Cardiology Paeds Flashcards
What happens in Congenital heart disease? (CHD)
Epidimiology- 8/1,000 live births have CHD, present as: heart murmur, HF, or cyanosis. VSD is the commonest lesion.
Inv- ECHO, ECG, CXR
Pre and postductal oxygen saturations, 4 limp BPs, hypoxia test.
CXR-
Boot-shaped heart: tetralogy of Fallot, tricuspid atresia.
Egg shaped heart- transposition of great arteries
“Snowman” heart- total anomalous pumlonary venous return
Cyanotic Vs Acyanotic CHD- what are the differences?
Cyanosis- Blue mucus membranes, nail beds and skin secondary to an absolute concentration of deO2 Hb of at least 30g/dL
Acyanotic: (L–>R shunt, obstruction occuring beyond lungs) : blood passes through pulm circulation–> oxygenation takes place–> low levels of CO2 blood in systemic circ–> no cyanosis.
Cyanotic HD- (R–> L shunt) : blood bypasses lungs-> no oxygenation occurs-> ⬆️ levels of CO2 blood enters systemic circ-> cyanosis.
What might cause Acyanotic CHD?
- L->R shunt lesions- ⬆️ Pulmonary pressures due to extra blood.
Shunt volume dependent on 3 fx-1) size of defect, 2) pressure gradient betwee chambers or vessels, 3) peripheral outflow resistance.
Untreated shunts- pulmonary vascular defect, LV dialation + dysfunction, RV HTN (extra work) + RVH (hypetrophy) and ultimatley R-> L shunts…> cyanotic.
Atrial Septal Defect (ASD)
Ventriucylar septal defect (VSD)
Patent Ductus Arteriosus (PDA)
Atropioventricular septal defect( endocardial cushion defect)
- Obstructive
Coarcation of aorta
Aortic stenosis
Pumnonic stenosis
Whats ASD?
3 types: ostium primum (common in DS) , ostium secundum (most common type 50-70%), sinus venosus ( defect lovated at entry of SVC into RA)
Epidimiology: 6-8% of CH lesions
Natural Hx
If ASD elective surgery or catheter closure b/w 2-5Y
Secondium ASD 80%-defect in centre of atrial septum involving foramen ovale. Partial AVSD (primum ASD, pASD) : In AV septum- inter -atrial communication betwen bottom end of atrial septum and AV valves. Abnormal AV valves, usually Left (tricuspid) leaks- regurgitant valve.
CF:
None (commonly)
Recurrent chest infx/wheeze
Arrythmias (4th decade onwards)
O/E
L->R shunt incepreased flow across pulmonary valve so- ejection systolic murmur best heard at ULSE (upper left sternal edge) (2ICS)
- fixed widely split S2 (hard to hear cz R Stroke volume is same in insipration and expiration)
W/ partial AVSD - apical pansystolic murmu from AV valve regurgitation.
Inv
CXR- enlarged heart, ; cardiomegaly enlarged pulm arteries, increased pulmonary vascular markings
ECG- sexondium ASD- partial RBBB, right axis deviation due to rVH
pAVSD- superior QRS- cz defect on AV node- displaced node then conducts to venrticles superiorly, giving abnormal axis.
ECHO- diagnostic
Mx
Sign ASD- large to cause RV dilation –> tx
Secondium ASD- cardiac catheterisation with insertion of an occlusion device
pASD- surgical correction at 3-5Y to prevent arrhtmias and RHF later in life.
Disease framework of VSD
Most common congenital heart defect(30-50%) defect in ventricular septum- perimembraneous-> adjacent to tricuspid valve) or muscular (completely surrounded by muscle)
Small VSD(majority) - smaller than aortic valve up to 3mm
CF:
Hx: asymptomatic, normal growth and development.
O/E- early systolic to pansystolic murmur, best heard at LLSE, thrill. Loud murmur implies small defect. Quiet P2. (Secondary pulmonary s)
Invx-> ECG and CXR normal, Echo to confirm. See if haemodynamic stable. No PulmHTN
Mx-> most close spontaneouly. Prevention of bacterial endocarditis by maintaining good dental care !
Moderate to large VSD:same size or bigger than aortic valve.
Epidimiology: CHF by 2 M, late secondary pulm HTN if left untreated.
Sx- HF with breathlessness + FTT after 1week old.
CF:
Hx- delayed growth, decased exercise tolerance, recurrent URTIx, or “asthma” episodes. Recurrent chest infx.
O/E: holosystolic murmur at LLSB, mid- diastolic rumble at apex(apical mid-diastolic murmur) from increased flow across mitral valve after blood has circulated through the lungs.
tachypnoea, tachycardia + enlarged liver from RHF. Active precordium. Soft pansystolic murmur or no murmur(implying large defect)
Loud P2- ⬆️ pulmn arterial pressure.
Size of VSD is inversly related to intensity of murmur.
