Cardiac Defects Patent Ductus Arteriosus Atrial Septal Defect Ventricular Septal Defect Tetralogy of Fallot Transposition of the Great Arteries Coarctation of the Aorta Anomalous Venous Return Truncus Arteriosus Hypoplastic Left-Heart Syndrome
Heart Congenital heart disease (CHD) occurs in 1/125 live births. Neonates may present with a variety of non- specific findings, including: - tachypnea - cyanosis - pallor - lethargy - FTT - sweating with feeds More specific findings include: - pathological murmurs - hypertension - abnormal pulses - syncope
Neonatal cardiac physiology The transformation from fetal to neonatal circulation involves two major changes: 1.A marked increase in systemic resistance. caused by loss of the low-resistance placenta. 2. A marked decrease in pulmonary resistance. caused by pulmonary artery dilation with the neonate’s first breaths.
Fetal Circulation No circulation to lungs Foramen ovale Ductus arteriosum Circulation must go to placenta Umbilical aa., vv.
Fetal cardiac physiology Fetal circulation: Blood flows from the placenta IVC RA through the PFO LA LV ascending aorta brain returns via the SVC
Fetal cardiac physiology Fetal circulation: From the SVC RA RV pulm aa through the PDA descending aorta lower extremities and placenta
Fetal cardiac physiology Fetal circulation: Only a very small amount of blood is directed through the right and left pulmonary aa’s to the lungs.
Neonatal cardiac physiology Neonate circulation: The transformation to neonatal circulation occurs with the first few breaths. The two remaining remnants of the fetal circulation are a patent foramen ovale... and ductus arteriosus.
Congenital Heart Disease Neonates with CHD often rely on a patent ductus arteriosus and/or foramen ovale to sustain life. Unfortunately for these neonates, both of these passages begins to close following birth. – The ductus normally closes by 72hrs. – The foramen ovale normally closes by 3 months. –
CHD That being said, in the presence of hypoxia or acidosis (generally present in ductus-dependent lesions), the ductus may remain open for a longer period of time. As a result, these patients often present to the ED during the first 1-3 weeks of life. – i.e. as the ductus begins to close.
Classifying CHD There are many different classification systems for CHD. – None are particularly good. I will be discussing the Pink/Blue/Grey-Baby system: 1.Pink Baby – Left to right shunt 2.Blue Baby – Right to left shunt 3.Grey Baby – LV outflow tract obstruction
Pink Baby (L R shunt) L R shunts cause CHF and pulmonary hypertension. This leads to RV enlargement, RV failure, and cor pulmonale. These babies present with CHF and respiratory distress. – They are not typically cyanotic. – =PLA81DD78BDE77FBFC =PLA81DD78BDE77FBFC
Pink Baby (L R shunt) ASD VSD These lesions include (among others) ASD’s, VSD’s, and persistently patent ductus arteriosus.
Pink Baby (L R shunt) Diagnosing L R shunts depends on: 1. Examination findings: Non-cyanotic infant in resp distress. Crackles, widely-fixed second heart sound, elevated JVP, cor pulmonale. 2. CXR: Increased pulmonary vasculature (suggestive of CHF). RA and/or RV enlargement.
Pink Baby (L R shunt) Initial management should be directed at reducing the pulm edema. – Adminster Lasix 1mg/kg IV. Peds Cardiology/ PICU should be consulted urgently regarding use of: – Morphine – Nitrates – Digoxin – Inotropes
Ductus Arteriosus Fetal Circulation Component – Connects Pulmonary Artery to Aorta – Shunts blood away from lungs – Maintained patent by presence of prostaglandins Closure secondary to: – Increase in PaO 2_ – Decrease in level of prostaglandins
Patent Ductus Arteriosus 5-10% of all births (1 of 2000 live births) – 80% of premature babies 2-3 times more common in females than males. 5 th or 6 th most common congenital cardiac defect. – Often associated with other defects. – May be desirable with some defects. Morbidity/Mortality related to degree of blood flow through PDA.
