DSON 5014: Congenital Heart Disease Midterm

Describe development of the heart: Days 18-19 (cardiogenic area)

• Heart begins to form near the fetus head, in the area called the cardiogenic area

• chemical signal the mesoderm to form into two strands that will become the endocardial tubes

Describe development of the heart: Days 20-21 (heart tube)

• cardiogenic cords develop a lumen, and they are now called endothelial tubes

• tubes migrate and fuse together to form the primitive heart tube

• the tube “beats”, or rhythmically contracts to help push blood through the tube

  • blood enter sinus venosus to truncus arteriosus due to contractions of primitive tube

• Form several distinct regions

Identify five regions of the fetal heart

• truncus arteriosus

• bulbus cordis

• primitive ventricle

• primitive atrium

• sinus venosus

What does truncus arteriosus become?

will eventually divide and become the ascending aorta and pulmonary trunk

What does bulbus cordis become?

will eventually become the right ventricle

What does primitive ventricle become?

will eventually become the left ventricle

What will primitive atrium become?

will become the anterior portion of both atria and the appendages

What will sinus venosus become?

will eventually become the ends of IVC and SVC, as well as parts of the atria

Describe development of the heart: Days 23-28 (heart tube)

• primitive heart tube elongates

• tube is fixed at its ends and restricted by the pericardium, so as it elongates it begins to form a curvature, or a “S” shape

Describe D-looping

• aka dextra-looping (latin for right)

• in a normal heart, as the heart elongates and forms the S curve, it should loop ventrally and to the patient’s right

Describe development of the heart: Weeks 4-6 (cardiac septation)

• results in division of the single atrio-ventricular canal into left and right sides

• includes events that happen at same time:

  • formation of MV and TV

  • atrial septation

  • formation of IVS

  • septation of truncus arteriosis

  • formation of the semilunar valves

How are MV and TV formed?

• proliferation of endocardial cushions for formation of MV and TV

How is IAS formed?

1. Septum primum grows inferiorly towards the endocardial cushions, space between = ostium primum

2. Seals with the endocardial cushions and leaving an opening = foramen secundum

3. Septum secundum grows besides the septum primum

4. The two septums fuse together to form interatrial septum

5. A small flap called foramen ovale remains center of the septum

How is IVS formed?

• Muscular IVS grows superiorly up from the apex until it meets the ridges of the bulbus cordis

• final step of IVS formation occurs when the membranous portion of the IVS forms and fuses with the endocardial cushions

How are septation of the truncus arteriosus formed ?

• splitting and rotating → pulmonary stays and aortic disappears

• Spiral formation at distal end, results in division of truncus into pulmonary artery and aorta

• subpulmonary conus/infundibulum remains = in a small distance between TV and PV

• aortic conus regresses/disappears = fibrous continuity between the AoV and MV

How are AoV/PV semilunar valves formed?

• Grows from endocardial cushions in the truncus arteriosus

• two of the encocardial cushions meet and fuse together to separate the AoV and PV, and the remaining endocardial cushions form the cusps of the valves

Describe development of the heart: Weeks 6 onwards

• by week 6: 4 chambers of the heart are fully formed, however the heart will continue to grow and develop over the remainder of the pregnancy

• muscle tissue will continue to develop and fully form by the end of week 20

What causes malformation of MV and/or TV

failure of endocardial cushions to develop

What causes ostium primum septal defect?

failure of the septum primum to fuse with endocardial cushions

What causes congenitally correct TGA or L-TGA

• L- looping, causing RV/LV in the wrong spots

What causes TGA or d-TGA

• failure of the spiral growth pattern results in transposition of the great vessels

