fit (r = 0.91). Peak aortic blood velocity and mean acceleration showed less good linear correlations with LV ejection fraction (r = 0.73 and r = 0.66, respectively). The mass of blood ejected during the acceleration time also showed a weak linear correlation with LV ejection fraction (r = 0.64). An LV ejection force less than 20 kdynes was associated with a depressed LV performance (LV ejection fraction less than 50%) with 91% sensitivity and 90% specificity. Thus, these findings suggest that LV ejection force is a new Doppler ejection phase index that appears to be more accurate than peak aortic blood velocity and mean acceleration for the assessment of systolic LV function.

Inducible multiform ventricular tachycardia in Wolff-Parkinson-White syndrome

The induction of ventricular tachycardia by ventricular stimulation was investigated in 46 patients with isolated Wolff-Parkinson-White syndrome (10 concealed) and 36 control patients with normal electrocardiograms and conduction systems. None of those studied had spontaneous ventricular arrhythmias or myocardial or valve disease. Single and double ventricular extrastimuli were delivered at 3 cycle lengths (sinus, 600 ms, 400 ms). In the controls ventricular simulation induced one episode (3%) of non-sustained ventricular tachycardia. Ventricular stimulation in patients with Wolff-Parkinson-White syndrome induced two episodes of ventricular fibrillation and 15 episodes of non-sustained multiform ventricular tachycardia (37%). Ventricular arrhythmias were induced only in patients with overt Wolff-Parkinson-White syndrome. In 14 patients the conformation of the electrocardiogram at the start of ventricular tachycardia resembled that of major pre-excitation. The absence of inducible ventricular tachycardia in patients with concealed Wolff-Parkinson-White syndrome suggests that anterograde conduction via an atrioventricular accessory pathway is required to initiate the ventricular arrhythmias: the ventricular tachycardia may be associated with reentry of impulses via atrioventricular connection during the phase of ventricular vulnerability. The similarity between the start of ventricular tachycardia and pre-excitatory complexes may also indicate local reentry into the ventricular area occupied by the bypass tracts. Patients with Wolff-Parkinson-White syndrome and anterograde pre-excitation are more likely to have inducible multiform ventricular tachycardia than individuals without Wolff-Parkinson-White syndrome.

Effect of flecainide on left ventricular ejection fraction

Antiarrhythmic agents may depress cardiac contractility and worsen heart failure. Flecainide is an effective antiarrhythmic drug, but when administered orally in patients with left ventricular (LV) dysfunction, its effect on LV function is unknown. To assess the effects of flecainide on cardiac function, LV ejection fraction (LVEF) was measured by radionuclide ventriculography in 36 patients with LV dysfunction (LVEF less than or equal to 40%), prior to, and 7 days after, drug therapy was initiated. To analyse the possibility of a dose-dependent effect on LVEF, 18 patients received 200 mg day-1 of flecainide and 18 patients with an identical initial LVEF (27 +/- 8 vs 27 +/- 9) (NS) received 300 mg day-1. The study was stopped in 7 patients because of severe cardiac adverse effects; in these patients the LVEF was significantly lower (15 +/- 7) than that of the 29 patients who completed the protocol (27 +/- 8) (P less than 0.01). In patients who completed the protocol, there was no significant change in LVEF either with a daily dosage of flecainide of 200 mg day-1 (27 +/- 8 vs 27 +/- 8) or with 300 mg day-1 (27 +/- 9 vs 28 +/- 13). Thus, in the patients with LV dysfunction studied, oral flecainide did not significantly affect LV function either with a low or with the usual daily dosage. However, in patients with severe impairment of LV function (LVEF less than 30%) flecainide must be used carefully owing to a higher incidence of adverse effects on cardiac rhythm.

