Cardiology - Valve Stenosis Flashcards
What is coarctation of the aorta?
Narrowing of the aortic arch around the ductus arteriosus
What genetic condition is coarctation of the aorta associated with?
Turners syndrome
What happens to blood pressure in aortic coarctation?
Distal to the narrowing = pressure is decreased
Proximal to narrowing = pressure is increased
How does coarctation of the aorta present?
- Weak femoral pulses
- Systolic murmur below left clavicle and below left scapula
- Tachypnoea
- Poor feeding
- Grey and floppy baby
After a period of time due to development
- LV heave, due to hypertrophy
- Underdeveloped left arm where there is reduced blood flow to left subclavian
- Underdevelopment of legs
What can be done to identify coarctation of the aorta?
Four limb blood pressure
High blood pressure in limbs before narrowing
Low in limbs after narrowing
How is coarctation of the aorta managed?
Mild cases are symptom free until adulthood
Severe cases needed emergency surgery after birth
Critical cases
- Risk of heart failure and death
- Prostaglandin E used to keep ductus arteriosus open while waiting for surgery
- Surgery then performed to correct coarctation and ligate ductus arteriosus
What are the aortic valve leaflets called?
Aortic sinuses of Valsalva
Patients with congenital aortic valve stenosis can have 1,2,3 or 4 leaflets instead of the usual 3
How does aortic valve stenosis present?
Mild
Asymptomatic
Discovered as incidental murmur during routine examination
Significant
Symptoms of fatigue
SOB
Dizziness and fainting
Symptoms are worse on exertion as outflow from LV cannot keep up with demand
How does severe aortic stenosis present months after birth?
Heart failure
What are the signs of aortic stenosis?
- Ejection systolic murmur heard best at the aortic area, crescendo-decrescendo character that radiates to carotids
- Ejection click just before murmur
- Palpable thrill during systole
- Slow rising pulse
- Narrow pulse pressure
What investigations are used for aortic stenosis?
Gold standard
Echocardiogram
ECGs
Exercise testing
(to monitor progression of the condition)
How is aortic stenosis treated?
Percutaneous balloon aortic valvopalsty
Surgical aortic valvotomy
Valve replacement
What are the complications of aortic stenosis?
Left ventricular outflow tract obstruction
Heart failure
Ventricular arrhythmia
Bacterial endocarditis
Sudden death, on exertion
What happens in congenital pulmonary valve stenosis?
Valve leaflets develop abnormally, becoming thickened or fused
Causes narrow pulmonary valve
What is congenital pulmonary valve stenosis associated with?
Tetralogy of Fallot
William syndrome
Noonan syndrome
Congenital rubella syndrome
How does pulmonary stenosis present?
Often completely asymptomatic, discovered incidentally as a murmur on routine baby checks
More signicant
- Fatigue on exertion
- SOB
- Dizziness and fainting
What are the signs of pulmonary stenosis?
Ejection systolic murmur heard best at the pulmonary area
Palpable thrill in the pulmonary area
RV heave due to RVht
Raised JVP with giant a waves
What investigations are used for pulmonary valve stenosis?
Gold standard
Echocardiogram
How are patients with pulmonary valve stenosis managed?
Mild- Watchful waiting
Symptomatic or more significantly stenosed
- Balloon valvuloplasty via venous catheter
- Open-heart surgery (second line)
What is Tetralogy of Fallot?
POSH
Pulmonary stenosis
Overriding aorta
Septal defect (ventricular)
Hypertrophy of RV
What is an overriding aorta?
Aortic valve is further to the right than normal
Above the VSD
So when the RV contracts and blood sent upwards, aorta is in the direction of travel of the blood
More deoxygenated blood enters the aorta from the right side of the heart
What causes right to left shunting in TOF?
Stenotic pulmonary valve increases resistance
This increases the pressure in the RV, encoruage blood to flow from right to left
Increased strain leads to RVht
Pressure in the RV > LV, blood bypasses lungs causes cyanosis
What is the key factor in right to left shunting in TOF?
Severity of pulmonary stenosis
What are the risk factors of TOF?
Rubella
Increased age of mother (over 40)
Alcohol during pregnancy
Diabetic mother
What investigations are used for TOF?
