PE22.2 | Cyanotic Heart Disease — Summary & Reflection

KEY TAKEAWAYS

Cyanotic congenital heart disease results from structural defects causing right-to-left intracardiac or great-vessel shunting, producing persistent central cyanosis. The five major lesions — the '5 Ts' — are TOF (most common; boot-shaped CXR, RAD, tet-spells), TGA (ventriculo-arterial discordance; egg-on-side CXR; Rashkind septostomy + arterial switch), TAPVC (all PV → right heart; figure-of-8 CXR; urgent repair), Truncus arteriosus (single trunk + VSD; plethoric CXR; associated DiGeorge), and Tricuspid atresia (absent TV; LAD on ECG — the unique discriminator; staged Fontan). For duct-dependent lesions, PGE1 at 0.05–0.1 mcg/kg/min IV is life-saving. Tet-spells in TOF require knee-chest position + morphine 0.1 mg/kg. Long-term complications of untreated cyanosis include polycythaemia, brain abscess (paradoxical septic embolism), paradoxical thromboembolism, and haemostatic disturbances. Hyperoxia test (PaO₂ <150 mmHg on 100% O₂) discriminates cardiac from respiratory cyanosis. Echocardiography is the gold-standard diagnostic tool.

REFLECT

Think about the 6-hour-old neonate in the hook scenario. Before reading this module, what did 'cyanotic heart disease' mean to you — a vague blue baby? Now consider the precision required: you need to know which X-ray to look for, whether the ductus needs to be kept open with PGE1, and that apnoea is a side effect you must anticipate. Reflect: If you were the intern at 3 AM and a nurse calls about a blue baby, what would you do in the first 3 minutes? Walk through it aloud — airways, hyperoxia test, CXR, ECG, call the senior, PGE1. What was the step you felt least confident about? Identify one concept from this module to review before your clinical posting.