Congenital Heart Disease is commonly classified as acyanotic and cyanotic.
Acyanotic
Left to right shunts
Obstructive Lesions
Cyanotic
Decreased Pulmonary Blood Flow
Increased Pulmonary Blood Flow
Miscellaneous
Maximum ESM is over main pullnonary artery (i.e. 2"d Left intercostal space) associated with systolic thiill. The intensity and length of ESM is directly proportional to severity of PS. Wide spitting of S2 due to delayed closure of pulmonary valve. Ejection click present the interval between S l and click varies inversely with the degree of PS, more severe the stenosis earlier the click'. ECG shows RVH. Neonates with critical PS may show LVH because of hypoplastic RV and relatively large LV. Sudden death is possible in patients with severe PSI during heavy exertion.
Coarctation of Aorta
More common in males (3:l). Narrowing of aorta typically located near aortic attachment of ligamenturn arteriosu~n or PDA. It can be a localized narrowing or associated with long segment tubular hypop1asia:In older children ESM is present over descending aorta, distal to obstruction (in left inter-scapular region).
Aorta
Sometimes, continuous murmur of collaterals between vessels arising from pre and post Coarctation segment present. Depending severity of obstruction the femoral pulses are both weak and delayed (due to delayed upstroke of arterial pulse in lower extremity sites) or absent. Minor symptoms are headache,epistaxis and leg fatigue.
Two types of presentations - (a) symptomatic infants with LV failure,(b) Asymptomatic adolescent or young adults. High incidence of Hypertension with significant difference in upper and lower limb systolic BP (>20 m m Hg), which exaggerates on exercise. Major symptoms includes congestive heart failure, especially in infants, rupture or dissection of para-coarctation aorta,infective endarteritis, and cerebral hemoi~hage due to rupture of aneurysm of circle of Willis. ECG in symptomatic infant shows RVH while LVH is present in older children and adult.
Congenital Mitral Stenosis
The onset of symptoms or signs depends on severity of the stenosis, severe the stenosis earlier the presentation. With significant MS, the LA becomes dilated and hypertrophied. The LA pressure increases which then raises pullnonary venous and capillary pressures. High LA pressure results in a high-pressure gradient between the LA and LV during diastole, giving rise to mid-diastole iumble best heard at apex. There is pre-systolic accentuation due to atrial contraction in late diastole, thus increasing pressure gradient. Loud S 1 due to wide-open rnitral valve at the onset of systole as a result of atrial contraction.Murmur is preceded by an opening snap when valve cusps are mobile. The high pulmonay capillary pressure results in reflex cvZeiiolar constriction, causing PAH and RV hypertrophy.
Acyanotic
Left to right shunts
Obstructive Lesions
Cyanotic
Decreased Pulmonary Blood Flow
Increased Pulmonary Blood Flow
Miscellaneous
Acyanotic Congenital Heart Disease
The following lesions will be discussed here:
Left to right shunts: Atrial Septal Defect (ASD), Ventricular Septal Defect (VSD),Patent ductus arteriosus (PDA) or Aorto-pulmonary window.Obstructive Lesions: Aortic valve stenosis, pulmonary valve stenosis, other forms of outflow obstruction, coarctation of aorta, left ventricular inflow obstruction.Congenital Heart Disease
Atrial Septal Defect (ASD)
ASD occurs as an isolated anomaly in 5- 10 per cent of all CHDs. These communications occur in four sites i.e. in the central portion of atrial septum, in the position of foramen teimed fossa ovalis or secundum defects. In the region of SVC -right atrium junction termed sinus venosus defects. Defect created by failure to seal the septum primum, called ostiurn primum defect. An unroofed corqnay sinus is a rare communication between the coronary sinus and the left atrium.