• aka great vessels in wrong spots

What causes persistent truncus arteriosus

failure of septation of truncus ateriosus

What causes bicuspid aortic valve AND Tetraolgy of Fallot

problem during formation of the endocardial cushions in the truncus arteriosus

Describe fetal circulation: oxygenated blood flow

1. Blood is oxygenated in the placenta instead of the lungs

2. Oxygenated blood travels through the umbilical vein and enters RA

3. Eustachian valve helps to push blood away from the TV and direct it towards the foramen ovale

4. Oxygenated blood enters the left side, and through the aorta

Describe fetal circulation: deoxygenated blood flow

1. Deoxygenated blood from head and upper extremities enters SVC, and then into RA

2. Oxygenated blood from babies lower body enters the heart via the umbilical vein, eventually into RA

3. In the RA, oxygenated + deoxygenated blood mix

4. Mixed blood will travel through the RV, PV, and PA

5. Due to the high resistance of the lungs in the fetus, most of the blood will travel through the ductus arteriosus and enter the aorta → aorta now have mixed oxygen content

6. some blood will travel through the lungs

7. The deoxygenated or mixed blood travels down the aorta and enters umbilical arteries

8. blood then travels to the placenta to become oxygenated again

Describe post natal circulation

1. During birth, there is compression of the chest as baby travels through birth canal

2. fluid is forced out of the bronchi and trachea

3. baby takes its first breath, air flows into lungs

4. pulmonary resistance drops and the umbilical cord is cut at the same time

5. systemic blood pressure increases → pulmonary pressure now lower than systemic pressure

Describe closure of the foramen ovale in post natal

• sudden decrease in pulmonary pressure → sudden increase in blood flow into left and right pulmonary arteries

  • increase flow through pulmonary veins

  • increases LA volume and pressure

• Increased LA pressure causes flap of the foramen ovale to close → no longer any communication between LA and RA

• all blood entering RA must travel through the lungs

Describe closure of Ductus Arteriosus

• happens a bit more delyed

• right sided pressures drop and left sided pressures increase

  • aortic pressure rises above pressure of pulmonary artery

• blood through the ductus arteriosus now changes direction, and travels from the aorta back into the pulmonary artery

• should only last a few hours, as soon the pressure changes, it will signal the ductus arteriosus to close permanently → no longer any communication between aorta and right pulmonary artery

Define Congenital Heart Disease (CHD)

• describe a structural abnormality of the heart and/or great vessels that you are born with

• ACHD: adult congenital heart disease

What are the common latin terms to describe heart locations

• situs → location

• solitus → usual/common

• inversus → inverted

• totalis → total/entire

• dextro → right

• levo → left

Describe segmental approach scanning technique for assessment of CHD (5 things to prove)

• do not assume chambers and valves are connected in proper order → assess every single chamber, valve, and great vessel

1. Cardiac position and visceral situs

2. Blood flow into the heart, # of IVC, SVC, etc

3. Blood flow through the heart

4. Blood flow out of the heart

5. Coronary artery anatomy

How to determine cardiac position and visceral situs? (step one)

• apex points to the patient’s left side but is sitting at a slightly different angle, may or may not be congenital

  • Left → levoposition

  • Midline → mesoposition

  • Right → dextroposition

• orientation of how the heart swing into a different position

What is cardiac situs

• situs is the term used to describe if an organ or position of abnominal organs, is sitting normally or flipped mirror image

• congenital

• example: levocardia, on the left is normal and dextrocardia, on the right is “mirror image”

What is dextrocardia

• congenital condition where the heart is on the right side of the chest and its apex points to the right

• can be asymptomatic and often associated with other congenital heart diseases

How can you check if levocardia or dextrocardia in echo?

• subcostal view, POM at 3-oclock

• confirm which side is apex is pointing

  • Levocardia

    • pointing left in adult and pediatric (upside down, TEE)

  • Dextrocardia

    • pointing right in adult and pediatric (upside down, TEE)

What are the 3 types of cardia situs

1. Situs Solitus Totalis

2. Situs Inversus Totalis

3. Situs Ambiguous

Describe Situs Solitus Totalis

• heart and abdominal organs in normal locations

• Left: Stomach, spleen, pancreas, sigmoid colon

• Right: Liver, cecum and appendix

Describe Situs Inversus Totalis

• heart and abdominal organs are flipped

• heart is dextrocardia, apex pointing to the right

• liver is mainly on the left

• stomach and aorta on the right

Describe Situs Ambiguous

• heart and/or abdominal organs are random

• the position of the vessels and the liver cannot be reliably determined

• higher incidence of associated congenital cardiac defects

What are the 3 types of atrial situs?

