45 Questions
What is the common characteristic of cyanotic heart defects?
Right-to-left cardiac shunt
Which of the following is a common cause of cyanotic heart defects?
Both maternal conditions and genetic defects
What is the typical clinical manifestation of cyanotic heart defects?
Cyanosis
How are cyanotic heart defects typically diagnosed?
Echocardiography
What is the typical treatment for heart defects that require intervention?
Catheter procedures or surgery
What is a common symptom of cyanotic heart defects?
Characteristic heart murmurs
What is the prognosis for untreated cyanotic heart defects?
Most are fatal within the first year of life
What is the pathophysiological characteristic of cyanotic heart defects?
Right-to-left cardiac shunt
Which of the following is a supportive medical therapy for patients with heart failure?
Diuretics
What is the common feature among Tetralogy of Fallot, Transposition of the great vessels, Tricuspid valve anomalies, Total anomalous pulmonary venous return, and persistent Truncus arteriosus?
They are all cyanotic CHDs
What is the purpose of administering prostaglandin E1 infusion in ductal-dependent CHDs?
To maintain patency of the ductus arteriosus
What is the primary reason for cyanosis in cyanotic CHDs?
Right-to-left cardiac shunting
Which of the following is NOT a characteristic of Tetralogy of Fallot?
Patent ductus arteriosus
What is the goal of diuretic therapy in patients with heart failure?
Decrease fluid volume and lower pulmonary vascular resistance
Why is antibiotic prophylaxis necessary during dental procedures for patients with unrepaired cyanotic CHDs?
To prevent bacterial endocarditis
What is the primary cause of 'blue baby' syndrome?
Right-to-left cardiac shunting
Which of the following conditions is a risk factor for CHDs?
Maternal diabetes
What is the purpose of surgical repair in patients with CHDs?
To correct the underlying anatomical defect
What is the survival rate of patients with TGA without treatment?
0% in the first year
What is the primary communication between the right and left heart in tricuspid valve atresia?
Atrial septal defect
What is the characteristic of the tricuspid valve in Ebstein anomaly?
Malformed and displaced into the right ventricle
What is the primary consequence of tricuspid regurgitation in Ebstein anomaly?
Right atrial dilation
What is the characteristic feature of total anomalous pulmonary venous return (TAPVR)?
All pulmonary veins drain into the systemic venous circulation
What is the typical clinical manifestation of tricuspid valve atresia?
Cyanosis and tachypnea
What is the confirmatory test for tricuspid valve atresia?
Echocardiography
What is the pathophysiological feature of Ebstein anomaly?
Incomplete delamination of valve tissue
What is the characteristic feature of the right ventricle in tricuspid valve atresia?
Hypoplasia
What is the most common cyanotic congenital heart defect?
Tetralogy of Fallot
What is the cause of Tet spells in Tetralogy of Fallot?
Increase in pulmonary vascular resistance or decrease in systemic vascular resistance
What is the characteristic heart shape on a chest x-ray in Tetralogy of Fallot?
Boot-shaped heart
What is the treatment for severe RVOTO in Tetralogy of Fallot?
PGE1 infusion until surgery
What is the definition of Transposition of the great vessels?
Reversal of the aorta and the pulmonary artery
What is the pathophysiology of Transposition of the great vessels?
Failed spiraling of the aorticopulmonary septum
What is the characteristic chest x-ray finding in Transposition of the great vessels?
Egg on a string appearance
What is the initial postnatal management of Transposition of the great vessels?
Initiate mixing between the two parallel circulations
What is the association of Tetralogy of Fallot with genetic disorders?
DiGeorge syndrome and Down syndrome
What is the primary mechanism of right-to-left shunting in total anomalous pulmonary venous return?
Mixing of deoxygenated and oxygenated blood via an interatrial connection
What is the most common cardiac defect associated with persistent truncus arteriosus?
VSD
What is the primary function of the PDA in hypoplastic left heart syndrome?
Providing a right-to-left shunt, allowing blood to flow to the pulmonary circulation
What is the characteristic cardiac examination finding in patients with persistent truncus arteriosus?
Bounding peripheral pulses
What is the role of the RV in hypoplastic left heart syndrome?
Pumping blood to both the pulmonary and systemic circulations
What is the initial medical management for hypoplastic left heart syndrome?
Continuous PGE1 infusion prior to heart surgery
What is the pathophysiological mechanism of cyanosis in total anomalous pulmonary venous return?
Right-to-left shunting of partially oxygenated blood via an interatrial connection
What is the characteristic chest x-ray finding in total anomalous pulmonary venous return?