The following lesions will be discussed here:
Left to right shunts: Atrial Septal Defect (ASD), Ventricular Septal Defect (VSD),Patent ductus arteriosus (PDA) or Aorto-pulmonary window.Obstructive Lesions: Aortic valve stenosis, pulmonary valve stenosis, other forms of outflow obstruction, coarctation of aorta, left ventricular inflow obstruction.Congenital Heart Disease
Atrial Septal Defect (ASD)
ASD occurs as an isolated anomaly in 5- 10 per cent of all CHDs. These communications occur in four sites i.e. in the central portion of atrial septum, in the position of foramen teimed fossa ovalis or secundum defects. In the region of SVC -right atrium junction termed sinus venosus defects. Defect created by failure to seal the septum primum, called ostiurn primum defect. An unroofed corqnay sinus is a rare communication between the coronary sinus and the left atrium.
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| Atrial septa1 defect |
Physiology
In ASD the magnitude of left to right shunt is determined by the size of thc defect and the relative compliance of the right ventricle and the left ventricle. Because the compliance of the right ventricle is greater that1 the left ventricle, left to right shunt is present. The heart murmur in ASD is not becr'luse of the shunt at the atrial level.Since h e pressure gradient between the atiia is so small and the shunt occurs throughout the cardiac cycle, the L>R shunt is silent.The heart murnlur in ASD originates from the pulmonary valve because of h e increased blood flow through this normal sized valve; therefore the murmur is systolic in timing. An increased flow through the tricuspid valve results in a diastolic iumblc at the lower left sternal border. The dilated RV cavity prolongs the time required for depolarization of RV resulting in delayed P2. addition the large ASD tends to abolish respiration related fluctuations in r systemic venous return to the right side of the heart; thereby the fixed S2.Child en rarely experience CHF. However CHF and pulmonay hypertension develop in the third or fourth decade of life.
Ventricular Septal Defect (VSD)
VSD accounts for 15-20 per cent of all CHDs. The ventricular septum may be divided into a small membranous portion and a large muscular portion. The muscular septum has three components: the inlet, the trabecular and the outlet septum. The trabecular septum is further divided inlo central, marginal and apical portions. A VSD may be classified into perimemnbranous, inlet, outlet, central muscular, marginal muscular and apical muscular defects.Common Cardiovascular
In ASD the magnitude of left to right shunt is determined by the size of thc defect and the relative compliance of the right ventricle and the left ventricle. Because the compliance of the right ventricle is greater that1 the left ventricle, left to right shunt is present. The heart murmur in ASD is not becr'luse of the shunt at the atrial level.Since h e pressure gradient between the atiia is so small and the shunt occurs throughout the cardiac cycle, the L>R shunt is silent.The heart murnlur in ASD originates from the pulmonary valve because of h e increased blood flow through this normal sized valve; therefore the murmur is systolic in timing. An increased flow through the tricuspid valve results in a diastolic iumblc at the lower left sternal border. The dilated RV cavity prolongs the time required for depolarization of RV resulting in delayed P2. addition the large ASD tends to abolish respiration related fluctuations in r systemic venous return to the right side of the heart; thereby the fixed S2.Child en rarely experience CHF. However CHF and pulmonay hypertension develop in the third or fourth decade of life.
Ventricular Septal Defect (VSD)
VSD accounts for 15-20 per cent of all CHDs. The ventricular septum may be divided into a small membranous portion and a large muscular portion. The muscular septum has three components: the inlet, the trabecular and the outlet septum. The trabecular septum is further divided inlo central, marginal and apical portions. A VSD may be classified into perimemnbranous, inlet, outlet, central muscular, marginal muscular and apical muscular defects.Common Cardiovascular
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| Ventricular septa1 defect |
Pathophysiology
The shunt in the VSD is left to right. The magnitude of the shunt is determined by the size of the VSD and the, level of pulmonay vascular resistance. The lower the PVR, the greater the magnitude of L>R shunt. This type of shunt is called dependent shunt. In VSD the LV starts contracting before RV, and high-pressure gradient is maintained between two ventricles throughout systole. Hence the murmur is pansystolic. Towards the end of the systole, the declining LV pressure becomes lower than the aortic valve with occurrence of A2. However the LVSP >RVSP, and left to right shunt continues. The pansystolic murmur therefore ends beyond A2 completely masking it. The increased volume of blood finally reaches the LA I LV resulting in volume overload if LA/ LV. Passing through a nonnal mitral valve, the large volume of blood results in MDM at the apex. This is a very useful clue indicating a large flow and operability of the lesion. Since the left ventricle has two outlets it empties relatively early, this results in early A2.Since ejection into RV and PA is increased, P2 is delayed. Therefore the S2 is widely split but varies with respiration. In a large VSD with increasing PVR, 52 splitting becomes less and less obvious. It is single once PVR is significantly elevated.