• atria determined by morphological features, not by their positions

1. Atrial Situs Solitus

2. Atrial Situs Inversus

3. Atrial Situs Ambiguous

Describe Atrial Situs Solitus

both atria are in their expected positions, with the RA on patient’s right and LA on the patient’s left

Describe Atrial Situs Inversus

the atria are reversed, with the LA on the patient’s right and the RA on the patient’s left

Describe Atrial Situs Ambiguous

• Right atrial isomerism: patient has 2 RA’s

  • will likely also have two right lungs and no spleen, and associated with anomalous pulmonary venous return

• Left atrial isomerism: patient has 2 LA’s

  • will likely also have two left lungs and is associated with anomalous systemic venous return

What are distinctive features of right and left atrium?

• Right atrium:

  • broad based, triangular appendage positioned anteriorly

  • Chiari network

• Left atrium:

  • narrow, elongated, finger-like appendage positioned posteriorly

How to determine blood flow into the heart (step 2) hint: assess systemic vs pulmonic features

Systemic:

• is there an SVC and an IVC entering the RA?

• are there extra connections entering the RA?

  • for example: persistent left SVC, patient with 2 SVCs

Pulmonic:

• are there 4 pulmonary veins entering LA?

• are there one or more pulmonary veins entering into different chamber?

  • for example: partial anomalous pulmonary vein return, total anomalous pulmonary vein return

How to determine blood flow through the heart (step three), what could go wrong (2)

• flow should be RA → RV → Lungs → LA → LV → Aorta

• wrong route if:

  • chambers in wrong location

    • D-Loop → normal

    • L-Loop → incorrect, ventricles switched sides

  • shunts

What are distinctive features of right and left ventricle? (4 ea)

Right ventricle:

• triangular shape with coarse trabeculations

• moderator band

• pap muscles attached to septum and free wall

• TV inserts more apically

Left ventricle

• cone shaped, small trabeculations

• no moderator band

• superiorly inserted MV annulus with 2 pap muscles attached to LV free wall

• may have false tendons

Describe atrioventricular connections (concordance vs discordance)

Atrioventricular concordance:

• right atrium attaches to right ventricle

• left atrium attaches to left ventricle

Atrioventricular discordance:

• right atrium attaches to left ventricle

• left atrium attaches to right ventricle

Where do the atrioventricular valves arise from?

• arise from respective ventricles

• Tricuspid valve → right ventricle no matter what side

• Mitral valve → left ventricle

Describe venticulo-arterial connection (concordant vs discordant)

Concordant

• pulmonary artery arises from morphological right ventricle

• aorta arises from the morphological left ventricle

Discordant

• pulmonary artery arises from morphological left ventricle

• aorta arises from the morphological right ventricle

What is the Rule of 50% for when atrioventricular or ventriculo-arterial connections are not clear?

1. a chamber is a ventricle if it receives >50% of an inlet, inlet refers to AV (atrioventricular valve)

2. if 50% or more of a great vessel arises above a chamber, the great artery is said to be connected to that chamber

Note: if chamber does not receive 50% of an inlet valve, then it is known as rudimentary chamber

How to determine blood flow out of the heart (step four)

• aortic arch patency and branching pattern

• pulmonary artery bifurcation, size, and patency

• presence/size of the ductus arteriosus

• patency: being open and unobstructed, can be good or bad

Describe the special pediatric views: suprasternal crab view (SAX)

• rotate 60 degrees clockwise from normal SSN

• to evaluate pulmonary veins and SVC, able to all 4 pulmonary veins at same time

Describe the special pediatric views: suprasternal arch position

• from the SSN SAX, further clockwise rotation/angulation toward opposite shoulder

• Left arch, normal

  • first branch going to the patient’s right (left side of screen) and bifurcating suggests left arch

