Congenital Heart Disease Conrad Cheung, MD Marie Sankaran, MD Department of Anesthesiology Boston University Medical Center Faculty Advisor: Elena Brasoveanu,

Congenital Heart DiseaseCongenital Heart Disease

Conrad Cheung, MDMarie Sankaran, MD

Department of AnesthesiologyBoston University Medical Center

Faculty Advisor: Elena Brasoveanu, MDMarch 9, 2006

Classification Classification Acyanotic

– Interrupted Aortic Arch– Aortic Stenosis– Ventricular Septal Defect– Atrial Septal Defect

Cyanotic Defects– Hypoplastic Ventricle– Pulmonary Stenosis– Tetralogy of Fallot– D transposition of the great vessels– Tricuspid atresia

PlanPlan

We will discuss few topics that are important from the anesthesiologist point of view– Septal Defects– Atrial Septal Defects– Patent Ductus Arteriosus– Interrupted Aortic Arch– Tetralogy of Fallot– Single ventricle

The Cyanotic NeonateThe Cyanotic Neonate Ductus Arteriosus closes within 6 hours of birth so

any congenital heart disease that relies on it for perfusion of oxygenated blood will present early

To prevent death from inadequate oxygenation, the duct has to be maintained open with prostaglandines

Any neonate with a congenital heart disorder that relies on an open ductus arteriosus for oxygenation will deteriorate rapidly and requires immediate transfer to a specialty center

Ventricular Septal Defect IVentricular Septal Defect I

Defect in the septum separating the left and right ventricles

Most common type of congenital heart disease accounting for 21% of all cases

Can occur singly or in multiples anywhere along the ventricular septum

Small defects often close spontaneously in the first 2 years of life while large defects require surgical repair within the 1st year

Ventricular Septal Defect IIVentricular Septal Defect II

Prevalence equal between boys and girlsDue to increased pressures in the left

ventricle, left to right shunting of oxygenated blood occurs

With the increased pulmonary blood flow, pulmonary hypertension can occur with large defects

Ventricular Septal Defect IIIVentricular Septal Defect III

Symptoms of Ventricular Septal Symptoms of Ventricular Septal DefectsDefects

Rapid breathingIrritabilityExcessive SweatingPoor weight gainCongestive Heart Failure, usually within 6

to 8 weeks of life if defect is largePulmonary Hypertension if defect is large

Treatments for Ventricular Septal Treatments for Ventricular Septal DefectsDefects

Lasix and Aldactone to decrease symptoms of CHF

Digoxin to increase effectiveness of myocardial function

If surgery needed, patching or suturing the defect can be done

Mortality from surgery is low

Atrial Septal Defect IAtrial Septal Defect I

Defect in the septum separating the left and right atria

Accounts for 5-10% of congenital heart disease

Twice as frequent in girls versus boysThree types of atrial septal defects

Atrial Septal Defect IIAtrial Septal Defect II

Ostium Primum: Defect located in the lower part of septum near tricuspid valve which separates the right atrium and right ventricle

Ostium Secundum: Defect located near center of atria septum (most common accounting for 50-70% of atrial defect)

Sinus Venosus: Located near the SVC or IVC’s entrances to the heart

Atrial Septal Defect IIIAtrial Septal Defect III

Atrial Septal Defect IVAtrial Septal Defect IV

Due to increased pressures, there is left to right shunting of oxygenated blood

If large defect, can cause enlarged right atria, right ventricle, and pulmonary artery resulting in abnormal arrhythmias

CHF can occur if left untreated till adulthood

Symptoms of Atrial Septal DefectsSymptoms of Atrial Septal Defects

Slender buildHeart murmur resulting from increased

blood flow through pulmonary valveUsually no significant exercise restriction

unless defect is large. SOB or palpitations are possible.

Treatment of Atrial Septal DefectsTreatment of Atrial Septal Defects

If defect is small (less than 2mm), will usually resolves spontaneously

If defect is large, surgical correction is needed

Minimally invasive procedures availableTranscatheter devices, such as a septal

occluder may be used

Patent Ductus ArteriosusPatent Ductus Arteriosus

The ductus arteriosus connects the pulmonary artery to the descending aorta during fetal life.

