Emergency Medicine Hub / Cardiovascular Emergencies • 3 min read • 3 sections

Brugada Syndrome & Cardiac Channelopathies

Comprehensive emergency evaluation and protocolized management of Brugada syndrome and primary inherited cardiac channelopathies: loss-of-function SCN5A sodium-channel mutations, transient outward potassium current (Ito) repolarization gradients, distinguishing diagnostic Type 1 coved ST-segment elevation from saddleback Type 2/3 patterns, unmasking via high precordial lead placement (2nd and 3rd intercostal spaces), fever as a potent pro-arrhythmic trigger, pharmacological unmasking vs. abortive therapies (Quinidine, Isoproterenol), and ICD risk stratification.

Resuscitation Quick Actions • First 2 Minutes

High-Acuity

Type 1 Diagnostic ECG

Coved ST elevation >= 2 mm in V1 or V2 followed by a symmetric negative T wave; this is the ONLY diagnostic pattern

High Precordial Leads

Move leads V1 and V2 up to the 2nd and 3rd intercostal spaces; increases sensitivity for unmasking the Brugada pattern by > 30%

Aggressive Antipyresis

FEVER dramatically impairs mutated SCN5A sodium channels and triggers VF arrest; administer acetaminophen + ibuprofen stat for ANY fever

Electrical Storm Rescue

Isoproterenol infusion (1 to 2 mcg/min titrated to HR increase >= 20%) OR Quinidine (300–600 mg PO/NG q6–8h); terminates storm by boosting ICa/blocking Ito

Contraindicated Drugs

Avoid sodium channel blockers (Flecainide, Procainamide, Lidocaine), Beta-blockers, Lithium, Propofol, and TCAs (see BrugadaDrugs.org)

ICD Implantation

Implantable Cardioverter-Defibrillator (ICD) is the ONLY definitive therapy proven to prevent sudden cardiac death in high-risk patients

Bottom-Line Clinical Pearl

Brugada syndrome is an autosomal dominant inherited channelopathy affecting cardiac sodium channels (SCN5A) that predisposes young, structurally normal hearts to sudden cardiac death from polymorphic ventricular tachycardia and ventricular fibrillation (often occurring during sleep or rest when vagal tone is high). Only the TYPE 1 pattern is diagnostic: coved ST-segment elevation >= 2 mm (0.2 mV) followed by a negative T wave in >= 1 right precordial lead (V1–V2). If suspected, place leads V1 and V2 in the 2nd and 3rd intercostal spaces ('high precordial leads') to unmask the pattern. FEVER is the most common trigger for electrical storm in Brugada; treat fever aggressively with round-the-clock antipyretics. Electrical storm in Brugada is terminated with IV Isoproterenol infusion (increases L-type calcium current) or oral Quinidine (blocks Ito); beta-blockers and lidocaine are contraindicated!

1. Molecular Pathophysiology: Phase 2 Early Repolarization Gradient

Brugada syndrome is predominantly linked to loss-of-function mutations in the SCN5A gene, which encodes the alpha-subunit of the cardiac voltage-gated fast sodium channel ($Na_V1.5$). In the right ventricular outflow tract (RVOT) epicardium, there is an unusually high baseline density of the transient outward potassium current ($I_{to}$).

During phase 1 and early phase 2 of the epicardial cardiac action potential, reduced inward sodium current ($I_{Na}$) fails to counterbalance unchecked outward potassium current ($I_{to}$). This produces a precipitous early repolarization notch in epicardial cells that is completely absent in endocardial cells. The resulting transmural voltage gradient manifests on surface ECG as ST-segment elevation in leads V1–V2. When localized epicardial repolarization occurs prematurely, it creates phase 2 re-entry, triggering spontaneous, lethal polymorphic ventricular tachycardia or ventricular fibrillation.

2. ECG Morphologies & High Precordial Leads

Brugada Pattern Type	ECG Morphology in V1–V2	Diagnostic & Clinical Significance
Type 1 (Coved Type) — THE ONLY DIAGNOSTIC PATTERN	Prominent coved ST-segment elevation $\ge 2\text{ mm}$ (0.2 mV) that slopes downward, terminating in an inverted, symmetric T wave with little or no isoelectric separation	Diagnostic of Brugada Syndrome when observed spontaneously or unmasked by fever/sodium-channel blockers in conjunction with clinical criteria (syncope, documented VT/VF, family history of sudden death $< 45$ years).
Type 2 (Saddleback Type)	Saddleback ST-segment elevation $\ge 2\text{ mm}$ with a trough $\ge 1\text{ mm}$, followed by a biphasic or positive T wave	Not diagnostic by itself. Suggestive of channelopathy; mandates high-lead ECG recording, fever provocation, or electrophysiology evaluation.
Type 3	Saddleback or coved ST elevation $< 1\text{ mm}$	Indeterminate; treated identically to Type 2.

High Precordial Lead Protocol: Because the right ventricular outflow tract sits anatomically superior to the standard 4th intercostal space position of leads V1 and V2, standard ECG leads may miss the repolarization gradient. When Brugada is suspected clinically, re-record the ECG with leads V1 and V2 moved up to the 2nd and 3rd intercostal spaces. This single maneuver increases the diagnostic sensitivity for detecting Type 1 Brugada pattern by over 30%.

3. Acute Management of Brugada Electrical Storm

Therapeutic Modality	Dosing & Mechanism	Critical Clinical Actions
Aggressive Antipyretics	Acetaminophen 1,000 mg IV/PO + Ibuprofen 600 mg PO	Hyperthermia accelerates the closing kinetics of mutated sodium channels. Rapidly reducing core temperature below $37.0^\circ\text{C}$ abolishes electrical storm in febrile patients.
Isoproterenol Infusion	1 to 2 mcg/min IV infusion, titrated to increase baseline heart rate by $20\%$ (or up to HR 100–120 bpm)	Beta-agonist stimulation augments inward L-type calcium current ($I_{Ca-L}$), overcoming the $I_{to}$ potassium efflux and abolishing the transmural voltage gradient.
Oral Quinidine	300 to 600 mg PO or via NG tube every 6 to 8 hours	Class IA antiarrhythmic that directly blocks the transient outward potassium current ($I_{to}$), restoring the phase 2 action potential dome. Highly effective bridge to ICD.

Critical Pitfall / Contraindication

LETHAL DRUGS IN BRUGADA: Administering Class IC sodium-channel blockers (Flecainide, Propafenone), Class IA agents (Procainamide), Lidocaine, Beta-blockers, Calcium channel blockers, Propofol (Brugada-like ECG and asystole in Propofol Infusion Syndrome), or Lithium can precipitate intractable ventricular fibrillation and death in patients with Brugada syndrome. Always cross-check medications on BrugadaDrugs.org before prescribing.

Board & Shelf Drill 5 Questions • Untimed Tutor Mode

Test Your Brugada Syndrome & Cardiac Channelopathies Clinical Acumen

Directly launch an active-recall practice block from our 8,400+ validated COMLEX Level 1, 2-CE & 3 board question bank with complete explanations.

Related Emergency Protocols & Differentials

Related EM Protocol