1. Introduction to cardiac conditions
PICU cardiac course 2014

3. Objectives: At the end of this session I will be able to…
Describe the normal heart structure
Describe common cardiac conditions including;
Signs and symptoms
Management and treatment
Discuss different cardiac shunts

4. Normal Heart Anatomy

5. Cardiac pressures and Sa02
This is important for later on when we review different cardiac conditions.

6. Cardiac Terminology Cardiac output- CO=HR x SV
(Heart rate- no of heart beats per minute) x (Stroke volume- the amount of blood expelled by the left ventricle with each contraction)
Preload- The stretch on the heart before it contracts
Afterload- It refers to the resistance against which the ventricles must work against to eject their blood volume
Contractility- Refers to the strength and efficiency of a contraction.
Rubber band analogy:
Need rubber bands
Need balloon with water
Show balloon with water to demonstrate preload- good amount of fill, plus low resistnace pushing it out as well as a forceful good contraction from the ventricle

7. 8–10 in 1000 births have some kind of congenital heart abnormality
Hear disease is the leading cause of childhood deaths with 1 in 3 children having a CHD

8. Classification of Congenital Heart Disease
Congenital Cardiac Disease
Acyanotic
75%
Cyanotic
25%
Increased pulmonary blood flow
Obstruction of flow from ventricles
Decreased pulmonary blood flow
Mixed blood flow
Source:

9. Lesions with increased blood flow (Acyanotic)
ASD
VSD
AVSD
PDA
Why do they have increased blood flow??
What does an unbalanced AVSD indicate?
Get particpants to draw defects on the whiteboard

10. Obstruction to blood flow from ventricles (Acyanotic)
Coarctation of the aorta
Aortic stenosis
Pulmonary stenosis

11. Decrease pulmonary blood flow (Cyanotic)
Tetralogy of fallot
Tricuspid atresia

12. Mixed blood flow (Cyanotic)
TGA
TAPVD
Truncus arteriosus
Hypoplastic left heart syndrome
Mixed blood flow...purple blood!
To pause pictures, right hand click the screen

13. Atrial Septal Defect
An Acyanotic increased pulmonary blood flow lesion.
Opening between the atria.
* 5-10% of congenital heart disease
More common in females than males
Atrial septum is divided into 2 parts- the primum, which is a thin mobile tissue which developes forst and then the septum secundum which is thick and muscular and develops second. It contains the PFO.
Types of ASD include;
Sinus venosus ASD: this occurs at the entrance of the SVC or IVC and close to the opening of the right atrium
Coronary sinus ASD: this is also known as unroofing of the coronary sinus- where deoxygenated blood from the heart muscle is returned to the left atrium. This will result in cyanosis.
Secundum ASD: this occurs at the PFO level. If the septum primum is normal then the defect is classified as a patent formaen ovale.
Primum ASD: Located at the bottom end of the septum, next to the AV valves.
Source:

14. Signs & Symptoms Left to right shunting Most patients asymptomatic
Present 3 to 6 weeks with soft murmur and can have a large heart on x-ray.
Present with poor feeding,
lower respiratory tract
infection and small amount
of heart failure.
Cyanosis infrequent.
Why left to right shunting??
Effects of left to right??
Why respiratory infection?
Why not cyanotic?

16. Treatment Spontaneous closure likely of small secundum type ASD’s.
Device closure.
Surgical correction either by pericardium patch or sutures.
What is a device closure?
How do they do a pericardium patch?
Source:

18. Ventricular Septal Defect
An Acyanotic lesion with increased pulmonary blood flow.
Opening between the right and left ventricle.
* 30% of congenital heart disease
Associated with Downs Syndrome in approximately 11% of patients. Also linked with parental use of marijuana and cocaine.
Why does it have more effects on pulmonary circulation?
What are the effects of too much pulmonary blood flow?
Why does it shunt left to right?
Different types of VSD:
Perimembranous VSD: Located within the membrane septum. The majority are classified in this group.
Muscular VSD: located anywhere in the muscular portion fo the septum. About 33% are muscular.
Inlet VSD: located beneath the AV valves
Outlet VSD: located within the septum and limited by the pulmonary valve.
Doubly committed VSD: close to the semilunar valves.
Source:

19. 1, 2, 3: Muscular VSD
4: Perimembranous VSD. Where they can sit posterior in the septum or anterior towards the aortic valve.
5: Doubly committed- where it sits just below the pulmonary and aortic valve

21. Signs & Symptoms
Majority of undiagnosed presentations occur at 6-8 weeks of age as the Pulmonary Vascular Resistance falls.
Left to right shunting
Small shunt causes patient to be asymptomatic
A large shunt will increase pulmonary blood flow, leading to tachycardia, increased respiratory rate, sweating, poor feeding and poor weight gain.
Why does it have more effects on pulmonary circulation?
What are the effects of too much pulmonary blood flow?
Why does it shunt left to right?
QP:QS ratio will be determined. If this is less than 2, then the child is at low risk of PHT and therefore, may not be operated on- will usually close spontaneously.
QP:QS ration >2 meaning that the ratio of pulmonary blood flow to systemic flow is 2 times greater- increasing risk of PHT.
Large VSD: when the VSD is the same size as the aortic valve opening.