PDA results when the ductus fails to close after birth.

Picture: www.lpch.org


Pathophysiology:– Blood flows from aorta to the

pulmonary artery, creating a left to right shunt, resulting in left atrium and ventricle overload.

– Increased pulmonary blood flow can result in pulmonary hypertension and reversal of the shunt, which is known as Eisenmenger’s Syndrome. This results in flow of desaturated blood to the lower extremities.


Patent Ductus ArteriosusPatent Ductus ArteriosusSymptoms:

– Children with small patent ductus are usually asymptomatic.

– Large left to right shunts develop symptoms of congestive heart failure such as tachypnea, tachycardia, poor feeding and slow growth

Physical exam:– Continuous murmur heard best at the left sternal

border.

Patent Ductus ArteriosusPatent Ductus ArteriosusLab Studies:

– CXR: enlarged cardiac silhouette secondary to left atrial and ventricular enlargement with prominent pulmonary vascular markings.

– EKG: left atrial enlargement, LVH– ECHO: doppler flow through the ductus

Treatment: – Surgical division or ligation of the PDA


Anesthetic Management:

-Maintain high arterial pressures as low diastolic pressure and pulmonary steal can result in decreased organ perfusion.

Concerns After Repair:– Rarely, recanalization or incomplete ligation of the

ductus occur.– Post repair, these patients can be treated as healthy

patients and do not require endocarditis prophylaxis.

Interrupted Aortic Arch IInterrupted Aortic Arch I

Relatively rare occurs in 2 cases per 100,000 live births

Consists of 2 different defects: divided aortic arch and ventricular septal defect

Divided Aortic arch results in continued blood flow to the upper extremities, but none to the lower extremities

Interrupted Aortic Arch IIInterrupted Aortic Arch II

Lower extremities oxygenated due to the combination of patent ductus arteriosus and ventricular septal defect

PDA connects lower portion of the aortic to the pulmonary artery

VSD allows travel of oxygenated blood to the right ventricle which in turns travels to the pulmonary artery.

Interrupted Aortic Arch IIIInterrupted Aortic Arch III

Symptoms of Interrupted Aortic Arch ISymptoms of Interrupted Aortic Arch I

Often discovered 3-4 days after birth when the patent ductus arteriosus closes

Symptoms of shock develops very rapidly as no oxygenated blood flows to the lower extremities

Rapid breathing, clammy sweating, and poor feeding often develops during the first week

Symptoms of Interrupted Aortic Arch IISymptoms of Interrupted Aortic Arch II

Most babies born at term with normal length and weight

Heart murmur usually heardLiver may be enlargedLeft arm/leg pulses may be diminished or

absentEchocardiogram for diagnosis

Treatment of Interrupted Aortic ArchTreatment of Interrupted Aortic Arch

Before surgery, try to keep the PDA open to provide oxygenated blood to the lower extremities

Surgery to suture together the two ends of the aorta, patch the VSD, and ligate the PDA

85-90% patients survive the hospital stay

Long Term Prospects for Interrupted Long Term Prospects for Interrupted Aortic ArchAortic Arch

Patients are at increased risk for subacute bacterial endocarditis requiring antibiotics before surgery and dental work

Restriction from vigorous or competitive sports. Emphasis placed on child to self-limit their level of exertion

Tetralogy of FallotTetralogy of Fallot

Anatomic Defects– Ventricular septal

defect– Overriding Aorta – Pulmonary artery

stenosis– Right ventricular

hypertrophy


Tetralogy of FallotTetralogy of FallotPathophysiology:Increased resistance by the

pulmonary stenosis causes deoxygenated systemic venous return to be diverted from RV, through VSD to the overriding aorta and systemic circulation systemic hypoxemia and cyanosis



Symptoms:– Dyspnea on exertion or when crying– Tet spells: irritability, cyanosis, hyperventilation

and sometimes syncope or convulsions due to cerebral hypoxemia.

