CONGENITAL HEART DISEASE

1. CONGENITAL HEART DISEASE DrSitiAisyahAbdMajid Family Medicine Trainee, PPUKM

2. Objectives • Recognisethe various presentations and causes of congenital heart conditions at birth, during infancy and childhood period • Manage and follow-up congenital heart conditions in children • Refer appropriately children with congenital heart diseases to the Paediatrician

3. OVERVIEW • Congenital heart disease (CHD) – the most common congenital disorder in newborns (6-21 per 1000 live births). • In preterm infants  2-3 times greater than term infants • One of the leading causes of perinatal & infant death from congenital malformations. (UK Northern Congenital Abnormality Survey)

4. Anatomy of the heart • 4 chambers • RA, RV • LA, LV • 4 valves • Mitral / bicuspid • Tricuspid • Aortic • Pulmonary

5. Anatomy of the heart • 5 great vessels • SVC, IVC • Pulm artery • Pulmonary vein • Aorta • Deoxygenated blood • From SVC + IVC • RA, RV • Pulm artery  lungs • Oxygenated blood • From pulm vein • LA, LV • Aorta  systemic circulation

6. Fetal circulation • In utero, placenta acts as the lungs, therefore less blood passes into the actual fetal lungs. • 2structures within a fetal heart that allow this "bypass“ • Patent ductusarteriosus • Foramen ovale

7. Fetal Circulation • PDA allows mixing between the pulmonary artery and the aorta as it is a passageway between these two major vessels. • PFOis a hole between the two atriums. It allows mixing of blood between the two right and left atrium.

8. Fetal Circulation • The pressure in the lungs of a fetus is higher than that in the body. • This increased pressure encourages the right to left shunt. • After a baby is born the pressure in the lungs decreases as the vessels in the lungs begin to relax. • This change in the pressures allows more blood to flow into the lungs. • The changes in pressure cause the PDA and PFO to eventually close. • The final closure usually takes several days.

10. AHA Classification of CHD

11. ASD • Opening in the atrial septum permitting free communication of blood between the atria. • 10% of all CHD • Hemodynamics: • Lt  Rt shunt • Increased blood flow into RA  enlarged RA + RV • Pulm HPT

12. VSD • opening in the ventricular septum, which allows free communication between the Rt & Lt ventricles. • 20 to 25% of all CHD • Hemodynamics: • Lt  Rt shunt • Increased blood flow into RV  enlarged RV • Pulm HPT

13. Aortic Stenosis (AS)

14. Aortic Stenosis (AS) • 5 percent of all CHD. • Narrowing of the aortic valve. • Depending on the severity of the stenosis, the symptoms at birth can vary from none to decreased blood flow and decreased oxygenation to the systemic circulation

15. Pulmonary Stenosis (PS) • 5-8% of all CHD. • Narrowing of the pulmonary valve. Hemodynamics: • RV pressure hypertrophy RV failure. • RV pressures maybe > systemic pressure. • Post-stenotic dilation of main PA. • W/intact septum & severe stenosis  R-L shunt through PFO  cyanosis. • Cyanosis is indicative of Critical PS.

16. Coarctation of Aorta (COA) • an obstruction to the outflow from the left ventricle at or near the aortic valve that causes a systolic pressure gradient of more than 10mmHg. • 7% of CHD. 3 Types • Valvular – Most common. • Subvalvular(subaortic) – involves the left outflow tract. • Supravalvular – involves the ascending aorta is the least common. Hemodynamics: • Obstruction of left ventricular outflow  pressure hypertrophy of the LV.

18. Tetralogy of Fallot (TOF)

19. TOF • Stenosis of the pulmonary artery • Interventricular communication • Deviation of the origin of the aorta to the right • Hypertrophy, almost always concentric in type, of the right ventricle. Failure of obliteration of the foramen ovale may occasionally be added in a wholly accessory manner Fallot, Ètienne-Louis-Arthur. Contribution to the pathologic anatomy of morbuscaeruleus (cardiac cyanosis). Marseilles Med. 1888; 25:418-20.

20. Transposition of Great Arteries (TGA)

21. TGA • 5% of all CHD • The aorta is connected to the right ventricle (rather than the left), so instead of pumping blood to the lungs it pumps it back to the body. On the left side of the heart the pulmonary artery is connected to the left ventricle which pumps the blood that returns from the lungs back to the lungs. • There are two separate circuits at work. One handles and recirculates the unoxygenated blood from and to the body; the other handles and recirculates the oxygenated blood from and to the lungs. • These babies need the PFO and PDA to remain open so there is mixing of oxygenated blood with unoxygenated blood.

