Echocardiography fundamentals for general paediatricians — branching viva

Opening question

This six-year-old boy's echo report describes a bicuspid aortic valve with a peak continuous-wave Doppler velocity of 4 metres per second. Walk me through the systematic approach you would use to read this report, and tell me why every chamber dimension must be interpreted against a Z-score rather than the raw millimetres. [1] [7]

Branch 1 — the echo modalities and what each shows

Take me through the modalities that build a comprehensive paediatric echocardiogram — two-dimensional imaging, M-mode, colour Doppler, pulsed-wave and continuous-wave spectral Doppler, and strain — and tell me what each one contributes that the others cannot. [1] [12]

Branch 2 — the comprehensive study versus the focused point-of-care ultrasound

Suppose you are asked whether a child in the emergency department needs a focused point-of-care cardiac study or a full laboratory echocardiogram. Tell me what each one is for, what binary question the point-of-care study may answer, and where the boundary lies between the general paediatrician's competence and the cardiologist's. [2] [9]

Branch 3 — the modified Bernoulli equation and what a velocity means

Return to the velocity of 4 metres per second across the aortic valve. Why does Doppler give you a velocity rather than a pressure, and how do you convert it? State the modified Bernoulli equation, calculate the gradient, and tell me how you would use a tricuspid regurgitation jet velocity to estimate the pulmonary artery pressure. [12]

Closing — resuscitation of a duct-dependent neonate

A three-day-old infant presents in shock with weak femoral pulses and a metabolic acidosis. What is the most likely diagnosis, why does it present on day three, and what drug would you start, by what route, at what dose, and why must it not wait for the cardiologist? [9] [1]