Inx- ECG: LVH, LAH, RVH
CXR- cardiomegaly, CHF, increased pulmonary vasculature, pulmonary oedema, enlarged pulmonary arteries
Echo: diagnostic- demonstrated haemodynamic defect anatomy and pulmonary HTN (due to high flow)
Mx–> tx of CHF and surgical closure by 1Y 3-6M since pulmonary HTn will lead to damage to pulm vascular capillary bed
Drugs- diuretics + captopril. Additional calorie input required.
Surgery:
Manage heart F and FTT
Prevent permanent lung damage from Pulm HTN and high blood flow.
What happens in a PDA?
Patent vessels between descending aorta and left pulmonary artery (normally closure within first 15hrs of life, anatomical closre within first days of life)? Failed to close by 1M after EDD. (Expected day of delivery) - constriction mechanism of duct.
Blood from aorta to pulmonary artery (following fall of pulmonary cascular resistance after birth- lower pressure) –
L->R . In preterms, its from prematurity and not CHD.
Epidimiology: 5-10% of all congnital heart defects
Delayed closure of ductus is common in premature infants (1/3 of infants
tachycardia, bounding pulses, hyperactive precordium, wide pulse pressure, continuous “machinery” murmur best heard at left infraclavicular area.beneath L clavicle. Murmur continuous into diastole cz lower pressure in pulm.a than aorta throughout cardiac cycle. Pulse pressure increased,- collapsing/bounding pulse.
Sx- unusual but if large - increased pulm. Blood flow w/ HF and pulm HTN.
Invx- ECG: may show left atrial enlargment, LVH, RVH. Or normal.
CXR: normal to midly enlarged heart, increased pulm vusculature, prominent pulmonary artery,
Echo: diagnostic
Mx:close to avoid lifelong risk of bacterial endocarditis + pulmonary vascular disease.
Indomethacin: (indocid) : antagonises prostaglandi E2, which maintains ductus arteriosus patency; only effective in premature infants.
Catheter or surgical closure (ligation) if PDA causes respiratory compromise, by coil or occlusion device intriduced by catheter at about 1Y. FTT, or persists beyond 3M of life.
What happens im obstructive lesions? Coarcation of aorta disease framework
Present with ⬇️UO, pallor, cool extremities + poor pulses, shock or sudden collapse.
Coarcation of aorta:
D: narrowing of aorta almost always at level of ductus arteriosus.
Epidimiology: commonly assc with bicuspid valve disease (50%), Turner syndrome (35%)
CF:
Hx: often asymptomatic
O/E–> blood pressure discrepancy- delaye/ difference between upper and lower extremities- severe if >20mmHg difference
Brachial-femoral delay
Possible systolic murmur with late peak at apex, left axilla, left back.
If severe: presents with shock in neonatal period when DA closes.
Inv- ECG- RVH early in infancy, LVH later childhood,
Echo + MRI for diagnosis.
Prognosis might be complicated by HTN if assc w/ multiple lesions (VSD, PDA) can lead to CHD.
Mx- give prostaglandins to keep ductus arteriosus patent for stabilisation + perform surgical correction in neonates. Older infants and kids- balloon arterioplasty alternative to surgical correction.
American cardiology heart assc- perform surgical correction of coarcation as early as possible to reduce long term morbidity and increase survival.
What happens in aortic stenosis?
4 types- valvular (75%), subvalvular(20%), supravalvular + idiopathic hypertrophic subaortic stenosis (5%)
Hx
Often asymptomatic, assc with CHF, exertional chest pain, syncope or sudden death.
O/E-> SEM at RUSB with aortic ejection click at apex (only for valvular stenosi)
Dx- Echo,
Mx-> valvular stenosis- baloon valvuloplasty,
pts with supravalvular and subvalvular stenosis require surgical repair
Exercise restriction required.
What happens in pumlonary stenosis? How do you investigate and treat?
3 types- valvular (90%), subvalvular, supravalvular
Critical pulmonary stenosis: inadequate pulmonary flow, dependedn on ductus for oxygenation, progressive hypoxia and cyanosis.
Natural history: may be part of other congenital lesions- tertalogy of fallot, or in assc with syndromes (congenital rubella, Nooan syndrome)
CF:
Hx: Spectrum from asymptomatic to CHF(swollen anlkes, SOB, fatigue)
O/E- wide split S2 on expiration, SEM at LUBS, pumonary ejection click for valvular lesions.
Inv- ECG: RVH
CXR- post- stenotic dilatation of main pulmonary artery
Echo: diagnostic
Mx- surgical repair if critically ill or symptomatic in older infants/ children
What happens in Cyanotic CHD? What are the causes?
Systemic venous return re-enters systemic circulation
Most prominent feature is cyanosis O2 sats obtain preductal, right radial ABG in room air, then repeat after child inspires 100% O2
If PaO2 improves to greater than 150mmHg, cyanosis less likely of cardiac origin
Pre-ductal and post ductal pulse oximetry
>5% difference suggests R-> L shunt.
