Congenital Heart Disease Children s Hospital Zhejiang University School of Medicine
Cardiovascular Development Key periods:the 2 nd ~8 th weeks
Fetal Circulation
Physiological Changes in the Circulation After Birth Changes in the pulmonary circulation Closure of the ductus arteriosus Closure of foramen ovale Arrest of circulation through the placenta
Epidemiology of Congenital Heart Disease Congenital heart disease occurs in approximately 8 of 1000 live births About 2-3 out of 1000 total newborn infants will be symptomatic with heart disease in the 1st yr of life
Etiology The etiology of most specific congenital heart defects is still unknown
Genetic Factors: (1) single gene mutation or multifactorial inheritance pattern (2) certain types of VSD (supracristal) are more common in children of Asian background (3) the recurrence risk of congenital heart disease increases from 0.8% to about 2-6% if a 1st degree relative is affected. (4) approximately 3% of patients with congenital heart disease have an identifiable single gene defect, such as Marfan or Noonan syndrome (5) 5-8% of patients with congenital heart disease have an associated chromosomal abnormality: 90% of trisomy 18, 50% of trisomy 21, 40% of Turner syndrome
Infective Factors: congenital rubella syndrome Environmental Factors: physical and chemical factors Drug Factors Maternal Diseases: Diabetes mellitus, SLE
Classification of Congenital Heart Disease Left to right Shunt Lesions: potential cyanotic CHD (ASD, VSD, PDA) Right to Left Shunt Lesions: cyanotic CHD (TOF, TGA) No Shunt Lesions: acyanotic CHD (PS, AS, COA, MS, MVP)
The Common Features of Left to Right Shunt CHD Potential cyanosis Systolic heart murmur in left sternal border (LSB) Pulmonary blood flow increase Systemic blood flow decrease
Diagnostic Methods History and Physical Examination ECG Chest X-ray Echocardiography M-mode, two dimension --- morphology Pulsed, continuous wave and colour doppler Transesophageal Echocardiography (TEE) Fetal Echocardiography
Catheterization pressure, resistance, oxygen saturation, cardiac output, pathway, angiocardiography, myocardial biopsy, electrophysiologic study, interventional treatment MRI, CT, ECT
Treatment in Patients with CHD Non-operation Drug: PGE 1, Indomethacin Interventional treatment Operation
Atrial Septal Defect (ASD)
Development of Atrial Septum
Classification of ASD Ostium Primum Defect (AV Canal or Endocardial Cushion or Atrioventricular septal defect) In the lower portion of the atrial septum and overlies the mitral and tricuspid valves, common with a cleft in the anterior leaflet of mitral valve and mitral regurgitation Ostium Secundum Defect Sinus Venosus Defect Patent foramen ovale Isolated patent foramen ovale is usually of no hemodynamic significance
Type of Secundum ASD
Pathophysiology of ASD
Pathophysiology of ASD SVC IVC ASD LV LA RA RV comparative pulmonary valve stenosis AO PV PA Hyperkinetic pulmonary hypertension extremely large pulmonary blood flow Obstructive pulmonary hypertension pulmonary arteriolar medial thickness pulmonary vascular obstructive disease RVP RAP RAP LAP RA to LA Shunt cyanosis-- Eisenmenger syndrome
Pathophysiology of ASD Left to right shunt can occur both in systole and diastole because the LA pressure is always little higher than the RA pressure both in systole and diastole The degree of Left-to-Right shunting is dependent on: 1. size of defect 2. relative compliances of the RV and LV 3. relative vascular resistances in the pulmonary and systemic circulations
Pathophysiology of ASD The large blood flow through the right side of the heart results in: l. enlargement of RA and RV and dilatation of PA 2. the pulmonary artery pressure (PAP) remains normal because of the absence of a high pressure communication between the pulmonary and systemic circulations 3. pulmonary vascular resistance remains low throughout childhood, but it may begin to increase in adulthood 4. the LV is normal in size
Clinical Manifestations Asymptomatic A soft systolic murmur at the 2nd intercostal space of LSB (increased RV blood flow across the pulmonary valve---comparative pulmonary valve stenosis) Typical wide and fixed splitting of P2 (The pulmonic 2nd heart sound) throughout the respiratory cycle (increased RV blood flow producing a prolonged pulmonary valve close constantly throughout the respiratory cycle)
Clinical Manifestations An early-to-mid diastolic murmur at the lower LSB (increased blood flow across the tricuspid valve---- comparative tricuspid valve stenosis) P 2 louder and pulmonic ejection click when pulmonary hypertension
Chest X-ray Enlargement of the RA and RV Pulmonary artery is large Pulmonary vascularity is increased LV is normal Enlargement of the LV in Ostium Primum Defect
