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Right ventricular outflow tract not seen in ultrasound

The right ventricular outflow tract (RVOT) view (or three vessel view/3VV) is one of the standard views in a fetal echocardiogram.It principally assesses the right ventricular outflow tract.. It is a long axis view of the heart, highlighting the path from the right ventricle into the pulmonary trunk (right ventricular outflow tract).. In this view, the right ventricle and pulmonary trunk. The basic view performed in cardiac ultrasound is the four-chamber view [], which can detect 43-96% of fetal anomalies [].]. Extended basic views of the left ventricular outflow tract (LVOT) and right ventricular outflow tract (RVOT) increase the sensitivity for the detection of anomalies

Right ventricular outflow. The pulmonary artery (PA) is seen in long axis (arrow in A) and short axis (arrow in B). Color Doppler (C) image shows color flow and the spectral waveform of the pulmonary artery (arrow). RV - right ventricl The best view for diagnosing VSD's is the subcostal four-chamber view as the ultrasound beam is perpendicular to the interventricular septum (axial resolution is better than lateral resolution). Other important views include the left and right ventricular outflow tract views and the short axis views of the ventricles. THE NORMAL VENTRICULAR SEPTU Left Ventricular Outflow Tract (LVOT) Above. The left ventricular outflow tract in the fetal heart is seen by obtaining a long-axis view of the heart. The scan head is angled slightly anteriorly and medially (right) from the aortic root. The right ventricle is anterior to the left ventricle. The normal aorta is about 3 mm at 20 weeks For the right ventricular outflow tract (RVOT), there is a subpulmonary conus (a conus is essentially a ridge of tissue), and for the LVOT, a subaortic conus. During the process of septation, the subpulmonary conus remains, which accounts for the distance between the tricuspid and pulmonary valves

  1. From the PLAX view, the right ventricular outflow tract view (RVOT) is obtained by angling the sound beam toward the patient's left shoulder. Slight adjustments in angle and rotation maybe necessary to demonstrate all the structures for this view optimally. 2D M-Mode - Parasternal Window - RVOT PSAX view @ bas
  2. Figure 9-39. Patch repair augmentation of the outflow tract is complete. The size of the patch is large enough to avoid residual blockage in the outflow tract but is not excessive; this may help avoid later development of a patch aneurysm. caud. Figure 9-39. Patch repair augmentation of the outflow tract is complete
  3. Right ventricular outflow tract A view of the right ventricular outflow tract (RVOT) documents the presence of a great vessel from a morphologic right ventricle with a moderator band (Figure 6). The pulmonary artery normally arises from the right ventricle and courses toward the left of the more posterior ascending aorta
  4. ation. The function of the tricuspid and mitral valves should be assessed using color Doppler with a velocity set at 60 to 80 cm/second (see Fig. 14-6 G)

Ultrasound of Fetal Cardiac Anomalies : American Journal

An 81-year-old man had a witnessed in-hospital cardiac arrest. He had been hospitalized on the gastroenterology ward for 3 weeks, recovering from a partial hepatectomy with bile duct resection and hepaticojejunostomy for a cholangiocarcinoma. His medical history also included well-controlled arterial hypertension and hypercholesterolemia During systole, the tumor moved in a to‐and‐fro manner into the main pulmonary artery (PA), distorting the pulmonary valve and thereby causing substantial obstruction of the right ventricular outflow tract (RVOT; Figure 1, C and D, and Videos 2-4). Only low antegrade turbulent flow was observed across the pulmonary valve

A Gallery of High-Resolution, Ultrasound, Color DopplerSinus of Valsalva Aneurysm With Right Ventricular Outflow

The intra-atrial septum was not well seen, but there was no obvious atrial-level shunt. and longitudinal dimensions only consider a section of the RV and do not take into account RV volume contained in the right ventricular outflow tract (RVOT), Cardiovasc Ultrasound. 2012; 10:1. doi: 10.1186/1476-7120-10-1 Right ventricular outflow obstruction is the most commonly associated type of pulmonary stenosis; Functional pulmonary atresia is demonstrated due to the reduced force of contraction of the right ventricle, true pulmonary atresia can be seen also; Prone to developing an arrhythmia, most commonly supraventricular tachycardi Association between left ventricular outflow tract opening and successful resuscitation after cardiac arrest. Resuscitation May 2019 - Pubmed Link. Take Home Points. 1. In this small case series, an open left ventricular outflow tract, as seen on TEE, was associated with successful resuscitation. 2 Teaching Points. This case demonstrates the VSD and overriding aorta of Tetralogy of Fallot. Obstruction of the right ventricular outflow tract seen in Tetralogy is variable in degree and was relatively mild in this case and thus not well visualized. Right ventricular hypertrophy does not develop until after birth

