congenital heart disease ii

Congenital heart disease(Formulation of the problem)

Antonio [email protected]

Médico coordenadorUnidade de Medicina Intensiva PediátricaUnidade de Medicina Intensiva Neonatal

Hospital Padre Albino

Professor de Pediatria nível II Faculdades Integradas Padre Albino

Catanduva / SP

Dr. Antonio Souto [email protected] 2013

UTI Pediátrica & Neonatal Hospital Padre Albino

What Are The Odds?

• Congenital Heart Disease 8/1000 live births

• “Critical” CHD 3/1000 live births

• In the USA:~ 32,000 children born/year with CHD~ 11,000/year with “Critical” CHD



Relative Frequency of Lesions %

• Ventricular septal defect 25-30 • Atrial septal defect 6-8 • Patent ductus arteriosus 6-8 • Coarctation of aorta* 5-7 • Tetralogy of Fallot 5-7 • Pulmonary valve stenosis 5-7 • Aortic valve stenosis * 4-7 • Transposition of great arteries 3-5 • Hypoplastic left ventricle * 1-3 • Hypoplastic right ventricle 1-3 • Truncus arteriosus 1-2 • Total anomalous pulm venous return 1-2 • Tricuspid atresia 1-2 • Double-outlet right ventricle 1-2 • Others 5-10



Left Ventricular Outflow Tract Obstruction

Major source of neonatal M&M from CHD

•10% of infant mortality

•Accounts for ~ 12% of congenital cardiac disease in infancy•~ 75% discharged from hospital w/o diagnosis•~ 65% - normal newborn screen examination•6% died before diagnosis•96% symptoms by 3 wks of life



Congenital heart diseases are a dynamic group of anomalies that originate in fetal life and change considerably during postnatal development.

Routine neonatal examination fails to detect more than half of babies with

heart disease; examination at 6 weeksmisses one third.



Early recognition , urgent identification and timelyreferral to a pediatric cardiologist and timely

intervention has great implications in prognosis,

is the key in reducing mortalityand morbidity .



Formulation of the problem

?a great concern to

pediatricians



Clinical Presentation of CHD in the Neonate

• Fetal Diagnosis• Cyanosis• CHF/Shock/Circulatory Collapse• Arrhythmia• Asymptomatic Heart Murmur



Congenital heart disease in thenewborn requiring

early intervention ????

Life threatening heart diseases may not have obviousevidence early after birth, the diagnosis is difficultsometimes and always a great concern to pediatricians.

High index of suspicion is essentialto decision making.



Classification of CHD ( clinical point of view)

1.Life-threatening CHD

-Cardiovascular collapse is likely and compromised if nottreated early

Transposition of the great arteries (TGA), criticalpulmonary and aortic valvular stenosis/atresia,

hypoplastic left heart syndrome (HLHS), obstructed total anomalous pulmonary venous

return (TAPVR).



Cardiac malformations - 10% of infant mortality

Most common lethal diagnosis:

Left ventricular outflow tract obstruction

•Hypoplastic left heart syndrome•Coarctation of aorta•Aortic stenosis



CyanosisChronically adapted to the hypoxia in the uterine life, newborn infants are able to tolerate some degree of cyanosis than older infants or children



Typically, 2 g/dL of reduced hemoglobin5g/dL of reduced Hb � clinical cyanosis

35%

65%

25%

75%



Cyanosis

•Central cyanosis

•noted in the trunk, tongue, mucous membranes

•due to reduced oxygen saturation

•Peripheral cyanosis

•noted in the hands and feet, around mouth

•due to reduced local blood flow



Cyanosis

Category of cyanotic CHD

decreased pulmonary flow with right to left shunting lesions (PA, TA with shunting at the atrial or ventricular level)

poor mixing lesions (transposition physiology)

right to left shunt with intra cardiac mixing lesio ns(TAPVR, single ventriclular physiology, truncusarteriosus).



• Total Anomalous Pulmonary Veins

• Tetrology of Fallot

• Tricuspid Atresia

• Transposition• Truncus Arteriosus

5 5 ““ TT’’ss””Most common cyanotic lesions of the newborn



Classification of CHD ( clinical point of view)

2. Clinically significant CHD-Cardiac malformations that have effects on heart function but where

the collapse is unlikely to be need early intervention.

