A Review ofCongenital Heart Disease

February 11, 2008

Presentation

• Symptomatic infants with congenital heart disease will have one or more of the following three main presentations:– Cyanosis– Heart Failure– Shock

• Infants with ductal dependent lesions usually present in the first week of life and are often critically ill

Presentation

• Infants with heart failure have nonspecific symptoms and signs, which are frequently very different from those of older children and adults.

• Symptoms can include poor feeding, weight loss, FTT, palpitations, apnea, chest pain, syncope, and fever.

• Signs can include murmurs, hypertension, dysrhythmias, respiratory distress or failure, cyanosis, heart failure, and shock.

Presentation: Vitals

• Hypertension– Can be a manifestation of underlying cardiovascular

diseases including coarctation and aortic stenosis

• Hypotension– Can be due to poor cardiac output from sepsis or shock

• A difference in blood pressure and/or pulses between the extremeties suggests coarctation of the aorta or an interruption of the aortic arch

Presentation

• Although a significant murmur implies the presence of cardiac disease, the absence of a murmur does not rule out underlying heart disease

• Some heart defects (for example transposition of the great arteries) may not have a murmur initially or may have only a nondescript murmur (e.g. single ventricle)

Physical Exam

• Abnormal heart sounds are a clue that underlying heart disease is present

• A wide, fixed, split S2 is characteristic of an atrial septal defect

• With pulmonary atresia or truncus arteriosus, S2 is single

Physical Exam

• After the first day of life, a systolic ejection click is always abnormal and is found with dilation of the aorta or pulmonic trunk

• The murmur of a patent ductus arteriosus is a continuous, even murmur “machine-like,” best heard in the left scapular area

Presentation

• Hepatosplenomegaly can occur with right-sided heart failure

• Palpation of the pulses can reveal bounding pulses with a wide pulse pressure indicative of a patent ductus arteriosus or aortic insufficiency, or the weak thready pulses occurring with low cardiac output

• Ashen, blue, grey, cold, clubbed, edematous and clammy extremities suggest a cyanotic lesion

Presentation

• Because specific cardiac defects are associated with chromosomal abnormalities, abnormal facies, or skin lesions can be a clue to underlying congenital heart disease

Heart Failure

• The usual age at which a large left-to-right shunt will become symptomatic is about six weeks

Heart Failure

• At birth there is a marked initial decrease in the pulmonary vascular resistance followed by a continued slow drop over the next 2-6 weeks of life, with more blood being shunted from left to right

• Infants with these defects are asymptomatic at birth, and symptoms appear and gradually worsen over the next few weeks

Heart Failure

• The classic heart failure triad in infancy is tachypnea, tachycardia, and hepatomegaly

• Pallor and diaphoresis are additional findings in infants

• Rales may be heard on auscultation, but the absence of rales does not rule out heart failure

Ductal-Dependent Congenital Heart Defects

• Many patients with congenital heart defects depend on a patent ductus arteriosus for blood flow

PDA

• When the ductus arteriosus closes, patients with ductal-dependent lesions develop symptoms of acute heart failure and cardiogenic shock with circulatory collapse

• Closure of the ductus usually occurs during the first week of life

PDA

• Functional closure occurs in the first 10-14 hours of life, although anatomic closure can be delayed for 2-3 weeks because of hypoxia, acidosis, and prematurity

• The classic presentation of patients with ductal-dependent lesions is an infant, asymptomatic at birth and in the first few hours or days of life, who develops shock/circulatory collapse toward the end of the first week of life or in the first few weeks of life

Who gets Prostin?

• For symptomatic patients with ductal-dependent congenital heart defects, a PGE1 infusion will keep the ductus arteriosus open until definitive therapy can be undertaken via interventional cardiac catheterization or surgery

Prostin

• PGE1 is given as an infusion, using the mimimum effective dose because side effects are dose dependent and include:– Apnea– Hypotension– Bradycardia– Seizures– Tremors

• Because of the side effects, patients are usually intubated prior to beginning PGE1

PDA in preemies• PDA is the most common cardiovascular abnormality in

preterm infants

• It occurs in up to 60% of infants born at less than 28 weeks gestation

• A significant L R shunt through a PDA increases the morbidity and mortality of these infants.

