Congenital Heart Disease I and II Flashcards

Question 1

Q

Congenital Heart Disease

General
Etiology
Genetic factors
Environmental factors

Answer

A

General
- Leading cause of neonatal mortality
Etiology
- Cardiac malformations arise during the development of the heart tube morphogenesis at 4-7 weeks gestation
Genetic factors
- Critical role
- > 10% have an identified chromosomal abnormality or single gene defect
Environmental factors
- Maternal health (ex. rubella infection)
- Infection (ex. diabetes
- Drug exposure (ex. lithium, alcohol)

Question 2

Q

Down Syndrome

Genetics
Other
Cardiac abnormalities

Answer

A

Trisomy 21
Hypotonia & developmental delay
AV or ventricular septal defects

Question 3

Q

Turner’s Syndrome

Genetics
Cardiac abnormalities

Answer

A

Female XO karyotype
Coarctation of the aorta & bicuspid aortic valve

Question 4

Q

William’s Syndrome

Genetics
Other
Cardiac abnormalities

Answer

A

Abnormality in elestan gene (7q11)
Developmental delay, loquacious personality, & facial dysmorphology (flat nasal bridge, long philtrum, wide mouth)
Supravalue aortic stenosis, pulmonary artery stenosis, & renal artery stenosis

Question 5

Q

Noonan’s Syndrome

Genetics
Other
Cardiac abnormalities

Answer

A

Autosomal dominant genetic abnormality (12q)
Turner’s phenotype, short stature, webbed neck, hypertelorism, & developmental delay
Pulmonary valve stenosis & hypertrophic cardiomyopathy

Question 6

Q

Diagnosis & Classification of Congenital Heart Disease

Diagnosis
Classification
- Acyanotic lesions
- Cyanotic lesions

Answer

A

Diagnosis
- History & physical exam
- Lab tests: ECG, chest x-ray
- Analysis: echo, MRI, CT, angiography
- Therapeutic interventional procedures: cardiac catheterization
Classification
- Acyanotic lesions
  - Septal defects
    - ASD
    - VSD
    - AV septal defect
    - Patent ductus arteriosus
  - Obstruction
    - Smilunar valve (pulmonic & aortic stenosis)
    - Coarctation of the aorta
- Cyanotic lesions
  - Abnormal connection
    - Transposition of the great arteries
    - Total anomalous pulmonary venous return
  - Septal defect + obstruction to pulmonary blood flow
    - Tricuspid atresia
    - Pulmonary atresia
    - Tetralogy of Fallot
  - Complete mixing
    - Aortic atresia / hypoplastic left heart syndrome
    - Truncus arteriosus
    - Single ventricle

Question 7

Q

Atrial Septal Defect

Defect
Types
Physiology
Clinical findings
Lab findings
- Chest x-ray
- ECG
- Echo
Natural history & complications
Management

Answer

A

Defect
- Acyanotic septal defect
Types
- Secundum defect: in the fossa ovalis region (most common)
- Sinus venosus defect: adjacent to the SVC or IVC
- Ostium primum (part of AV septal defect)
Physiology
- Left to right shunt
- Volume overload of RA & RV
Clinical findings
- Increased parasternal impulse
- Fixed splitting of S2
- Grade II-III ejection murmur mid to upper left sternal border
- Mid diastolic murmur low left sternal border
  - Due to flow across the tricuspid & pulmonic valves resulting in tricsupid & pulmonic stenosis
  - Not due to flow across the atrial septum b/c this is low velocity w/ minimal turbulence
Lab findings
- Chest x-ray
  - Cardiomegaly
  - Increased pulmonary vascularity
- ECG
  - Right axis deviation
  - RVH
- Echo
  - Defines the type & size of the defect
  - Provides indirect evidence of the degree of left to right shunting by the degree of RA & RV enlargement
Natural history
- Children: rarely symptomatic
- Adults: complications
  - Right heart failure from chronic volume overload
  - Atrial arrhythmias from chronic atrial stretching
  - Pulmonary hypertension from excessive pulmonary blood flow over a long period of time
  - Paradoxical emboli related to intermittent right ot left shutnign across the defect
Management
- Surgical closure
- Transcatheter closure (avoid open heart surgery)