Ventricular septal defect (VSD), complete atrioventricular septal defect (AVSD), atrial septal defect (ASD) andtetralogy of Fallot (TOF) with good pulmonary artery

anatomy.

3. Clinically non-significant CHD-No functional and clinical significance. Small VSD, atrial septal defect (ASD), mild pulmonary stenosis (PS).



•The neonatal myocardium has fewer myofibrils in a disordered pattern, making the myocardium stiffer .

•The neonatal heart follows the Frank e Starlingrelationship but with a limited increase in strokevolume for a given increase in ventricular fillingvolume.

•The neonatal myocardium is dependenton heart rate to increase cardiac output.



•Near peak of Starling curve•Stroke volume relatively fixed•C.O. relatively heart rate dependent



60%



Ductus Arteriosus

•Shunt between the descending aorta to the leftpulmonary artery

•Open because low PaO2 andcirculating prostaglandins (PGE2)

•Ductus closes within the firstdays (24/48 h) of life in theterm infant

•Permanent closure due to fibrosistakes 4-6 weeks



Ductus Arteriosus

When patent ductus arteriosus (PDA) is opened widely, many serious

malformations may not be noticed easily in the early life.

Most of anomalies compatible with six months of intrauterine life permit live offspring at term (Fetal circulation)



Ductal-dependent Heart Disease ?

Inadequate systemic oxgenation / pulmonary blood flow due to heart disease

• Inadequate pulmonary blood flow• Inadequate systemic delivery of oxygenated blood• Inadequate mixing



Right sided obstruction



Left sided obstruction



Inadequate Mixing

Survival Depends Upon Mixing Between Systemic and Pulmonary Circuits



Ductus Arteriosus

•Congenital heart disease in which either pulmonary or systemicblood flow is dependent on shunting through the ductus arteriosus.

•Postnatally closure of the ductus arteriosus would be fatal, progressas severe acidosis/shock/cyanosis.

•Prostaglandin E1 (PGE1 or Alprosdatil™) allow stabilization.

•PGE1 must be started immediately afterdelivery.



Prostaglandin E 1

•Always given as continous IV infusion.

•Start at 0.05-0.1µg/kg/min, can be reduced to 0.005 -0.01µg/kg/min once duct is opened

•Efficacy ↓ with ↑ age, less effective after 2 weeks of life, not effective after 4 weeks

•Continous cardiorespiratory monitoring



Ductus Arteriosus

•Before anatomic closure of the ductus arteriosus andforamen ovale, certain stresses can cause the newbornto revert to fetal circulation

•Increased pulmonary vascular reactivity, raised PVR (Pulmonary Hypertension) and right-to-left shunting at thePFO and PDA, the clinical result is cyanosis.

Hypothermia, hypercarbia, acidosis, hypoxia and sepsis can all cause a reversion to fetal circulation .



FLUID DYNAMICS

The function of the human heart is that of a mechanicalpump that receives the low pressure blood from the venoussystem and ejects it with higher pressure into the arterial system.



FLUID DYNAMICS



DiagnosisApplied clinical logic

Heart and circulationPerfect harmony between structure and function

Logical thoughtGross morphology / physiologic derangements

Clinical manifestation

Accurate observation + Correct inferences



General Approach to CHD Patient

1. Define cardiovascular pathology

2. Predict pathophysiology

3. Determine hemodynamic goals

4. Anticipate emergency treatments



Formulation of the problem

Basic questions

1. Is the patient acyanotic or cyanotic?2.How is body/pulmonary arterial blood flow ?

3. Does the malformation originate in the left or ri ght side of the heart?

4. Which is the dominant ventricule?5. Is pulmonary hypertension present or not?



• Commonly divided into acyanotic and cyanotic• 9 common conditions

ACYANOTIC

LEFT �� RIGHT SHUNTSVentricular septal defect (30%)Patent ductus arteriosus (12%)Atrial septal defect (7%)

OUTFLOW OBSTRUCTIONPulmonary stenosis (7%)Aortic stenosis (5%)Coarctation of the aorta (5%)

CYANOTIC

Tetralogy of Fallot (5%)Transposition of the great arteries (5%)Atrioventricular septal defect –complete (2%)

Other complex – 20%



Clinical manifestations

-The clinical sign in the neonate may be vague

For pediatricians:

-identify the newborn “not doing well”

•Persistent central cyanosis, unexplained acidosis, tachypnea withoutlung problems, etc.