– Patients learn to alleviate symptoms by squatting which increases systemic resistance and decreases the right-to-left shunt and directs more blood to the pulmonary circulation.


Physical exam:– Clubbing of the fingers and toes– Systolic ejection murmur heard at the upper left sternal

border created by turbulent blood flow through stenotic RV outflow tract

Lab Studies:– CXR: prominent RV– EKG: RVH, right axis deviation– ECHO: displays and quantifies extent of RV outflow

tract obstruction

Tetralogy of FallotTetralogy of Fallot Treatment:

– Surgical closure of the VSD and enlargement of the pulmonary outflow tract

Anesthetic Management:-The goal is to control the magnitude of the right to left intracardiac shunt,

which is increased by: 1) Decreased SVR2) Increased PVR3) Increased myocardial contractility

-Patient given beta blockers for prophylaxis against Tet spells-Inhalation induction can be employed in an attempt to avoid Tet spells

while placing an intravenous line.-Physiologic monitoring includes standard ASA monitors and an arterial

line. Echocardiography and EEG may also be employed.


Concerns After Surgical Repair:– Endocarditis prophylaxis– Residual VSD secondary to incomplete closure– Residual RV outflow tract obstruction– Chronic pulmonary valve regurgitation results in a large volume load

on the right ventricle that can lead to cardiomegaly and increased incidence of arrhythmias.

– Right ventriculotomy during the repair leads to scarring which increases the risk of dysrhythmias and conduction abnormalities.

Overall incidence of sudden death in TOF patients after surgical repair is about 0.3%.

Single Ventricle PhysiologySingle Ventricle Physiology

Group of congenital heart diseaseInstead of 2 separate ventricles, there is

essentially 1 ventricle pumping blood to the aortic and pulmonary artery

Complete mixing of oxygenated and deoxygenated blood occurs

Examples of Single Ventricle Examples of Single Ventricle Congenital ProcessesCongenital Processes

Tricuspid atresia: Narrowed pulmonary arteries. At Birth patent PDA allows sufficient oxygenation to occur, however after closure of PDA cyanosis results

Hypoplastic Left heart: Blood flow to the body severely restricted. Once PDA close, patient has profound shock

Tricuspid AtresiaTricuspid Atresia

Hypoplastic Left HeartHypoplastic Left Heart

Treatment of Tricuspid AtresiaTreatment of Tricuspid Atresia

Blalock-Taussig shunt placed to form a conduit between pulmonary artery and aorta to maintain oxygenation

Prior to surgery, maintain PDA patency

Treatment of Hypoplastic Left HeartTreatment of Hypoplastic Left Heart

Keep PDA patent prior to procedure to prevent patient from going into shock

Aorta is formed from the base of the pulmonary artery and narrowed aorta

Modified Blalock-Taussig shunt formed to maintain adequate oxygenation

Long Term outlook of Single VentricleLong Term outlook of Single Ventricle

Activity limitationsProphylactic antibiotics prior to surgery and

dental workLife-long checkups and medicationsProne to rhythm disturbances, fluid

retention, and increased risk of CHF

Anesthetic Considerations for Non-Cardiac Anesthetic Considerations for Non-Cardiac Surgery in Patients with Congential Heart Surgery in Patients with Congential Heart

DiseaseDisease

Has the heart defect been corrected?If so, what kind of follow-up has the patient

had?Should the surgery be done at a specialized

center with expertise in congential heart disease?

Will a cardiology consult be needed to help plan the anesthetic management?

Anesthetic Considerations for Non-Cardiac Anesthetic Considerations for Non-Cardiac Surgery in Patients with Congential Heart Surgery in Patients with Congential Heart

Disease IIDisease II

Pre-op the patient as you would any other with special emphasis on the heart

What is the patient’s functional capacity?Any recent echos or EKGs?Patients with a history of ASD or VSD

repairs are prone to arrhythmias and endocarditis

Documents

Congenital Heart Disease Conrad Cheung, MD Marie Sankaran, MD Department of Anesthesiology Boston University Medical Center Faculty Advisor: Elena Brasoveanu,