DSON Congenital Heart Disease Post Midterm

What are the types of acyanotic CHD? (7)

1. Coarctation of aorta

2. Cor Triatriatum

3. Ebstein’s Anomaly

4. Congenitally Corrected TGA (cc-TGA)

5. Partial Anomalous Pulmonary Venous Return (PAPVR)

6. Persistent Left Superior Vena Cava (L-SVC)

7. Dextrocardia

What does Q_P:Q_S measure/compare

• compare the flow through the pulmonary valve with the flow through the aorta, should be exact same (equal to 1) except for shunts

  • Q= flow= SV, SV =CSA x VTI

• Q_P : Stroke volume at the pulmonary valve area

  • SV of pulmonary system = CSA of RVOT x VTI of the RVOT

• Q_S : Stroke volume at the aorta valve area

  • SV of systemic circulation = CSA of LVOT x VTI of the LVOT

Describe Q_P/Q_S for normal, insignificant shunts, and hemodynamically significant shunts + Eisenmenger

• normal heart: both sides equal, thus Q_P/Q_S = 1.0

• insignificant shunts: travel left to right, thus lungs get more blood flow, Q_P/Q_S = > 1.0 - 1.5 <

• hemodynamically significant shunt when Q_P/Q_S > 1.5

• Eisenmenger shunt is reversed, thus Q_P/Q_S < 1.0

What are echo measurements for Q_P/Q_S

Describe what happens to Q_P/Q_S for Eisenmenger shunts

• shunt ratio will drop, and eventually reverse direction (L to R becomes R to L)

• Beginning stages → Q_P/Q_S lower than expected bc the shunt direction is starting to reverse

  • measured normal but visual assessment is not normal

• Eisenmenger shunts → Q_P/Q_S <1.0 bc the shunt direction completely reverses (R to L, RAP > LAP)

  • systemic getting more blood than pulmonary, and patient will also be getting deoxygenated blood sent to the body

Describe what happens to Q_P/Q_S for PDA when calculated normal way

• insignificant PDA: LA → LV/LVOT → Aorta → PA → LA → LV/LVOT = shunt missed RVOT and went LVOT twice (more blood)

  • Q_P/Q_S for insignificant PDA → < 1.0 if calculated normal way (looks like it signals for Eisenmenger’s)

• significant PDA with Eisenmenger: RV → PA → Aorta → body = blood skips LVOT (less blood than RVOT)

  • Q_P/Q_S for Eisenmenger PDA → > 1.0 if calculated normal way

Describe the adjusted Q_P/Q_S calculations for PDA

• in general, reverse the direction which you divide the numbers:

  • Q_P is measured at LVOT level

  • Q_S is measured at RVOT level

• as a result:

  • insignificant shunts between 1-1.5

  • Eisenmenger shunts to be <1.0

Describe coarctation of the aorta

narrowing of the descending aorta in the areas of the ductus arteriosus (DA)

What is coarctation of aorta associated with? (2)

• bicuspid aortic valve → most common

• Turner Syndrome

  • Genetic condition in only females, leading to infertility, appears short stature with webbed neck

What are hemodynamic consequences: Coarctation of the Aorta (4)

• Causes increased afterload → LVH

• May have reduced flow to lower extremities

• Systolic pressure higher in upper extremities

• Development of collateral arteries to supply lower body

Role of Sonography for: Coarctation of the Aorta

• best seen in SSN, look for shelf-like narrowing or tissue ridge extending to aortic lumen

• CW Doppler for highest velocity→ Measure peak velocity and maximum pressure gradient across narrowing

  • PW walkdown to confirm coarctation, then CW to determine highest velocity (>2.5 m/s)

• for severe: persistent pressure gradient across narrowing in systole and diastole

  • not severe: see step up only in systole

What are treatment options for: Coarctation of the Aorta (2)

• infancy: prostaglandin to maintain ductus arteriosus patency (open, keep flow into PDA)

