Fetal & Neonatal Circulation
What are the three fetal shunts?
Foramen ovale, ductus arteriosus, ductus venosus
What is the most common congenital heart defect?
Ventricular Septal Defect (VSD)
What is the formula for cardiac output (CO)?
Volume/stretch in ventricles at end-diastole; measured indirectly by CVP or JVD
What is 2013 Louisiana CHD Screening Law
Mandates pulse oximetry screening for all newborns in Louisiana
Before giving digoxin to an infant, you must check the apical pulse. What is the hold parameter?
Hold if HR <90–110 bpm in infants
What causes fetal shunts to close after birth?
Increased oxygenation and decreased prostaglandins
What four defects make up Tetralogy of Fallot (TOF)?
VSD, Pulmonary stenosis, Overriding aorta, RV hypertrophy
What is afterload and what law governs it?
Resistance LV must overcome; governed by Poiseuille’s Law
What non-invasive imaging test uses sound waves to evaluate cardiac structure?
Echocardiogram
What class of drugs reduces preload by removing excess fluid?
Diuretics (e.g., Lasix)
What structure allows blood to bypass the fetal lungs by shunting from right atrium to left atrium?
Foramen ovale
What defect involves a large septal defect and single AV valve?
AV Canal Defect
What electrolyte abnormality causes peaked T waves on ECG?
Hyperkalemia (↑ potassium)
What are signs of CHF in infants?
Tachypnea, poor feeding, hepatomegaly, FTT, edema
What drug is used to maintain ductus arteriosus patency?
Prostaglandin E1
What happens to pulmonary and systemic vascular resistance at birth?
Pulmonary resistance ↓, systemic resistance ↑
What is a cyanotic heart defect that requires a PDA to survive?
Transposition of the Great Arteries (TGA)
What cardiac law states: “The greater the stretch, the stronger the contraction”?
Starling’s Law
What is the best pulse to assess cardiac output in infants?
Pedal pulses
What is the purpose of a PA (pulmonary artery) band?
Restrict pulmonary blood flow and control shunting
What is the effect of removing prostaglandins in neonates with ductal-dependent CHD?
Closure of ductus arteriosus → can be life-threatening
What condition leads to decreased blood flow from the left heart and may be treated with the Norwood procedure?
Hypoplastic Left Heart Syndrome (HLHS)
What is preload, and how is it measured?
Volume/stretch in ventricles at end-diastole; measured indirectly by CVP or JVD
What is Beck’s Triad in cardiac tamponade?
Hypotension, muffled heart sounds, JVD
What are potential side effects of prostaglandin E1 in neonates?
Apnea, bradycardia, flushing, fever