Question 8

Q

Ventricular Septal Defect

Defect
Anatomy
Physiology
Clinical implications dependent on…
Clinical findings
- Small VSD
- Large VSD
Large VSD shunt variability
- Newborn
- First few weeks of life
- Tetralogy of Fallot
Lab findings
- Chest x-ray
  - Small defect
  - Large defect
- ECG
  - Small defect
  - Large defect
- Echo
- Catheterization
Natural history & complications
- Small defects
- Large defects
Management

Answer

A

Defect
- Acyanotic septal defect
Anatomy
- Perimembranous region
- Muscular septum
- Doubly committed or supracristal (immediately subjacent to the aortic & pulmonary valves)
Physiology
- Left to right shunt
- Volume overload of LV, LA, & RV
- Pressure &/or volume overload to right heart
Clinical implications dependent on…
- Size of the hole
- Downstream resistance to flow
  - Pulmonic stenosis
  - Pulmonary vascular resistance
Clinical findings
- Small VSD
  - Left to right shunt
  - Normal intracardiac pressures
  - No symptoms
  - High pitched, pansystolic murmur at LLSB
  - Normal S2
- Large VSD
  - Pulmonary hypertension
  - CHF
  - Failure to thrive in infancy
  - Ejection murmur due to equal pressures in the two ventricles
  - Loud, single S2
Shunt is variable in large VSD due to presence & degree of pulmonary stenosis & level of pulmonary vascular resistance
- Newborn
  - Very small shunt b/c neonatal pulmonray vascular resistance is high, providing almost as much resistance to flowa s the systemic vascular bed
- First few weeks of life
  - As pulmonary resistance falls, left to right shunt increases w/o changing the defect size
- Tetralogy of Fallot
  - Predominant right to left shunt due to severe pulmonary stenosis
Lab findings
- Chest x-ray
  - Small defect
    - Normal
  - Large heart
    - Cardiomegaly & increased vascularity
- ECG
  - Small defect
    - Normal
  - Large defect
    - LVH +/- RVH
- Echo
  - Diagnostic
- Catheterization
  - Rarely necessary
Natural history
- Spontaneous closure or decrease in size common
- Small defects
  - Don’t require any intervention
- Large defects
  - CHF & failure to thrive
  - Pulmonary HTN & vascular disease
  - Bacterial endocarditis
Management
- Surgical repair
- Medical therapy for CHF
- Prevention of pulmonary vascular disease

Question 9

Q

AV Septal Defect

Defect
Anatomy
Physiology
- General
- Partial defect
- Complete defect
Clinical findings
- Common in…
- Partial defect
- Complete defect
Lab data
- ECG
- Chest x-ray
- Echo
- Catheterization
Complications
Management

Answer

A

Defect
- Acyanotic septal defect
Anatomy
- Deficiency of the AV (lower atrial & ventricular) septum
- Affects the atrial septum, AV valves, & ventricular septum
Physiology
- General
  - ASD + VSD
  - Left to right shunts w/ volume overload of RA, RV, & LV
- Partial defect: physiology of an atrial defect
  - Atrial defect only & cleft (abnormal) AV/mitral valve
  - No intraventricular communication
  - Volume overload of RA & RV
  - Cleft AV valve –> mitral regurgitation
- Complete defect: physiology of a ventricular defect
  - Atrial & ventricular defects
  - Large left to right shunt
  - Volume overload of the RA, RV & LV
Clinical findings
- Common in…
  - Down syndrome
- Partial defect
  - Findings of an ASD
  - Murmur of mitral regurgitation
- Complete defect
  - Findings of a large VSD
  - Pulmonary HTN & CHF
Lab data
- ECG
  - Superior or left axis deviation
- Chest x-ray
  - Large heart w/ increased markings / vascularity
- Echo
  - Diagnostic
- Catheterization
  - Rarely needed
Complications
- AV valve regurgitation
- CHF
- Pulmonary HTN & eventual vascular disease
- Endocarditis
Management
- Surgical repair / closure

Question 10

Q

Patent Ductus Arteriosus

Defect
Anatomy
Physiology
Clinical findings
Complications
Management
Lab findings
Management

