4.1 Congenital heart defects Flashcards
What 4 things can cause congenital heart defects?
Genes
Environment
Drugs
Maternal infections
What 2 screening methods are used to detect congenital heart defects?
Prenatal ultrasound
Foetal echocardiogram
What are the 3 cyanotic congenital heart defects?
Tetralogy of Fallot
Transposition of the great arteries
Eisenmenger syndrome
What are the 3 left-to-right shunt defects?
ASD
VSD
PDA
What are the 3 obstruction defects?
Congenital aortic stenosis
Pulmonic stenosis
Coarctation of aorta
What is the most common ASD and where is it located on the septum?
Secundum ASD located on the fossa ovalis
How does an ASD cause Eisenmenger syndrome?
Left-to-right shunt causes RV overload.
This causes pulmonary hypertension and pressure in RV increases to be higher than pressure in LV, so shunt reverses.
What are the symptoms of an ASD?
Shortness of breath on exertion
Palpitations
Repeated respiratory infections
What do you see in physical examination of an ASD?
Parasternal heave
Murmur at upper-left sternal border (due to increased blood flow across PV)
Murmur at lower-left sternal border (due to increased blood flow across TV)
What is patent foramen ovale?
When the foramen ovale doesn’t disappear after birth
When is patent foramen ovale clinically relevant?
When RV pressure is higher than LV pressure - patent foramen ovale acts as right-to-left shunt
Where does the most common VSD occur?
Membranous portion of the interventricular septum
What are the symptoms of a VSD?
Small VSDs are symptom-free
Large VSDs cause symptoms of heart failure
Repeated respiratory infections
What do you see in physical examination of a VSD?
Holosystolic murmur at left sternal border
Systolic thrill at left sternal border
Apical mid-diastolic rumble murmur
What is patent ductus arteriosus (PDA)?
When the ductus arteriosus doesn’t disappear after birth
What are the symptoms of PDA?
Small PDA is symptom-free
Moderate PDA has AF, fatigue, dyspnoea and palpitations
Large PDA has heart failure, tachycardia, and can cause Eisenmengers where only lower extremities have cyanosis
What do you see in a physical examination of PDA?
Machine-like murmur in left subclavicular region
Cyanosis of only lower extremities if Eisenmengers happens
What is aortic stenosis?
When calcification or fibrosis causes reduced blood flow through the aortic valve.
What are the 3 classes of aortic stenosis?
Valvular (in the valve)
Subvalvular (below the valve)
Supravalvular (above the valve)
What are the symptoms of aortic stenosis?
LV hypertrophy
Fatigue
Dyspnoea on exertion
Angina
Syncope (fainting)
What do you see in a physical examination of aortic stenosis?
Crescendo-decrescendo murmur
What is pulmonic stenosis?
Stenosis of the pulmonary artery
What are the symptoms of pulmonic stenosis?
RV hypertrophy
Dyspnoea on exertion
Exercise intolerance
Pedal oedema (swelling of feet)
What do you see in a physical examination of pulmonic stenosis?
Parasternal heave over sternum
Early systolic ejection murmur in upper left sternal border
Splitting of S2 heart sound
Prominent A-wave on JVP
