Congenital Heart Defects Flashcards
Define ventricular septal defects
An abnormal opening in the interventricular septum
Describe ventricular septal defects
– usually occurs in the membranous portion of the septum
- BLOOD FLOW from left to right due to pressure gradient – acyanotic
– 25% of all congenital heart defects
What can ventricular septal defects cause?
- LV hypertrophy as LV volume is overloaded
- Pulmonary hypertension after pulmonary venous congestion
- Pneumothorax
- Dyspnoea
- Pulmonary oedema
Define atrial septal defect
An abnormal opening in the septum between the two atria which persists following birth
Describe atrial septal defect
Foramen ovale fails to close in majority of cases
Causes L to R flow – acyanotic
Define patent foramen ovale
Foramen ovale fails to close properly
– higher LA pressure tends to close gap so patients are asymptomatic
What are the four anomalies found in tetralogy of fallout?
Ventricular septal defect
Overriding aorta
Pulmonary stenosis
Right ventricular hypertrophy
What are the main effects of tetralogy of fallot?
What determines the severity?
Pulmonary stenosis – persistent right ventricular hypertrophy as higher pressure os needed to pump blood
Cyanosis due to VSD and OA causing R to L shunting.
Severity of pulmonary stenosis
What are the symptoms of tetralogy of fallot?
Low blood O2 Difficulty with eating Failure to weight gain Retarded growth "Tet spells" -- marked increase in cyanosis followed by syncope. Can cause brain injurt and death
Define tricuspid atresia
Lack of development of the tricuspid valve so there is no inlet into the right ventricle
- R to L atrial shunt
- Ventricular septal defect allows flow to lungs
- is incurable as can’t replace ventricles
Define transposition of the great arteries and give its cause
Two unconnected parallel circuits instead of one
Caused by conotruncal septum not adopting a spiral course
Describe transposition of the great arteries
RV connected to aorta. LV connected to pulmonary artery
– causes major cyanosis
(deoxygenated blood continues in systemic circulation and oxygenated blood continues in pulmonary circulation)
What is the treatment for transposition of the great arteries?
- need communication as fetus will not be viable
- - surgery is required straight after birth
Define total anomalous pulmonary venous drainage
ll 4 pulmonary veins drain into the vena cava or the right atrium causing systemic and venous blood to mix in the right atrium.
What is univentricular heart?
Both the atria drain into one ventricle.
What is hypoplastic left heart?
LV and ascending aorta fail to develop properly.
Is lethal without surgery
What does hypoplastic left heart cause?
Underdeveloped left ventricle
Small ascending aorta
RV supports the systemic circulation via patent foramen ovale or atrial septal defect
Define stenosis
abnormal narrowing of a blood vessel
Define atresia
absence of abnormal closure of blood vessel
What is aortic stenosis?
Abnormal narrowing of aortic valve
What are the effects of aortic stenosis?
Valve leaflets are stiff, leads to reduced systolic opening and increased left ventricular pressure.
What are the symptoms of aortic stenosis?
Exercise induced angina
Syncope
Heart failure – due to ischaemia of LV myocardium
Define aortic atresia
no left ventricular outlet causing impeded blood flow. The only source of blood flow is via a patent ductus arteriosus
Define pulmonary stenosis
Abnormal narrowing of pulmonary valve
What are the effects of pulmonary stenosis?
What causes it?
– RV systole is obstructed, so RV and RA become hypertrophied
– tends to be due to a congenital lesion (rubella)
What are some symptoms of pulmonary stenosis?
fatigue, syncope and right heart failure
Define pulmonary atresia
No right ventricular outlet is present
What are the effects of pulmonary atresia?
–R to L shunt of the entire venous system and blood flow to the lungs occurs via a patent ductus arteriosus
Define patent ductus arteriosus
Ductus arteriosus does not close and is present after birth.
– connects pulmonary artery to the aorta in the fetus
When should the ductus arteriosus close?
After birth, when the lungs receive oxygen and the pressure in the pulmonary artery drops
What are the effects of a patent ductus arteriosus?
Causes L to R shunt
– large shunt can lead to pulmonary hypertension, vascular remodelling of the pulmonary circulation and increased pulmonary resistance.
Define Eisenmenger syndrome
Increased pulmonary resistance can lead to the shunt reversing if pressure is greater than systemic pressure
Define coarctation of the aorta
Is a narrowing of the aortic lumen where the ductus arteriosus inserts.
What are the effects of coarctation of the aorta?
- Increases the after load (tension developed in the wall) of the LV
- Causes left ventricular hypertrophy (heart has to pump harder to reach the same outflow)
- Blood flow to lower body and trunk is reduced (vessels emerge from heart distal to coarctation)
- Blood flow to head and neck not affected as they leave proximal to coarctation.
What are the symptoms of coarctation of the aorta?
- babies can be born with signs of heart failure in severe cases.
- mild cases can be detected in adult life.
- femoral pulses are weak and delayed and there will be upper body hypertension.