Patent Ductus Arteriosus
It is the persistence of normal fetal channel connecting the aorta and pulmonay artery. It accounts for 5-10 per cent of all CHDs. Functional closure of the ductus occurs within 12-24 hours after birth due contraction of the medial snlooth muscle.Anatomic closure occurs between 2-3 weeks and is produced by fibrosis of the ductal tissue. In cases where the ductus fails to close nornlally, blood will shunt from left to light into PA and lungs. This occurs increasingly as the PVR drops and the pressure in the aorta exceeds that of PA. The volume of shunted blood will increase pulmonay blood flow, increase venous return to LA and cause LA /LV volume overload. The flow in the PDA occurs throughout the cardiac cycle. This results in a murmur which starts in systole after Sl, peaks at S2 and continues indiastole. This is continuous murmur. The passage of increased blood across the rnitral valve produces MDM. The prolonged LV sy.stole results in delayed closure of the aortic valve and a late A2.With large L>R shunts the S2 may be paradoxically split.
The shunt in the VSD is left to right. The magnitude of the shunt is determined by the size of the VSD and the, level of pulmonay vascular resistance. The lower the PVR, the greater the magnitude of L>R shunt. This type of shunt is called dependent shunt. In VSD the LV starts contracting before RV, and high-pressure gradient is maintained between two ventricles throughout systole. Hence the murmur is pansystolic. Towards the end of the systole, the declining LV pressure becomes lower than the aortic valve with occurrence of A2. However the LVSP >RVSP, and left to right shunt continues. The pansystolic murmur therefore ends beyond A2 completely masking it. The increased volume of blood finally reaches the LA I LV resulting in volume overload if LA/ LV. Passing through a nonnal mitral valve, the large volume of blood results in MDM at the apex. This is a very useful clue indicating a large flow and operability of the lesion. Since the left ventricle has two outlets it empties relatively early, this results in early A2.Since ejection into RV and PA is increased, P2 is delayed. Therefore the S2 is widely split but varies with respiration. In a large VSD with increasing PVR, 52 splitting becomes less and less obvious. It is single once PVR is significantly elevated.
Patent Ductus Arteriosus
It is the persistence of normal fetal channel connecting the aorta and pulmonay artery. It accounts for 5-10 per cent of all CHDs. Functional closure of the ductus occurs within 12-24 hours after birth due contraction of the medial snlooth muscle.Anatomic closure occurs between 2-3 weeks and is produced by fibrosis of the ductal tissue. In cases where the ductus fails to close nornlally, blood will shunt from left to light into PA and lungs. This occurs increasingly as the PVR drops and the pressure in the aorta exceeds that of PA. The volume of shunted blood will increase pulmonay blood flow, increase venous return to LA and cause LA /LV volume overload. The flow in the PDA occurs throughout the cardiac cycle. This results in a murmur which starts in systole after Sl, peaks at S2 and continues indiastole. This is continuous murmur. The passage of increased blood across the rnitral valve produces MDM. The prolonged LV sy.stole results in delayed closure of the aortic valve and a late A2.With large L>R shunts the S2 may be paradoxically split.
