Cardiovascular Assessment and Management Flashcards

A neonate with hypoplastic left heart syndrome (HLHS) becomes critically ill when the ductus closes. The primary reason is:

Answer: The ductus was providing the only source of systemic blood flow

In HLHS, the underdeveloped left heart cannot support systemic circulation, so the ductus arteriosus provides the only route for oxygenated blood to reach the body.

What is the hallmark finding on ECG in a neonate with complete heart block?

Answer: P waves that bear no relationship to QRS complexes

Complete (third-degree) heart block shows P waves and QRS complexes firing independently, with no conduction between atria and ventricles.

A neonate with supraventricular tachycardia (SVT) at a rate of 280 bpm and hemodynamic instability requires:

Answer: Immediate synchronized cardioversion

Hemodynamically unstable SVT requires immediate synchronized cardioversion; adenosine is used for stable SVT.

Which echocardiographic finding is characteristic of total anomalous pulmonary venous return (TAPVR) with obstruction?

Answer: Severe pulmonary hypertension with right heart enlargement and small left heart

Obstructed TAPVR causes pulmonary venous obstruction, severe pulmonary hypertension, right heart dilation, and a small left heart due to decreased pulmonary venous return.

Which neonatal cardiac finding requires emergent balloon atrial septostomy (Rashkind procedure)?

Answer: Transposition of the great arteries with intact atrial septum

In TGA with an intact atrial septum, blood cannot mix adequately; atrial septostomy creates an atrial communication to allow oxygenated blood to reach the systemic circulation.

Dopamine at low doses (2-5 mcg/kg/min) primarily acts on which receptors in neonates?

Answer: Dopaminergic receptors increasing renal and mesenteric perfusion

Low-dose dopamine primarily stimulates dopaminergic receptors, promoting renal and mesenteric vasodilation, though this effect is less reliable in neonates.