Flashcards in CVS Deck (39):
most common cause of cyanotic congenital heart disease?
tetralogy of Fallot:
overriding aorta with respect to ventricular septum
subpulmonary stenosis causing RV outflow tract obstruction
heart murmur detected in 1st 2 mnths of life that may be seen with tetralogy of Fallot?
loud harsh ejection systolic murmur at left sternal edge from day 1 of life:
due to RV outflow tract obstruction
as this increases, murmur will shorten and cyanosis will increase.
CXR findings in tetralogy of Fallot?
relatively small heart
pulmonary artery 'bay'=concavity on L heart border where convex shaped main PA and RV outflow tract would normally be profiled
decreased pulm vascular markings (oligaemia) due to reduced pulmonary blood flow.
ECG findings in tetralogy of Fallot?
RV hypertropy-tall R waves V1 and V2, when child is older, and R axis deviation
how is tetralogy of Fallot managed?
initial management=medical-morphine, beta blockers, phenylephrine-increase systemic vasc resistance to force more blood to lungs
if emergency tment required, can do shunt from a systemic artery e.g. SCA to PA to increase pulmonary blood flow (Blalock-Taussig shunt)
definitive tment=surgery, usually around 6mnths of age, with aim of closing VSD and relieving RV outflow tract obstruction, sometimes with an artificial patch (often pericardial)-although increased risk of pulm regurg and RV dilatation, which extends across pulm valve.
hypercyanotic spells-if more than 15min, treat with sedation and analgesia-morphine, IV propranolol, IV vol administration, IV bicarb for acidosis, artificial ventilation to reduce metabolic O2 demand.
indication for urgent surgical intervention in tetralogy of Fallot?
hypercyanotic spells-rapid increase in cyanosis, usually assoc. with irritability or inconsolable crying due to severe hypoxia, and breathlessness and pallor as tissue acidosis, short murmur on auscultation.
risk of MI, brain ischaemia and death
role of beta blockers in tetralogy of Fallot?
relax contracted infundibulum (where pulm trunk arises from RV) and allow more time for RV filling, improving pulmonary blood flow
lifelong risk with PDA?
pulm vascular disease and heart failure
why might neonates with tetralogy of Fallot be given PGs?
e.g. alprostadil, if severely limited pulm blood flow causing profound cyanosis, to maintain DA patency so that an alternative source of pulmonary blood flow can be provided.
features o/e of child with tetralogy of Fallot?
clubbing of fingers and toes
loud harsh ejection systolic murmur at left sternal edge
cyanosis at 3mnths of age-may not initially be cyanotic, ? as dependent on RV hypertrophy which if not present means L sided pressures greater so L to R shunt across VSD?**
define patent ductus arteriosus
remnant of 6th aortic arch connecting PA and aorta has failed to close by 1 mnth after expected date of delivery due to defect in duct constrictor mechanism.
presence in preterm infant is not from congenital heart disease but from prematurity.
allows a L to R acyanotic shunt unless pulmonary HTN occurs
defined as persistent patency of ductus arteriosus if remains open after 3 mnths in preterm infant and 1 year in full term as spontaneous closure after these times is very low.
normal closure is functionally within 12-18hrs, and anatomically within 2-3 wks
management of PDA?
need to close to minimise lifelong risk of bacterial endocarditis and pulm vascular disease
medical management in term infants limited to decongestive measures e.g. diuretics, if features of HF-?due to LV overload following increased pulmonary b.flow
must close if symptomatic, or if features of LV overload
at about 1 yr of age, closure with coil or occlusion device via cardiac catheter: if asymptomatic infants, wait until 1 yr with regular ECHO r/v to see if spontaenous closure, if not then endovascular closure.
surgical ligation occasionally required-e.g. if HF or pulm HTN infants-duct ligated and divided through left posterolateral thoracotomy without cardiopulmonary bypass.
may give prophylactic indometacin or ibuprofen in preterm neonates
clinical features of persistent ductus arteriosus?
small shunts usually asymptomatic, but large shunts may LRTIs and feeding difficulty, and poor growth during infancy with failure to thrive due to heart failure.
continuous murmur beneath left clavicle (after 3 mnths), pansystolic in neonates
increased pulse pressure-BOUNDING or collapsing pulse?-distal pulses will be easily palpable e.g. DP-normally difficult to palpate in baby*-due to pulmonary circulation overload, run off here drops diastolic pressure-also causes tachycardia and tachypnoea
HF and pulm HTN when large duct with increased pulm blood flow, can be LVH and RVH-forceful apex beat and L parasternal heave.