• Right arch, abnormal

  • first branch going to the patient’s left (right side of screen) and bifurcating suggests mirror image of right arch

Define hypertrophic cardiomyopathy (HCM) (3 traits)

• refers to LVH in absence of any underlying cause such as hypertension or aortic stenosis

• LVH is most often asymmetric rather than concentric

  • usually interventricular septum is thicker than other walls

• most common cause of death in young athletes

  • higher HR, long QT syndrome

  • coronary artery abnormalities, compressed during exercise

Describe the etiology of hypertrophic cardiomyopathy

• inherited in an autosomal dominant pattern

  • person w/ autosomal dominant disorder has 50% chance of having affected child with mutated gene/dominant gene

• gene mutations cause alterations in contractile elements of cardiac sarcomere which causes myocardial hypertrophy and fibrosis

• specific gene mutations determines:

  • age of onset of hypertrophy

  • extent and pattern of hypertrophy

  • risk of sudden death (common heart related sudden death in <30 yro)

Describe pathophysiology of hypertrophic cardiomyopathy

• characteristic features are ventricular hypertrophy and myocardial (myocyte) disarray → looks thicker than normal

• 25-40% HCM patients have dynamic LVOT obstruction, sometimes called hypertrophic obstructive cardiomyopathy (HOCM)

What are the types of ventricular hypertrophy (5)

1. asymmetric septal hypertrophy (ASH): 90% of HCM cases

   • only septum is big, other walls are normal

2. concentric hypertrophy: 4% of HCM cases

   • all walls thickened, should rule out normal causes of LVH, may or may not have LVOTO

3. apical hypertrophy: 25% of Japanese HCM patients, rare outside of Japanese population

   • thickened in the apical walls

4. mid-ventricular hypertrophy with an apical aneurysm: very rare

   • mid ventricle wall is thick

5. posterior wall hypertrophy with no septal involvement: very rare

   • only posterior wall

What are the types of asymmetric septal hypertrophy + 3 dynamic obstruction classifications

1. Resting LVOTO: gradient of >30 mmHg (2,7 m/s) at rest

2. Latent (provocable/dynamic) LVOTO: gradient of >30 mmHg only with provocation/Valsalva

3. Non-obstructive HCM: no gradient in LVOT, even during provocation/Valsava

Describe the hemodynamic consequences for ALL types of hypertrophic cardiomyopathy

• Diastolic dysfunction due to thick walls

  • dilated LA, increased LAP, increased pulmonary pressures

• Myocardial Ischemia

  • increased LV muscle mass → increases oxygen demand

  • decreased capillary network → decreases oxygen supply

  • elevated LV cavity pressures → compresses coronary arteries

Describe the hemodynamic consequences for SOME types of hypertrophic cardiomyopathy

• LVOTO and SAM of Mitral Valve

  • obstructs LVOT and mimics AS

    • LV must contract to higher pressure to eject blood

    • can worsen LVH/diastolic dysfunction

    • can reduce cardiac output

  • Can cause mitral regurgitation

    • increased LA volume/pressure

    • increased pulmonary pressures

• Arrhythmias

  • sudden death in HCM caused by lethal arrhythmia (ventricular tachycardia and ventricular fibrillation)

  • probably originates from disorganized heart muscle structure or from small scars

Hemodynamic consequences of HCM flow chart (4 main symptoms)

List signs and symptoms of hypertrophic cardiomyopathy (7)

• majority asymptomatic

• murmur

• SOB

• angina

• syncope/pre-syncope

• palpitations/arrhythmias/ sudden death

• fatigue with physical activity

Role of Sonography in hypertrophic cardiomyopathy (5)

1. determine presence and distribution of hypertrophy

2. assess LV systolic function and diastolic function

3. determine presence and cause of LVOT obstruction

4. determine the exact location and magnitude of dynamic LVOT obstruction

5. assess the mechanism and degree of MR

How to determine presence distribution of hypertrophy

• where is the hypertrophy located

• HCM defined as LV hypertrophy >15 mm in absence of any underlying causes such as hypertension or AS