22. Tricuspid Atresia

23. Tricuspid Atresia • Atresia = blocked • Right atrium is unable to allow blood flow into the right ventricle because the tricuspid valve is blocked. • Since the right ventricle has not been working, it becomes smaller in size and underdeveloped. This defect may be seen with a single ventricle, which means instead of a left and right ventricle there is just one large ventricle. • The survival of an infant with tricuspid atresia is dependent on communication between the right and left atriums via an ASD, VSD or PFO.

24. Pulmonary Atresia • <1% of all CHD • PA + VSD = a feature of TOF • PA + no VSD = hypoplasticright ventricle • The PFO allows mixing of unoxygenated blood from the right to mix with oxygenated blood on the left. • The PDA or patent ductusarteriosus (also a normal fetal structure) also allows for mixing of blood, which provides a means to get blood to the lungs after the baby is born.

25. TruncusArteriosus

26. TruncusArteriosus • <1% of all CHD • Combination of the aorta and pulmonary artery into one large arterial vessel rather than two. • This large, single vessel usually sits above a large VSD, a/wvalve abnormalities. • The result of the common aorta and pulmonary artery is unrestricted left to right shunting which cause congestive heart failure (CHF).

27. Total Anomalous Pulmonary Venous Connection (TAPVC)

28. 1% of all CHD • Some or all of the pulmonary veins are abnormally connected and drain into the right atrium. • These babies are dependent on the fetal circulation remaining intact after delivery. Blood passing through the PFO allows for filling of the left atrium. • The oxygen rich blood in the pulmonary veins mixes with the oxygen depleted blood normally found in the right atrium. This is the blood that flows into the left atrium. From the left atrium the blood goes into the left ventricle and is then pumped to the body via the aorta. The mixed blood that is pumped out through the aorta to the body is usually quite low in oxygen.

29. Hypoplastic Left Heart Syndrome (HLHS)

30. 1 to 2 percent of all CHD. • With this syndrome the left side of the heart is smaller than normal. The structures affected can include the left ventricle, the mitral and aortic valve, as well as the aorta. These babies are dependent on the fetal circulation remaining intact after delivery. • For oxygenated blood to reach the body the right ventricle pumps the blood into the pulmonary artery and some of this blood passes through the PDA (patent ductusarteriosus) into the aorta and eventually to the body

31. Critical CHD • CHD requiring surgery or catheter based intervention in the 1st year of life. • High risk of mortality & morbidity when there is delay in Dx & referral to tertiary centre. • 25% of those with CHD

32. Timing of presentation: • At birth – presents with serious life-threatening clinical findings  immediate intervention • After discharge – diagnosis missed prior to discharge as the infants appear normal on routine examination, esp in ductal dependent lesions • Ductaldependent lesions • Coarctation of aorta • Interrupted aortic arch • Aortic stenosis • HLHS (hypoplastic left heart syndrome) • TGA (transposition of the great artery) • Trunsusarteriosus • TOF (Tetralogy of Fallot) • Total anomalous pulmonary venous connection

33. Presentations at birth • No symptoms • Shock • Cyanosis – detected when the concentration of reduced Hb is 4-5g/dL • Severe pulmonary oedema resulting in tachypnoea & increased work of breathing

34. History • Maternal DM and/or obesity increase the risk of CHD • Smoking in the 1st trimester • Congenital infx – CMV, herpesvirus, rubella, coxsackie • Drugs – hydantoin, lithium, alcohol • ART (assisted reproductive therapy) • Family Hx • Cardiomyopathies, sudden death, unexpected death in infancy • 3x increased risk of CHD when 1st degree relative has CHD • 15.2x for monozygotic twin

35. Physical examination • General • Cyanosis • Pulse oxymetry screening (SpO2) • Tachypnoea • Coughing & wheezing • Peripheral arterial pulses • Extracardiac abnormalities • Hyperoxia test

36. Physical examination • CVS • Abnormal heart rate • Thrill • S2 splitting • Other heart sounds • Murmurs (innocent / pathologic) *** Absent of murmurs does not rule out CHD • The velocity of turbulent blood flow may not be high enough to generate a murmur • Decreased ventricular function can limit generation of murmur • Elevated pulmonary resistance may limit flow  may not be sufficient to be audible until the resistance has fallen