Echocardiogram, investigation of choice for diagnosis
Doppler flow studies, assessing severity of the abnormality and shunt
CXR
Shows characteristic boot shaped heart due to RVht
How does TOF present?
- Most picked up before birth during antenatal scans
- Ejection systolic murmur caused by pulmonary stenosis heard on new-born baby check
- If severe will present with heart failure before 1
- In milder cases can present as older children when they develop heart failure symptoms
What are the signs of TOF?
Tet spells
Cyanosis
Clubbing
Ejection systolic murmur
Poor feeding
Poor weight gain
What are tet spells?
Intermittent symptomatic periods where right to left shunt is worsened precipitating a cyanotic episode `
What is the physiology of a tet spell?
Pulmonary vascular resistance increases or systemic vascular resistance decreases
e.g. if lots of exertion, carbon dioxide acts as a vasodilator, decreasing systemic vascular resistance
Blood therefore will be pumped from RV to aorta bypassing lungs
What are the causes of a tet spell?
Waking
Physical exertion
Crying
Severe spells
Can cause reduced consciousness
Seizures
Death
How are tet spells treated?
Older children may squat
Younger children positioned with knees to their chest
Increases the systemic vascular resistance
Medical treatment
- Supplementary oxygen
- Beta blockers, relaxes RV
- IV fluids to increase pre-load to increase blood flow to pulmonary vessels
- Morphine, decreases respiratory drive
- Sodium bicarbonate- metabolic acidosis
- Phenylephrine infusion- increase systemic vascular resistance
What can be given in neonates to allow blood flow to pulmonary arteries in TOF?
Prostaglandin infusion to maintain ductus arteriosus
Bloods flows back from aorta to pulmonary vessels
What is the definitive management of TOF?
Total surgical repair by open heart surgery
5% mortality
What is the prognosis of TOF?
Poor without treatment
With corrective surgery, 90% live to adulthood
What is Ebstein’s anomaly?
Congenital heart condition where tricuspid valve is set lower in right side of the heart
Causes a bigger RA and smaller RV and an atrial septal defect
What does Ebstein’s anomaly lead to?
Poor flow from RA to RV, therefore poor flow to pulmonary vessels
Associated with a right to left shunt across ASD
Leads to cyanosis
What is Ebstein’s anomaly associated with?
Wolf-Parkinson-White syndrome
How does Ebstein’s anomaly present?
Evidence of heart failure
Gallop rhythm on auscultation
Cyanosis
SOB and tachypnoea
Poor feeding
Collapse or cardiac arrest
When do symptoms of Ebstein’s anomaly present?
Few days after birth when ductus arteriosus closes
When there is right to left shunt via ductus arteriosus allows blood to get oxygenated
How is Ebstein’s anomaly diagnosed?
Echocardiogram
And used for assessing severity
How is Ebstein’s anomaly managed?
Medical management
- Treat arrhythmias
- Treat heart failure
- Prophylactic antibiotics for potential endocarditis
Surgical
- Fix the underlying defect
What is transposition of the great arteries?
Condition where attachments of aorta and pulmonary trunk are swapped
RV pumps blood into aorta
LV pumps blood into pulmonary vessels
Two separate circulations that don’t mix
What is transposition of the great arteries associated with?
Ventricular septal defect
Coarctation of the aorta
Pulmonary stenosis
What happens during pregnancy with transposition of the great arteries?
Gas and nutrient exchange occurs at placenta
After birth there is immediate threat to life
Baby will be cyanosed
What does immediate survival depend on in transposition of the great arteries?
Shunt between systemic circulation and pulmonary circulation
Allows some oxygenation to occur
PDA
ASD
VSD
How is TOGA diagnosed?
Diagnosed during pregnancy with antenatal ultrasounds
Should be arranged in a hospital capable of managing the condition
How does TOGA present?
Cyanosis at or within a few days of birth
Respiratory distress
Tachycardia
Poor feeding
Poor weight gain
Sweating
How is TOGA managed?
VSD allows some mixing of blood to provide time for definitive management
Prostaglandins
- Used to maintain ductus arteriosus
Balloon septostomy
- Catheter into foramen ovale via umbilicus
- Inflating balloon to create a large ASD
Open heart surgery-
Definitive management
- Cardiopulmonary bypass machine used to perform an arterial switch procedure within a few days of birth, can fix any VSDs or ASDs at same time