ECG Right axis deviation Enlargement of the RA and RV Minor right ventricular conduction delay (ICRBBB: an rsr' pattern in the right precordial leads) Enlargement of the LV in Ostium Primum Defect
Echocardiography Enlargement of the RA and RV Ventricular septum and posterior wall of LV move in same direction Position and size of ASD Direction and degree of shunt in ASD
Catheterization Oxygen saturation in RA is higher than in SVC and IVC Right cardiac catheter is easy to enter LA through the ASD
Prognosis and Complications symptoms usually do not appear until the 3rd decade or later pulmonary hypertension and heart failure are late manifestations infective endocarditis is extremely rare
Treatment Surgery is advised for all symptomatic patients and also for asymptomatic patients with a shunt ratio of at least 2 : l The timing for elective closure is usually at some time prior to entry school Occlusion devices implanted by interventional cardiac catheterization
Interventional Treatment ASD 封堵器
Ventricular Septal Defect (VSD)
The most common cardiac malformation accounting for 25-50% of CHD
Classification of VSD Membranous VSD most common defect Outlet (supracristal, infundibular, subpulmonary) VSD situated just beneath the pulmonary valve Inlet VSD Muscular VSD
Pathophysiology of VSD AO VSD LV RVH PA LA PV Hyperkinetic pulmonary hypertension extremely large pulmonary blood flow Obstructive pulmonary hypertension pulmonary arteriolar medial thickness pulmonary vascular obstructive disease RVP RVP LVP RV to LV Shunt cyanosis-- Eisenmenger syndrome
Pathophysiology of VSD The degree of Left-to-Right shunting is dependent on: 1. size of defect 2. pulmonary and systemic vascular resistances Left to right shunt is only in systole because the LV pressure is higher than the RV pressure in systole, and the both pressure is equal in diastole
Pathophysiology of VSD The large blood flow through the VSD results in: l. Enlargement of LV and LA (volume overload), dilatation of PA, enlargement of RV when pulmonary hypertension 2. Pulmonary hypertension: early: extremely large pulmonary blood flow Hyperkinetic pulmonary hypertension late: pulmonary arteriolar medial thickness and pulmonary vascular obstructive disease Obstructive pulmonary hypertension When the ratio of pulmonary to systemic resistance approaches 1:1, the shunt become bidirectional, signs of heart failure abate, and the patient becomes cyanosis ---- Eisenmenger syndrome
Clinical Manifestations according to the size of defect and the pulmonary blood and pressure
Small VSD Asymptomatic A loud, harsh, or blowing holosystolic murmur at the 3rd - 4th intercostal space of LSB with thrill Chest X-ray: normal or minimal cardiomegaly and a borderline increase in pulmonary vasculature ECG: normal or left ventricular hypertrophy
Large VSD Dyspnea, feeding difficulties, poor growth, profuse perspiration, recurrent pulmonary infections and cardiac failure in early infancy Prominence of the left precordium and sternum, parasternal lift and systolic thrill A loud, harsh, or blowing holosystolic murmur at the 3rd - 4th intercostal space of LSB P 2 louder when pulmonary hypertension Mid-diastolic, low-pitched rumble at the apex: increased blood flow across the mitral valve
Large VSD Chest X-ray: Gross cardiomegaly with prominence of LV, RV, LA and PA Pulmonary vascular markings increase and frank pulmonary edema may be present Aortic knob is small ECG: Biventricular hypertrophy, P waves may be notched or peaked
Echocardiography Enlargement of the LA and LV, and RV and PA in patients with pulmonary hypertension Position and size of VSD Direction and degree of shunt in VSD
Catheterization Oxygen saturation in RV is higher than in RA RV and PA pressure are normal or increase Right cardiac catheter can enter LV and Aorta through defect in some very large VSD patients
Prognosis The natural course of VSD depends to a large degree on the size of the defect 30-50% of small perimembranous and muscular VSD will close spontaneously, most frequently during the 1st yr of life. The vast majority of defects that close will do so before age 4~5 yr. It is less common for moderate or large defects to close spontaneously. Outlet VSD is no possible to close spontaneously
Complications The large VSD: repeated episodes of respiratory infection, congestive heart failure (CHF) and failure to thrive, and pulmonary hypertension Infective endocarditis
Treatment Small VSD does not need restrictions of physical activity and surgery repair. These patients can be followed by a combination of clinical examinations and noninvasive laboratory tests until the defects has closed spontaneously Large and outlet VSD needs medical management to control CHF and to prevent the development of pulmonary vascular disease, and surgery repair early in patients with pulmonary hypertension
Interventional Treatment 肌部 VSD 封堵器
Interventional Treatment
