Flashcards in Presentations of cardiac disorders Deck (13):
What circulatory changes occur at birth?
In a fetus left atrial pressure is low
Blood is shunted from the left atrium to the right atrium, the right atrium maintains a high pressure as it receives all systemic venous circulation.
With the first breaths, volume of blood through the lungs increases x6 and pulmonary blood flow resistance falls leading to increased pressure. The formaen ovale closes.
The ductus arteriosum (connects the pulnary artery and aorta) closes after a few hours/days
How does congenital heart disease present?
antenatal cardiac ultrasound diagnoses
What is the difference between a normal heart murmur and innocent heart murmur?
An innocent heart murmur occurs from turbulent flow in the outflow tracts or great vessels on either side of the heart
What are the two types of innocent heart murmurs?
Ejection- generated in the ventricle, outflow tracts or great vessels on either side by turbulent flow. There is no structural abnormality
Venous hum- occurs from turbulent flow in the head or neck veins. It is a continuous low pitch rumble heard beneath the clavicles. Increases with inspiration, louder after exercise, disappears after lying flat and compressing jugular vein
what are the hallmarks of an innocent ejection murmur?
local to left sternal edge
soft blowing systolic murmur (right) or short buzzing (left side)
no diastolic component
no parasternal thrill
normal heart sounds with no additional sounds
5 S's of innocent murmurs
left Sternal edge
What are the causes of cardiac cyanosis?
reduced pulmonary blood flow: infants can become severely cyanosed when the ductus arteriosus closes after birth if they have duct dependent circulation
Abnormal mixing of systemic venous and pulnoary venous blood
What are the causes of heart failure? i.e. differentials
neonates: obstructed systemic circulation
-hypoplastic left heart syndrome
-critical aortic valve stenosis
-severe coarctation of the aorta
-interruption of the aortic arch
-large persistent ductus arteriosus
What are the symptoms of heart failure?
recurrent chest infections
What are the signs of heart failure?
failure to thrive
heart murmur, gallop rhythm
Heart failure in neonatal period
usually left heart obstruction e.g. coarctation
duct dependent: closure can lead to acidosis, collapse and death
Heart failure beyond neonates
usually progressive due to left to right shunts
symptoms increase up to about 3 months, they may improve if pulmonary vascular resistance rises
Eisenmengers syndrome: irreversibly raised pulmonary vascular resistance