• percutaneous, surgical repair in hemodynamically significant obstruction

Describe Cor Triatriatum

• a perforate membrane caused by failure of regression of an embryonic membrane

• partitions the left or right atrium into two chambers

• size of orifice that divides the atrium determines the severity of obstruction, symptoms, and age of presentation

  • large = asymptomatic/no obstruction of flow

  • small = have to squeeze harder, thus more severe

Compare Cor Triatriatum Sinister vs Dexter

• Cor Triatriatum Sinister: divides the left atrium

  • symptoms similar to valvular mitral stenosis

• Cor Triatriatum Dexter: divides the right atrium

  • extremely rare, and symptoms similar to tricuspid stenosis

How to differentiate Cor Triatriatum Sinister from supravalvular mitral ring in echo (2)

• by relationship of membrane to LAA

  • Cor triatriatum is superior to LAA, and will be further away from MV annulus

  • Supravalvular is inferior to LAA, and will be near MV

• assess membrane/orifice with colour and spectral Doppler:

  • if you see blood pooling before squeezing out, likely a cor triatriatum

  • Coumadin ridge in LA looks similar but the flow will be free flowing and only seen in PLAX

Describe Ebstein’s Anomaly

abnormality of tricuspid valve where there is apical displacement of the septal/posterior leaflets by AT LEAST 8mm (because its already naturally apical of MV)

What are consequences of Ebstein’s Anomaly (3)

• Distortion and displacement of tricuspid leaflets

• Atria-lization of RV→ some of the RV chamber become like an enlarged RA

• Often severe amount of TR → amount determines hemodynamic consequences

  • severe TR → RA/RV dilation → can lead to RHF

• Note: some people may not need treatment, others may need to surgery to replace the TV

Describe Congenitally Corrected TGA (cc-TGA)

• Transposition of the great arteries, also known as L-TGA → aorta and pulmonary artery switched spots

• Due to an error during first 8 weeks of fetal development, and exact cause is unknown (maybe genetics?)

Describe the blood flow in cc-TGA/L-TGA

• blood flow maintained bc connections are switched twice, called double discordance → both atrioventricular (ventricles switched) and ventriculoarterial (great arteries attached to wrong ventricles)

• circulation physiological normal but anatomy is abnormal, may be completely asymptomatic

  • blood goes into lungs to get oxygenated, while body still gets oxygenated blood

• morphologic RV acts as systemic ventricle → has to pump blood to whole body

What are the associated lesions with cc-TGA (4)

• VSD

• Tricuspid valve anomalies

• outflow tract obstruction (usually RVOT)

• conduction defects

What are some long-term hemodynamic consequences of cc-TGA (3)

• RV and TV are in systemic location, which is higher pressure than they were designed for thus overtime:

  • tricuspid regurgitation

  • RV failure bc cannot pump as well as LV = congestive heart failure

  • rhythm problems: heart blocks are common

What are some treatment options for cc-TGA

• often only if they have associated defects such as VSD or RVOT obstruction

• If needed:

  • heart failure medication

  • pacemaker (bc of heart blocks)

• in severe cases:

  • “double switch surgery” which is rare

Describe Partial Anomalous Pulmonary Venous Return (PAPVR)

• one or more(< 3), BUT not all (not 4), of the pulmonary veins are not connected to the LA → drains into wrong chamber (often RA)

  • they may be connected to systemic vein (SVC/IVC), RA, coronary sinus, and/or left innominate vein

• Left sided pulmonary veins → may connect to coronary sinus and/or the left innominate vein

• Right sided pulmonary veins → usually connect to RA, SVC/IVC

What are the hemodynamic consequences of PAPVR?

• similar to an ASD or VSD

• R-side volume overload → RA and RV dilation

• Dilation of PA

• RV hypertrophy if longstanding shunt causes pulmonary hypertension

Anomalous connection of a single pulmonary vein to the right SVC may be an…

isolated lesion or in combination with a sinus venosus ASD

What are echo features of PAPVR (3)

• Dilated right side

• absence of obvious ASD or VSD

• possibly a dilated coronary sinus

How else to confirm PAPVR?

