ECG changes found in .4% of asymptomatic people in the
· 4 to 5% of sudden cardiac deaths, predominantly those occurring at night and in young people. Males predominate.
· 50% have an identified genetic component – probably a sodium channel gene.
· 20% of cardiac arrests where the heart is structurally normal.
· Most people are asymptomatic. ECG may show Brugada pattern.
· Commonest presentation is syncope or sudden death. Chest pain is not common.
· Atrial fibrillation is more likely to occur. Think about this diagnosis.
· Pre-terminal rhythms most commonly polymorphic or monomorphic ventricular tachycardia leading to ventricular fibrillation.
· Common contributor to cocaine-induced arrhythmias.
· Possibly triggered by any drug blocking sodium channels including tricyclic overdose, psychotropics, flecanide and procainamide.
· May be a history of chest pain, palpitation, syncope or family history of sudden death.
· Polymorphic or monomorphic ventricular tachycardia when symptomatic.
· Asymptomatic patients – usually changes in V1, V2, and sometimes V3. Pseudo RBBB pattern (not seen in limb leads) with convex or concave ST elevation, T wave inversion, and no reciprocal findings.
· Pattern can come and go. Unmasked by fever, alcohol, cocaine, and some medications
ECG findings plus at least 1 of the following:
· Documented ventricular fibrillation
· Self-terminating polymorphic ventricular tachycardia (VT)
· Family history of sudden cardiac death at <45 years
· Type 1 ST segment elevation in family members
· Electrophysiologic inducibility of VT
· Unexplained syncope suggestive of a tachyarrhythmia
· Nocturnal agonal respiration
· Symptomatic – cardioversion or defibrillation based on ECG. If polymorphic ventricular tachycardia remember to use unsynchronized shocks at 200-360 joules.
· Asymptomatic – refer quickly for electrophysiologic testing. Avoid drugs which block sodium channels. Most patients require and implantable cardioverter-defibrillator.
· Audio – Digest Emergency Medicine 2007. Vol 24(1)
· UpToDate Ver. 17.3 2011. Brugada syndrome and sudden cardiac death.
· Canadian Journal of Diagnosis. Feb. 2012