The Daily Differential — Wednesday, July 22, 2026

Brugada Updates

Brugada syndrome is an arrhythmic substrate in which fever, sodium-channel blockade, and autonomic shifts can precipitate ventricular fibrillation and sudden death. The ECG may be intermittent, and a normal tracing does not eliminate risk.

By the Blue Fish Med Desk Jul 22, 2026 · Phoenix

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A 34-year-old man lies shirtless beneath the fluorescent lights, drenched in sweat and shivering despite the July heat. His partner says he briefly stiffened and gasped during sleep, then woke confused; the monitor now shows intermittent wide-complex beats with a coved ST segment in V1–V2. He has no chest pain, and his blood pressure is 118/72, but his temperature is 39.4°C. The next decision is still waiting: determine whether this rhythm will remain a warning or become an electrical storm.

— What’s your move? Read on.

Before you read

Which therapies are appropriate for electrical storm, and which commonly used antiarrhythmics can worsen it?
Who needs an ICD rather than outpatient evaluation?

When to Think of It

Think Brugada with syncope, nocturnal agonal respirations, polymorphic VT/VF, or sudden cardiac arrest—especially in a younger patient with a family history of sudden death, fever, or a type 1 ECG pattern: ≥2-mm coved ST elevation in V1–V2 followed by a negative T wave. Place right precordial leads high, in the second or third intercostal spaces, if suspicion persists.

Sick or Not Sick

The call that matters most is active electrical instability versus an incidental ECG pattern. VF/polymorphic VT, aborted sudden death, or recurrent arrhythmic syncope requires urgent electrophysiology involvement and usually secondary-prevention ICD evaluation; an asymptomatic patient with a drug-provoked pattern is not equivalent.

The First Fifteen Minutes

Fever ≥38°C → acetaminophen 1,000 mg PO or IV now, then 650–1,000 mg every 6–8 hours; reducing temperature lowers sodium-channel inactivation stress. Maximum generally 4 g/day; use ≤3 g/day with liver disease, heavy alcohol use, or frailty.
Sustained VT/VF or hemodynamic instability → immediate unsynchronized defibrillation, 200 J biphasic, escalating per device; electrical termination is definitive for the rhythm.
Recurrent polymorphic VT/electrical storm despite shocks → isoproterenol 1–2 mcg/min IV infusion, titrated to suppress arrhythmia and avoid excessive tachycardia; β-adrenergic stimulation increases inward calcium current and can normalize the Brugada substrate. Check institutional/EP protocol because dosing and targets vary.
Electrical storm with recurrent VF despite isoproterenol or when oral therapy is feasible → quinidine 200–300 mg PO every 6–8 hours; blockade of transient outward potassium current reduces phase-2 reentry. Verify formulation, QT monitoring, interactions, and local protocol before use.
Suspected sodium-channel blocker toxicity with wide QRS or shock → sodium bicarbonate 1–2 mEq/kg IV bolus, repeat to narrow QRS, then infusion if needed; sodium loading and alkalinization overcome sodium-channel blockade. Dose and infusion strategy vary; use a toxicology reference or institutional protocol.
Avoid giving routine amiodarone, procainamide, flecainide, or propafenone for Brugada-related VT without expert guidance; sodium-channel blockade or repolarization effects may worsen the substrate.

Definitive Care & Disposition

Admit any patient with syncope plus a type 1 pattern, ventricular arrhythmia, or significant fever-associated ECG change to a monitored setting; electrical storm requires ICU and electrophysiology consultation. Correct electrolytes, stop provoking drugs, evaluate for ischemia, myocarditis, structural disease, and toxicologic causes, and obtain serial ECGs. Survivors of VF or spontaneous sustained VT generally require an ICD; asymptomatic drug-provoked patterns usually need specialist risk assessment rather than automatic device placement. Counsel relatives regarding ECG evaluation and fever treatment.

How This One Kills

The lethal error is treating fever as incidental—or administering a sodium-channel blocker for “wide-complex VT”—while the patient’s intermittent type 1 ECG is dismissed as a benign variant.

The Differential — What Else Looks Like This

Acute myocardial ischemia — territorial ST changes, troponin rise, and coronary symptoms; confusing it with Brugada can delay reperfusion.
Hyperkalemia — peaked T waves, widening QRS, and abnormal electrolytes; missing it delays membrane stabilization.
Arrhythmogenic right ventricular cardiomyopathy — structural RV disease and ventricular ectopy; confusing the two changes genetic counseling and device assessment.
Early repolarization — stable inferior/lateral J-point elevation without the characteristic coved right-precordial pattern; overcalling it can cause unnecessary testing.

The Second-Day Story

Older adults may present with unexplained nocturnal falls, delirium during a urinary infection, or recurrent “seizures” rather than classic syncope. A partially treated fever may leave a normal ECG by the time of evaluation. Ask specifically about nocturnal agonal breathing, family sudden death, medication exposures, and fever; repeat ECGs with high right-precordial leads during symptoms.

Back to Our Patient

Back to our 34-year-old man: the fever, nocturnal gasping, and coved V1–V2 pattern make Brugada syndrome with fever-triggered electrical instability the leading diagnosis. He is currently perfusing and has no sustained arrhythmia, so the immediate priorities are acetaminophen, continuous monitoring, serial high-right-precordial ECGs, electrolyte/toxicology review, and avoidance of sodium-channel blockers. If VF or recurrent polymorphic VT develops, he needs immediate defibrillation and EP-guided isoproterenol, with quinidine considered for persistent storm. He is admitted to the ICU for monitoring and electrophysiology evaluation, not discharged after a single reassuring rhythm strip.