Answer

A

Defect
- Acyanotic septal defect
Anatomy
- Normal component of fetal circulation: extension of main pulmonary artery to descending aorta
- Failure of the normal process of spontaneous closure of the ductus arteroisus immediately after birth
Physiology
- Left to right shunt due to run off from aorta to pulmonary artery
- Volume overload of LA & LV
- Increased pulmonary blood flow
Clinical findings
- Continuous murmur at LUSB
- Bounding pulses due to diastolic run-ff from the aorta to the pulmonary artery
- If duct is large: CHF & pulmonary HTN
Complications
- Endocarditis
- CHF
- Pulmonary HTN & pulmonary vascular disease
Management
- Surgical ligation
- Transcatheter coil embolization
Lab findings
- Chest x-ray
  - Large heart & increased vascularity
- Hemodynamics
  - CHF
  - Pulmonary HTN
Management
- Most are successfully closed in the cath lab w/ transcatheter coil or device placement

Question 11

Q

Left to Right Shunt Summary

Result in…
Chest x-ray
If the degree of shunting is hemodynamically significant…
Eisenmenger’s syndrome

Answer

A

Result in…
- Increased pulmonary blood flow –> volume overload of various heart chambers
Chest x-ray
- Cardiomegaly
- Increased pulmonary vascularity
If the degree of shunting is hemodynamically significant…
- CHF + pulmonary HTN
Eisenmenger’s syndrome
- Long standing increased pulmonary blood flow & pulmonary HTN
- –> damaged pulmonary vasculature at the arterioles
- –> increased pulmonary vascular resistance to the point where it exceeds systemic vascular resistance
- –> reversed direction of the shunt from left-to-right to right-to-left
- –> cyanosis

Question 12

Q

Pulmonic Stenosis

Defect
Anatomy
Physiology
Clinical findings
Lab data
- ECG
- Chest x-ray
- Echo
- Catheterization
Complications
Management

Answer

A

Defect
- Acyanotic obstruction defect
Anatomy
- Fusion &/or thickening of valve leaflets
- Dysplastic pulmonic vavle leaflets (seen in Noonan syndrome)
Physiology
- Obstruction to RV outflow
- Elevated pressure in the RV
- RVH
Clinical findings
- SEM at the LUSB radiating to the back
- Ejection click
Lab data
- ECG
  - RVH
- Chest x-ray
  - Dilated main pulmonary artery due to post-stenotic dilation
- Echo
  - Diagnostic
  - Quantitates the degree of stenosis
- Catheterization
  - For intervention
Complications
- Right heart failure
- Cyanosis if right to left atrial shunt
- Endocarditis (rare)
Management
- Surgery
- Transcatheter balloon valvuloplasty

Question 13

Q

Aortic Stenosis

Defect
Anatomy
Physiology
Clinical findings
Lab data
- ECG
- Echo
- Catheterization
Complications
Management

Answer

A

Defect
- Acyanotic obstruction defect
Anatomy
- Thickened leaflets, fused commissures
- Bicuspid aortic valve
Physiology
- Obstruction to LV outflow
- LVH
Clinical findings
- SEM at the RUSB
- Apical ejection sound
- Decreased upstroke of the carotid & peripheral pulses (if severe)
- Commonly associated w/ coarctation of the aorta
Lab data
- ECG
  - LVH
- Echo
  - Diagnostic
  - Quantitates the degree of stenosis
- Catheterization
  - For intervention
Complications
- CHF
- Sudden death
- Exertional syncope
- Endocarditis
Management
- Transcatheter balloon valvuloplasty (initial palliative procedure)
- Surgical replacement of their aortic valve (eventually later in childhood or adulthood)

Question 14

Q

Coarctation of the Aorta

Defect
Anatomy
Etiology
Clinical presentation
Clinical findings
- ECG
- Chest x-ray
- Echo
- MRI

