DPDoctor's PassportEducation
Cardiology indexPassport
Educational draft · awaiting clinical reviewUse Rapid for revision, not patient-care decisions. Check current national and local guidance and the BNF or BNFC before acting.
Textbook/Cardiovascular medicine/Tetralogy of Fallot and cyanotic congenital heart disease/Rapid
Rapidtetralogy of Fallotcyanosispulmonary regurgitationright ventricleventricular tachycardia

Tetralogy of Fallot and cyanotic congenital heart disease

Essential points for quick revision.

2 min synopsisUK scopeSources checked 27 Aug 2026Clinical review pending
!
Escalate

A hypercyanotic spell, rapidly falling saturation, haemoptysis, syncope or sustained ventricular tachycardia requires immediate ABC care, oxygen when hypoxaemic, correction of precipitants and urgent congenital-cardiology/resuscitation support.

Synopsis

Recognise unrepaired and repaired tetralogy physiology, manage cyanotic emergencies and identify late right-ventricular, pulmonary-valve and arrhythmic complications.

  • Tetralogy comprises VSD, overriding aorta, right-ventricular outflow obstruction and right-ventricular hypertrophy.
  • Severity of RV outflow obstruction determines the degree of right-to-left shunt and cyanosis.
  • Squatting or knee-to-chest positioning raises systemic vascular resistance and can reduce right-to-left shunting during a hypercyanotic spell.

Key red flags

Hypercyanotic spell

Sudden deepening cyanosis, tachypnoea, agitation or syncope from increased right-to-left shunting; the RVOT murmur may soften as flow falls.

Investigation priorities

01
12-lead ECG and ambulatory monitoringFirst step

Assess conduction, QRS duration and atrial/ventricular arrhythmia.

Management branches

FirstAcute cyanotic deterioration

Sudden increased cyanosis, dyspnoea, agitation or collapse.

  1. Call for resuscitation help; assess airway, breathing, circulation, rhythm, saturation and glucose while giving oxygen for hypoxaemia.
  2. Keep the person calm, use knee-to-chest positioning when hypercyanotic physiology is suspected and obtain IV access without delaying stabilisation.
NextRoutine repaired-tetralogy review

Any adult after tetralogy repair, symptomatic or not.

Open full textbook →Answer 2 questionsCardiology check
Sources and review status4 sources · checked 27 Aug 2026 · clinical review pending
Sources

Sources and review status

National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 27 Aug 2026; clinical approval remains outstanding.

Authoring stateRapid draftClinical stateAwaiting reviewJurisdictionUnited Kingdom