• ASH defined as IVS to PW thickness ratio of 1.3 to 1

• Assess RV bc 1/3 of patients have RV involvement

How to assess LV diastole and systole function

• Systole:

  • most patients with HCM, the LV function with be normal or hyper-dynamic

  • patients with end stage HCM can develop LV dilation and decreased EF

• Diastole

  • HCM causes increased wall stiffness, which in turn leads to diastolic dysfunction

  • impaired ventricular filling

  • increased LV filling pressures

How to determine presence and cause of LVOT obstruction (2)

• Septal hypertrophy:

  • causing narrowed LVOT

• Systolic anterior motion (SAM) of the mitral valve

  • venturi effect: pressure drop in LVOT → MV is sucked toward thick septum

  • abnormal valve apparatus → malposition of the papillary muscles, and/or longer than normal MV leaflets (drag)

  • assess thoroughly in 2D → Zoom, M-mode, then assess with Doppler → Colour and Spectral

Differentiate M-mode on normal mitral valve versus SAM

What are some ways to provoke or assess dynamic obstructions of LVOT?(4)

• Main idea: make ventricle contract harder, or cavity smaller → bringing septum and MV closer → narrowing LVOT more

• Vasodilators: amyl nitrate

  • increase force of LV contraction and induce LVOT obstruction (decreases afterload)

• Exercise

  • increase force of LV contraction

• Ectopic beats

  • increase force of LV contraction

  • ventricle has more time to fill, preload is increased as is the force of contraction (Frank-Starling)

• Valsalva maneuver

  • pressure inside the chest rises, which impedes blood flow into the heart

  • preload and stroke volume decrease, and the LVOT is narrowed

Describe Valsalva Maneuver

• Valsalva (strain phase):

  • Forced exhalation → ↑ intrathoracic pressure

  • Vein compression (IVC/SVC) → ↓ venous return

  • ↓ Preload → ↓ LV size

  • Smaller LV → ↑ LVOT obstruction (esp. in HCM)

• Release:

  • Pressure normalizes

  • Blood rushes back → ↑ preload

How to determine the exact location and magnitude of LVOTO

1. Prove where velocity is normal

   • Use PW to find location of stenosis, starting at apex or mid cavity and “walk down” the PW trace until you find the velocity increase

   • store an image just before the stenotic area and label where the PW trace

2. Prove stenosis location

   • store image of PW in the area of stenosis and label where you are

   • increase scale as high as possible, store the image, even if aliasing off screen

   • proves velocity is very high in LVOT versus aortic valve

     • cannot tell how high because of aliasing

3. Assess for gradient at rest

   1. PW is preferred to measure the LVOT gradient, but is often not possible due to the high gradients; switch to CW only if you have to

   2. Trace and label LVOT

   3. determine and record LVOT peak and mean pressure gradient at rest

4. Assess for gradient during Valsalva

   1. Label trace as “LVOT Valsalva”

   2. Ask patient to perform a Valsalva maneuver

   3. Record highest gradient → Doppler profile will often have dagger shape

   4. Trace Doppler curve to determine LVOT mean pressure gradient with provocation

   5. Record peak and mean pressure gradient at rest

What are the 4 minimum images to assess LVOTO

How to assess the aortic valve area in HOCM?

• will not be able to use continuity equation because LVOT velocity will be elevated due to obstruction

• have to visually assess AoV or perform valve planimetry from SAX

How to assess mechanism and degree of MR

• SAM causes mitral regurgitation due to incomplete-coaptation/distortion of the MV leaflets in systole

• mechanism for MR: Eject → Obstruct → Leak

• MR jet is often posteriorly directed due to misplacement of anterior mitral valve leaflet

How to differentiate Doppler signal is MR or LVOT?

• LVOT:

  • dagger shaped

  • occurs later in systole than MR

  • often lower velocity

• MR:

  • round shape

  • occurs earlier in systole than LVOT obstruction

  • often higher velocity

How to diagnose HCM by definition? What are other causes of LVH (5)?