Answer

A

Defect
- Acyanotic obstruction defect
Anatomy
- Obstruction of aortic arch adjacent to insertion of the ductus arteriosus
Etiology
- Closure of hte ductus arteriosus shortly after birth
- –> migration of ductal tissue into the descending aorta
- –> precipitous manifestation of arch obstruction from coarctation
- –> severe CHF & cardiogenic shock
Clinical presentation
- Cardiogenic shock in the newborn period
- Asymptomatic
  - Upper extremity HTN
  - Decreased lower extremity pulses
Clinical findings
- Discrepancy in blood pressure: normal or hypertensive upper extremity pulses w/ weak or absent femoral pulses
- Systolic murmur at the LUSB, axilla, & back
- Associatd lesions: bicuspid aortic valve, VSD
Lab data
- ECG
  - Infants: RVH (related to increased fetal pulmonary HTN)
  - Children/adults: LVH
- Chest x-ray
  - Figure “3” in the descending aorta
  - If unrepaired for >5 years: rib notching due to collateral flow through dilated intercostal arteries
- Echo
  - Diagnostic in infants
- MRI
  - Diagnostic in older children
Management
- Surgical repair
- Transcatehter balloon dilation
- Stent placement for therapy of post-operative recurrent coarctation

Question 15

Q

Cyanotic Heart Disease

Pathophysiology
Hyperoxia test
Three mechanisms of cyanotic heart disease

Answer

A

Pathophysiology
- Desaturated venous blood enters systemic circulation through intracardiac mixing
- Normal saturation = 95%
- Depressed pO2 (to 60 mmHg) = 90% saturation
- Cyanotic saturation < 85-90%
Hyperoxia test
- Expose patient to 100% O2 to differentiate cardiac & pulmonary causes of desaturation
- Airway or pulmonary etiology: pO2 will rise above 100 mmHg
- Cyantoic heart disease: pO2 barely or doesn’t increase due to fixed right-to-left shunt that’s not exposed to alveolar oxygen
Three mechanisms of cyanotic heart disease
- Abnormal connections of the great vessels to the heart
- Septal defect + obstruction to pulmonary blood flow
- Complete mixing of desaturated ysstemic venous & saturated pulmonary venous return

Question 16

Q

Transposition of the Great Arteries

Defect
Pathophysiology
Clinical findings
Lab data
- ECG
- Chest x-ray
- Echo
- Catheterization
Natural history
Management

Answer

A

Defect
- Cyanotic abnormal great vessel connection
- Most common cyanotic anomaly in newborns
Pathophysiology
- Normal atrial & ventricular connections
- Reversal of the great vessel relationships so that the aorta arises from the RV & the pulmonary artery from the LV
- Parallel systemic & pulmonary circuits
  - Systemic venous blood goes from the RA to the RV & out the aorta w/o exposure to oxygenated blood
- Requires intracardiac or great vessel mixing to be compatible w/ life
  - All newborns have some interatrial connection through the foramen ovale
  - Foramen ovale allows enough satured pulmonary venous blood from the LA to mix w/ the systemic venous return in the RA to achieve a survivable level of systemic saturation
- Inherently unstable situation: infants become critically hypoexmic within the first hours after birth
Clinical findings
- Extreme cyanosis w/o labored respirations in a newborn
- Single S2
- Unimpressive or no murmur
Lab data
- ECG
  - Normal for age
- Chest x-ray
  - Narrow base
    - Due to the aorta being directly anterior to the pulmonary artery
    - Minimizes the usual shadow from the pulmonary artery which is normally positioned to the left of the aorta
- Echo
  - Diagnostic
- Catheterization
  - For atrial septostomy if the patient doesn’t have a reasonable large atrial communication
Natural history
- High mortality if untreated due to severe hypoxemia
Management
- Prostaglandins to maintain ductal patency
  - Increase pulmonary venous return to the LA
  - Facilitate left-to-right shunting
- Balloon atrial septostomy (Rashkin procedure)
  - Catheter w/ a deflated balloon is advanced across the atrial septum
  - Inflate balloon –> pull back from the LA to the RA –> enlarge atrial communication
  - Allows systemic arterial saturations to increase to a level high enough to maintain homodynamic stability
  - Allows recovery from the initial stress until stable enough to under go open heart surgery
- Arterial switch operation
  - Done in the first week of life
  - Removes the aortic & pulmonary trunks from their semilunar valves & attaches them to the appropriate ventricle
  - Transposes coronaries from the original aortic root to the posterior pulmonary root which will become the aortic outflow track

