4.2 Paediatric Cardiac Conditions

Vocabulary flashcards covering embryological development, fetal circulation, preterm implications, diagnostic methods, and common congenital heart defects as discussed in the lecture.

Cardiogenic Area

Region in the early embryo where the heart begins to form (week 3 gestation).

Primitive Heart Tube

Single tubular structure created by fusion of two endocardial tubes; first recognizable form of the heart.

Cardiac Looping

Bending and twisting of the primitive heart tube that establishes the basic right-left, top-bottom orientation of future chambers and vessels.

Truncus Arteriosus

Superior segment of the primitive heart tube that will divide into the aorta and pulmonary artery.

Bulbus Cordis

Section of the heart tube that contributes to the right ventricle and outflow tracts.

Primitive Atrium

Early chamber of the heart tube that will separate into right and left atria.

Atrioventricular (AV) Canal

Primitive inlet between atria and ventricles; later forms the tricuspid and mitral valve orifices.

Interventricular Septum

Wall that separates the right and left ventricles during embryonic development.

Semilunar Valves

Aortic and pulmonary valves that develop from endocardial cushions around weeks 9–10 gestation.

Foramen Ovale

Fetal opening in the atrial septum allowing blood flow from right to left atrium; normally closes after birth.

Ductus Arteriosus

Fetal vessel connecting pulmonary artery to aorta, bypassing the lungs; should close soon after birth.

Ductus Venosus

Shunt carrying oxygenated placental blood into the inferior vena cava, bypassing the fetal liver.

Fetal Circulation

Unique blood flow pattern using the foramen ovale and ductus arteriosus to bypass non-functional fetal lungs.

Maturation and Growth (Weeks 11–40)

Stage where four chambers and valves refine and fetal circulation prepares for extra-uterine life.

Preterm Birth

Delivery before 37 weeks gestation; associated with patent ductus arteriosus, immature myocardium, and long-term cardiac risks.

Persistent Pulmonary Hypertension of the Newborn (PPHN)

Failure of normal decrease in pulmonary vascular resistance after birth, leading to right-to-left shunting and hypoxemia.

Congenital Heart Disease (CHD)

Structural heart abnormality present at birth; affects ~1 in 100 babies.

common:

1. Atrial Septal Defect

2. Ventricular Septal Defect

3. Patent Ductus Arteriosus

4. Tetralogy of Fallot

5. Single Ventricle Defects

Atrial Septal Defect (ASD)

Hole in the atrial septum; Secundum ASD is the most common subtype.

Secundum ASD

Defect located at the fossa ovalis region; often leads to right-sided volume overload.

Ventricular Septal Defect (VSD)

Opening between ventricles; most common CHD overall, producing a loud systolic murmur.

Large VSD

Big ventricular defect causing excessive pulmonary blood flow, poor growth, and possible need for surgical closure.

Patent Ductus Arteriosus (PDA)

Persistence of the ductus arteriosus after birth, increasing pulmonary circulation and risking pulmonary hypertension.

Tetralogy of Fallot (TOF)

Four-part defect: VSD, pulmonary stenosis, overriding aorta, and right ventricular hypertrophy.

Tetralogy Spell

Acute episode of cyanosis in TOF due to sudden drop in systemic oxygenation from increased right-to-left shunt.

Hypoplastic Left Heart Syndrome

Single-ventricle defect where the left heart structures are under-developed; right ventricle supplies systemic flow.

Tricuspid Atresia

Absence of tricuspid valve, eliminating direct RA-to-RV flow and necessitating inter-atrial or ventricular shunts.

Cyanosis

Bluish discoloration of skin, lips, or nails due to reduced arterial oxygen saturation; a key sign of many CHDs.

Non-invasive Cardiac Testing

Diagnostics like ECG, echocardiogram, Holter monitor, stress test, and pacemaker checks that do not breach the skin.

Exercise Stress Test

Assessment of ECG and hemodynamic response during controlled physical exertion.

Cardiac Catheterization

Invasive test inserting catheters into the heart and vessels to measure pressures, oxygen levels, or perform interventions.

Electrophysiology Study (EPS)

Invasive mapping of the heart’s electrical pathways to diagnose or treat arrhythmias.

Transesophageal Echocardiogram (TEE)

Ultrasound probe in the esophagus offering high-resolution images of cardiac structures, especially posterior ones.

Persistent Lung Resistance (Fetal)

High pulmonary vascular resistance in utero, steering blood through fetal shunts rather than lungs.

Exercise Intolerance

Reduced ability to perform physical activity; common symptom in children and adults with unrepaired CHD.