Fetal echocardiography - PubMed Central (PMC

intracardiac ultrasound can provide additional information, on the right ventricular abnormalities compared to 2D echo. Patient concerns: Case 1 is a 30-year-old patient that presented in the Emergency Department with multiple episodes of fast monomorphic ventricular tachycardia (VT) manifested by palpitations and diziness. Case 2 is a 65-year-old patient that also presented with episodes of. While this improvement in left ventricular outflow tract velocity time integral parallels the trend seen in mortality outcomes across the three groups, it only correlates with changes seen in pulmonary artery systolic pressure, not in other markers of echocardiographic right ventricular dysfunction (tricuspid annular plane systolic excursion. We have diagnosed HOCM in a 680g chinchilla, with systolic anterior motion of mitral valve (SAM), dynamic left ventricular outflow tract obstrcution and dynamic right ventricular outflow tract obstrcution (DRVOTO) Definition, Spectrum of Disease, and Incidence. A ventricular septal defect (VSD) is an opening in the ventricular septum, leading to a hemodynamic communication between the left and right ventricles. VSDs are common congenital heart defects, second only to bicuspid aortic valve ( 10 ). Isolated VSDs account for 30% of children born with.

Ultrasound of Ventricular Septal Defect

  1. Freed, Michael Cuttica, Daniel Schimmel * Corresponding author for this work
  2. The industry standard for printing separations to film transparency media. AccuRIP™ and Spot Process™ Sep Studio™ 4: Imagined, Engineered and Created by U
  3. The basic view performed in cardiac ultrasound is the four-chamber view [], which can detect 43-96% of fetal anomalies [].]. Extended basic views of the left ventricular outflow tract (LVOT) and right ventricular outflow tract (RVOT) increase the sensitivity for the detection of anomalies
  4. wall motion abnormality. There is left ventricular outflow tract partial obstruction/severely turbulent evaluation with transesophageal echocardiogram is recommended. 2. Normal left and... View answer. Done with ultrasound of heart and showing mild septal weakness with a slight ventricular regurgitation
  5. The RVOT (right ventricular outflow tract) is located between supraventricular crest and pulmonary valve; comprised of the conus arteriosus (infundibulum), ventricular septum and right ventricular free wall. Function: Carries blood out of the ventricle in an anterior-superior direction

Right Ventricular Outflow Tract. Anyone else had trouble seeing right ventricular outflow on the anatomy scan. They said bc of baby positioning they couldn't get the measurement they needed. I go back in 8 weeks. Said everything else heart and organ wise looked normal. It's just hard not to worry especially when you start looking up. Schematic illustration of parasagittal view, showing left ventricle (LV) and aortic outflow tract (Ao). A portion of the right ventricle (RV) is noted anteriorly, opposite the left atrium (LA). The interventricular septum can be readily assessed in this plane. B. Ultrasound appearance of the parasagittal view Right ventricular hypertrophy can be seen in various pathological states: RV pressure overload, biventricular hypertrophic cardiomyopathies, and deposit diseases. Right ventricular outflow tract shortening fraction but a good alignment of the ultrasound beam with the interrogated wall becomes increasingly difficult in dilated ventricles. Of course, there are not really 5 chambers in the heart but in echocardiography, the 5th chamber is when you can see the appearance of the aortic valve and the left ventricular outflow tract. Sometimes you will want to intentionally obtain this view in order to calculate the cardiac output of the left heart The PLAX view should have ascending aorta, mitral valve, left ventricle, left ventricle outflow tract, aortic valve, interventricular septum, right ventricular outflow tract, and descending aorta. For hand positioning, you should put the transducer indicator dot toward the right shoulder in the 3rd to 5th intercostal space

