Congenital Heart Disease I and II Flashcards Preview

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Flashcards in Congenital Heart Disease I and II Deck (27):
1

Congenital Heart Disease

  • General
  • Etiology
  • Genetic factors
  • Environmental factors

  • 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)

2

Down Syndrome

  • Genetics
  • Other
  • Cardiac abnormalities

  • Trisomy 21
  • Hypotonia & developmental delay
  • AV or ventricular septal defects

3

Turner's Syndrome

  • Genetics
  • Cardiac abnormalities

  • Female XO karyotype
  • Coarctation of the aorta & bicuspid aortic valve

4

William's Syndrome

  • Genetics
  • Other
  • Cardiac abnormalities

  • 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

5

Noonan's Syndrome

  • Genetics
  • Other
  • Cardiac abnormalities

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

6

Diagnosis & Classification of Congenital Heart Disease

  • Diagnosis
  • Classification
    • Acyanotic lesions
    • Cyanotic lesions

  • 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

7

Atrial Septal Defect

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

  • 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)

8

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

  • 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

9

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

  • 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

10

Patent Ductus Arteriosus

  • Defect
  • Anatomy
  • Physiology
  • Clinical findings
  • Complications
  • Management
  • Lab findings
  • Management

  • 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

11

Left to Right Shunt Summary

  • Result in...
  • Chest x-ray
  • If the degree of shunting is hemodynamically significant...
  • Eisenmenger's syndrome

  • 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

12

Pulmonic Stenosis

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

  • 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

13

Aortic Stenosis

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

  • 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)

14

Coarctation of the Aorta

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

  • 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

15

Cyanotic Heart Disease

  • Pathophysiology
  • Hyperoxia test
  • Three mechanisms of cyanotic heart disease

  • 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

16

Transposition of the Great Arteries

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

  • 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

17

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

  • 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

18

Tricuspid Atresia

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

  • 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

19

Pulmonary Atresia

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

  • 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

20

Tetralogy of Fallot

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

  • 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

21

Septal Defect + Obstruction to Pulmonary Blood Flow Summary

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

22

Aorta to Pulmonary Shunts

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

  • 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

23

Septal Defect + Obstruction to Pulmonary Blood Flow Summary

  • Lesions
  • Prostaglandins
  • Aorta to pulmonary shunts

  • 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

24

Aortic Valve Atresia

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

  • 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

25

Truncus Arteriosus

  • Defect
  • Pathophysiology
  • Clinical findings
  • Management

  • 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

26

Single Ventricle

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

  • 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

27

Congenital Heart Disease Summary

  • Timing of presentation
  • Modes of presentation
  • Management

  • 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