22. Eisenmenger’s Complex
Increasing Pulmonary Vascular Resistance to protect overflow of blood.
Causes changes to vasculature- irreversible.
PVR>SVR= shunt reversal= cyanosis
This is for a large VSD which is big enough to cause a large Left to right shunt.
If surgical intervention is not performed, the damage to the vessels becomes ireversible and the patient will end up with PHT.

23. Treatment Medical Therapy i.e.. Lasix, Aldactone
Surgical Repair with a
device.
Source:

24. Patent Ductus Arteriosus
A cyanotic heart disease with increased pulmonary blood flow
Persistent opening between the main pulmonary artery and aorta.
Closure begins
10-15mins after birth.
Complete closure
3 weeks post birth.
Question to participatns: Do they remember the term persistent fetal circulation?
A: when the pulmonary vascular resistance doesn’t naturally fall as it does in a normal baby, and the PVR remains high.
Source: Pedheart

25. 5-12% of congenital heart disease
Again, more common in females than males if term,
More common in premature babies compared to term
In fetal circulation, approximately 60% of the normal right heart cardiac output is directed into the duct and aorta. At this stage the duct is as large as the descending aorta.
YOUTUBE VIDEO

26. Signs & Symptoms Left to right shunt controlled by diameter of PDA.
Small PDA – Resistance to flow high
across ductus.
Large PDA – CHF, poor feeding, increased respiratory rate and slow weight gain.
When they say left to right what do they mean? Where does it flow?

27. Failure of the PDA to close
Closure depends on:
1) increased oxygenation with first breaths= constriction of the ductal tissue
2) Reduction in naturally occurring prostaglandin= contraction of the muscular ductal tissue.
Delayed closure due to; prematurity, mechanical ventilation and diuretics, reduced partial pressure of oxygen, maternal infection
Prematurity: the development of contractile tissue only occurs after 30 weeks gestation and the duct is significantly less sensitive to the increase in partial pressure of oxygen resulting in a persistent PDA.
Mechanical ventilation and diuretics: triggers an increase in circulating prostaglandins and relaxes the muscular wall of the PDA
Reduced partial pressure of oxygen: due to a cyanotic heart condition, living at high altitude, respiratory distress syndrome
Maternal infection: for example rubella syndrome/ GBS positive- if become septic can cause increased pulmonary hypertension

28. Treatment Medical Management Cardiac Catheter Surgical Management
– Use of diuretics and fluid restrictions.
Cardiac Catheter
– Coils or balloons used to ligate PDA via cardiac catheter.
Surgical Management
- Ligation via thoracotomy with no bypass.
Limit fluid, give diuretics...why??
Pre and post ductal Sa02....have a think for the next lectures

29. Tetralogy of Fallot A cyanotic lesion with decreased blood flow.
2 types of TOF - Pink TOF
- Cyanotic TOF
Made of 4 components:
1. Stenosis of Pulmonary
Artery
2. Ventricle Septal Defect
3. Right sided aorta.
4. Hypertrophic right ventricle.
Source: Pedheart.org.au

30. Signs & Symptoms Right to left shunting Hypoxic Spells or ‘TOF Spells’
- Induced by crying, cyanosis, increased respiratory rate.
- Decreased pulmonary blood flow caused by infundibula muscle spasm.
- Prolonged hypoxia = Loss of consciousness, brain damage.
Why right to left shunting?
Why are the pressures all of a sudden higher on the right?
Great word...infundibular!!
Child cries, tenses, infundibular muscle spams= worsening of pulmonary stenosis= less blood flow to the lungs, therefore less return to the heart= low blood pressure.
What do parents do to helpt heir child?
Squatting, lift legs and feed to keep calm
Therefore, these children are often very well fed!!
Pink Tof- not many spells
Blue TOF- many TET spells

