[02.20b] CM - Congenital Heart Diseases_ Cyanotic V2.pdf

Bluish discoloration of the skin and mucous membranes

What is the clinical definition of cyanosis

about 35 g per dL

What is the concentration of deoxygenated or reduced hemoglobin that results in central cyanosis according to the source

Central cyanosis

Which type of cyanosis results from the desaturation of arterial blood

Peripheral cyanosis

Which type of cyanosis is caused by increased oxygen extraction by peripheral tissues in the presence of normal arterial saturation

Central cyanosis

Under which type of cyanosis do cyanotic congenital heart diseases fall

Circulatory shock, vasoconstriction from cold, and acyanosis of newborn

What are three clinical causes of peripheral cyanosis listed in the text

Right to left shunting

What direction of shunting occurs when right ventricular inflow or outflow obstruction causes decreased pulmonary blood flow

Mixing of pulmonary and systemic venous return

What structural anatomical defect combination allows deoxygenated blood to reach the systemic circulation in the absence of pure outflow obstruction

Persistent fetal circulation pathways

What pathways allow right to left shunting to occur in the presence of pulmonary hypertension

Patent ductus arteriosus and intracardiac shunts

What are two examples of persistent fetal circulation pathways through which right to left shunting can occur in pulmonary hypertension

Persistent pulmonary hypertension of the newborn and shunt lesions with Eisenmenger syndrome

What are two conditions that lead to right to left shunting through persistent fetal pathways

Not always present

Is a cardiac murmur always present in patients with cyanotic congenital heart disease

Not always obvious at birth or in infancy

Is cyanosis always obvious at birth or in infancy in a patient with cyanotic congenital heart disease

Digital clubbing

What physical sign of the fingers only appears after a few months of chronic hypoxia

Polycythemia

What hematologic condition is associated with hypoxia and can cause congested vessels in the sclera

Sclera

In what anatomical location may vessels become congested as a physical sign of polycythemia

DiGeorge syndrome

What is the common clinical name for 22q11.2 deletion syndrome

Tetralogy of Fallot and other conotruncal abnormalities

What congenital cardiac anomalies are classically associated with DiGeorge syndrome

Edwards syndrome

What is the common clinical name for Trisomy 18

Certain cyanotic heart diseases

With what cardiac conditions is Trisomy 18 associated

Heart failure, ventricular dysfunction, and arrhythmia

What are three cardiac complications of cyanotic congenital heart disease listed in Table 1

Hypercyanotic or tet spells, severe hypoxemia, and acidosis

What are three acute respiratory or metabolic complications listed under cardiac causes in Table 1

Sudden cardiac arrest

What fatal cardiac event is listed as a complication in Table 1

Extreme polycythemia

What hematologic complication is listed under other organ systems in Table 1

Thromboembolism, cerebral thrombosis, and stroke

What are three thromboembolic complications listed under other organ systems in Table 1

Brain abscess

What infectious central nervous system complication is listed as a major noncardiac risk of cyanotic heart disease in Table 1

Infective endocarditis

What infectious cardiac complication is listed under other organ systems in Table 1

Cyanotic nephropathy

What renal disease can develop as a complication of chronic cyanotic heart disease

Developmental delay and other disability

What are two chronic neurodevelopmental complications listed under other organ systems in Table 1

Mental health, malnutrition, and developmental delay

What are three systemic, nutritional, or psychological complications listed under other causes in Table 1

Total hemoglobin concentration

What patient factor determines how much deoxygenated hemoglobin is needed to make cyanosis clinically evident

Anemic

In which hemoglobin state does a patient require more deoxygenated hemoglobin for cyanosis to become more evident

Skin pigmentation

Which physical characteristic makes cyanosis more evident in fair-skinned individuals compared to others

Filipinos

In which population does skin pigmentation make it particularly difficult to notice cyanosis clinically

Shift the oxygen dissociation curve to the left

What do factors like pH, CO2, and temperature do to affect cyanosis detection in terms of the oxygen curve

pH, CO2, and temperature

What are three physiological factors mentioned that shift the oxygen dissociation curve to the left

Hyperoxic test

What test was historically used to differentiate whether the cause of cyanosis was pulmonary, cardiac, or other

Partial pressure of oxygen or PaO2

The hyperoxic test checks the response of which blood gas parameter to the administration of 100 percent oxygen

Unable to significantly raise PaO2

How does a patient with cyanotic congenital heart disease respond to the hyperoxic test

Deoxygenated blood still reaches the systemic circulation

Why is cyanotic congenital heart disease unable to significantly raise PaO2 during the hyperoxic test

May overcome ventilation perfusion abnormalities and reverse hypoxia

Why does pulmonary disease allow PaO2 to rise significantly with oxygen during the hyperoxic test

Right radial preductal arterial blood gas at room air

What is the optional first step of the hyperoxic test

If the patient is obviously very frankly cyanotic

Under what clinical condition can you proceed directly to oxygen administration in a hyperoxic test

Oxygen hood

What oxygen delivery device is preferred over a nasal cannula or face mask to ensure delivery of almost 100 percent oxygen

10 to 15 minutes

For how long should oxygen be administered via hood during a hyperoxic test

Repeat or obtain right radial ABG

What is step 3 of the hyperoxic test after administering oxygen

Less than 100 mmHg

What PaO2 level after the hyperoxic test indicates a cyanotic congenital heart disease with decreased pulmonary blood flow

100 to 150 mmHg

What PaO2 level after the hyperoxic test indicates a cyanotic congenital heart disease with increased pulmonary blood flow or persistent pulmonary hypertension of the newborn