Figure 5 Severe pulmonary regurgitation seen simultaneously in the parasternal short (reference image) and long-axis view in xPlane mode. RVOT, right ventricle outflow tract; MPA, main pulmonary artery. Figure 6 Severe pulmonary regurgitation seen in the RV coronal view in iRotate mode. RV, right ventricle; RA, right Structures that are typically seen with this view include the coronary sinus (within the atrioventricular groove), left ventricle in sagittal view, right ventricular inflow tract, the left ventricular outflow tract, and the descending aorta (posterior to the left atrium) . When the transducer is properly aligned one can assess and measure the. Image 1: Subcostal cardiac view angled anteriorly to see the aortic valve; There is a small pericardial effusion anteriorly which seems to be exerting some pressure effect on the right ventricle with minor atrial and ventricular collapse. Both right and left sided chambers appear small and in this view the LV cavity appears almost obliterated. Although off axis the LV walls appear t The transducer notch is pointing toward the patient's right shoulder, with the patient in the left lateral position and the transducer just to the left of the sternum in the third intercostal space. This view allows for 2D assessment of the right ventricular outflow tract, pulmonic valve, and pulmonary trunk

Normal Fetal Heart Ultrasound OB Image

Introduction The Parasternal Short Axis view at the aortic valve level allows for 2D assessment of the aortic valve, tricuspid valve, pulmonic valve, right ventricular function, and identification of the cusps of the aortic valve. Color flow Doppler assessment of the tricuspid valve and pulmonic valve is evaluated in this view. Continuous wave Doppler can be performed through the tricuspid. ASE guidelines require the LVOT diameter to be measured in the parasternal long axis view. I have seen the LVOT diameter measurement performed in the apical views before. The reason why we do not measure in the apical window is actually a boring physics reason! Axial resolution is better than lateral resolution in ultrasound The left ventricular outflow tract (LVOT) is the term for the aortic root and proximal ascending aorta. A portion of the right ventricle is seen in the near field. Image 2. Parasternal long axis view. RV = Right ventricle. LV = left ventricle. MV = mitral valve. LVOT = left ventricular outflow tract. LA = left atrium The formal report stated there was a mass causing right ventricular outflow tract obstruction with a gradient of 60 mm Hg. Subsequent competed tomography (CT) showed a new lobulated enhancing 7.0 cm by 2.9 cm soft tissue mass within the right ventricle and right ventricular outflow tract The right heart views demonstrate the right ventricle and the right ventricular outflow tract. The main pulmonary artery originates from the anterior ventricle and trifurcates into a large vessel, the ductus going into the descending aorta, and two small vessels, the pulmonary arteries Pulsed Doppler ultrasound, in combination with two.

Fetal Cardiac Outflow Tracts: Normal and Abnormal Anatomy

(4) Left ventricular outflow tract (LVOT) obstruction is seen in 5-10% of cases. The term 'simple' transposition refers to the malformation in which the ventricular septum is intact or nearly intact in the presence of a small VSD and the LVOT is not obstructed Transthoracic echocardiography (TTE) found a pedunculated, highly mobile, mass in the right ventricular outflow tract (Figure 1, Video-see additional file 1). It was not possible to describe precisely the attachment of this mass or its underlying cause. However, its floppy nature and echodensity was compatible with a vegetation

Parasternal Window Sonography Resource

Parasternal short axis view showed D-shaped left ventricle (C). Parasternal short axis view of aortic valve level. In this view, right ventricular outflow tract (RVOT) mass (arrowhead) was hardly seen (D). Parasternal short axis view of RVOT level demonstrated 5.5 × 3 cm sized mass (arrowhead) nearly obstructing the RVOT (E) Fetal cardiac screening required by national guidelines (American Institute of Ultrasound in Medicine, American College of Radiology, The American Congress of Obstetricians and Gynecologists, and Society of Radiologists in Ultrasound) consists of four-chamber, right ventricular outflow tract, and left ventricular outflow tract views Right ventricular outflow tract (showing branching of the PA) 3 Vessel view (help diagnose conotruncal heart defects: Examples of conotruncal defects include, but are not limited to: truncus arteriosus, transposition of the great vessels, Tetrology of Fallot) Aortic Arch . Ductal Arch . IVC / SVC . Pericardial Effusio Right ventricular hypertrophy: The right ventricle is more muscular than normal, causing a characteristic boot-shaped (coeur-en-sabot) appearance as seen by chest X-ray. Due to the misarrangement of the external ventricular septum, the right ventricular wall increases in size to deal with the increased obstruction to the right outflow tract