31. Treatment Hypoxic Spells – Squatting increases systemic
vascular resistance
-Morphine, volume
- Oxygen and mechanical ventilation.
TOF – Surgery – BT Shunt
- TOF Repair
Squatting increases the SVR, therefore there is more reistance to blood flow to the aorta, and more available for the pulmonary circulation.
Parents also feed a TOF to keep them calm, therefore they end up being somewhat chubby!
Source:

32. Coarctation of the Aorta
Acyanotic heart lesion with obstruction to flow from left ventricle.
Discrete Narrowing of the aortic arch.
Source:

33. 6-12% of Congenital heart disease
More common in males than females. 2:1 ratio

34. Signs & Symptoms Right to left flow across PDA to descending aorta.
Higher BP’s in arms than legs.
Degree of cyanosis depending on degree of narrowing of coarctation.
Severe coarctation will show signs of decreased ventricular function,
heart failure, poor feeding etc.

35. Pre and Post Duct presentation
Post ductal is more common
Perfusion of the lower limbs depends on coallterals being formed
Where does the Sa02 probe go

36. Treatment Prostin at birth to reopen/ maintain PDA
Catheter – Dilation of aorta
with balloon.
Surgical Repair –
Aorta dissected and
end-to-end/ end to side
anastomosis
Source:

37. Transposition of the Great Arteries
A cyanotic heart lesion with mixed blood flow.
Aorta and Pulmonary artery positioned across ventricle from original position.
On average greater than
normal birth weight
The eggbeater disease- each ahs it’s own circulation- no interaction!
What will happen when the PDA closes?
What would happen if there was no VSD/ ASD?
CCTGA
The heart has recognised the abnormal position of the great arteries and so the ventricles grow to accommodate this change. The Right ventricle which is meant to be pumping to the lungs and therefore not as strong becomes the left ventricle and the left ventricle pumps to the lungs- this is an issue as the higher pumping venetricle is now pushing at high pressures to the lungs.
Source: Pedheart

38. 4-5% of congenital cardiac disease
Second most common lesion
More common in males than females withr atio of 3:1
If left untreated, high mortality in first year of life

39. Treatment At birth – Prostin to maintain PDA
Balloon Atrial Septostomy, if no VSD
Switch Repair- usually Day 7-10
Reimplantation of the coronary arteries therefore there can be some ischaemic changes- high troponin levels and may need to be commenced on GTN.
Source:

40. Hypoplastic Left Heart Syndrome
A cyanotic heart lesion with mixed blood flow.
Hypoplastic left atrium, left ventricle and aorta arch.
25% chance of death in first week of life.
No Systemic flow unless PDA or intra atrial communication is present.
Source: rch.org.au and Pedheart

41. Signs and Symptoms
Right to left shunting across PDA to allow systemic blood flow.
Falls in pulmonary vascular resistance sees blood diverts to lungs rather than systemic system i.e. SaO %
Rise in pulmonary vascular resistance sees greater systemic blood flow at a price of hypoxia.
Increased systemic resistance drops systemic output leading to shock.
Pulmonary congestion can occur if atrial communications are small.
Cyanosis present even with PDA.

42. 1-2% of all congenital heart defects
Resposible for the highest cause fo death.

43. Treatment Medical – Prostin used prior to surgery to maintain PDA.
Surgical:
Norwood – Day 2.
- Main pulmonary artery divided to construct aorta.
- PDA ligated, BT shunt inserted and ASD maintained.
BCPS – aprox 4months
Fontan – aprox 4-5yrs
Why do they have to wait before moving to the next stage…why no just do fontan from the start???

44. Types of Shunts
Blalock-Taussig shunt (BT Shunt) (Classic and Modified)
Bidirectional cavopulmonary shunt (BCPS)
Central shunt
Fontan

45. Blalock-Taussig Shunt
Alfred Blalock
Helen Taussig
Vivien Thomas- Surgical tech
Source:

46. “as an utterly miserable, small six-year old boy who was no longer able to walk." His skin was intensely blue, his lips deep purple. Just after the final stitches were tied and the clamps released, the anesthesiologist called out, "The boy's a lovely color now!" Dr. Taussig remembered the thrill of walking around to the head of the operating table to see those "lovely normal pink lips." She reported that after his recovery from the operation he was a happy, active child.
This was the first op notes from the BT shunt
This was the account of the third child to receive the BT shunt

47. Modified Blalock-Taussig Shunt
Gortex tube sewn between aorta and pulmonary artery
Palliative shunt
Steals from systemic blood flow to increase pulmonary blood flow
Draw on whiteboard the sharing of systemic and pulmonary blood flow
Why do this instead of the central shunt?
MBTS is useful when CBTS cannot easily be performed, such as on the same side as the aortic arch. They also maintained that pulmonary artery distortion is less likely than with CBTS.