Patent Ductus Arteriosus (PDA)
During fetal life, most of the pulmonary arterial blood is shunted through the ductus arteriosus into the aorta. Functional closure of the ductus normally occurs soon after birth Figure of PDA The aortic end of the ductus is just distal to the origin of the left subclavian artery, and the ductus enters the pulmonary artery at its bifurcation
Pathophysiology of PDA PDA AO PA PV LV LA Hyperkinetic pulmonary hypertension extremely large pulmonary blood flow Obstructive pulmonary hypertension pulmonary arteriolar medial thickness pulmonary vascular obstructive disease PAP AOP RVP RVH PA to AO Shunt Low extremity cyanosis (differential cyanosis)--- Eisenmenger syndrome
Pathophysiology of PDA Differential Cyanosis
Pathophysiology of PDA The degree of Left-to-Right shunting is dependent on: 1. the size of the ductus 2. ratio of pulmonary and systemic vascular resistances Left to right shunt can occur both in systole and diastole because the aortic pressure is always higher than the pulmonary arterial pressure both in systole and diastole
Pathophysiology of PDA The large blood flow through the PDA results in: 1. enlargement of LV and LA (volume overload), dilatation of PA, enlargement of RV when pulmonary hypertension 2. pulmonary hypertension: early: extremely large pulmonary blood flow --- Hyperkinetic pulmonary hypertension late: pulmonary arteriolar medial thickness and pulmonary vascular obstructive disease --- Obstructive pulmonary hypertension 3. when the ratio of pulmonary to systemic resistance approaches 1:1, the shunt becomes bidirectional, signs of heart failure abate, and the patient becomes cyanosis (differential cyanosis) --- Eisenmenger syndrome
Pathophysiology of PDA Small PDA: PAP, RVP and RAP are normal Large PDA: PAP may be elevated to systemic levels during both systole and diastole
Clinical Manifestations According to the size of the ductus: Small PDA: Asymptomatic Large PDA: poor feeding and retardation of physical growth, sometimes with hoarseness
Clinical Manifestations Prominence of the left precordium and apical impulse in large PDA Wide pulse pressure ( 40 mmhg) and bounding arterial pulse: peripheral blood vessel sign due to runoff of blood into pulmonary artery during diastole Thrill, maximal in the 2nd left intercostal space, may radiate toward the left clavicle, down LSB or toward apex, usually in systole, but also may be throughout the cardiac cycle
Clinical Manifestations Classic murmur: 1. Continuous, machinery and rolling thunder murmur 2. Begining soon after onset of the 1st sound, reaches maximal intensity at the end of systole, and wanes in late diastole 3. Located at the 2nd left intercostal space and radiate down the LSB or to left clavicle 4. When pulmonary vascular resistance increases or heart failure, the diastolic component of the murmur may be less prominent or absent
Chest X-ray Prominent pulmonary artery with increased intrapulmonary vascular markings Normal or minimal cardiomegaly in small PDA and marked cardiomegaly in large PDA. The chambers involved are LA and LV, and RV when pulmonary hypertension Aortic knob is prominent
ECG normal in small PDA left ventricular or biventricular hypertrophy in large PDA
Echocardiography enlargement of the LA and LV, and RV and PA in patients with pulmonary hypertension position, shape and size of PDA direction and degree of shunt in PDA
Catheterization 1. Oxygen saturation in PA is higher than in RV 2. RV and PA pressure are normal or increase 3. Right cardiac catheter can enter descending aorta through PDA in most of patients 4. Angiocardiography is needed in some patients with very tiny PDA
Prognosis and Complications The patients with a small PDA may live a normal span with few or no cardiac symptoms Spontaneous closure of the ductus after infancy is extremely rare The repeated episodes of respiratory infection, congestive heart failure, failure to thrive and pulmonary hypertension are common in large PDA Infective endocarditis may be seen at any age, pulmonary and systemic emboli may occur Aneurysmal dilatation of the pulmonary artery or the ductus
Treatment PDA in premature infant: indomethacin Irrespective of age, patients with PDA require treatment (including surgical and interventional closure) in order to prevent infective endocarditis, congestive heart failure and the development of pulmonary vascular disease
Interventional Treatment
Eisenmenger syndrome 艾森曼格综合征 Those patients with left to right shunt (VSD, PDA, ASD, et) whose shunts have become partially or totally right to left as a result of the development of pulmonary vascular disease 所有左向右分流的先天性心脏病 (ASD VSD PDA 等 ) 由于器质性肺血管病变导致梗阻性肺动脉高压, 右心系统压力等于或超过左心系统, 出现双向或右向左分流
Tetralogy of Fallot (TOF)