Pathophysiology - PDA With a drop in pulmonary arterial pressure (reduction in hypoxic pulmonary vascular constriction), blood will flow through PDA. – LEFT TO RIGHT SHUNT Increased pulmonary blood flow may lead to pulmonary edema. – Reduced blood flow to all postductal organs NEC If pulmonary artery pressure rises above Aortic pressure, blood will move in the other direction. – RIGHT TO LEFT SHUNT
Diagnosis - PDA Loud grade I to grade III systolic murmur at left sternal border. – Washing machine Echocardiography
Atrial Septal Defect 6-10% of all births (1 of 1500 live births) 2 times more common in females than males. Types: – Ostium Secundum (at or about the Foramen Ovale) – Sinus Venous – In 1950 most children with ASD did not reach the first grade. Today, first year surgery facilitates normal growth and development.
ASD: Pathophysiology and Diagnosis Pathophysiology – Left to Right Shunt Inefficient recirculation of good blood through pulmonary arteries. – May not manifest symptoms and may be found later in life. – If defect is significant, may cause problems later in life due to inefficiencies. Diagnosis – Murmur – Echocardiography
Ventricular Septal Defect 1% of all births (2 to 4 of 1000 live births) – Vast majority the hole is small. In 1950, fatal. Today almost all VSD can be closed successfully, even in small babies. Lillehei was the first person in history to correct both ASD and VSD on 8/31/54.
VSD: Pathophysiology & Diagnosis Pathophysiology – May be isolated or associated with other congenital cardiac defects. – With normal PVR: LEFT TO RIGHT SHUNT – With elevated PVR (RDS): RIGHT TO LEFT SHUNT Diagnosis – Echocardiography
Treatment - VSD Nothing if VSD is small. With CHF or Failure to Thrive: Surgical closure.
Blue Baby (R L shunt) R L shunts cause hypoxia and central cyanosis. Neither hypoxia or cyanosis tend to improve with 100% oxygen. R L lesions include (among others): – Tetralogy of Fallot (TOF) – Transposition of the Great Arteries (TGA)
Blue Baby (R L shunt) Hypoxia and cyanosis (unresponsive to oxygen) in the neonatal period suggests a ductus-dependent lesion. Treatment is a prostaglandin-E1 (PGE 1 ) infusion. – Dosing discussed momentarily This should obviously be accompanied by urgent Peds Cardiology and PICU consultation.
Tetralogy of Fallot Characterized by: 1.Pulmonary aa OTO 2.RV hypertrophy 3.VSD 4.Over-riding aorta With severe pulmonary OTO... * * * * bloodflow to the lungs may be highly ductus-dependent.
Tetralogy of Fallot The classic CXR finding in TOF is the boot-shaped heart. Pulmonary vasculature is typically decreased.
Tetralogy of Fallot 1% of neonates. cyanotic Most common of the cyanotic cardiac diseases. Mortality increases with age (1 year-old has a 25% mortality, 40 year-old has 95%). In 1950, fatal. Today, less than 5% mortality with children operated on in infancy, leading normal lives. Four Defects – Pulmonary Artery Stenosis (determinant factor related to severity) – VSD (usually large) – Overriding Aorta – RV hypertrophy
Tetralogy of Fallot: Diagnosis and Treatment Tet Spells (Blue spells) CXR: Boot-shaped Heart Diagnosed with echocardiography. Surgical correction. – Reparative or Palliative (Blalock-Taussig)
Blalock-Taussig Something the Lord Made. – Vivien Thomas
Tetralogy of Fallot
Transposition of the Great Arteries TGA is one of the most common cyanotic lesion presenting in the first week of life. Anatomically: – RV aorta – LV pulmonary aa To be compatible with life, mixing of the two circulations must occur via an ASD, VSD, or PDA. h?v=O83cYwKOKtI&list=PLA8 1DD78BDE77FBFChttp://www.youtube.com/watc h?v=O83cYwKOKtI&list=PLA8 1DD78BDE77FBFC
Transposition of the Great Arteries The CXR findings in TGA are typically less dramatic than in TOF. Pulmonary vasculature is typically increased. TkE_wygT4&list=PLA81DD78BDE77FBFC&index =1 TkE_wygT4&list=PLA81DD78BDE77FBFC&index =1
Complete Transposition of the Great Arteries Second most common form (5-7%) of congenital cardiac anomalies. Aorta arises from RV and Pulmonary Arteries from LV. Without an abnormality, life would not be possible. – ASD – VSD (30-40%) – PDA
Transposition – Diagnosis and Treatment Diagnosis – Chest X-Ray: “Egg on a String” – Echocardiography – Cardiac Catheterization (?) Treatment – Balloon septostomy during cardiac cath. Rashkind’s Procedure Reestablish Foramen Ovale – Prostaglandin E 1 to keep PDA open. – Surgical Correction Jantene Operation
Grey Baby (LVOTO) Left-ventricular outflow tract obstructions (LVOTO’s) lead to cyanosis, acidosis, and shock early in the neonatal period. Complete obstruction is universally fatal unless shunting occurs through an ASD, VSD, or PDA. Examples of these lesions include: – Severe coarctation of the aorta – Hypoplastic left heart syndrome (HLHS) X
Grey Baby (LVOTO) Treatment: – Any neonate presenting with shock unresponsive to fluids +/- pressors has a LVOTO until proven otherwise. – As with the Blue babies, appropriate management is an urgent PGE1 infusion and emergent consultation.
