CVS Session 3 (Lecture 3.2)

Question 1

What are the common genetic, environmental and infectional aetiologies of congential HD?

Answer 1

Genetic - Down’s, Turner’s, Marfan’s
Env - Teratogenicity from drugs, alcohol, lithium
Maternal infec - rubella, CMV, toxoplasmosis

Question 2

What is an atrial septal defect?

Answer 2

Opening in the septum between the atria. This is known as the foramen ovale and allowed blood to bypass the lungs to shunt blood from right to left. After birth it closes normally but sometimes an abnormal closing or communication causes left > right shunt. Usually occurs in the ostium secundum.

Acyanotic lesion as oxygenated blood in LA&raquo_space; RA as it is at a higher pressure.

Question 3

What is a patent foramen ovale?

Answer 3

Clinically silent, non true ASD. Can be the route of venous embolism into systemic circulation if RA>LA pressure.

Question 4

What are the haemodynamic effects of an ASD?

Answer 4

RV volume overload.
Increased pulmonary artery/pumonary venous pressure. (rare).
Leads to RHF.

Question 5

What is a ventricular septal defect?

Answer 5

Abnormal opening in the interventricular septum. Commonly occurs in membranous part of the septum. Left to right shunt.

Question 6

What are the haemodynamic effects of a VSD?

Answer 6

L>R shunt
LV volume overload (due to recirculation of blood)
Pulmonary venous congestion
Pulmonary hypertension (due to increased RV pressure)

Question 7

What is the DA and what is a PDA?

Answer 7

Ductus arteriosus shunts blood in the fetus from the PA to the aorta.

Patent DA is the failure to close. Causes blood to shunt from aorta > PA (due to pressure).

Question 8

Why can a PDA be a problem if left untreated?

Answer 8

Leads to L>R shunting.
Increases pulmonary resistance which can lead to remodelling of pulmonary circulation if persists.
If resistance in PA > Aorta then reversal of shunting can occur with blood flowing from Aorta to PA. (Eisenmenger syndrome)

Question 9

What is coarctation of the aorta?

Answer 9

Narrowing of the aortic lumen in the region of the ligamentum arteriosum (DA).

Question 10

What are the problems with coarctation of the aorta?

Answer 10

Increases afterload on LV leading to left ventricular hypertrophy.
Blood flow to body (except head and upper limbs due to proximity) is reduced
Femoral pulses will be weak and delayed with upper body hypertension.
In infant, can cause heart failure.

Question 11

How are acyanotic HD defined? Give examples.

Answer 11

Left > Right shunts

ASD, VSD, PDA, aortic stenosis (hypoplasia), pulmonary stenosis, CoA, mitral stenosis.

Question 12

What is tetralogy of fallot?

Answer 12

Group of 4 lesions occuring together as the result of a single developmental defect which places the outflow portion of the interventricular septum too far in the anterior and cephalad directions.

Question 13

What are the 4 lesions of ToF?

Answer 13

1) VSD
2) Overriding aorta (aorta situated above VSD rather than LV)
3) Variable degree of pumonary stenosis
4) RV hypertrophy

Question 14

What are the consequences of ToF?

Answer 14

Variable to extent of pulmonary stenosis.

Pulmonary stenosis causes the RV to hypertorphy. The VSD, overriding aorta and increased RV pressure causes R > L shunting where deoxygenated blood is pumped via the systemic circulation resulting in cyanosis.

Question 15

What is a tricuspid atresia?

Answer 15

Lack of development of the tricuspid valve leaving no RV inlet valve.

Question 16

What are the consequences of a tricuspid atresia?

Answer 16

Hypoplastic RV due to no blood flow.
No oxygenation of blood so another way must be present, therefore an ASD must be present to shunt all venous return from RA to LA.
LA pumps blood to LV which pumps, via a VSD or PDA, to both the PA and aorta to allow oxygenation and systemic blood flow.

Question 17

What is the transposition of the great arteries?

Answer 17

Two unconnected parallel circulations instead of two circulations in series. Defects in spatial arrangements of the PA and aorta.

Question 18

What is the defect and consequences of a ToGA?

Answer 18

1) RV is connected to aorta and LV to the pulmonary trunk.
2) Not compatible with life after birth unless a shunt exists between the two circulations. Either a ASD or PDA maintained until surgical correction can take place.

Question 19

What is a hypoplastic left heart?

Answer 19

LV and ascending aorta are underdeveloped causing a R > L shunt with the RV supporting the systemic circulation via a PDA. Usually a PFO or ASD are present.

Question 20

What occurs in a pulmonary atresia?

Answer 20

No RV outlet leading to a R>L shunt of entire venous return.

Blood flow to lungs via PDA.

Question 21

What is the natural history of an ASD?

Answer 21

Usuall asymptomatic late into adulthood. Late onset arrythmia and RHF

Question 22

What is the natural history of a VSD?

Answer 22

Present in infancy with LHF. Untreated, can lead to in-operable pulmonary HT.

Question 23

What is the natural history of a coarctation?

Answer 23

Neonatal variety: associated with PDA, R > L shunt

Adult variety: complicated by renal HT, LV hypertrophy, often assos with aortic valve stenosis

Question 24

What is the natural history of a ToF?

Answer 24

Present in infancy or early childhood with cyanotic spells. Mild cases compatible with adulthood

Question 25

What is the natural history of a transposition/HLH/ pre-ductal coarctation/pulmonary atresia?

Answer 25

Presenting as neonatal emergencies, often due to reduced pulmonary blood flow

Question 26

What are the cyanotic HD? (5Ts mnenomic hint + 1)

Answer 26

Univentricular heart.

Truncus arteriosus
Transpostion of GA
Tricuspid atresia
ToF
Total anomalous pulmonary venous drainage