congenital heart disease and other abnormalities-viewable-skempley-2012-mbbs2 (1)

7/29/2019 Congenital Heart Disease and Other Abnormalities-Viewable-SKempley-2012-MBBS2 (1)

1/40

Congenital heart disease and

other abnormalities

Dr Steve Kempley


2/40

Congenital heart disease

Embryological basis of abnormalities

Compatibility with fetal life

Effect of perinatal physiological changes Effects of structure on postnatal function

Possibilities and limitations of postnatal

therapeutic interventions


3/40

Cardiac embryology

Clusters of angiogenic cells

mesodermal cardiogenic plate

R/L endocardial tubes fuse to single cardiac tube

by day 21, beating by day 23

Folding into bulboventricular loop

Atrial, ventricular and outflow tract septation (Day 28)

Failure of separation can be primary (endocardial cushion

- AVSD) or secondary (ASD or VSD)

Postnatal closure of fetal connections


4/40

AS = Aortic sac BC = Bulbus cordis CC = Conus cordis

SV = Sinus venosus TA = Truncus arteriosus EC = Endocardial cushions

RA = Right atrium LA = Left atrium FO = Foramen ovale

O1 = Ostium primum S1 = Septum primum S2 = Septum secundum

Source: Christa Wellman, John A McNulty, www.meddean.luc.edu


5/40

Fetal circulation

Anatomical connections

Foramen ovale

Ductus arteriosus

Ductus venosus

High resistance pulmonary circulation

Low resistance systemic circulation


6/40


7/40

Fetal

circulation

PDA

PFO

Ductus

venosus

Pulmonary

pressure >

systemic


8/40

Transitional

circulation

PDA

PFO

Systemic

pressure >

pulmonary


9/40

Persistent

pulmonary

hypertensionof the

newborn


10/40

Cyanotic congenital heart disease

Cyanosis = deoxygenated Hb>5g/dl in capillary

blood

>3.4g/dl in arterial blood

More obvious in polycythemic neonate, less

obvious in anaemic infant

17% of Hb 20g/dl (SaO2 83%)

24% of Hb 14g/dl (SaO2 76%)

43% of Hb 8g/dl (SaO2 57%)


11/40

Cyanosis-

Congenital heart

disease

Normal alveolar gas

exchange (normal CO2) No dyspnoea

Normal pulmonary venous

saturations

Results from shunting ofdeoxygenated blood from

RL side of circulation

Cyanosis

- Lung disease

(incl. Pulmonaryoedema)

Impaired alveolar gas

exchange (CO2 may be ) Tachypnoea & recession

Reduced pulmonary venous

saturations

Results from oxygendiffusion problems or

ventilation-perfusion

mismatch within the lung


12/40

Cyanotic CHD: Plumbing problems

Transposition of the Great Arteries


13/40

Cyanotic CHD: Restricted pulmonary blood flow

Tetralogy of Fallot


14/40

Other forms of Cyanotic CHD

Tricuspid atresia

Pulmonary valve atresia

Critical pulmonary stenosis

Truncus arteriosus

Total anomalous pulmonary venous

drainage (TAPVD)


15/40

Acyanotic congenital heart disease

Two major groups:

LR shunts which increase pulmonary blood flow

( pulmonary oedema/hypertension)

Left heart outflow tract obstruction (pulmonaryoedema, impaired tissue perfusion, lactic acidosis)


16/40

Acyanotic congenital heart disease

Cyanosis is not a fixed feature

Cyanosis can develop as a secondary feature

Pulmonary oedema impairs gas exchange (will

therefore be dyspnoeic)

Pulmonary hypertension causes RL shunting

(Eisenmenger shunt)


17/40

Acyanotic CHD: LR shunts:

Ventricular septal defect (VSD)


18/40

LR shunts:

Qp:Qs

Ratio of

pulmonary to

systemic blood

flow


19/40

Acyanotic CHD: LV outflow tract obstruction

Preductal Coarctation of the Aorta


20/40

Other forms of Acyanotic CHD

Atrial septal defect

Atrioventricular septal defect

Patent ductus arteriosus

A-V malformations (liver, brain)

Critical aortic stenosis

Complex mixed presentations Hypoplastic left heart

Double outlet right ventricle


21/40

Hypoplastic left heart


22/40

Delayed presentation and initial

treatment

Ductus arteriosus and foramen ovale may :