•Assessment of saturation monitoring, status of perfusion (blood gasanalysis) and pulses/blood pressures in all extremities.



Maternal Risk Factors

• Congenital heart disease• Cardiac teratogen exposure

– Lithium – Amphetamines– Alcohol– Anticonvulsants: phenytoin, valproic acid,

carbamazepine, and trimethadione– Isotretinoin



Maternal Risk Factors

• Diabetes mellitus• PKU• Hyperthyroidism• Lupus, collagen vascular disease• Rubella, CMV, Coxsackie, Parvovirus



Fetal Risk Factors

• Trisomies, Turner’s syndrome, abnormal karyotype• Congenital malformations: duodenal atresia, TEF,

omphalocele, diaphragmatic hernia, renal dysgenesis, and hydrocephalus

• Fetal arrhythmias• IUGR• Nonimmune hydrops• ?2 vessel cord




Dyspnea

• Lung or heart problems?

• Large shunt lesions:dyspnea, tachypnea, feedingdifficulty, irritability and distress.

• Ventilator weaning can be difficult in premature infantswith large left to right cardiac shunts.

Cyanosis with markedly reduced pulmonaryblood flow usually leads to "quiet tachypnea”,

without significant respiratory distress.




Sign of poor perfusion

• Ductus dependent systemic circulatory ?

• Progressive dyspnea, cold, clammy mottled skin, whichindicates poor perfusion and acidosis, shock, oliguria

• Cardiovascular collapse at the time of ductal closure

• Shock in newborn ?



Rosen: “any neonate in shock that does not respond to fluids or pressors has LV outflow obstructionuntil proven otherwise”



Evaluation for and treatment of presumptive sepsis should be

undertaken simultaneously with evaluation for cardiac and pulmonary

disease.




Cyanosis

• Pulmonary X cardiac problems ?

• Persistent hypoxia refractory to 100% oxygen supply would indicate cyanotic CHD rather than pulmonary problems.

• Hyperoxia test



central peripheral

CAUSE ARTERIAL BLOOD DESATURATION OR ABNORMAL Hb

CUTANEOUS VASOCONSTRICTION DUE TO LOW CO

CONDITIONS Seen in R-L shunt, impaired pulmonary function, abnormal Hb

exposure to cold air or water and abnormally greater extraction ofO2 from normally saturated blood

SITES conjunctiva,palate,tongue,inner side of lips& cheeks

limited to ears,nose,cheeks outer side of lips hands feet&digits

certainly central if associated with clubbing and polycythemia,

clubbing is absent

probably central if it deepens on effort




Hyperoxia testarterial blood gas analysis while 100% oxygen

• PaO2 > 220 mm Hg would suggest respiratory disease

• PaO2 100‒220 mm Hg would require evaluation for cyanotic CHD

• PaO2 < 100 mm Hg would suggest cyanotic CHD

• PaO2 < 40‒50 mm Hg would be likely to have a poormixing disease such as TGA



HYPEROXIA TEST

GIVE 100% O2ASSES PO2

PO2>200 PO2<150

NO CCHD CCHD

PASS FAIL150-200

?CCHD WITH PBF OR PPHN



What information do we require?

– 4 extremity BP’s– H & P

• Murmurs• Organomegaly• Pulses• ECG • Labs, CXR findings, saturations



The “Noncardiac” Cardiac Exam

• Vital signs, growth percentiles• UE/LE blood pressure & pulse oximetry• Color - cyanosis, pallor, mottling• Lungs - work of breathing, rate, equality, crackles• Abdomen - hepatomegaly, situs• Extremities - pulses, capillary refill time• Dysmorphic features, other organ system abnormalities



Initial evaluation of child’s heart

•Listen to heart first when/if infant quiet•First concentrate on S1 and especially S2

•Louder than normal?•Split normally?