The parasternal long axis plane—This displays the right ventricular outflow tract which is usually a third of the normal left ventricle. The right ventricular free wall can be seen just in the front, but optimal gain settings may be necessary for its optimal visualisation. Posteriorly, the ventricular septum can be seen (fig 4) The five-chamber view [Figure 4] is similar to the four-chamber view except that the aortic valve and the left ventricular outflow tract are seen. This is a great view for the Doppler interrogation of the aortic valve as the flow through it is almost parallel to the ultrasound beam (ideal Doppler angle) in systole. The ultrasound beam should interrogate across the LVOT which means that obstruction is not occurring across the whole outflow tract unless the patient is asystolic. LVOT, left ventricular outflow tract; SAM, systolic anterior motion of the mitral valve A Potpourri of cases. Surprise. Issakwisa Habakkuk Mwakyula from Tanzania sent us a case of a 26-year-old woman, a mother of four children, who presented with signs and symptoms of congestive cardiac failure and bluish discoloration of the lips, five weeks after spontaneous vaginal delivery (she delivered twins) To describe the institutional experience, technical aspects and outcome of stenting of the right ventricular outflow tract (RVOT) in the initial palliation of symptomatic patients with severely limited pulmonary blood flow. Retrospective case note and procedure review of patients undergoing stenting of the RVOT over a 10 year period at a quarternary institution

Repair of Hypoplastic Right Ventricular Outflow Tract

common abnormal ultrasound appearances of the abdomen & anterior abdominal wall Learning objectives. Left ventricular outflow tract (LVOT) Right ventricular outflow tract (RVOT) & crossover of LVOT 3 vessel trachea (3VT) view of heart If the stomach is not seen, or found to be small, with normal amniotic fluid volume, most likely. Anatomy of the PLAX. At the top of the screen, closest to the ultrasound probe, is the right ventricular outflow tract (RVOT). Moving clockwise, the aortic valve (AV) and proximal ascending aorta (Ao) are seen, then the left atrium (LA), mitral valve (MV) and left ventricle (LV). PLAX indicates parasternal long axis sided vegetation attached to the muscular bundle of the right ventricle is presented. Transthoracic echocardiography revealed a vegetation in the right ventricular outflow tract. Transesophageal echocardiography clearly showed that the 1.8 cm vegetation was not adherent to the pulmonary valve but attached to a muscular bundle

Cardiac screening examination of the fetus: guidelines for

Monochorionic twin pregnancies are at increased risk of perinatal mortality and morbidity due to twin-twin transfusion syndrome (TTTS), selective intrauterine growth restriction (sIUGR), and higher incidence of congenital heart malformations. The incidence of right ventricular outflow tract obstruction (RVOTO) in recipients with TTTS is known to be higher than in the general population Figure 4-1 Right parasternal echocardiographic views. A, Long-axis four-chamber view optimized for left ventricular inlet.B, Long-axis view optimized for left ventricular outflow tract.C, Short-axis view at the papillary muscle level. D, Short-axis view at chordal level.E, Short-axis view at mitral valve lavel.F, Short-axis view at the heart base, optimized for left atrium and aortic valve The transducer sends ultrasound waves through your chest toward your heart. A computer interprets the sound waves as they bounce back to the transducer. and right-sided cardiac output using spectral Doppler through the right ventricular outflow tract can be accomplished in this view. The anterior pericardium can be seen, and systolic right.

Ultrasound Findings. Gray Scale. Most cases of pulmonary stenosis are not clearly demonstrated on the second trimester ultrasound. When pulmonary stenosis is suspected prenatally, the four-chamber view typically shows right ventricular hypertrophy with bulging of the interventricular septum into the left ventricle (Fig. 24.2).The right ventricular lumen may appear small due to the. Increasing right ventricular contractility will also be useful in right ventricular failure as long as there is no left ventricular outflow tract obstruction. In that situation, phosphodiesterase inhibitor or beta agonist alone or in combination with vasopressin or α-agonist, if required, can be used to maintain right coronary perfusion pressure You will also see turbulent flow in the left ventricular outflow tract (hypertrophic cardiomyopathy). In theory the jet orientation in these pathologies is perpendicular to the Doppler orientation. Therefore, one would not anticipate a good display of jets. In clinical practice the opposite is the case