Pathophysiology Obstruction to right ventricular outflow tract (infundibular stenosis) -- the most important malformation (sometimes with pulmonary valve and artery stenosis) Ventricular septal defect large and nonrestrictive VSD just below the aortic valve Override of the aorta (dextroposition of the aorta in 25% patients) Right ventricular hypertrophy
Pathophysiology The degree of right ventricular outflow obstruction determines the timing of onset of symptoms, the severity of cyanosis, and the degree of right ventricular hypertrophy The degree of right ventricular outflow obstruction and override of the aorta can become more and more severe with growth
Pathophysiology of TOF Obstruction to right ventricular outflow tract Spasm of Stenotic Infundibulum RVP Hypoxic Spells RVP LVP Pulmonary Blood Flow Collateral Artery From DAO RVH VSD Override of the aorta RV to LV Shunt Gas Exchange in Lung AO Blood from LV and RV Artery Oxygen Saturation Cyanosis Polycythemia Clubbing Squatting Cerebral thromboses Brain abscess
Clinical Manifestations Cyanosis Often is not present at birth, but with increasing hypertrophy of the RV infundibulum and growth, cyanosis occurs later in the 1st yr of life It is most prominent in the mucous membranes of the lips and mouth, and in the fingernails and toenails In infants with severe RV outflow obstruction, cyanosis is noted immediately in the neonatal period
Clinical Manifestations Paroxysmal hypercyanotic attacks (hypoxic spells) 1. Spasm of stenotic infundibulum pulmonary blood flow most of all RV blood into aorta severe systemic hypoxia and metabolic acidosis 2. A particular problem during the first 2 yr of life 3. Hyperpneic, restless, cyanosis increases, gasping respirations ensue and syncope
Clinical Manifestations 4. Frequently in the morning upon first awakening or following episodes of vigorous crying 5. Temporary disappearance or decrease in intensity of the systolic murmur due to the decrease of flow across the RV outflow tract 6. Last a few minutes or hours, rarely fatal. Followed by generalized weakness and sleep. Sevre spells may progress to anconsciousness and mnvulsions or hemiparesi
Clinical Manifestations Clubbing of fingers and toes Dyspnea and Squatting l. Squatting systemic artery pressure and resistance increase LVP increase 2. Squatting venous return decrease RVP decrease l, 2 Right to left shunt decrease through VSD and hypoxia can be improved Growth and development may be delayed in patients with severe untreated tetralogy of Fallot
Clinical Manifestations Left anterior hemithorax may bulge anteriorly due to RV hypertrophy Substernal right ventricular impulse Systolic thrill in the 3rd and 4th parasternal spaces along LSB in 50% cases
Clinical Manifestations Systolic Murmur 1. ejection or holosystolic, loud and harsh 2. most intense in the 2nd -4th intercostal space of LSB 3. caused by turbulence through the RV outflow tract due to the infundibular stenosis The 2nd heart sound is single or the pulmonic component is soft
Chest X-ray Narrow base, concavity of pulmonary artery and normal heart size Rounded apical shadow above the diaphragm than normal Pulmonary vascular marking decrease Large aorta and 25% cases with dextroposition of aortic arch Cardiac silhouette ----- boot or wooden shoe
ECG Right axis deviation and RVH
Echocardiography The aorta widen and override on the large ventricular septal defect Obstruction to right ventricular outflow tract (infundibular stenosis) Right ventricular hypertrophy Left ventricular is small
Cardiac Catheterization and Angiocardiography RVP increases and equals to the LVP Oxygen saturation in Ao and LV decreases Angiocardiography in RV and LV can show the position and size of VSD, size of LV, width and overriding degree of aorta, and degree of obstruction of RVOT, et.
Prognosis and Complications Cerebral thromboses 1. usually in cerebral veins, occasionally in cerebral arteries 2. common in the presence of extreme polycythemia and dehydration under the age of 2 yr Brain abscess usually over the age of 2 yr Bacterial endocarditis Congestive heart failare unusually in TOF
Treatment of hypoxic spells Depending on the frequency and severity of hypercyanotic attacks, one or more of the following procedures should be instituted in sequence: 1. Knee-chest position 2. Administration of oxygen 3. injection of morphine subcutaneously in a dose not in excess of 0.2 mg/kg 4. Correction of metabolic acidosis with intravenous administration of sodium bicarbonate if the spell is unusually severe and there is lack of response to the foregoing therapy 5. β- Adrenergic blockade by intravenous administration of propranolol (0.1 to a maximum of 0.2 mg/kg) 6. Drugs that increase systemic vascular resistance, such as intravenous methoxamine or phenylephrine, decrease the right-to-left shunt
Treatment of TOF Depend on the severity of the RVOT obstruction palliative surgery total correction
Thank You 谢谢