Echocardiographic Assessment of ASD

Md. Mashiul AlamPhase B resident

UCC

Chairperson: Assoc. Prof. Naveen Sheikh

Atrial Septal Abnormalities

1. Atrial septal defect (ASD)---- 5 to 10% of CHD2. Patent foramen ovale (PFO)3. Atrial septal aneurysm

Types of ASD

1. ASD secundum2. ASD primum3. Sinous venosus4. Coronary sinus variety

1. 80% secundeum, located in the region of the fossa ovalis and its surrounding

2. 15% Primum, located near the crux, AV valves malformed with regurgitation

3. 5% SVC type sinus venosus, defect located near to SVC, assocaited with anomalous pulmonary venous return

4. <1% IVC type sinus venosus, defect located near IVC5. <1% Unroofed coronary sinus, separation from the LA

partially or completely missing

Associations of other…

• Secundum ASD: MVP• Primum ASD: AV canal defect (Down syndrome)• Sinus venosus: Partial anomalous pulmonary

venous retrun• Conornary sinus variety: complete AV septal

defect, absence of coronary sinus, left SVC that drains into the left atrium

Facts about ASD

• Asymptomatic until adulthood• Symptoms beyond the fourth decade• Life expectency reduced• Quality of life decreased• Eisenmenger rare (<5%)

Echocardiography in ASD

• To identify and confirm ASD• To identify associated anomalies• To diagnose complications of ASD• For therapeutic purpose

Echocardiographic modalities

1. Transthoracic echocardiogram (TTE)2. Transoesophgeal echocardiogram (TEE)3. Intracardiac echocardiogram (ICE)

Modes:2D, M mode, Doppler study, 3D

• TEE > TTE

• TTE-----Subcostal view

• TEE-----High transverse and longitudinal planes

Routine measurement and report

• ASD type• Doppler flow- presence of shunt• ASD size• ASD location• Measure all rims• Shape of ASD---round, oval, irregular

Calculate

• ASD measurements • Qp/Qs• Pulmonary hypertension

Common views in TTE

• Subxiphoid Frontal (Four-Chamber)• Subxiphoid Sagittal• Left Anterior Oblique• Apical Four-Chamber• Modified Apical Four-Chamber• Parasternal Short-Axis• High Right Parasternal View

TTE views for ASD

• Subxiphoid Frontal (Four-Chamber) The subxiphoid frontal (four-chamber) view

allows imaging of the atrial septum along its anterior–posterior axis from the SVC to the AV valves.

• Subxiphoid Sagittal The subxiphoid sagittal TTE view is acquired by

turning the transducer 90 clockwise from the frontal view. This view can be used to measure the rim from the defect to the SVC and IVC and is an excellent window to image a sinus venosus type defect

• Apical Four-Chamber : This view is used to assess the hemodynamic

consequences of ASDs, such as RA and RV dilation, and to estimate RV pressure using the tricuspid valve regurgitant jet velocity. This view is also used to evaluate for right-to-left shunting with agitated saline

• Parasternal Short-AxisThis view is ideal to identify the aortic rim of the

defect. It also highlights the posterior rim (or lack thereof) in sinus venosus and posteroinferior secundum defects.

• Left Anterior Oblique.The left anterior oblique is acquired by turning

the transducer approximately 45 counterclockwise from the frontal (four-chamber) view. This view allows imaging of the length of the atrial septum and is therefore ideal to identify ostium primum ASDs and for assessment of coronary sinus dilation

• Modified Apical Four-Chamber (Half Way in Between Apical Four-Chamber and

Parasternal Short-Axis View): In the patients in whom the subcostal views are

difficult to obtain, the modified apical four-chamber view is an alternative method for imaging the atrial septum

• High Right Parasternal View. The high right parasternal view is a parasagittal

view performed with the patient in the right lateral decubitus position with the probe in the superior–inferior orientation. In this view, the atrial septum is aligned perpendicular to the beam and is ideal for diagnosing sinus venosus defects, particularly when the subxiphoid windows are inadequate

ASD secundum rims

• SVC or superior margin• IVC or inferior margin• Posterior margin• Anterior or retroaortic margin• Mitral rim

Views to identify the ASD rims

PSAX view at great vessel level:Aortic and Post rim

A4CV:Mitral Rim

Subcostal view: SVC and IVC rim

Qp/Qs

• Qp – pulmonary flow• Qs – systemic flow• Qp/Qs = 1 in normal• Qp/Qs > 1.5 significant shunt

• Qp = VTI, RVOT diameter• Qs = VTI, LVOT diameter

Pulmonary hypertension

by TR if no RVOT obstruction

Also by PR max velocity or RVOT acceleration time

ASD with Eisenmenger syndrome

• pulmonary hypertension,• reversal of flow, • and cyanosis

ASD secundum Device closureCRITERIA:

1. “Significant” ASDs (Qp/Qs >1.5 or ASDs associated with right ventricular volume overload) should be closed

2. Secundum ASD that has a stretcheddiameter of less than 38 mm and more than 10 mm

3. Adequate rims (5 mm) to enable securedeployment of the device

4. Anomalous pulmonary venous connectionor proximity of the defect to the AV valves or coronary sinus or systemic venous drainag, intracardiac thrombie absent

Device in situ

Device in situ

Follow up echo after device closureAfter device closure, patients require 6 months of aspirin and

endocarditis prophylaxis until the device endothelializes, following which, assuming that no residual shunt is present

all patients who have undergone device closure should probably have an echocardiogram taken every 5 years or so because of the possibility of late issues, especiallyerosion.

Ref: Braunwald 10th ed

ASD after surgical closure

TEE for ASD

THANK YOU