Coarctation of the Aorta 7% of congenital cardiac defects. Constriction of the aorta. – Results in severely reduced blood flow. Increased work on the heart leading to CHF and cardiovascular collapse. Location of narrowing determines the clinical signs. Usually associated with PDA, VSD and a defective aortic valve.
Location of Coarctation Pre-Ductal – Less common but more serious – Associated with VSD, PDA, Transposition Post-Ductal – More common – Often associated with collateral circulation beyond coarctation, which minimizes effect. – Diagnosed by a difference in blood pressure between lower extremities and upper ones. Pressure in upper extremities > lower
Coarctation – Diagnosis and Treatment Diagnosis – Chest X-Ray – Echocardiography – Cardiac catheterization Treatment – Support with inotropic agents (Dopamine). – Prostaglandins to maintain PDA. – Surgical repair –
Anomalous Venous Return Return of pulmonary venous blood to the right atrium instead of the left. – ASD is present to sustain life. – Can also be partial. Cyanosis usually present. Diagnosed with echocardiography. Surgical correction with reimplantation of pulmonary veins.
Truncus Arteriosus Defect in which one large vessel arises from right and left heart over a large VSD. Cyanosis is often present. CHF common. Diagnosed with echocardiography and cardiac catheterization. Surgery: – Separate pulmonary arteries from truncus. – Closure of VSD – Create valved connection between RV and Pulmonary Artery –
Repair of Truncus Arteriosus
Hypoplastic Left-Heart Syndrome Several anomalies: – Coarctation of the aorta – Hypoplastic left ventricle – Aortic and mitral valve stenosis or atresia. Cyanotic defect. Right heart pumps blood to body through PDA. Closure of PDA results in hypotension, shock, and death. – Maintain hypoxemia with normalized CO 2 levels. “40-40 Club”
1 Patent foramen ovale 2 Coarctation of the aorta 3 Patent ductus arteriosus 4 Narrowed aorta 5 Hypoplastic left ventricle 6 Aortic atresia
Surgical Treatment of Hypoplastic Left Heart Syndrome Three separate surgeries. – Norwood procedure First few days after birth. – Glenn Shunt (Cavo Pulmonary Connection) 3-9 months of age – Fontan Procedure 2 years of age – Less wait because of damage from pulmonary hypertension.
Stage I - Norwood Procedure
Stage II - Glenn Shunt
Stage III – Fontan Procedure
Prostaglandin-E1 PGE 1 promotes ductus arteriosus patency. Use an IV infusion at ug/kg/min. A response should be seen within 15 min. – If ineffective, try doubling the dose. – If effective, try halving the dose. The lowest possible dose should be used– as adverse-effects of PGE 1 can include: - fever - flushing - diarrhea - periodic apnea (be ready to intubate)
Remnants of Fetal Circulation Ligamentum teres = Round ligament – Remnant of the umbilical vein – Anterior abdominal wall Ligamentum venosum – Remnant of ductus venosum – On liver’s inferior surface Medial Umbilical Ligaments – Remnant of umbilical arteries – Anterior abdominal wall below navel – Also gives branch to urinary bladder