48. Central Shunt Graft between ascending aorta and main pulmonary artery
High pressures
Graft size determines the size of the shunt
The advantages of this technique are as follows:
Applicability to small children with small peripheral vessels
Prevention of distortion of pulmonary arteries
Provision of equal pulmonary blood flow to both lungs
Lower occlusion rate (compared with the CBTS or MBTS techniques)
Avoidance of subclavian artery steal
Ease of closure during corrective repair

49. Bidirectional Cavopulmonary Shunt (BCPS)
SVC separated at the join to right atrium
SVC anastomose to right pulmonary artery
Increases pulmonary blood flow
Decrease volume of blood returning to heart
Improved arterial oxygenation
First stage of Fontan
More definitive than the BT shunt.
Source:

50. Aims of BT and BCPS/Glenn
Palliative measure
Growth of Pulmonary arteries
Lead up to fontan
Reduces cardiac workload/CCF
Provides adequate pulmonary flow and better systemic oxygen delivery
Usually done at about 6 months, to allow growth of the PA’s to cope with increased blood flow.

51. Fontan Final stage of palliation Done from 18months of age.
Seperates the systemic and pulmonary circulations.
Right ventricle has to be the systemic pu,ping chamber.
Not definitive!

52. The Fontan 3rd stage can be performed from 2-16 years of age
Systemic blood flow is redirected from both IVC and SVC directly to pulmonary arteries
Optimises cardiac output
Intracardiac and Extracardiac

53. Intracardiac
A tunnel-like patch is placed inside the atrium so that blood returning from the IVC is directed through this tunnel
Atrial Septum removed
Less common
After many years, it was observed that the right atrium of some of the children who had a Fontan operation was progressively dilating. This dilatation seems to be occurring because of the turbulences of the blood as it was arriving from the veins coming from the body into this collecting chamber. This dilatation was annoying, because it was responsible for the formation of clots in the heart, and some of these patients had fast heart rates that made them sick

54. Extracardiac Fontan
The IVC is sewn directly onto a conduit, and the underside of the pulmonary artery
Routing the blood flow outside of the heart
The atrial septum is removed if not done already
Less complicated
Less incidence of effusions and arrhythmias
Fenestrated Fontan:
Pop off valve for the blood flow.
If the pressures are too high in the pulmonary system, blood will pop off into the right atrium- which is actually the systemic atrium so the baby will be bluer and have lower sats.

55. Fenestrations In either method, a hole or “fenestration”
is often made between the Fontan circuit
and the right atrium
Fenestrated Fontan:
This fenestration is like a pop-up valve acting as a safety mechanism. It is known to be particularly useful soon after surgery.
If the pressures are too high in the pulmonary system, blood will pop off into the right atrium- which is actually the systemic atrium so the baby will be bluer and have lower sats.
It is not yet known whether it is good or not to keep this fenestration open for a long time or not. Some believe that it improves the exercise capacity, because on the peak of maximal exercise, some more blue blood will go to the heart and the heart will then be able to pump more blood through the body. Others think that the heart will not function as well if the blood that the heart ejects is more blue (with less oxygen), and believe that the patients will be able to exercise better with the fenestration closed. We hope that future research will be able to show wether Fontan patients would be better with or without fenestration late after surgery.
Circulation Journal (Circulation. 2007;116(suppl 1): ) 

56. Who qualifies for a Fontan
Generally children with single ventricle lesions
Tricuspid Atresia
HLHS
Pulmonary Atresia Double Inlet Left Ventricle
Double outlet Right Ventricle (with other defects)
Ebstein's Anomaly
all children who are born with abnormal hearts that cannot be repaired with two pumping chambers (ventricles

57. Outcomes Post fontan- Sa02 90’s <4 mortality rates 20%
4-16yo mortality rates 7-8%
Limitations
Experience can vary greatly on how active they were prior to surgery
Still Palliative!!
Will need a heart transplant in the future.
Results from a study last year announced that almost all children (98%) survived the first 14 years after their Fontan operation. Overall the outcomes of the patients were by far better than all expectations!!!
Fontan registry
The Fontan Registry is a database collecting health information on Fontan patients living in Australia and New Zealand. It is hoped this will be the largest Fontan database in the world, providing researchers and doctors with information to help improve treatment options and long-term health outcomes for patients. The database does not identify patients, with personal data only accessible to the patient's treating doctor in the same state or country
2 questions the fontan registry needs to answer…
How long can the Fontan operation last, and can it last forever?
Which are the best drugs to take after a Fontan operation to maintain the best possible health?

59. Questions??