Question 17

Q

Total Anomalous Pulmonary Venous Return

Defect
Pathophysiology
- Blood mixing
- Pulmonary venous return
- RA flow
- 3 main avenues of drainage of the pulmonary venous confluence into the systemic veins
- All avenues
Clinical presentation
- Depends…
- Descending vein to the portal circulation
- Other forms of pulmonary venous return
- Opperative approach

Answer

A

Defect
- Cyanotic abnormal great vessel connection
Pathophysiology
- Complete mixing of pulmonary & systemic venous return
  - All pulmonary veins return to a systemic vein
  - Appropriately connected atria, ventricles, & great vessels
- Pulmonary veins return to a confluence behind the LA & don’t enter the heart directly
  - Abnormal vein forms from this confluence & enters the systemic venous circulation
  - Results in total mixture of the pulmonary venous return w/ the sytemic venous return when flow reaches the RA
- RA flow
  - Most will pass through the tricuspid valve into the RV & pulmonary artery
  - Some will pass across the atrial septum w/ right-to-left shunting entering the LA, LV, & aorta to provide systemic cardiac output
- 3 main avenues of drainage of the pulmonary venous confluence into the systemic veins
  - Vertical vein –> innominate vein –> SVC
  - Vein that descends below the diaphragm –> portal circulation
    - Almost associated w/ severe obstruction to pulmonary venous return
  - Confluence –> coronary sinus
- All avenues
  - Increase pulmonary blood flow
  - Pulmonary HTN
  - Obligatory right-to-left hsunt across the atrial communication providing cardiac output
Clinical presentation
- Depends on degree of obstruction to pulmonary venous return
- Descending vein to the portal circulation
  - Almost always –> pulmonary venous obstruction –> severe pulmonary edema immediately after birth –> urgent need to surgically repair
- Other forms of pulmonary venous return
  - Eventually cause severe heart failure & pulmonary HTN –> need for early surgical intervention
- Opperative approach
  - Oppose the pulmonary venous confluence to the back wall of the LA
  - Create a wide anastomosis b/n these chambers
  - Ligate the anomalous vein that connects the confluence to the systemic venous circuit

Question 18

Q

Tricuspid Atresia

Defect
Pathophysiology
Clinical presentation
Degree of cyanosis
- Small VSD
- Large VSD
Lab data
Management

Answer

A

Defect
- Cyanotic septal defect + obstruction to pulmonary blood flow
Pathophysiology
- Obligatory right to left atrial shunt across foramen ovale or ASD
  - Total mixture of systemic & pulmonary venous return in the LA
  - Flow goes from the LA to the LV out into the aorta
- VSD allows some flow from the LV to the RV to provide a source of pulmonary blood flow
- Hypoplastic RV b/c it doesn’t receive the normal amount of inflow during fetal life to promote normal development of the chamber
Clinical presentation
- Cyanosis
- Systolic murmur related to pulmonary stenosis or VSD
- Single 2nd heart sound
Degree of cyanosis
- Inversely related to amount of pulmonary blood flow
- Small VSD
  - Pulmonary outflow track obstruction
  - Most of the flow from the LV will go out the aorta
  - Pulmonary blood flow will be diminished –> significant hypoxemia
- Large VSD
  - Modest pulmonary stenosis
  - Enough pulmonary blood flow –> mild cyanosis
  - Prominent systolic murmur from pulmonic stenosis or VSD & a single S2
Lab data
- ECG
  - LAD (unusual in a newborn)
  - LVH due to under-developed of the RV
- Chest x-ray
  - Decreased pulmonary vascularity
- Echo
  - Diagnostic
Management
- Prostaglandins if cyanosis is severe & ductal dependent
  - Allows opening of the ductus arteriosus to provide adequate pulmonary blood flow to achieve a sustainable systemic arterial saturation
- Aorta to pulmonary artery shunt if cyanosis is severe