Snowman sign
What is the etiology of persistent truncus arteriosus?
Failure of neural crest cells to migrate during cardiac outflow tract development
Study Notes
Cyanotic Heart Defects (CHDs)
- Congenital cardiac malformations affecting atrial walls, ventricular walls, heart valves, or large blood vessels
- Common causes: genetic defects, maternal conditions (e.g., diabetes), and spontaneous genetic mutations
- Pathophysiology: right-to-left cardiac shunt, leading to deoxygenated blood entering the systemic circulation, resulting in hypoxemia and cyanosis
Symptoms and Diagnosis
- Symptoms: cyanosis, failure to thrive, characteristic heart murmurs, and symptoms of heart failure
- Diagnosis: confirmed through echocardiography, with low oxygen saturation and characteristic x-ray findings
Treatment and Prognosis
- Heart defects requiring treatment are repaired via catheter procedures or surgery
- Supportive medical therapy is required in patients with heart failure or if surgery cannot be performed
- If untreated, most cyanotic heart defects are fatal within the first year of life
Associated Conditions and Risk Factors
- Tetralogy of Fallot
- DiGeorge syndrome
- Down syndrome
- Maternal risk factors: alcohol consumption, phenylketonuria, and diabetes
- Tricuspid valve atresia
- Total anomalous pulmonary venous return
- Heterotaxy syndromes
- Persistent truncus arteriosus
- Hypoplastic left heart syndrome
General Pathophysiological Processes
- Right-to-left cardiac shunting: deoxygenated blood entering the systemic circulation, leading to cyanosis
- Fetal and postnatal circulation: changes in blood flow and oxygenation during development
Topic-Specific Notes
Tetralogy of Fallot
- Definition: simultaneous occurrence of four defects: RVOTO, RVH, VSD, and overriding aorta
- Epidemiology: most common cyanotic CHD
- Etiology: typically sporadic, associated with genetic disorders (DiGeorge syndrome, Down syndrome)
- Pathophysiology: anterior and superior deviation of the infundibular septum during fetal development
- Clinical findings: cyanosis, RVOTO, and characteristic cardiac examination findings
- Treatment: surgical repair, PGE1 infusion, and treatment of tet spells
Transposition of the Great Vessels (TGV)
- Definition: anatomical reversal of the aorta and pulmonary artery
- Etiology: failed spiraling of the aorticopulmonary septum during fetal development
- Pathophysiology: complete isolation of the pulmonary and systemic circuits, leading to cyanosis
- Clinical findings: postnatal cyanosis, tachypnea, and single, loud S2
- Treatment: mixing of the two parallel circulations, balloon atrial septostomy, and surgical repair
Tricuspid Valve Atresia
- Definition: absent or rudimentary tricuspid valve
- Pathophysiology: RV hypoplasia, RA dilation, and interatrial and interventricular communications
- Clinical findings: cyanosis, tachypnea, and cardiac examination findings
- Treatment: cardiopulmonary stabilization, PGE1 infusion, and surgical palliation
Ebstein Anomaly
- Definition: malformed tricuspid valve leaflets displaced into the RV
- Pathophysiology: incomplete delamination during valve development, leading to tricuspid regurgitation and RV atrialization
- Clinical findings: cyanosis, cardiomegaly, and cardiac examination findings
- Treatment: surgical repair
Total Anomalous Pulmonary Venous Return (TAPVR)
- Definition: all four pulmonary veins draining into the systemic venous circulation
- Pathophysiology: venous mixing, leading to right-to-left shunting and cyanosis
- Clinical findings: cyanosis, respiratory failure, and cardiac examination findings
- Treatment: surgical repair
Persistent Truncus Arteriosus
- Definition: underdevelopment of the aorticopulmonary septum, resulting in a single trunk
- Pathophysiology: deoxygenated and oxygenated blood mix via a VSD
- Clinical findings: cyanosis, respiratory distress, and cardiac examination findings
- Treatment: surgical repair
Hypoplastic Left Heart Syndrome (HLHS)
- Definition: spectrum of disease consisting of severe hypoplasia of the left ventricle
- Pathophysiology: hypoplastic left ventricle is nonfunctional, with RV becoming the primary supply for pulmonary and systemic circulations
- Clinical findings: cyanosis, tachypnea, and cardiac examination findings
- Treatment: initial medical management, PGE1 infusion, and surgical repair
Learn about the congenital cardiac malformations affecting the heart's atrial and ventricular walls, valves, and blood vessels, including causes and pathophysiological characteristics.
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