Is the aorta truly dextroposed in tetralogy of Fallot? A two-dimensional echocardiographic answer

The embryogenesis of tetralogy of Fallot is still much debated. In particular, the dextroposition of the aorta is not considered by all pathologists as a genuine abnormality in this congenital heart disease but rather as a false impression due to an exaggeration of the normal overriding caused by dilatation of the aorta secondary to abnormal hemodynamics. We used two-dimensional echocardiography to examine the spatial position of the aortic root in 22 patients with tetralogy of Fallot (aged 5 days to 24 years, mean 6.4 years) and in 23 normal subjects (aged 1 month to 27 years, mean 7.6 years). Using the parasternal short-axis view, we determined the percent rightward displacement of the aortic root in relation to the plane of the atrial septum, and the relationship between the aortic cusps and the atrial septum. We measured the value of the angle luminal diameter, which was defined as the angle between the plane of the atrial septum and the plane of the left coronary-noncoronary commissure and leaflet appositional plane. In the control group, the aortic root was displaced to the right by only 23.6 +/- 7.6%; the atrial septum crossed the posterior aspect of the aortic root at the middle (n = 19) or at the right half of the posterior cusp (n = 4), and the angle luminal diameter had a value of 43.3 +/- 8.8 degrees. In the 22 patients with tetralogy, the percent rightward shift of the aortic root was augmented to 55.5 +/- 9% (p less than .001) and the atrial septum was related to the posterior commissure in 14 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

[Measurement by Doppler echocardiography of the pulmonary arterial pressure in children with ductus arteriosus. Simultaneous Doppler and hemodynamic study]

The aim of this study was to evaluate Doppler echocardiography in the non invasive assessment of pulmonary artery pressures in children with patent ductus arteriosus. Systolic pulmonary artery pressure was measured simultaneously at cardiac catheterisation and by pulsed Doppler in 11 children (mean age 1.8 +/- 2 years) with patent ductus arteriosus alone (6 cases) or associated with a malformation of the heart or great arteries (5 cases). Doppler assessment of systolic pulmonary artery pressure was performed by subtracting the value of the maximal pressure gradient between the aorta and pulmonary artery from the systolic systemic pressure measured simultaneously by sphygmomanometry. The maximal pressure gradient between the aorta and pulmonary artery was calculated using the modified Bernouilli formula and the maximal velocity (v) of the shunt flow (gradient = 4 v2). Ductal flow was recorded from the suprasternal approach by direct interrogation of the patent ductus visualised by 2D echocardiography. The systolic pulmonary arterial pressure measured by catheterisation ranged from 21 to 82 mmHg (mean 58 +/- 21 mm Hg) and by pulsed Doppler from 20 to 89 mm Hg (mean 56 +/- 24 mm Hg) (correlation r = 0.94). This study illustrates the value of Doppler echocardiography in the assessment of systolic pulmonary artery pressures in children with patent ductus arteriosus.

[Hemodynamic effects of an alpha-blocking vasodilator in cardiac insufficiency caused by left-right shunt in children]

The acute haemodynamic effects of an alpha-blocking vasodilator, nicergoline, observed during cardiac catheterisation were studied in 9 babies and 1 infant (mean age 11 months) with severe cardiac failure due to a large left-to-right interventricular shunt. Nicergoline was administered intravenously at a dose of 0.05 mg/kg/mn to 0.2 mg/kg/mn to lower mean systemic blood pressure by at least 10 mmHg. No significant changes in heart rate or in right and left atrial pressures were observed. On the other hand, mean systemic and pulmonary arterial pressures fell by 16% (p less than 0.001) and 13% (p less than 0.01) respectively. The ratio of pulmonary and systemic flow (Qp/Qs) decreased in 8 patients by an average of 21% (p less than 0.002). This fall was accompanied by a parallel reduction in oxygen concentrations of pulmonary arterial blood (16%) compared with mixed venous blood. However, the Qp/Qs ratio increased in the other 2 patients by over 50%. In the group of 8 patients in which the left-to-right shunt decreased, the ratio of pulmonary to systemic resistance (Rp/Rs) increased by 33% (p less than 0.002) whilst this value fell by 36% in the 2 patients in whom the volume of the shunt increased. There were no discriminatory parameters between the two groups with regards to age, pulmonary artery pressures, the volume of the shunt (Qp/Qs) or level of pulmonary resistances (Rp/Rs) to explain the variability of the therapeutic response on the left-to-right shunt.(ABSTRACT TRUNCATED AT 250 WORDS)

Pulsed Doppler flow characteristics of ductus arteriosus in infants with associated congenital anomalies of the heart or great arteries