Question 19

Q

Pulmonary Atresia

Defect
Pathophysiology
Lab data
- EKG
- Chest x-ray
Management

Answer

A

Defect
- Cyanotic septal defect + obstruction to pulmonary blood flow
Pathophysiology
- Complete obstruction to outflow from the RV –> tricuspid regurgitation
- Right to left shunt across the atrial septum
- Systemic venous return mixes w/ pulmonary venous return in the LA & flows into the LV & out into the aorta
- Patent ductus arteriosus provides some pulmonary blood flow
  - Otherwise condition would be letal
- Hypoplastic RV b/c blood can’t flow easily into or out of the RV
Lab data
- EKG
  - LV predominance due ot RV hypoplasia
- Chest x-ray
  - Variable heart size
  - Decreased pulmonary vascularity
Management
- Prostaglandins maintain ductal patency
- Aorta to pulmonary shunt eventually needed

Question 20

Q

Tetralogy of Fallot

Defect
4 features
Physiology
Clinical findings
Lab data
- ECG
- Chest x-ray
- Echo
- Catheterization
Management

Answer

A

Defect
- Cyanotic septal defect + obstruction to pulmonary blood flow
4 features
- (1) VSD
- (2) Pulmonic stenosis
- (3) Overriding aorta
- (4) RVH
Physiology
- Pulmonary stenosis + VSD –> right ot left shunt across VSD
- Anterior deviation of outlet septum
  - –> aorta overrides the VSD & partially arises from the RV
  - –> narrowed RV outflow tract –> subvalvular & valvular pulmonic stenosis
- Right aortic arch in 25%
- Main variability: degree of pulmonary stenosis determines…
  - Severity of right-to-left ventricular shunting
  - Degree of cyanosis
Clinical findings
- Variable cyanosis
- SEM from pulmonary stenosis
- Single S2
- Flow across non-restrictive VSD is silent b/c the defect is large & RV systolic pressure = LV systolic pressure
  - Murmur inversely related to severity of pulmonary stenosis
  - Severe pulmonary stenosis –> increased right-to-left shunt across VSD w/ small amount of flow across the pulmonary stenosis –> soft murmur
  - Moderate pulmonary stenosis –> large amount of flow across the outflow tract –> turbulent flow –> loud murmur
Lab data
- ECG
  - RAD
  - RVH
- Chest x-ray
  - Small, “boot” shaped heart due to absent main pulmonary artery shadow at LUSB
  - Right aortic arch may be present
  - Decreased pulmonary vascularity
- Echo
  - Diagnostic
- Catheterization
  - Rarely needed prior to intervention
Management
- Almost always complete repair w/ open heart surgery to close the VSD & relieve pulmonray stenosis (repair)
- In low birth weight infants or infants w/ severe anatomy, pulmonary artery shunt (palliative)
- Repair: close VSD & relieve the pulmonary stenosis

Question 21

Q

Septal Defect + Obstruction to Pulmonary Blood Flow Summary

Answer

A

May be ductal dependent
Prostaglandins provide dramatic improvement in oxygenation
Aorta to pulmonary shunt for palliation

Question 22

Q

Aorta to Pulmonary Shunts

Classic Blalock Taussig Shunt
Modified Blalock Taussig Shunt
Waterston Shunt
Potts Shunt
Central Shunt

Answer

A

Classic Blalock Taussig Shunt
- Division of left subclavin artery with end to side anatomosis of the proximal subclavisn artery to the pulmonary artery
Modified Blalock Taussig Shunt
- Gore-tex tube connecting the subclavian artery to the pulmonary artery with bilateral end to side anastomoses
Waterston Shunt
- Creation of an aorto-pulmonary window connecting the posterior ascending aorta to the anterior right pulmonary artery
Potts Shunt
- Creating an aorto-pulmonary window by connecting the anterior wall of the descending aorta to the posterior wall of the left pulmonary artery
Central Shunt
- Gore-tex tube connecting any portion for the aorta to the pulmonary artery

Question 23

Q

Septal Defect + Obstruction to Pulmonary Blood Flow Summary

Lesions
Prostaglandins
Aorta to pulmonary shunts

Answer

A

Lesions
- May be dependent on ductal flow in the newborn period to maintain adequate levels of systemic arterial saturation in the setting of greatly diminished pulmonary blood flow
Prostaglandins
- Provide dramatic improvement in oxygenation by increasing ductal flow to the pulmonary artery
Aorta to pulmonary shunts
- May be required for palliation proir to complete repair