• Cyclooxygenase inhibitors such as indomethacin or ibuprofen are used to induce closure of the PDA in preterm infants

Cyanotic Infants

• The “five Ts” are common etiologies of cyanotic congenital heart disease:– Tetralogy of Fallot– Transposition of the great arteries– Truncus arteriosus– Tricuspid valve abnormalities– Total anomalous pulmonary venous return

• The letter “S” is added to include severe or “critical” pulmonic stenosis

Cyanotic lesions

• The first priority is to determine whether the etiology of the cyanosis is cardiac or noncardiac

• The hyperoxia test or oxygen challenge test can make this clear.

• The patient is placed on 100% oxygen:– If pulmonary disease is present, the PaO2 should rise

by 30 mmHg or to >150 mmHg, and the pulse ox should rise by at least 10%

– There will be negligible or minimal improvement if the cyanosis is due to CHD

Cyanotic CHD with Decreased Pulmonary Blood Flow

• Cyanotic CHD with decreased pulmonary blood flow include:– Severe tetralogy of Fallot– Pulmonary atresia – Tricuspid atresia– Severe Ebstein anomaly– HRHS– Critical or severe pulmonic stenosis

Cyanotic CHD with Decreased Pulmonary Blood Flow

• These lesions usually are ductal dependent

• These patients will present critically ill and cyanotic (and sometimes with heart failure and shock) in the first few hours or days of life when the ductus arteriosus closes

• The management of such infants involves supporting the ABCs and administering PGE1

Tetralogy of Fallot

• Tetralogy of Fallot is the most common cyanotic congenital heart defect after infancy, accounting for 5%-10% of all congenital heart disease

• It consists of:– VSD– Obstruction of the RV outflow tract– Overriding aorta– RVH

Tetralogy of Fallot

Tetralogy of Fallot

• Patients with TOF usually present as older infants with paroxysmal hypercyanotic attacks (tet spells)

• However, TOF can present in neonates, critically ill and severely hypoxic with extreme pulmonic stenosis

• These infants are dependent on a PDA for pulmonary blood flow, and prostin is necessary

Tetralogy of Fallot

• Conversely are the “pink tets” who have mild right ventricular outflow tract obstruction and present with heart failure from the large LR shunt and have little or no cyanosis

• Older infants and children can present with a tet spell, cyanosis, murmur, exercise intolerance, dyspnea on exertion, clubbing, poor growth, or failure to thrive

Tetralogy of Fallot

• Classic physical findings include:– Holosystolic VSD murmur at the left 3rd intercostal

space– A systolic diamond-shaped pulmonic stenosis

murmur at the left 2nd intercostal space– An abnormal second heart sound split with a soft

P2

Tetralogy of Fallot

• Chest radiograph findings are:– cardiomegaly (especially RV)– Decreased pulmonary vascularity– The characteristic “boot-shaped” heart created by

a concavity in the left heart border usually occupied by the pulmonary artery

“Boot Shaped”

Tetralogy of Fallot

• “Boot-shaped”

Tetralogy of Fallot

Tetralogy of Fallot

• Tet spells occur especially during the first 2 years of life

• They can be precipitated by any physical activity or can occur spontaneously and can last a few minutes or for hours

• Since there is a fixed right ventricular outflow tract obstruction, increased right-to-left shunting occurs

Tetralogy of Fallot

• Factors presdisposing to a tet spell include:– Dehydration– Anemia– Acidosis– decreased systemic vascular resistance– increased catecholamine levels