• must be no known cause for hypertrophy

• other causes of LVH:

  • Aortic stenosis

  • coarctation of aorta

  • Fabry’s disease (fatty tissue deposits in heart)

  • Hypertension

  • Infiltrative disease (amyloidosis)

What are medical treatment options for patients with hypertrophic cardiomyopathy (3)

• Beta blockers

  • decrease oxygen demand by slowing HR and force of contraction

  • decrease LVOT gradient during exercise by decreasing the force of contraction

  • increase passive diastolic ventricular filling time due to slower HR

  • decrease the frequency of PVCs

• Calcium Channel Antagonists

  • decrease stiffness and improve exercise tolerance in those who cannot tolerate beta blockers

• Anti-arrhythmic Drugs

  • atrial fibrillation is not tolerated well in patients with HCM

What are surgical treatment options for patients with hypertrophic cardiomyopathy (3)

• Septal Myectomy

  • surgical removal of the thickened septum, which widens the LVOT and eliminates the LVOT obstruction

• Alcohol Septal Ablation

  • a small amount of alcohol is injected into a major septal perforator branch of the LAD, causing an MI in the basal IVS

  • the IVS becomes akinetic scars, and over time the wall will thin

  • this increases the LVOT area and decrease the severity of obstruction

• Implantable Cardiac Defibrillator

  • an ICD is a pacemaker than can recognize dangerous heart rhythms and “shock” the patient back into normal sinus rhythm when needed

Define Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) (5)

• aka arrhythmogenic right ventricular dysplasia (ARVD)

• inherited in an autosomal dominant pattern

• characterized by fibro fatty replacement of RV myocardium

  • usually right but can be left

• myocytes are replaced with scar and fat tissue, leaving portions of heart with areas that do not conduct electricity or contract normally

• fatty areas develop in small sections of the RV, but over time spread throughout the entire RV, and can even spread into the LV in severe cases

Describe etiology of ARVC (3)

• Ventricular arrhythmias

• heart failure

• sudden cardiac death

Describe patient signs and symptoms of ARVC

• arrhythmias ranging from PVC’s to sustained VT and ventricular fibrillation

  • requisitions of frequent PVCs → always assess for ARVC (esp in younger patients)

• sudden cardiac death (due to arrhythmias)

• patients usually present in their 20s, 30s, or 40s

Role of Sonographer in ARVC

1. Help with the diagnosis of ARVC

2. Assessment of RV function

3. Assessment of LV systolic function

4. Evaluation of TR severity

5. Estimate the RVSP

How to help with the diagnose of ARVC

• biopsy can confirm, but sometimes false negatives due to segmental progression of disease

• on echo, assess multiple views and windows and look for:

  1. wide spectrum of RV involvement

  2. global or regional RV dysfunction

  3. RV structural abnormalities, wall thinning, RV aneurysm, RV dilation

  4. highly reflective (echo-genic) moderator band

  5. abnormal trabeculations

How to assess RV function, LV systolic function, TR severity and estimate the RVSP in ARVC

1. Assessment of RV function

   • TAPSE/TDI/Visual

   • more than 1 measurement for RV function should be performed

2. Assessment of LV systolic function

   • in severe cases of ARVC, fatty tissue can infiltrate LV

3. Evaluation of TR severity

   • TR occurs secondary to dilation of RV

4. Estimate the RVSP

   • in cases of “wide open” TR, TR velocity is usually low and the RVSP cannot be accurately estimated

   • RAP is unknown

Describe treatment options for ARVC (2)

• pharmacologic therapy (anti-arrhythmic drugs)

• implantable cardioverter-defibrillator (ICD)

Define LV non-compaction

• “spongy myocardium” → things protruding out

• characterized by 2 layered myocardium:

  • thin, compacted layer and an extensive non-compacted layer, with prominent trabeculations and deep recesses that communicate with left ventricular cavity but not with coronary circulation

• caused by arrest of normal embryogensis of the endocardium and myocardium

Describe etiology of LV non-compaction

• rare congenital abnormality

• possibly due to failure of normal trabecular resorption or compaction during embryonic development, resulting in double layered LV myocardium

