5 T's
Cyanotic Congenital Heart Defects
Five T's = babies turn blue.
Memory aids matter when a board vignette describes a blue newborn and the answer hinges on naming a defect you have never personally seen. The 5 T's of cyanotic congenital heart disease are Truncus arteriosus, Transposition of the great arteries, Tricuspid atresia, Tetralogy of Fallot, and Total anomalous pulmonary venous return — many lists add pulmonary atresia as a sixth. Each lesion mixes deoxygenated blood into systemic circulation and presents with cyanosis at or shortly after birth. AANP exam questions test recognition of the prostaglandin-dependent lesion (transposition, tricuspid atresia) and the classic boot-shaped heart (tetralogy). Refer urgently; PGE1 keeps the ductus open until surgery.
- TTruncus arteriosusSingle common trunk from both ventricles.
- TTransposition of the great arteriesAorta from RV, pulmonary artery from LV — parallel circulations.
- TTricuspid atresiaAbsent tricuspid valve — requires ASD or VSD for survival.
- TTetralogy of FallotVSD + overriding aorta + pulmonary stenosis + RV hypertrophy.
- TTAPVRTotal anomalous pulmonary venous return — pulmonary veins drain to right atrium.
Clinical Context
Major cyanotic congenital heart defects presenting with cyanosis at or shortly after birth (right-to-left shunting). Contrast with acyanotic defects (ASD, VSD, PDA) — left-to-right shunt, CHF symptoms over weeks to months rather than immediate cyanosis.
Tetralogy of Fallot is the most common cyanotic lesion seen beyond infancy. "Tet spells" (hypercyanotic episodes) respond to knee-chest position (increases SVR, reduces the right-to-left shunt). AANP pediatric cardiology tests identification by timing of presentation and classic physical findings.
Related Mnemonics
- 6 P's — Acute Limb Ischemia
- CHA₂DS₂-VASc — Stroke Risk in Non-Valvular Atrial Fibrillation
- HAS-BLED — Bleeding Risk on Anticoagulation
- MR. PASS MVP — Systolic Murmurs
- MS ARD — Diastolic Murmurs
Sources
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