150 to 300 mmHg

What post-hyperoxic test PaO2 level points to a noncardiac etiology like pulmonary, CNS, or methemoglobinemia

Greater than 300 mmHg

What PaO2 level is seen in a healthy newborn during the hyperoxic test

Less than 150 mmHg

What PaO2 value classically suggests a cardiac cause of cyanosis

Greater than 150 mmHg

What PaO2 value classically suggests a pulmonary or other noncardiac cause of cyanosis

Some cyanotic CHD may raise PaO2 to 150 mmHg

What is a key cardiac limitation of the hyperoxic test

Normalize completely with artificial ventilation

How does the PaO2 of patients with CNS disorders typically respond to artificial ventilation

Invasive

What clinical disadvantage is noted for the hyperoxic test in terms of procedure style

Echocardiography is more readily available

Why is the hyperoxic test now seldom performed

Cardiac catheterization

Which invasive diagnostic test is now used more for further testing and interventions rather than for simple confirmation of cardiac anatomy

Critical congenital heart disease

What group of congenital heart diseases have a very high mortality rate and require urgent or emergent surgery or catheter interventions

Death within the first days to first year of life

What is the risk of critical congenital heart disease if left without intervention

15 to 25 percent

What percentage of congenital heart diseases are classified as critical congenital heart disease

Up to 25 percent

What is the mortality rate of critical congenital heart disease in the first year of life without intervention

Preductal and postductal

Between which two sites is oxygen saturation compared during CCHD newborn screening

Right hand

What is the preductal measurement site used in CCHD screening

One of the feet

What is the postductal measurement site used in CCHD screening

Less than 90 percent on either the right hand or foot

What absolute oxygen saturation threshold on screening constitutes an immediate fail in CCHD screening

Difference of 3 percent or more

What oxygen saturation difference between the preductal and postductal measurements constitutes a fail on CCHD screening

Refer to cardiology for further assessment

What is the immediate action required if a patient fails CCHD screening

Positive or failed screening does not necessarily mean the cause is cardiac

Is a failed CCHD screening completely diagnostic of cardiac disease

Age 24 hours or more or pending discharge

At what age or clinical status is the CCHD screening algorithm initiated for newborns off supplemental oxygen

Retest in 1 hour

What is the next step in the CCHD screening algorithm if the pulse oximetry is not an immediate pass or fail

Pulse oximetry of 95 percent or more at both sites and saturation difference of 3 percent or less

What constitutes a passing result in the CCHD screening algorithm

History, physical examination, and pulse oximetry

What three methods are used to determine if cyanosis is present in suspected CHD

Pulse oximetry

What diagnostic tool is important because cyanosis is not always obvious on physical examination

Chest X-ray

What imaging modality is used to determine if pulmonary blood flow is increased, normal, or decreased

Appearance of the pulmonary vascular markings

What specific feature on a chest X-ray is assessed to determine pulmonary blood flow

Right, left, or combined ventricular hypertrophy

What three chamber hypertrophy states are evaluated in Step 3 of suspected CHD evaluation

Chest X-ray and electrocardiogram

Which two diagnostic tools are used to determine cardiac chamber hypertrophy in suspected CHD

Electrocardiogram

Which diagnostic tool helps specifically determine if there is right, left, or biventricular hypertrophy

Echocardiography

What is the primary, non-invasive method used to confirm cardiac anatomy in suspected CHD

Cardiac CT, cardiac MRI, and cardiac catheterization

What are three advanced imaging modalities used to determine structures and anatomy for complex lesions

RV inflow or outflow obstruction leading to right to left shunting through an intracardiac shunt

What is the primary physiological mechanism of cyanotic CHD with decreased pulmonary blood flow

Aortopulmonary shunt

What alternative pathway like a PDA or APCAs is required for survival in ductal dependent decreased pulmonary blood flow lesions

Shunt at the atrial level

What kind of shunt like a PFO or ASD allows blood to enter the left side of the heart for systemic flow in decreased PBF lesions

Obligatory shunting at atrial level

What is the term for the required atrial-level shunt in patients with RV inflow or outflow obstructions

Tetralogy of Fallot

What is the most common cyanotic heart disease overall

Anterior deviation of the infundibular septum

What developmental error causes Tetralogy of Fallot

RVOT obstruction, malaligned VSD, overriding aorta, and RVH

What are the four classical features of Tetralogy of Fallot

Right-sided aortic arch

What aortic arch variant occurs in 20 percent of TOF patients

Persistent left superior vena cava

What venous anomaly can be associated with Tetralogy of Fallot

Coronary artery anomalies

What vascular anomalies occur in 5 to 10 percent of TOF patients

DiGeorge syndrome

With what genetic deletion syndrome are TOF and conotruncal malformations associated

Dyspnea on exertion and squatting

What two physical symptoms may appear in TOF patients after a few months of life

Hypercyanotic, hypoxic, or Tet spells

What is one of the most concerning acute clinical symptoms in patients with TOF

Cerebral thrombosis, brain abscess, and infective endocarditis

What are three major neurological or infectious complications of TOF

Precordial bulge, RV impulse, soft P2 or single S2, and PS murmur

What are four key physical examination findings in TOF

Systolic ejection murmur

What type of murmur is heard in TOF due to pulmonary stenosis

Left middle and upper parasternal border

Where is the PS murmur in TOF most intense

Axillae and back

Where does the PS murmur in TOF radiate

Systolic thrill

What physical finding is present in TOF if the PS is more severe

Right axis deviation and RVH

What are the characteristic ECG findings in TOF