Question 24

Q

Aortic Valve Atresia

Defect
Pathophysiology
Clinical findings
Lab data
- EKG
- Chest x-ray
- Echo
Management

Answer

A

Defect
- Cyanotic complete mixing of systemic venous & pulmonary venous return at atrial, ventricular, or great vessel level
Pathophysiology
- Underdeveloped left heart –> hypoplatic left heart syndrome
- Obstruction to outflow from the LV
  - –> blood returning to the LA is divered across the atrial septum
  - –> complete mixing of pulmonary & systemic venous return in the RA
- All of the venous return crosses the tricuspid valve –> RV –> main pulmonary
  - –> branch pulmonary arteries
  - –> shunt right-to-left across the patent ductus out into the systemic circulation
- Abnormal fetal flow –> under-developed LV, mitral valve, & ascending aorta
- Systemic perfusion is completley dependent on ductal patency
Clinical findings
- Constricting ductus –> cardoigenic shock within first several days of life
- Hyperactive precordium w/ weak or absent pulses
Lab data
- EKG
  - RVH
- Chest x-ray
  - Cardiomegaly
  - Increased pulmonary vascularity
- Echo
  - Diagnostic
Management
- Prostaglandins maintain ductal patency & allow adequate systemic perfusion
- Norwood operation
  - After the infant is stable, redirect the outflow across the pulmonary artery to the aorta to provide an alternate source of pulmonary blood flow via an aorta to plumonary shunt
- Heart transplant

Question 25

Q

Truncus Arteriosus

Defect
Pathophysiology
Clinical findings
Management

Answer

A

Defect
- Cyanotic complete mixing of systemic venous & pulmonary venous return at atrial, ventricular, or great vessel level
Pathophysiology
- A single arterial trunk arises from the heart overriding a large VSD & receives outflow from both the RV & LV
- Pulmonary arteries arise directly from the root of the “truncus” (ascending aorta)
  - No pulmonary valve –> ungarded pulmonray arteries –> icnreased pulmonary blood flow from the aorta
- Complete mixing of systemic & pulmonary venous return
Clinical findings
- Increased pulmonary blood flow
- Pulmonary HTN
- CHF
Management: Rastelli procedure (surgical)
- Closure of the VSD such that only the LV outflow reaches the aorta
- B/c there’s no outlet form the RV after closure, a conduit is placed from the RV to the pulmonary artery

Question 26

Q

Single Ventricle

Defect
Pathophysiology
Clinical presentation w/ pulmonary stenosis
Clinical presentaiton w/o pulmonary stenosis
Management

Answer

A

Defect
- Cyanotic complete mixing of systemic venous & pulmonary venous return at atrial, ventricular, or great vessel level
Pathophysiology
- One dominant ventricle + hypoplastic chamber via a ventricular communication
- Both the pulmonary artery & aorta arise from a “functionally common” chamber
- Both right 7 levt AV valves empty into the common chamber –> “double inlet ventricle”
Clinical presentation w/ pulmonary stenosis
- Blood diverts out into the aorta –> pulmonary blood flow will be insufficient –> systemic desaturation –> cyanosis
- Sometimes, just enough pulmonary stenosis allows balanced pulmonary & aortic flow
Clinical presentation w/o pulmonary stenosis
- Pulmonary over-circulation
- Lower pulmonary vascular resistance compared to systemic resistance –> pulmonary HTN
- CHF
Management
- Early surgical intervention

Question 27

Q

Congenital Heart Disease Summary

Timing of presentation
Modes of presentation
Management

Answer

A

Timing of presentation
- Presents from fetal life to adulthood
- Severe cyanosis or cardiogenic shock in newborn period (aortic atresia, transposition)
- Asymptomatic w/ murmur in an adult (ASD)
Modes of presentation
- Murmur
- Abnormal pulses or BP
- CHF
- Cyanosis
Management
- Surgery
- Interventional cath
- Prevent endocarditis