Cardio - structural Flashcards
what are the four features of tetralogy of fallot?
Ventricular septal defect (VSD)
Pulmonary stenosis (PS)
Right ventricular hypertrophy (RVH)
Overriding aorta
what % of congenital heart disease is tetralogy of fallot?:
10%
what are some risk factors for tetralogy of fallot?
male
1st degree FHx
teratogens - alcohol, warfarin, trimethadione
genetics - 22q11 deletion
what two components make up the septum of the ventricles?
smaller membraneous septum superiorly
larger muscular septum inferiorly
what is the most common type VSD?
perimembraneous VSD
state three types of VSD?
perimembraneous VSD
muscular VSD
doubly committed VSDs (near pulmonary and aortic valves)
why are most people with VSD acyanotic ?
the left ventricle has a higher pressure than the right ventricle so there is a left to right shunt which can have a complication of pulmonary hypertension and ultimately right to left shunt
what is the most common type of pulmonary stenosis?
infundibular septum
what % of PS involves valvular stenosis?
10%
what are tet spells ?
intermittent RVOT (right ventricle outflow tract) obstruction - hypoxic episodes
what sign on CXR does RVH have?
boot sign
in severe tetralogy of fallot what may form around the aorta?
multiple aorto-pulmonary collateral arteries (“MAPCAs”) may also form to help increase pulmonary blood flow
what are the clinical signs of TOF?
asymptomatic murmur cyanosis respiratory distress faltering growth
what ages are usually affected by tet spells ?
2-4 months of life
what three things characterise tet spells?
paroxysm of hyperpnoea
irritability
increasing cyanosis
what can precipitate hypoxic spells?
dehydration, anaemia, prolonged crying
what type of murmur is present with VSD?
pan systolic murmur
what murmur is present with dilated aorta?
ejection click
do murmurs increase or decrease in intensity during hypoxic spells?
decrease in intensity
what are some signs of congestive heart failure?
sweating, pallor, tachycardia, HSM, generalised oedema, bilateral basal crackles
what murmur is present with pulmonary stenosis?
loud single S2 murmur
what are DD for TOF?
isolated VSD sepsis transposition of the great arteries hypo plastic left heart syndrome totally anomalous pulmonary venous drainage
what investigations should be done for TOF?
ECG Microarray CXR ECHO cardiac CT angiogram cardiac MRI cardiac catheter
what medical treatment is available for TOF?
squatting - increases venous return and increases systemic resistance
prostaglandin infusion (PGE1 - alprostadil or PGE2 - dinoprostone)
beta blockers
morphine
saline 0.9% bolus (increases pulmonary flow through the RVOTO)
what surgical treatment is available for TOF?
transcatheter RVOT sent insertion (done until child is bigger for valve replacement)
modified blalock taussig shunt (increases pulmonary flow)
stenosis resection, VSD repair
what are the complications of TOF?
Polycythaemia Cerebral abscess Stroke Infective endocarditis Congestive cardiac failure Death (up to 25% in the 1st year of life4) Arrhythmias
when should TOF be followed up ?
life long
- with regular ECG, ECHO, cardiopulmonary exercise testing (CPET)
what is the gold standard for diagnosing TOF?
echo
what genetic defect has the highest percentage incidence of TOF associated with it?
CHARGE syndrome
what gives the boot shaped heart on CXR?
RVH
what is the mortality of TOF in the first year of life?
25%
what is dextro-transposition of the great arteries?
the aorta is anterior and to the right of the pulmonary artery
what is levo-transposition of the great arteries?
the aorta may be anterior and to the left of the pulmonary artery
is dextro-transposition or levo-transposition more common?
dextro-transposition
what is the most common cause of cyanosis in a new born?
transposition of great arteries
what gender is most affected by transposition of great arteries ?
males
what three locations can mixing of blood occur to sustain life during transposition of great arteries ?
patent foramen ovale
ventricular septal defect
patent ductus arteriosus
what valvular problem can result from levo-TGA ?
tricuspid regurgitation and heart failure due to high pressure on left side of heart
what are maternal risk factors for TGA?
>40yrs DM rubella poor nutrition alcohol
what would be found on examination with TGA?
Prominent right ventricular heave
Single second heart sound, loud A2
Systolic murmur potentially if VSD present
No signs of respiratory distress
what would be since on ECG for tricuspid atresia?
left axis deviation
what would be seen on CXR for TGA?
egg on a string
what investigation is used to diagnosis TGA?
echo
what is the management of TGA?
Emergency prostaglandin E1 infusion to keep the ductus arteriosus patent as a temporary solution that allows mixing of blood
Correct metabolic acidosis
Emergency atrial balloon septostomy to allow for mixing
what are the complications of TGA?
Neopulmonary stenosis
Neoaortic regurgitation
Neoaortic root dilatation
Coronary artery disease
what acid base imbalance does TGA have?
metabolic acidosis
- distal organs have low oxygen supply and this respire anaerobically producing lactate
what two things are poor development predictors for TGA?
low gestational age
high pre operative lactate
what is the most common congenital heart defect?
VSD
what is right to left shunt called?
Eisenmengers syndrome
what are risk factors for VSD?
maternal DM rubella alcohol uncontrolled maternal phenylketonuria FHx of VSD Downs syndrome Trisomy 18/13
what clinical features will patients with small VSD have?
systolic murmur
asymptomatic
what clinical features will patients with moderate VSD have?
excessive sweating
tachypnoea
most obvious at 2-3months
what clinical features will patients with large VSD have?
symptoms of congestive heart failure
development problems
frequent chest infections
what are some DD for VSD?
mitral regurg tricuspid regurg ASD patent ductus arteriosus pulmonary stenosis tetralogy of fallot
what is the medical management of VSD?
increased caloric density of feedings - ensures weight gain
diuretics
ACEi
digoxin - increases heart muscle strength during heart failure
what advice should be given long term management of VSD due to increased risk of endocarditis ?
good dental hygiene
avoid piercing and tattoos
what are complications of VSD?
Congestive heart failure Growth failure Aortic valve regurgitation Eisenmenger’s Syndrome Frequent chest infections Infective Endocarditis Arrhythmias Sudden death
what % of small VSDs close spontaneously by 10years?
75%
what % of downs syndrome have cardiac abnormalities ?
40-50%