Pulsed Doppler echocardiography (PDE) from the suprasternal approach was used to assess flow characteristics of ductus arteriosus (DA) in 145 infants (aged 1 day to 6 months) with major congenital heart disease. Direct ductal Doppler interrogation was possible in 138 patients and serial studies before and after medical treatment were performed in 28 infants. According to pulmonary artery pressure and associated heart lesions, 3 ductal shunting patterns were identified. An isolated left-to-right shunt, observed in isolated DA or in right ventricular outflow tract obstruction, was characterized by a continuous flow with a peak velocity in late systole. An isolated right-to-left shunt, observed in persistent fetal circulation and aortic arch abnormalities, was characterized by a continuous flow with a peak velocity in early systole. In patients with a bidirectional ductal shunt, the right-to-left shunt always occurred in systole and the left-to-right shunt began in late systole and extended into diastole. A systolic right-to-left shunt always corresponded to the presence of significant pulmonary hypertension. Ductal flow changes could be documented after prostaglandin E1 therapy in patients with ductus-dependent heart disease or after tolazoline therapy in patients with persistent fetal circulation. Thus, PDE with direct ductal Doppler interrogation is an important complement to the echocardiographic evaluation of DA. It is a safe noninvasive approach to ductal shunt and permits convenient evaluation of the effects of drugs on pulmonary artery resistance (tolazoline) and ductal patency (prostaglandin E1).

Assessment of right ventricular outflow tract in children by two-dimensional echocardiography using a new subcostal view. Angiocardiographic and morphologic correlative study

Evaluation of the right ventricular (RV) outflow tract in congenital heart disease is extremely important for surgical management. Therefore, the value of 2-dimensional echocardiography (2-D echo) to assess the RV outflow tract was studied using a new approach: the subcostal elongated right oblique view. Twenty normal children and 49 children with congenital heart disease, aged 1 day to 11 years, were studied. Significant pulmonary infundibular obstruction was present in 22 patients with conotruncal malformations. To obtain the subcostal elongated right oblique view from the short-axis view at the aortic valve level, the transducer was slightly rotated clockwise with an anterior angulation of about 30 degrees so that the ascending aorta was seen in its long axis, providing an image similar to that obtained by a right ventriculogram in the elongated right anterior oblique view. The deviation of infundibular septum was appreciated by measurement of the angle alpha, defined by the long axis of the infundibular septum and the plane of aortic cusps. This view could be obtained in 64 patients (92%). In correlation with angiographic or anatomic data, the subcostal elongated right oblique view permitted recognition of several types of RV outflow tract: type I--normally formed RV outflow tract; type II--disorganized RV outflow tract with obstruction (alpha less than 90 degrees); type III and IV--disorganized RV outflow tract with obstruction (alpha greater than 90 degrees). This view could visualize the crista supraventricularis in type I, but also the anatomic components of RV outflow tract that may contribute to obstruction in the other types: infundibular septum, septoparietal trabeculations and trabecula septomarginalis.(ABSTRACT TRUNCATED AT 250 WORDS)

[Two-dimensional echocardiography and left heart obstruction in the newborn infant. Diagnostic contribution and impact on therapy]

Thirty-nine neonates with left heart obstructions (LHO) were investigated by two-dimensional echocardiography (2 D echo). Results of 37 investigations were compared with angiographic data (15 cases) and/or anatomic data (surgery: 20 cases; post-mortem examination: 20 cases). 2 D echo was always performed as an emergency procedure and was interpreted before further hemodynamic investigation. Accurate investigation of the left ventricle and of the aorta (arch and proximal branches) was possible in 38 patients (97%) by combining the supra-sternal and subcostal approaches. The existence of LHO and its localization were correctly predicted by 2 D echo in 37 of 39 cases including: aortic coarctation (Ao co) (23 cases), isolated aortic stenosis (iAo S) (5 cases), interruption of the aortic arch (IAA) (3 cases), hypoplastic left ventricle (6 cases), and ranged LHO (2 cases). In 2 patients, one of whom presented with transposition of the great arteries, a coarctation was overlooked and a false positive (Ao co) was found during the same period in a prospective study of 100 neonates by 2 D echo (sensibility 95%, specificity 99%, predictive value 97%). In all patients, 2 D echo made it possible to establish the associated lesions that could modify therapeutics. In no case was emergency diagnostic surgery necessary and the last 9 patients of this series underwent successful therapeutic surgery only on the basis of echographic data.