37. Later presentation SYMPTOMS • Difficulty in feeding • Limited milk intake • Feedings take too long • Frequent disruption of sleeping • Choking, gagging • Vomiting • Changes of colour (pallor, central cyanosis) • Excessive unexplained irritability • Excessive sweating (with feeding) • Poor weight gain • Inactive, excessive sleeping SIGNS • Central cyanosis • Pallor • Murmurs • Diminished or absent peripheral pulses (in COA)

38. Presentations - infancy • Poor feeding • Lethargy & tiring with early stopping of feeds • Respiratory distress – tachypnoea, wheezing • Trouble coordinating feeding & breathing • Irritability • Sweating while feeding • Poor weight gain (decreased caloric intake because of poor feeding & increased metabolic demands because of the underlying cardiac disease • Grunting (low-pitched sound generated when the infant closes the glottis)

39. Hypoxemic spells (“tet spells”) are one of the hallmarks of severe tetralogy • Tet spells most commonly start around 4 to 6 months of age and are characterized by: • onset or deepening of cyanosis • Sudden onset of dyspnea • Alterations of consciousness • Decrease in intensity of systolic murmur

40. Presentations - children • Non-specific symptoms • Inability to keep up with peers • Respiratory distress • Sweating (diaphoresis) esp with exertion • Poor weight gain

41. Chest pain • Severe & crushing pain – radiates to arm/jaw  Cardiac ischemia • Retrosternal sharp, severe & constant pain – radiates to Lt shoulder  pericarditis • Severe, sharp & tearing pain – radiates towards the back btwnscapulas  dissecting aneurysm • Exertion-induced chest discomfort  coronary heart disease or hypertrophic cardiomyopathy • Chest pain a/w syncope or palpitation  tachyarrhythmias

42. Fever • Endocarditis – need to be considered in a febrile pt with a new or changing heart murmur • Rheumatic fever – a sequela of group A streptococcal pharyngitis, can present with myocarditis or pericarditis • Kawasaki disease – should be considered in child with fever > 5 days, particularly if it is accompanied with rash, lymphadenopathy, conjunctivitis & distal extremity changes. The majjor complication  coronary artery aneurysm

43. Family History • Infant risk of CHD with affected parent (AVSD or TOF)  4% • Infant risk of CHD with an affected sibling  2% Burn J, Brennan P, Little J, et al. Recurrence risks in offspring of adults with major heart defects: results from first cohort of British collaborative study. Lancet 1998; 351:311 • Other heart diseases that have familial predisposition: • Family dilated cardiomyopathy • Hypertrophic cardiomyopathy • Familial causes of sudden cardiac death (long QT syndrome)

44. Physical findings GENERAL • Tachycardia • Causes: arrhythmia (SVT, VT), heart failure, Lt to Rt shunt disease • ECG is helpful in evaluating cause of tachycardia • Tachyarrhythmia - Require urgent referral, risk for potentially life-threatening cardiac disease • HPT • Need to rule out COA

45. Failure to thrive • Due to inadequate food intake, increased metabolic demands • Suggestive of cardiac cause if child easily tired while feeding, have Sx of respi distress, murmurs+ • Poor perfusion – due to low cardiac output • CRT > 3 secs • Cool extremities • Decreased peripheral pulses • May lead to shock / impending shock • Febrile – as mentioned

46. RESPIRATORY ABNORMALITIES • Wheezing – primary pulmonary disease, cardiac disease a/w elevated Lt venticular end-diastolic pressure, pulm HPT • Tachypnoea due to: • Increased pulmonary blood flow / pulm venous congestion b) Elevated Lt ventricular end-diastolic pressure • Rales – heart failure, pulmonary overcirculation • Stridor – due to airway obstruction, caused by congenital vascular anomaly eg vascular ring

47. CVS – FINDINGS THAT WARRANT REFERRAL TO CARDIOLOGIST

49. Innocent / functional murmurs • Majority murmurs in infants/children • Due to turbulence across the branch pulmonary arteries that are not fully developed because of the relatively small amount of pulmonary blood flow in utero • Typically disapears by 6 months of age  increase in size of the branch pulmonary arteries  reduction in turbulence • Characters: • a/w quiet precordium • a/w normal S2 • Crescendo-decrescendo pattern • Intensity < Grade 3 • Asymptomatic child

50. MANAGING CHILDREN WITH CHD IN PRIMARY CARE • Developmental issues • Feeding & growing • Medications • Immunization • Infective endocarditis prophylaxis