Describe signs and symptoms of LV non-compaction (4)

• heart failure

• arrhythmias (atrial fibrillation/ ventricular tachyarrhythmia)

• endocardial clot with systemic embolization

• sudden death

Role of Sonographer in LV non-compaction

1. Diagnose presence of LV non-compaction

2. Assess diastolic dysfunction

3. Assess systolic dysfunction and arrhythmia

How to determine diagnosis on LV non-compaction

• more than three trabeculations protruding from LV free wall, visible in a single image plane

• blood flow from the LV cavity into the intertrabecular recesses as seen with colour Doppler

  • ultrasound contrast may be used to help visualize trabeculations and deep recesses

• two-layered myocardium, with thin outer compacted layer and a thickened inner non-compacted layer

• Differential from: apical HCM, endomyocardial fibrosis, apical LV mass/thrombus

How are diastolic and systolic dysfunction caused from LV non-compaction

Diastolic dysfunction:

• due to abnormal relaxation caused by the numerous prominent trabeculae

Systolic dysfunction and arrhythmias:

• possibly due to sub-endocardial hypo-perfusion and micro-circulatory dysfunction

  • The inner heart muscle isn’t getting enough blood because the tiny vessels aren’t delivering it properly.

• non compacted myocardial segments have decreased contractility, therefore LV EF is decreased

Describe treatment options for LV non-compaction (4)

• pharmacologic therapy (anticoagulation, anti-arrhythmic drugs)

• implantable cardioverter-defribillator (ICD)

  • heart rhythms

• Ventricular assist device

  • blood circulations

• cardiac transplant

Define atrial septal defects

• defect in the tissue of interatrial septum that allows blood to flow directly from one atrium to the other

• blood flow direction is determined by pressure gradient between the atria

What are the types of atrial septal defects (5)

• Ostium secundum ASD

• Ostium primum ASD

• Sinus venous ASD

• Unroofed coronary sinus

• Patent foramen ovale (not true ASD)

Describe ostium secundum ASD (where, vs PFO, treatment)

• most common, 70% of ASD

• occurs in area of fossa ovalis

• differentiated from a PFO by:

  • absence of valve/ flap of tissue of foramen ovale

  • presence of continuous flow (PFO is intermittent)

  • bigger than PFO

• often closed percutaneously with closure device in cath lab, between opening

Describe ostium primum ASD (where, CHD (3), treatment)

• 20% of all ASD

• located adjacent to atrioventricular valves (TV and MV), at the crux of heart

• associated with other congenital heart diseases → atrioventricular septal defects (inlet VSD), with cleft mitral valve and Trisomy 21 (down syndrome)

• surgery treatment bc cannot be treated with percutaneous device

  • not enough tissue to attach patch bc too close to AV valves and AV node

Describe sinus venous ASD

• uncommon, 7% of ASD

• located near SVC or IVC

• associated with congenital diseases, with partial anomalous pulmonary vein return

• best seen in bicaval view (see SVC and IVC)

Describe unroofed coronary sinus (associated w/ …)

• rare, aka coronary sinus defect

• not true ASD bc not IAS → but similar hemodynamic consequences

• complete or partial unrooting of coronary sinus with direction communication to left atrium

  • because LAP > RAP → blood in LA enters CS tube and will lead to RA

    • will reverse if RAP > LAP

• almost always associated with connection of a persistent left SVC to coronary sinus

What are some clues for unroofed coronary sinus (5), seen best in ?

• better seen in TEE

• unknown cardiac murmur

• right sided heart enlargement

• dilated coronary sinus → biggest clue

• transient cyanosis or hypoxia

• stroke

Describe patent foramen ovale

• not true ASD bc not a hole, has a flap

• 25% of adults

• foramen ovale should functionally close post-natally when LA P > RA P→ should seal over and remain shut

• some adults, foramen does not shut and remains as “flap”

  • can open when RA P > LA P

• no hemodynamic consequences expected with PFO, except increased risk of stroke/embolus