Bypass obstruction (Tetralogy of Fallot, pulmonary

atresia, coarctation, hypoplastic left heart) Allow mixing (Transposition)

Mild cyanosis is easily missed


23/40

Delayed presentation and initial

treatment

Symptoms only obvious once ductus closes

(usually in first few days of life)

Re-opening ductus (Prostaglandin E) or

enlarging foramen ovale (balloon septostomy

for transposition) can be acutely life-saving


24/40

Treatment of Cyanotic CHD

Establish adequate pulmonary blood flow

Prostaglandin E

Laser+balloon valvotomy (pulmonary atresia)

Modified Blalock-Taussig shunt

Definitive correction of anatomical

abnormality:

Arterial switch operation (Transposition)

Surgical valvotomy

Closure of ventricular/atrial septal defects


25/40

Treatment of Acyanotic CHD

Symptomatic

Expectantsmall muscular VSDs, PDA and

ASD/PFO may close spontaneously

Diuretics +/- ACE inhibitor for LR shunts

Prostaglandin E for LV outflow tract obstruction


26/40

Treatment of Acyanotic CHD

Definitive correction

Percutaneous catheter closure of PDA

Balloon dilatation of valvular stenosis

Repair of coarctation

Open heart surgery for VSD/ASD


27/40

Limiting factors in treatment of CHD

Anatomical disuse atrophy Cannot grow new ventricles univentricular

anatomy may be best solution (e.g. Fontan

operation for tricuspid atresia)

Pulmonary arteries may be too small (use B-T

shunt to enlarge in pulmonary atresia)

Functional

Chronically elevated pulmonary blood flow irreversible pulmonary hypertension (particular

risk with AVSD with trisomy 21, truncus, DORV)


28/40

Eisenmenger syndrome in VSD

secondary pulmonary hypertension reverses

direction of shunt


29/40

Other abnormalities

Neural tube defects

Abdominal wall defects

Cleft lip and palate These are only examples any organ may be

affected eye, brain, gut, urogenital tracts,

bones, limbs


30/40

Failure of normal zipping up of neural

tube

Spina bifida occulta

Meningocoele

Myelomeningocoele (spina bifida)

Encephalocoele

Anencephaly

Neural tube defects


31/40

Primitive streak and neural folds

Dr Mark Hill (2007) UNSW
http://embryology.med.unsw.edu.au/wwwhuman/Stages/Stage11.htm


32/40

Zipping up of the neural tube

http://embryology.med.unsw.edu.au/wwwhuman/Stages/Stage11.htmhttp://embryology.med.unsw.edu.au/wwwhuman/Stages/Stage12.htm


33/40

Closure of

neural tube

complete byday 28


M l i l
http://embryology.med.unsw.edu.au/wwwhuman/Stages/Stage12.htm


34/40

Myelomeningocoele

Simon EPediatr Radiol 2004


35/40

Localised lumbar

myelomeningocoele


36/40

Treatment of myelomeningocoele and hydrocephalus

Closure reduces risk of

infection - does not restore

normal neural function

Hydrocephalus common and

needs V-P shunt


37/40

Neurological consequences of lumbar

myelomeningocoele

Mixed sensory, motor and autonomic problems

Dependent on level of lesion and degree of

neural disruption Loss of bladder control incontinence +/-

urinary retention

Faecal incontinence Paralysis and loss of sensation in legs


38/40

Abdominal wall defects gastroschisis

Gastroschisis full thickness small defect in abdominal

wall lateral to umbilicus

Bowel free within amniotic cavity

Surgical closure possible

Bowel may take 1-3 months to start functioningnormally


39/40

Cleft lip and palate

Failure of fusion of

maxillary and frontonasal

processes

Complete surgicalcorrection possible

Minor abnormalities of

palatal control may persist

Eustachian tube function

risk of conductive hearing

lossArchie

CLAPA


40/40

Congenital abnormalities

Origin mostly during early development (first

trimester of pregnancy)

Understanding embryological origin helps plan

effective treatment

Many primary defects can be surgically

corrected

Secondary effects of abnormalities on organ

growth and development may preclude

complete functional cure

congenital heart disease and other abnormalities-viewable-skempley-2012-mbbs2 (1)

Documents