5Ts Trancus arteriosus Transposition of the great vessels Tricuspid atresia Tetralogy of fallot Total anomalous pulmonary venous return
- R-> L lesions, what happens?
Tetralogy of Fallot + great transposition of arteries
PC: cyanosis, blue, oxygen sats L shunt so no cyanosis but RVOTO is progressive, leading to increasing R-> L shunting with hypoxaemia + cyanosis.
Degree of RVOTO determines direction and degree of shunt and so the extend of clinical cyanosis and degree of RVH.
Pale- tissue acidosis
CF- hx- hypoxic tet spells.
During exertional states( incosolable crying, exercise ) the ⬆️ pumplmonary vascular resistance and decrease in systemic resistance causes an increase in R->L shunting
–> paroxysms of rapid and deep breathing, irritability and crying, increasing cyanosis, decreased intensity of murmur (decreased flow across RVOTO,
If severe, can lead to decreased level of consciousness, seizures, death.
O/E–> single loud ejection sound S2 due to severe pulmonary stenosis at LSE from day 1.
Short murmur during a spell
Signs: clubbing on older kids,
Inv-
ECG, RAD, RVH
CXR- boot shaoed heart fue to RVH, decreased pulmonary vasculature due to reduced pulmonary flow. right aortic arxh (20%) , small heart, pulmonary artery bay
Echo- diagnostic but cardiac catheter may be needed for detailed coronary anatomy.
Mx of hypercyanotic spells- self limiting followed by sleep episodes. >15mins-> sedation amd pain relief! Morphine or a adrenoceptor agonist ; peripheral vasoconstrictor + relieves pulmonary blood flow obstruction. IV fluids, bicarbonate to correct acidosis, muscle paralysis and artificial ventilation to reduce oxygen demand. o2, knee to chest position, fluid bolus, morphine sulphate, propranolol.
Tx- surgical repair at 4-6M, earlier if marked cyanosis or tet spells.
Surgical xlosure of VSD and artificial patching for RVTO
Most diagnoses antenatally or after following a murmur in first 2M. A few- cyanosis.
Classical sx in developing countries:
Severe cyanosis,mhypercapnoeitc spells (!! –> MI, strokes and death) and squitting on exercise.
What are some other congenital cyanotic heart diseases?
- Transposition of the great arteries- commonest in neonates, parallel pulmonary and systemic circulations- neonates- ductus closure causes rapidly progressive severe hypoxemia.
Echo- diagnostic- Mx- sx- prostaglandin E1 infusion to keep ductus open until balloon trial septostomy. Surgical repair without VSD. - Total anomalous pulmonary venous return
All pulmonary veins drain into R side circulation (systemic veins, RA)
No direct oxygenated blood retunring to LA, often assc with obstruction at connecting sides. ASD must excist for oxygentaed blood to shunt to LA and systemic circulation
Mx- ‼️ URGENT surgerical repair. - Trunchus Arteriosus
Single great vessel gives rise ro aorta, pulm and coronary arteries.
Trunchal valvle overlies a large VSD
Potential for coronary iscaemia with fall in pulmonary vascular resistance
Mx- surgical repair within 6w of life - Hypoplastic left heart syndrome. - hypoplastic LV, narrow mitral/ aortic valves, small ascending aorta, coarcation of aorta. –> systemic hypoperfusion.
Most common cause of death from CHD in 1st Month.
Systemic circulation depends on patency of ductus, upon closure infant presents with circulatory shock and metabolic acidosis !
Mx-> intubate and correct metabolic acidosis
IV infusion of prostaglandin E1 to keep DA open
Surgical palliation -50% survival to later childhood, or heart transplant.
What are heart murmurs?
50-80% of kids will have audible heart murmur as some pt in childhood
Most are functional (innocent) without assc structural abnormalities and have normal ECG and radiological findings.
Murmurs can become audible or accentuated in high output states (e.g. Fever, anaemia)
Innocent: asymptomatic, SEM, grade _3/6, palpable thrill, harsh, may have fixed split or single S2, may have extra sounds/clicks, unchanged position.
What are dysrythmias?
Can be transient or permanent, congenital (structurally normal or abnormal) or aquired (toxin, infx, infraction)
Sinus arrythmia?
Phasic variations with respiration- present in almost all normal kids
Sinus tachycardia?
Rate of impulses arising from sinus node is elevated (>150bpm in infants, >100bpm in older)
Narrow QRS, normal other. Beat to beat heart rate.
Etiology:
HTN, fever, anxiety, sepsis, anaemia/hypoxia, PE, drugs.
Differentiate from SVT by slowing the sinus rate (vagal massage, b-blockers) to identify P waves.
Supraventeicular tachycardia?
Abn heart rate originates above the ventricles- most frequent sustained dysrythmia in children.
No beat to beat HR variability, >220bpm (infants) or >180bpm (children) , P waves abscent/abnormal, PR indeterminable, QRS narrow.