ULTRASOUND EVALUATION OF THE FETAL HEART Radiology Ke

Objectives . To describe the process of selection of candidates for fetal cardiac intervention (FCI) in fetuses diagnosed with pulmonary atresia-critical stenosis with intact ventricular septum (PA/CS-IVS) and report our own experience with FCI for such disease. Methods . We searched our database for cases of PA/CS-IVS prenatally diagnosed in 2003-2012 This course will cover the left ventricular outflow tract view, the right ventricular outflow tract view, the three-vessel view and the three-vessel trachea view. The anatomy of the formation of the outflow tracts and great vessels will be discussed to allow better understanding of the anatomical relationships of these structures The long axis view of the left ventricular outflow tract (LVOT) is seen (panel 1). Step 3: the cross hair is moved to the region of the aortic valve (Ao, panel 1) and the short axis view of the right ventricular outflow tract (RVOT) can be seen on the reconstructed sagittal plane (panel 2) Right Ventricular Outflow Tract Demonstrates: Small or absent left ventricle seen by ultrasound. Hypoplastic Left Heart Syndrome-underdevelopment of the LV, MV, Aorta and aortic valve -Most severe form of CHDs/ lethal-Common cause of death-13% of all CHDs-more common in males

Fetal Cardiac US: Techniques and Normal Anatomy Correlated

In this view, we can observe the left ventricular (LV) free wall, the mitral valve with its attachement to the LV free wall, the fibrous continuity between the aortic valve and the mitral valve. Anteriorly, we can see the right ventricular outflow tract (RVOT) and the septum seperating the LV from the RVOT Measurement of Velocity-Time Integral (VTI) of the Left ventricular outflow tract (LVOT) Set Ultrasound machine to Pulse Wave doppler (PWD) Place cursor in Left ventricular outflow tract (LVOT) Place cursor as close to aortic valve without including it; Capture Pulse Wave doppler (PWD) wave form and freeze the image. PWD wave form will appear.

This educational activity will review the importance of understanding the use of echocardiography to evaluate left and right basic ventricular function. This class will review the different techniques, limitations and clinical implications of using echocardiography to evaluate both global and regional left and right ventricular function No right ventricular outflow tract (RVOT) stenosis is seen. This is Eisenmenger defect. Malaligned superiorly displaced outlet septum is seen (yellow arrow, bottom left). Membranous septum (MS) is absent, and septal tricuspid (STV) leaflet is almost in fibrous continuity with aortic leaflet Right Ventricular Outflow Tract (RVOT) The right ventricular outflow tract flow profile is similar to the LVOT flow profile, except the RVOT does not produce the peak velocities seen in the LVOT. The shape of the flow profile is similar. A swift upstroke, a smooth curve, followed by a swift down stroke is normally seen Keywords: Tetralogy of Fallot, Right ventricular outflow tract obstruction, Stent, Congenital heart disease Background The initial management of patients with normally re-lated great arteries and a narrow right ventricular out-flow tract (RVOT) with reduced pulmonary blood flow, as classically seen in Tetralogy of Fallot, remains challen-ging RV infarction is generally not seen in isolation but does occur in upwards of ⅓ of inferior myocardial infarctions. An RV outflow tract (RVOT) Figure 2: Pulse Wave Doppler of the Right Ventricular Outflow Track

Example 1. Baseline ECG of a patient with Arrhythmogenic Right Ventricular Dysplasia (ARVD), demonstrating: T-wave inversion in precordial and inferior leads, without RBBB pattern. Epsilon wave in V1. Localised widening of QRS in V1-2. Example 2. Right Ventricular Outflow Tract (RVOT) Tachycardia, demonstrated by: Regular broad complex. Video 7: 31 weeks, Tomographic ultrasound imaging: coronary fistula is seen mimicking normal outflow form right ventricle, it begins in the right ventricle wall. Image on the right explains the structures visible on the video 7 (LV - left ventricle, RV - right ventricle, LA - left atrium, RA right atrium, Ao - aorta, Fis - fistula) These authors take a look at a new echocardiographic parameter that might be even more accurate in diagnosing the subset of massive and submassive PE: the right ventricular outflow tract early systolic notch (ESN). Check out The Evidence Atlas - Echo for a review of prior evidence on point of care ultrasound in pulmonary embolism. Question

