2Cardiac Defects Patent Ductus Arteriosus Atrial Septal Defect Ventricular Septal DefectTetralogy of FallotTransposition of the Great ArteriesCoarctation of the AortaAnomalous Venous ReturnTruncus ArteriosusHypoplastic Left-Heart Syndrome
3Heart 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 feedsMore specific findings include:- pathological murmurs hypertension- abnormal pulses syncope
4Neonatal cardiac physiology The transformation from fetal to neonatal circulation involves two major changes: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.
5Fetal Circulation No circulation to lungs Foramen ovale Ductus arteriosumCirculation must go to placentaUmbilical aa., vv.
7Fetal cardiac physiology Fetal circulation:Blood flows from the placenta IVC RA through the PFO LA LV ascending aorta brain returns via the SVC
8Fetal cardiac physiology Fetal circulation:From the SVC RA RV pulm aa through the PDA descending aorta lower extremities and placenta
9Fetal cardiac physiology Fetal circulation:Only a very small amount of blood is directed through the right and left pulmonary aa’s to the lungs.
10Neonatal 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.
11Congenital 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.
12CHDThat 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.
13Classifying CHDThere are many different classification systems for CHD.None are particularly good.I will be discussing the Pink/Blue/Grey-Baby system:Pink Baby – Left to right shuntBlue Baby – Right to left shuntGrey Baby – LV outflow tract obstruction
14Pink 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.
15Pink Baby (L R shunt)These lesions include (among others) ASD’s, VSD’s, and persistently patent ductus arteriosus.VSDASD
17Pink 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.
18Pink 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:MorphineNitratesDigoxinInotropes
19Ductus Arteriosus Fetal Circulation Component Closure secondary to: Connects Pulmonary Artery to AortaShunts blood away from lungsMaintained patent by presence of prostaglandinsClosure secondary to:Increase in PaO2_Decrease in level of prostaglandins
20Patent Ductus Arteriosus 5-10% of all births (1 of 2000 live births)80% of premature babies2-3 times more common in females than males.5th or 6th 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.
22Pathophysiology - PDAWith a drop in pulmonary arterial pressure (reduction in hypoxic pulmonary vascular constriction), blood will flow through PDA.LEFT TO RIGHT SHUNTIncreased pulmonary blood flow may lead to pulmonary edema.Reduced blood flow to all postductal organsNECIf pulmonary artery pressure rises above Aortic pressure, blood will move in the other direction.RIGHT TO LEFT SHUNT
23Diagnosis - PDALoud grade I to grade III systolic murmur at left sternal border.Washing machineEchocardiography
25Atrial 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 VenousIn 1950 most children with ASD did not reach the first grade. Today, first year surgery facilitates normal growth and development.
29ASD: Pathophysiology and Diagnosis Left to Right ShuntInefficient 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.DiagnosisMurmurEchocardiography
30Treatment - ASD Surgical closure. Non-Surgical closure via cardiac catheterization.
31Ventricular 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.
34VSD: Pathophysiology & Diagnosis May be isolated or associated with other congenital cardiac defects.With normal PVR:LEFT TO RIGHT SHUNTWith elevated PVR (RDS):RIGHT TO LEFT SHUNTDiagnosisEchocardiography
35Treatment - VSD Nothing if VSD is small. With CHF or Failure to Thrive: Surgical closure.
36Blue 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)
37Blue Baby (R L shunt)Hypoxia and cyanosis (unresponsive to oxygen) in the neonatal period suggests a ductus-dependent lesion.Treatment is a prostaglandin-E1 (PGE1) infusion.Dosing discussed momentarilyThis should obviously be accompanied by urgent Peds Cardiology and PICU consultation.
38Tetralogy of Fallot * * * * Characterized by:Pulmonary aa OTORV hypertrophyVSDOver-riding aortaWith severe pulmonary OTO...***bloodflow to the lungs may be highly ductus-dependent.*
39Tetralogy of Fallot Pulmonary vasculature is typically decreased. The classic CXR finding in TOF is the boot-shaped heart.Pulmonary vasculature is typically decreased.
40Tetralogy of Fallot 1% of neonates. 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 DefectsPulmonary Artery Stenosis (determinant factor related to severity)VSD (usually large)Overriding AortaRV hypertrophy
47Transposition of the Great Arteries TGA is one of the most common cyanotic lesion presenting in the first week of life.Anatomically:RV aortaLV pulmonary aaTo be compatible with life, mixing of the two circulations must occur via an ASD, VSD, or PDA.
48Transposition of the Great Arteries The CXR findings in TGA are typically less dramatic than in TOF.Pulmonary vasculature is typically increased.
49Complete 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.ASDVSD (30-40%)PDA
54Grey Baby (LVOTO)XLeft-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 aortaHypoplastic left heart syndrome (HLHS)
55Grey 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.
56Coarctation 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.
58Location of Coarctation Pre-DuctalLess common but more seriousAssociated with VSD, PDA, TranspositionPost-DuctalMore commonOften 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
59Coarctation – Diagnosis and Treatment Chest X-RayEchocardiographyCardiac catheterizationTreatmentSupport with inotropic agents (Dopamine).Prostaglandins to maintain PDA.Surgical repair
61Anomalous 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.
63Truncus ArteriosusDefect 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 VSDCreate valved connection between RV and Pulmonary Artery
66Hypoplastic Left-Heart Syndrome Several anomalies:Coarctation of the aortaHypoplastic left ventricleAortic 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 CO2 levels.“40-40 Club”
672 Coarctation of the aorta 3 Patent ductus arteriosus 4 Narrowed aorta 1 Patent foramen ovale2 Coarctation of the aorta3 Patent ductus arteriosus4 Narrowed aorta5 Hypoplastic left ventricle6 Aortic atresia
68Surgical Treatment of Hypoplastic Left Heart Syndrome Three separate surgeries.Norwood procedureFirst few days after birth.Glenn Shunt (Cavo Pulmonary Connection)3-9 months of ageFontan Procedure2 years of ageLess wait because of damage from pulmonary hypertension.
72Prostaglandin-E1 PGE1 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 PGE1 can include:- fever- flushing- diarrhea- periodic apnea (be ready to intubate)
73Remnants of Fetal Circulation Ligamentum teres = Round ligamentRemnant of the umbilical veinAnterior abdominal wallLigamentum venosumRemnant of ductus venosumOn liver’s inferior surfaceMedial Umbilical LigamentsRemnant of umbilical arteriesAnterior abdominal wall below navelAlso gives branch to urinary bladder
74Clinical Monitoring Blood pressure Oxygen saturation End tidal carbon dioxide
75Respiratory Care of Patients with Cardiac Anomalies Vascular resistanceVentilator managementInhaled nitric oxideSubambient oxygenHypercarbia