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| Patent ductus arteriosus |
Aorto Pulmonary Window
This uncomnnlon malfoimation consists of communication usually non-restrictive between the adjacent walls of the ascending aorta and pulmonary trunk. The Pathophysiology of AP window is similar to that of a large PDA. In 80 per cent of the patients Ihe murmur is systolic rather than continuous and is punctuated by eddy sounds. A moderately restrictive AP window generates a continuous murmur.Apical rnid.diastolic murmur represents increased flow across the rnitral valve.
Obstructive Lesions
These lesions can be divided into two groups:
1) Ventricular outflow obstructive lesions i.e.
Aortic Steilosis (AS)
Pulmonary Stenosis (PS)
Coarctation of Aorta (CoA)
Peripheral Pulmonary Artery Stenosis
2)Steilosis of atrio-ventricular (AV) valves/ ventricular inflow tract:
Congenital Mitral Stenosis (MS)
Supra rnitral ring
Cor lriatrium
Tricuspid stenosis
Features coininon in ventricular outflow obstiuction are:
An ejection systolic murmur (ESM) due turbulent flow of blood through the obstruction. Hypertrophy of the chamber proxiinal to obstruction due to pressure overload resulting in concentric hypertrophy without cardiomegaly. Post-stenotic dilatation as seen in chest X-ray.
Congenital Aortic Stenusis
More common in males (4: 1). High incidence of Bicuspid Aortic valve. Murmur present from early infancy and sonletirnes at birth if severe AS is present.Present with LV failure in neonatal period in severe case. Supravalvular AS is associated with Congenital Rubella syndrome and William Syndrome. Effort dyspnea, syncope and fatigue reflect an inadequate increment in cardiac output.High risk of sudden death especially in adolescent and young adults. Angina Pectoiis can occur in young patients. The murmur of AS is loudest over the ascending aorta (i.e. upper right sternal border (URSB) or aortic valve area).
LVH in ECG.
Aortic
stenosis
Left
ventricle
Congenital Pulmonary Stenosis
The murmur present since birth. PS may be valvular, sub-valvular, or supra-valvular. An obstruction may occur within the RV cavity by an abnormal muscle bundle (i.e. " double chambered RV"). In valvular PS the valve is thickened,with fused or absent commissures and, a sinall orifice dysplastic valves are frequent in Noonan Syndrome. Supra-valvulal- PS is associated with Congenital Rubella Syndrome and Williain Syndrome. Most patients are acyanotic and well developed. Newboins with critical PS are cyanotic and tachypneic. Majority of patients are asymptoinntic in infancy and childhood. Dyspnea and fatigue are mild as long as the right ventricle maintains normal stroke volume at rest and augments its stroke volume with exercise.Con g enital Heart Disease
This uncomnnlon malfoimation consists of communication usually non-restrictive between the adjacent walls of the ascending aorta and pulmonary trunk. The Pathophysiology of AP window is similar to that of a large PDA. In 80 per cent of the patients Ihe murmur is systolic rather than continuous and is punctuated by eddy sounds. A moderately restrictive AP window generates a continuous murmur.Apical rnid.diastolic murmur represents increased flow across the rnitral valve.
Obstructive Lesions
These lesions can be divided into two groups:
1) Ventricular outflow obstructive lesions i.e.
Aortic Steilosis (AS)
Pulmonary Stenosis (PS)
Coarctation of Aorta (CoA)
Peripheral Pulmonary Artery Stenosis
2)Steilosis of atrio-ventricular (AV) valves/ ventricular inflow tract:
Congenital Mitral Stenosis (MS)
Supra rnitral ring
Cor lriatrium
Tricuspid stenosis
Features coininon in ventricular outflow obstiuction are:
An ejection systolic murmur (ESM) due turbulent flow of blood through the obstruction. Hypertrophy of the chamber proxiinal to obstruction due to pressure overload resulting in concentric hypertrophy without cardiomegaly. Post-stenotic dilatation as seen in chest X-ray.
