Paediatric Cardiology Acyanotic CHD -...

Paediatric Cardiology

Acyanotic CHD

Prof F F Takawira

Aetiology

• Chromosomal – Down syndrome, T13, T18

• Genetic syndromes (gene defects) – Velo-Cardio-facial (22 del)

• Genetic syndromes (undefined aetiology)

• Toxins – alcohol, warfarin

• Diabetes, SLE, rubella

Most cases without clear explanation

recurrence risk incr 3 - 4 fold

Fetal circulation

• Oxygenated blood from

placenta via umbilical vein

– 50% passes through liver

via portal veins

– 50% crosses ductus

venosus and continues up

inferior vena cava. IVC

also receives blood leaving

liver via hepatic veins and

returning from lower half

of body of fetus

Umbilical vein

Ductus venosus

Inferior vena cava

Fetal circulation

• Blood from Inferior vena cava:

– Most passes through foramen ovale to left atrium and left ventricle, ascending aorta and coronary circulation

– Small amount crosses tricuspid valve into right ventricle

Foramen ovale

Tricuspid valve

RA

LA

RV

LV

Fetal circulation

• Blood returning from head and neck enters right atrium via superior vena cava, is joined by coronary sinus blood and then enters right ventricle and pulmonary artery

Superior vena cava

RA

RV

PA

Fetal circulation

• 2/3 of combined ventricular output from right ventricle

• 85% of RV output goes via ductus arteriosus into descending aorta and 15% enters lungs via pulmonary arteries

• Blood in descending aorta travels via internal iliac and then umbilical arteries to placenta

Aorta

RV

Ductus arteriosus

PA

LV

RV

Ductus arteriosus

Aorta

PA

LV

Normal Transition

• Commencement of breathing

• Decrease in PVR

• Increase in SVR

• Closure of the three fetal systemic-pulmonary shunts:

– Ductus arteriosus

– Foramen ovale

– Ductus venosus

Age Related Changes

• Fetal communications

– ductus arteriosus

– foramen ovale

– ductus venosus

• Pulmonary vascular resistance

• Growth

• Importance of 6 week baby check

History

• Brainstorm: What are the key areas for paediatric history taking relating to heart conditions?

History

• Shortness of breath/tachypnoea

• Sweating

• Persistent cyanosis

• Feeding problems

• Growth problems

• Family history of CHD

Location of murmurs

•

pansystolic

ejection

truncated

continuous

Nature of Murmurs

decrescendo

mid diastolic flow

clicks, snaps, etc

Grades of murmurs • Grade 1

– scarcely audible • Grade 2

– Soft, easily audible • Grade 3

– loud, thrill absent • Grade 4

– loud, thrill present • Grade 5

– very loud, audible with stethoscope just off chest

• Grade 6 – audible without a stethoscope

Congenital Heart Disease

Acyanotic CHD

Approach to CHD

Cyanosis, SOBFTT, Sweats

Poor feeding, Chest defCCF, Cardiom, Congest

TGATruncusTAPVCHLHS

Increased PBF

CyanosisNo cardiom-usually

No CCFOligaemia

TOFTricuspid AtresPA, Critical PS

Ebstein

Decreased PBF

Cyanotic

ASCoarct

PSTR, MR

Normal PBF

Acyanotic, SOBFTT, Sweats

Poor feeding, Chest defCCF, Cardiomegaly, Conges

Lft-Rght shuntVSD

PDA; ASDAVSD

Increased PBF

Acyanotic

CHD

Growth Charts

Pectus Carinatum

Harrison’s sulcus

Box diagram of normal heart

Acyanotic Left to right shunts

• VSD

• PDA

• ASD

• AV septal defect (Endocardial Cushion defect)

Ventricular Septal Defect Physiology

Box diagram of ASD

Acyanotic Obstructive lesions

• Pulmonary stenosis

• Aortic stenosis

• Coarctation

Evaluation and Management of the Child with “Heart Disease”

Differentiate Normal from Abnormal

(dispelling doubts)

Decision regarding referral / Investigation

Ongoing Care

Features of an Innocent Murmur

• Normal peripheral examination

– “murmur in isolation”

• Typical features

– systolic

– ejection

– musical

– soft murmurs (grade 2/6 or less)

– change with body position

– varies with review / augmented by illness

Innocent murmurs

• Still’s

• Pulmonary flow murmur

• Carotid bruit

• Venous hum

Routine Investigation

• Chest X-Ray

– position

– contour

– pulmonary vascularity

• ECG

– “right sided” forces prominent

– include V3r / V4r

Advanced Investigation

• Echocardiography

• Cardiac catheterisation / Angiography

– diagnostic

– haemodynamic

– intervention

Clues to Congenital Heart Disease • Does the patient appear normal?

• Is the patient thriving?

• Is the patient cyanosed?

• Are there symptoms of heart failure? – Tachypnoea, poor feeding, exercise intolerance etc

• Are there other signs of heart disease? – Clubbing

– pulses / distribution / blood pressure

– hepatomegaly

– pericardial overactivity / thrill

– Murmur

• Is there any doubt?

Growth Charts

Summary

• Important and complex area

• Needs lots of practice

• Essential to know the basics - ie know what you are looking and listening for

• Essential to gain experience in CVS examination and looking at and interpreting ECG

• If in doubt => REFER!!