•Systolic murmur:•Diastolic murmur?•Widely radiating murmur?•Palpate liver•BP in arm and leg•Tongue - cyanosis



Murmurs

• Loudness graded 1-6. Presence of thrill > 4• Timing – systolic/diastolic• Duration – ejection/mid/pansystolic• Site where loudest• Radiation



Grading of murmurs

• Grade 1: only a cardiologist can hear• Grade 2: murmur softer than S1/S2• Grade 3: murmur louder than S1/S2• Grade 4: thrill palpable• Grade 5: murmur audible with stethoscope partially

off chest• Grade 6: murmur audible with stethoscope

completely off chest



Diagnosis

Chest x ray

• Usually performed to rule out pulmonary disease as well as to evaluate pulmonary vascular marking andcardiomegaly.

• Some CHD has characteristic features

• Most of the serious CHD have no specific findingsexcept vague cardiomegaly, change of pulmonaryvascular marking and subtle finding of pulmonaryvenous congestion.



Diagnosis

Chest x ray



Diagnosis

Electrocardiography

EKG has been considered a useful tool in the diagnosis ofCHD,especially if echocardiogram is not easily available.

Ventricular maturation and associated ECG changes

• The fetal heart is right-side dominant• Right axis deviation and R wave dominance in lead V1 and S wave

dominance in lead V6. • At 3 e 6 months the classical left ventricular dominance pattern of

adulthood is established as ventricular hypertrophy occurs in response to increased systemic vascular resistance.



DiagnosisEchocardiography

Echocardiogram is the most valuablemethod in the diagnosis of CHD.

• Identification of cardiac anatomy• Assessment of systolic ventricular function• Measurement of chamber dimensions and wall thickness• Assess the pressure gradients across the stenotic or regurgitation flow

through the valves• Assess abnormal cardiac physiology• Flow in the descending aorta • Estimation of pulmonary arterial pressure• Defining the direction of flow when valve regurgitation and shunt exist



Diagnosis

Cardiac Catheterization

• The diagnostic frequency of cardiac catheterization is relatively decreasing especially in the neonate.

• It is still the key in defining certain anatomic variantsdifficult to be delineated by echocardiography alone

• Therapeutic catheterizations are considered as one ofthe life savingmodalities in some fields.



Diagnostic ladder



•Clinical evaluation with CXR and Hyperoxia test excludes CHD in most cases.

•Echocardiography recommended in all doubtful cases.

• % exames negativos (normais)



Consultation: may be more cost-effective! 95%

sens/spec for discriminating CHD from

innocent murmur



Hypercyanotic spells

Cyanotic heart diseases

• Tetralogy of Fallot

• Pulmonary atresia• Transposition of great arteries• Tricuspid atresia



• Sudden severe episodes of intense cyanosis caused by reduction of pulmonary flow

• The level of cyanosis and onset of cyanotic spell is determined the SVR & level of PS component



Clinical Presentation

• peak incidence age: 3 to 6 months• often in the morning, can be precipitated by crying,

feeding or defecation• severe cyanosis, hyperpnoea, metabolic acidosis• in severe cases, may lead to syncope, seizure, stroke or

death• there is a reduced intensity of systolic murmur during spell



Management

• treat this as a medical emergency• knee-chest/squatting position:

- place the baby on the mother’s shoulder with the knees tucked up underneath.

- this provides a calming effect, reduces systemic venous return and increases systemic vascular resistance

• administer 100% oxygen

• give IV/IM/SC morphine 0.1 – 0.2 mg/kg to reduce distress and hyperpnoea



Management

• IV Propranolol 0.05 – 0.1 mg/kg • IV Esmolol 0.5 mg/kg slow bolus over 1 min,followed by 0.05 mg/kg/min for 4 mins.• volume expander, crystalloid, 20 ml/kg rapid IV push to

increase preload• give IV sodium bicarbonate 1 mEq/kg to correct metabolic

acidosis• heavy sedation, intubation and mechanical ventilation



• a single episode of hypercyanotic spell is an indication for early surgical referral

(either total repair or Blalock Taussig shunt)

• oral propranolol 0.2 – 1 mg/kg/dose 8 to 12 hourly should be started soon after stabilization while waiting for surgical intervention.



Keep in your mind



•Routine neonatal examination fails to detect more thanhalf of babies with heart disease

•High index of suspicion is essential to decision making

•“not doing well”•Any neonate in shock that does not respond to fluids or pressors has LV outflow obstruction until proven otherwise

•If you think you have a ductal dependent lesionPGE1 must be started immediately(don’t be afraid of prostin)



Thanks a lot!!!

congenital heart disease ii

Health & Medicine