ECG findings if large VSD?
biventricular hypertrophy-tall R waves throughout chest leads, apparent by 2mnths of age.
why is surgery required in a large VSD?
usually performed at 3-6mnths of age to manage HF and failure to thrive, and prevent permanent lung damage from pulm HTN and high blood flow.
small VSDs (smaller than aortic valve in diameter, maybe up to 3mm) will close spontaneously.
characteristics of innocent heart murmurs?
vary in intensity with posture and respiration
normal peripheral pulses
characteristics of ASD murmur?
soft systolic murmur in 2nd left IC space due to high flow across normal pulmonary valve, wide fixed splitting of S2*-due to R sided fixed volume overload.
pansystolic in neonates
continuous murmur after 3mnths
clinical features of an ASD?
systolic murmur in 2nd left ICS, and widely split fixed S2
occasionally may be SOB, tiredness on exertion or recurrent chest infections
if moderate or large defect, close with occluding device placed by cardiac catheterisation or open heart surgery.
commonest congenital heart lesion?
clinical features of large VSD?
SOB on feeding and crying
failure to thrive
recurrent chest infections
harsh pansystolic murmur at lower L sternal border
murmur may radiate over whole chest and cause thrill
CXR if large defect-cardiomegaly and large PAs
initial management of large VSD?
medical-aimed at controlling heart failure:
diuretics, and high energy feeds
ACEIs-reduce afterload on heart so aid flow from LV out into aorta rather than across defect into RV
pulmonary vascular disease and shunt reversal with eisenmenger's syndrome development
perimembranous defects can devlop aortic valve prolapse and eventual regurge
can be muscular obstruction in RV or LV outflow tract
RBBB can be caused by operative trauma, and occasionally complete heart block.
what considerations need to be made with regards to contraceptive advice in women with congenital heart disease?
COCP CI in any pt with pulmonary HTN due to thrombogenic effect of oestrogen
and pregnancy can be life threatening in those with pulmonary HTN
which is the only congenital heart defect for which strenuous activity should be avoided?
aortic stenosis as at risk of sudden death
manage with balloon valvuloplasty, open heart surgery if this is unsuccessful.
what do serious complications develop due to in patients with untreated coarctation of the aorta?
clinical features of coarctation of the aorta?
this is a localised aortic constriction in region of the ductus arteriosus origin
upper limb HTN, but note L arm BP may be normal or low if coarctation involves origin of L SCA
in severe cases, baby may present with collapse after 1st wk of life when DA, which was maintaining systemic blood flow, closes.
differential cyanosis-upper body pink, lower body blue
systolic murmur in left infraclavicular area
ejection click may suggest assoc. bicuspid aortic valve=most common congenital heart defect in adults
what is the concern if pt with coarctation of the aorta presents with sudden onset thunderclap headache?
SA haemorrhage due to berry aneurysm rupture assoc. with coarctation of aorta
presentation of tetralogy of fallot?
most either diagnosed antenatally, present with low SpO2 or diagnosed following assessment for a heart murmur
minority will present with:
severe cyanosis at birth if pulm atresia
low BW, growth restriction
poor feeding, SOB, agitation
squatting to rest whilst exercising-characteristic of R to L shunt in older child
what is transposition of the great vessels?
PA originates from LV and aorta from RV, so deoxygenated blood passes out of RV into systemic circulation, causing cyanosis in babies
ductus arteriosus between PA and aorta allows mixing of venous and arterial blood so oxygentated blood from LV can pass into the aorta and cause less cyanosis, mixing may also occur though septal defect which may accompany condition.
PG infusion to keep pda open
Arterial switch procedure to treat
RFs for a patent ductus arteriosus?
alongside critically timed environmental exposure e.g. asphyxia at birth, rubella infection during pregnancy, or unknown viral infections or chemicals
valproic acid exposure during pregnancy
birth at high altitude-exposure to low oxygen tension
investigation findings other than ECHO in PDA?
ECG-often normal, may be LV hypertrophy-tall R waves V5 and V6
if large, may be biventricular hypertrophy, and RV hypertrophy in pulmonary HTN
CXR-if large shunt, then PAs, PVs, LA and LV enlargement
when should PDA be suspected in the preterm infant?
if resp distress due to hyaline membrane disease (surfactant deficiency) worsens or does not improve after initial improvement and baby cannot be weaned off the ventilator.
complications of surgical duct ligation for a PDA?
what specific investigation in girls must be performed if coarctation of aorta present?
karyotype-for Turner syndrome-45 X
how are heart murmurs graded?
1-murmur heard by an expert in optimum conditions
2-murmur heard by a non-expert in optimum conditions
3-easily heard murmur, no thrill
4-palpable thrill, loud murmur
5-palpable thrill, very loud murmur often heard over wide area
6-heard without stethoscope, very loud
causes of a continuous heart murmur?
AV fistulae-systemic, pulmonary or coronary
systemic venous collaterals
most common congenital heart defect to be found in adulthood?