fetal heart ultrasound how t

*Right ventricular outflow tract (RVOT) **Visual estimation or measured with M-mode about 2-3cm distal from its entrance into the right atrium . or just distal to where the right hepatic vein joins the IVC (see image 11). ***Focused cardiac ultrasound finding equivalent to pulsus paradoxus Validation of a cardiac ultrasound method to quantify right ventricular stroke volume and end systolic volume 3.1 Introduction. To establish a pressure volume loop using ultrasound, RV pressure changes and RV volume changes during the cardiac cycle must be determined

Right ventricular outflow tract obstruction diagnosis. Gold standard diagnosis of right ventricular outflow tract obstructions and assessment of severity is done by 2D echocardiography 38). Cardiac MRI is very useful to study the anatomy of the right ventricular outflow tract, pulmonary artery and to locate the exact level of stenosis 39) Magnetic resonance imaging (MRI) revealed that the left ventricle was compressed by the large right ventricle (maximum diameter was 53mm), which contained a huge nonhomogenic mass measuring 30x60x70mm rising from the basal interventricular septum and growing throughout the right ventricular outflow tract to the truncus pulmonalis (see Figure 2) Abnormal left-looping (l-ventricular looping) Morphologic RV becomes left sided. Morphologic LV becomes right sided. IVS more horizontal due to relative supero-inferior positioning of ventricles. Conotruncal septum does not rotate resulting in the parallel arrangement of outflow tracts. Atrio-ventricular arrangement. Concordance. Discordanc Right ventricular multiple myxomas obstructing right ventricular outflow tract. J Thorac Cardiovasc Surg 2003;126:913-4. 8. van der Heusen FJ, Stratmann G, Russell IA. Right ventricular myxo-ma with partial right ventricular outflow tract obstruction. Anesth Analg 2006;103:305-6

Point-of-Care Ultrasound diagnosis of Endocarditis. A healthy patient presents to the Emergency Department (ED) where you are working one night. He complains of a four-day history of progressively worsening fatigue, constant and diffuse headache, neck stiffness, fever, chills and night sweats. There was no associated photophobia or phonophobia It is often seen in tropical countries in the developing world. Right ventricular outflow is spared resulting in RV outflow pulsations. Thrombi or spontaneous echo contrast may be seen in right atrium and ventricle. Severe low velocity tricuspid regurgitation is common. A high velocity TR is only seen if accompanied with pulmonary hypertension.

fetal heart ultrasound how toFocused Cardiac Ultrasound for the Nephrologist: TheProspective evaluation of the fetal heart using Fetal

Casazza F, Bongarzoni A, Capozi A, Agostoni O. Regional right ventricular dysfunction in acute pulmonary embolism and right ventricular infarction. Eur J Echocardiogr. 2005;6(1):11-4. López-Candales A, Edelman K. Right ventricular outflow tract systolic excursion: a distinguishing echocardiographic finding in acute pulmonary embolism Since both anomalies are associated with an obstruction of the right ventricular outflow tract (pulmonary stenosis or atresia), it is mandatory to analyze the perfusion in the pulmonary trunk. In severe obstruction, retrograde flow within the ductus arteriosus is found (see Figure 6) Maternal right ventricular (RV) dysfunction (measured by echocardiography) is associated with impaired uteroplacental circulation, however echocardiography has important limitations in the assessment of RV function. We therefore aimed to investigate the association of pre-pregnancy RV and left ventricular (LV) function measured by cardiovascular magnetic resonance with uteroplacental Doppler. Ventricular ectopy seen on a surface EKG in the setting of ARVD is typically of left bundle branch block (LBBB) morphology, with a QRS axis of -90 to +110 degrees. The origin of the ectopic beats is usually from one of the three regions of fatty degeneration (the triangle of dysplasia): the RV outflow tract, the RV inflow tract, and the RV apex Initial transthoracic echocardiogram (TTE) revealed a 1×2 cm mobile echodensity in the right ventricle, suggestive of a right ventricular thrombus (RVT) that appeared to be attached to the ventricular wall or chordae and extended into the right ventricular outflow tract (figures 1 and 2, videos 1-3). Ejection fraction was normal and right. 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