Congenital Aortic Stenusis
More common in males (4: 1). High incidence of Bicuspid Aortic valve. Murmur present from early infancy and sonletirnes at birth if severe AS is present.Present with LV failure in neonatal period in severe case. Supravalvular AS is associated with Congenital Rubella syndrome and William Syndrome. Effort dyspnea, syncope and fatigue reflect an inadequate increment in cardiac output.High risk of sudden death especially in adolescent and young adults. Angina Pectoiis can occur in young patients. The murmur of AS is loudest over the ascending aorta (i.e. upper right sternal border (URSB) or aortic valve area).
LVH in ECG.
Aortic
stenosis
Left
ventricle
Congenital Pulmonary Stenosis
The murmur present since birth. PS may be valvular, sub-valvular, or supra-valvular. An obstruction may occur within the RV cavity by an abnormal muscle bundle (i.e. " double chambered RV"). In valvular PS the valve is thickened,with fused or absent commissures and, a sinall orifice dysplastic valves are frequent in Noonan Syndrome. Supra-valvulal- PS is associated with Congenital Rubella Syndrome and Williain Syndrome. Most patients are acyanotic and well developed. Newboins with critical PS are cyanotic and tachypneic. Majority of patients are asymptoinntic in infancy and childhood. Dyspnea and fatigue are mild as long as the right ventricle maintains normal stroke volume at rest and augments its stroke volume with exercise.Con g enital Heart Disease
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| Congenital pullnonary stenosis |
Maximum ESM is over main pullnonary artery (i.e. 2"d Left intercostal space) associated with systolic thiill. The intensity and length of ESM is directly proportional to severity of PS. Wide spitting of S2 due to delayed closure of pulmonary valve. Ejection click present the interval between S l and click varies inversely with the degree of PS, more severe the stenosis earlier the click'. ECG shows RVH. Neonates with critical PS may show LVH because of hypoplastic RV and relatively large LV. Sudden death is possible in patients with severe PSI during heavy exertion.
Coarctation of Aorta
More common in males (3:l). Narrowing of aorta typically located near aortic attachment of ligamenturn arteriosu~n or PDA. It can be a localized narrowing or associated with long segment tubular hypop1asia:In older children ESM is present over descending aorta, distal to obstruction (in left inter-scapular region).
Aorta
Sometimes, continuous murmur of collaterals between vessels arising from pre and post Coarctation segment present. Depending severity of obstruction the femoral pulses are both weak and delayed (due to delayed upstroke of arterial pulse in lower extremity sites) or absent. Minor symptoms are headache,epistaxis and leg fatigue.
Two types of presentations - (a) symptomatic infants with LV failure,(b) Asymptomatic adolescent or young adults. High incidence of Hypertension with significant difference in upper and lower limb systolic BP (>20 m m Hg), which exaggerates on exercise. Major symptoms includes congestive heart failure, especially in infants, rupture or dissection of para-coarctation aorta,infective endarteritis, and cerebral hemoi~hage due to rupture of aneurysm of circle of Willis. ECG in symptomatic infant shows RVH while LVH is present in older children and adult.
Congenital Mitral Stenosis
The onset of symptoms or signs depends on severity of the stenosis, severe the stenosis earlier the presentation. With significant MS, the LA becomes dilated and hypertrophied. The LA pressure increases which then raises pullnonary venous and capillary pressures. High LA pressure results in a high-pressure gradient between the LA and LV during diastole, giving rise to mid-diastole iumble best heard at apex. There is pre-systolic accentuation due to atrial contraction in late diastole, thus increasing pressure gradient. Loud S 1 due to wide-open rnitral valve at the onset of systole as a result of atrial contraction.Murmur is preceded by an opening snap when valve cusps are mobile. The high pulmonay capillary pressure results in reflex cvZeiiolar constriction, causing PAH and RV hypertrophy.
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