• echo helps, but cannot see outside of the heart structure so most likely will be confirmed by other forms of testing:

  • MRI

  • catheterization

  • OHS

Describe Persistent Left Superior Vena Cava (LSVC)

• L-SVC is formed by confluence of the left jugular and subclavian veins, and descends inferiorly parallel to the RSVC in most cases

• commonly enters coronary sinus, but may enter LA (rare)

• very rare, but likelihood increased with patients with other CHD

  • most commonly associated with ASD

Describe the consequences of persistent LSVC

• LSVC drains into RA via the coronary sinus, so likely no hemodynamics

  • coronary sinus may be dilated

What are some extra steps to confirm persistent LSVC?

• injection of agitated saline or dextrose into peripheral left arm vein → opacification of coronary sinus

• persistent LSVC may pose difficulties during cardiac catheterization and/or cardiac surgery

Describe the Dextrocardia echo scanning protocol (4)

1. Subcostal view, with POM 3’o clock as normal (left) → do not correct images

   • Apex pointing left, but heart is right = dextroposition

   • Apex pointing right, but heart is right = dextrocardia

2. Assess liver and great vessel location to see if they have situs inversus

3. Label images as “Dextro”

4. Perform PLAX, Apical windows with patient turning to right side instead

   1. PLAX: align transducer in plane with heart, POM to base of heart (towards aorta and PA) → heart look same/normal on screen

   2. PSAX: clockwise from PLAX → left and right will not be opposite from normal PSAX

   3. A4C: transducer to apex, maintaining PSAX POM → left and right reversed on screen

   4. A2C, A3C: counter clockwise from A4C as normal

   5. SSN: in situs inversus only, the arch will be directed to the right shoulder instead of left

      • rotate transducer to align with structure, a SAX arch sweep will display this more accurately

Define cyanosis

• blue skin tone caused by low blood oxygen

• deoxygenated blood enters the systemic system (bypassing the lungs)

What are types of Cyanotic CHDs? (8)

1. Interrupted Aortic Arch

2. Total Anomalous Pulmonary Venous Return (TAPVR)

3. Tetralogy of Fallot

4. Double Outlet Right Ventricle (DORV)

5. Complete Transposition of the Great Arteries (d-TGA)

6. Truncus Arteriosus

7. Hypoplastic Right Heart Syndrome

8. Hypoplastic Left Heart Syndrome

Describe Interrupted Aortic Arch

• very rare and low survivability

• represents the most severe form of coarctation, narrowing to the point it completely closed off

  • lack of continuity between ascending and descring aorta

• can occur anywhere within the arch

• if PDA remains open, there will be some blood flow into the aorta via PDA, however it will be deoxygenated

What are other cardiac abnormalities associated with interrupted aortic arch? (5)

• PDA

• VSD

• subaortic stenosis

• bicuspid AoV

• ASD

Describe hemodynamic consequences of interrupted aortic arch with no ASD versus with ASD

No ASD

• upper body receives oxygenated blood

• lower body received deoxygenated blood

• incompatible with life

With ASD

• ASD allows some mixed O₂ blood in the RA, which eventually enters lower body, but still overall receive very low O₂ content

• with addition of PDA (still open) → can provide time for baby to live longer prior to surgery

Describe the prognosis of interrupted aortic arch

• failure to treat will result in 90% mortality rate by 4 days old

• Cause of death include:

  • if there is an associated ASD/VSD, excessive blood flow through the defect → severe RHF

  • if no ASD/VSD, death will occur if PDA closes naturally and no blood will enter lower body → organ failure

    • acute kidney failure will cause blood to become too acidic → death

Describe treatment options for interrupted aortic arch

• prostaglandin given intravenously immediately after birth to avoid closure of the ductus arteriosus

• surgical connection of the aorta through thoracotomy incision → preferably within 1st week of life

Describe Total Anomalous Pulmonary Venous Return (TAPVR) or TAPVC (Connection)

• all 4 pulmonary veins have no connection to LA → no blood to the left side at all

• drain directly or indirectly into RA

• can occur with or without obstruction of the pulmonary veins

What are the 3 types of TAPVR, and are there different hemodynamics?