Tetralogy of Fallot

• Treatment:– Calming the child– Supplemental oxygen– Morphine calms/sedates the child, depresses

respiration, decreases SVR, and decreases RVOT obstruction

– Volume infusion can increase the RV preload and correct systemic hypotension

– Propranolol is given as a negative inotropic on the RVOT

Tricuspid Valve Abnormalities

• Tricuspid valve abnormalities include:– Tricuspid valve stenosis– Tricuspid valve displacement (Ebstein anomaly)– HRHS

Ebstein Anomaly

• An Ebstein anomaly is the downward displacement of an abnormal TV into the RV

• May be due to maternal use of lithium

• Part of the TV—the anterior cusp—has some attachment to the valve ring, and the other valve leaflets are attached to part of the RV wall

Ebstein Anomaly

Cyanotic Congenital Heart Diseasewith Increased Pulmonary Blood Flow

• Includes:– Transposition of the great arteries– Truncus arteriosus– Total anomalous pulmonary venous return

Transposition of the Great Arteries

• Most frequent diagnosis in critically ill neonates with cardiac disease

• Pulmonary artery arises from the LV and the aorta from the RV

Transposition of the Great Arteries

Transposition of the Great Arteries

• Some mixing of blood is needed for survival through a:– Patent foramen ovale,– PDA, or– VSD

Transposition of the Great Arteries

• “egg on a string” appearance– Narrow

mediastinum and small thymus

– Narrow cardiac silhouette

Truncus Arteriosus

• A single arterial trunk overrides a VSD and receives mixed arterial and venous blood from the RV and LV

• This one arterial trunk provides blood flow to the systemic, pulmonary, and coronary circulations

• The one “truncal” valve is an abnormally formed semilunar valve

Truncus Arteriosus

• First few hours and days of life:– Pulmonary vascular resistance is highpulmonary

blood flow is normal

• Later during first month of life:– Pulmonary blood flow increases with the

postnatal decrease in pulmonary vascular resistanceheart failure

Truncus Arteriosus

• Cyanosis can be mild because of the increased pulmonary blood flow

• Eventually Eisenmenger syndrome occurs if untreated

Truncus Arteriosus

Truncus Arteriosus

Total Anomalous Pulmonary Venous Return

• The pulmonary veins return to and enter a structure other than the left atrium

• Can be partial:– Some oxygenated blood enters the LA, and some

enters another anomalous structure– acyanotic

Total Anomalous Pulmonary Venous Return

• Can be total:– None of the pulmonary veins enter the LA– Cyanotic: complete mixing of both systemic and

pulmonary venous return either at or before the RA

– The mixed blood in the RA either is ejected into the RV or through an ASD or PFO into the LA

Total Anomalous Pulmonary Venous Return

• When the anomalous pulmonary veins enter the brachiocephalic vein and the persistent left superior vena cava, there is a “snowman” or “figure 8” appearance created by a large supracardiac shadow along with the normal cardiac shadow

Total Anomalous Pulmonary Venous Return

• “Snowman”or “Figure 8”

Eisenmenger Syndrome

• When a large LR shunt eventually causes increased pulmonary blood flow and volume overload to the lungs, resulting in pulmonary vascular disease/pulmonary hypertension

• This causes a reversal to a RL shunt and cyanosis, often by teenage years or as a young adult

Eisenmenger Syndrome

• Symptoms:– Cyanosis– Exertional dyspnea– Fatigue– Hemoptysis– palpitations

Eisenmenger Syndrome

• Physical exam reveals a loud P2 from pulmonary HTN

• The CXR will reveal decreased pulmonary vascularity

• EKG shows RVH

• Therapy involves pulmonary vasodilator therapy

References

• Mace, S. Broken Hearts: Infants With Acyanotic Congenital Heart Disease. CDEM. 2007; 21(11): 2-9.

• Mace, S. Broken Hearts: Infants With Cyanotic Congenital Heart Disease. CDEM. 2007; 21(11): 12-23.

• Multimedia Library. Childrens Hospital Boston. http://www.childrenshospital.org/

• Beerman, L; et al. Cardiology. Atlas of Pediatric Physical Diagnosis. Fifth Edition. 2007; 127-160.