• hemodynamics are the same for all 3 types

1. Supracardiac: pulmonary veins drain into the SVC → above heart

2. Infracardiac: pulmonary veins drain into the portal vein, IVC, or ductus venous → below heart

3. Cardiac: pulmonary veins drain into coronary sinus

Describe hemodynamic consequences of TAPVC with no septal defects or PDA versus with ASD or VSD or PDA

No septal defects or PDA

• Blood go to pulmonary veins → IVC → RA → mix blood → PA → oxygenation → pulmonary veins: never pass left side

• no blood in left side AND to body → incompatible with life

With ASD or VSD or PDA

• Shunts will go from right to left because the RAP > LAP

• Blood will mix in the RA and go two routes:

  • → RV → PA → lungs

  • → LA → LV → body

• allow mixed blood to enter left side, which gives enough time for baby to go into surgery

  • mixed blood is not sufficient for long term, still not enough oxygenated blood

• RA and RV volume and pressure overloading → pulmonary hypertension

What are some treatment options for TAPVC

• palliative/relief care:

  • atrial septostomy until corrective surgery is performed

• corrective:

  • anasotomosis of common pulmonary vein to left atrium

  • closure of ASD

What is the prognosis of TAPVC?

• post surgery prognosis is excellent

Describe the Tetralogy of Fallot

• most common cyanotic lesion, comprised of 4 cardiac abnormalities:

1. Overriding aorta (sit directly over both RV and LV):

   • aorta override ventricular system

2. VSD

   • large subaortic defect that extends from right and non-coronary cusps of the aortic valve superiorly to the membranous septum inferiorly

3. RVOT obstruction and/or Pulmonary Stenosis → symptoms determining factor/ hemodynamic severity

   • muscular obstruction usually beings at crista supraventricularis and extends to pulmonary valve annulus, which is often hypoplastic (underdeveloped)

4. RVH

   • caused by RVOT obstruction or pulmonic stenosis

   • RVH may become stiff and eventually fails

When is Tetralogy of Fallot diagnosed

usually during infancy, but if severity of defects is minor, may go unnoticed for years

What are some risk factors for Tetralogy of Fallot (bc unknown cause)

• viral illness during pregnancy, such as rubella

• alcoholism during pregnancy

• poor nutrition during pregnancy

• mother older than age 40

• parent who as Tetralogy of Fallot

• presence of down syndrome or DiGeorge syndrome

What are hemodynamic consequences of Tetralogy of Fallot

• baby will be blue/cyanotic because oxygen going to the body does not carry enough oxygen

• blood from RA → RV cannot go to PA due to RVOT obstruction, and some goes to LV from the VSD → mixed blood, with low oxygenated content will go to the rest of the body

What are some signs and symptoms of Tetralogy of Fallot

• cyanosis

• SOB

• Loss of consciousness

• clubbing of fingers and toes

• poor weight gain

• irritability

What happens to patients with untreated Tetralogy of Fallot

• survival to adulthood is rare → only 2% to age 40, most will die by age 20

• underdeveloped, weak, easily tired due to low oxygen circulation

• decreased oxygenated blood through coronary arteries leads to cardiac dysfunction and fatal ventricular arrhytmias

What are some treatment options for Tetralogy of Fallot, what are the 2 types of surgical options?

• surgical repair is recommended between ages of 3-11 months, options include Rastelli Procedure or Intracardiac Repair:

1. Intracardiac Repair:

   1. Patch the VSD

   2. PV repair or replacement

   3. Surgically widen the pulmonary artery to reduce RVOT obstruction

2. Rastelli

Role of sonography for Tetralogy of Fallot

• may be first person to diagnose this disease, if the severity of pulmonary stenosis is very minor bc most blood can get to PA → asymptomatic \

• Assess the following:

  • degree of PS

  • VSD → hold size

  • other complications (RVH, RVF) or congenital defects

  • RV pressure overload → “D” in PSAX

• Post-surgery follow up echos, and assess for the following:

  • residual shunting across VSD patch

  • PV area, and flow through PA

  • any complications