Patient Presentation to Attending

How you’d present this patient on the floor — tight, pertinent positives and negatives, no rambling

“This is a 34-year-old man with syncope-like nocturnal stiffening and diaphoresis, now febrile to 39.4°C with an intermittent type 1 Brugada ECG pattern in V1–V2. His partner reports gasping during sleep, but he denies chest pain, stimulant use, or prior cardiac history; blood pressure is 118/72 and he is currently perfusing without sustained VT. I’m concerned for fever-triggered Brugada electrical instability rather than simple vasovagal syncope. I’m starting acetaminophen, placing him on continuous defibrillator-capable monitoring, repeating ECGs with high right-precordial leads, checking electrolytes, troponin, and toxicologic exposures, and avoiding sodium-channel blockers. He needs ICU admission and urgent electrophysiology consultation, with immediate defibrillation and isoproterenol if electrical storm develops.”

Study Directive

Draw the type 1 Brugada ECG from memory and practice identifying it on three sample tracings. Memorize the acute sequence: fever control → defibrillation for unstable rhythm → isoproterenol for storm → EP/ICD assessment. Review a current “drugs to avoid in Brugada syndrome” list and create a one-screen reference for the ED. Complete five ECG-based questions distinguishing Brugada from early repolarization, STEMI, and hyperkalemia.

Recent Literature

Review or guideline Brugada syndrome: update and future perspectives
Marsman EMJ, Postema PG, Remme CA · Heart, 2022 · PMID 34649929 · cited 56×

Provides a focused update on recognizing the Brugada ECG pattern, excluding phenocopies, managing fever and drug triggers, and stratifying patients for sudden-death prevention.

Full text · open access

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Vasoactives in Cardiogenic Shock

Cardiogenic shock is both a pressure problem and a flow problem. Vasoactives can temporarily restore organ perfusion, but excessive vasoconstriction or...

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The Case

A 72-year-old man sits forward, gasping, with pink froth collecting at the corner of his mouth. His hands are cold and mottled; the monitor shows an anterior infarct, and the cuff reads 74/48 despite a liter of crystalloid already given. His jugular veins are distended, and the lungs crackle to the apices. The next infusion must raise perfusion without turning a failing ventricle into a faster, more ischemic one.

Before You Read

Which vasoactive agent is the default when cardiogenic shock is hypotensive?
When does inotropy help, and when does it simply worsen myocardial oxygen demand?
What bedside data tell you that the chosen drug is actually working?

Why It Matters

Cardiogenic shock is both a pressure problem and a flow problem. Vasoactives can temporarily restore organ perfusion, but excessive vasoconstriction or tachycardia increases afterload and ischemia while definitive revascularization and mechanical support are delayed.

When to Think of It

Hypotension or narrow pulse pressure with pulmonary edema, elevated JVP, cool extremities, altered mentation, oliguria, metabolic acidosis, or rising lactate—especially with ACS, myocarditis, severe arrhythmia, acute valvular failure, or decompensated cardiomyopathy.

Sick or Not Sick

The pivotal call is perfusion failure with congestion versus isolated low blood pressure. If shock is present, support perfusion while identifying whether the dominant problem is vasodilatory hypotension, low contractility, RV failure, mechanical complication, or obstructive physiology.

The First Fifteen Minutes

MAP <65 mm Hg or signs of hypoperfusion → norepinephrine 0.05–0.1 mcg/kg/min IV infusion, titrate to perfusion; predominantly α-mediated vasoconstriction restores coronary and systemic pressure with less tachycardia than dopamine. Peripheral initiation is acceptable through a good proximal IV while central access is obtained.
Persistent low cardiac output after adequate pressure restoration, with hypoperfusion and no severe obstructive/mechanical lesion → dobutamine 2–5 mcg/kg/min IV infusion, titrate, usual range 2–20 mcg/kg/min; β1 stimulation increases contractility and forward flow. It can cause tachyarrhythmia and hypotension; check a reference or local protocol for titration.
Refractory vasodilatory hypotension despite norepinephrine → vasopressin 0.03 units/min IV infusion; V1-mediated vasoconstriction raises vascular tone without directly increasing heart rate. Use institutional protocol; routine high-dose escalation risks ischemia.
Severe hypotension with imminent peri-arrest collapse despite norepinephrine, or selected refractory shock → epinephrine 0.05–0.1 mcg/kg/min IV infusion; combined α/β effects increase pressure and contractility. It commonly worsens tachycardia, lactate, and myocardial oxygen demand, so reserve it for selected situations.
Adequate blood pressure but persistent low output, particularly with β-blockade or pulmonary hypertension → milrinone 0.125–0.25 mcg/kg/min IV infusion, without a loading dose in shock; PDE-3 inhibition increases inotropy and vasodilation. Reduce dose in renal failure and monitor for hypotension/arrhythmia; check institutional dosing.
Hypertensive cardiogenic pulmonary edema with adequate perfusion → nitroglycerin 5–10 mcg/min IV infusion, titrate; venodilation and arterial dilation reduce preload and afterload. Do not use in hypotension, RV infarction with preload dependence, or recent PDE-5 inhibitor exposure.

Definitive Care & Disposition

Activate the shock and cardiology teams, obtain urgent echocardiography, ECG/troponin, lactate, blood gas, renal function, and serial urine output. ACS with shock generally requires emergent culprit-vessel revascularization; treat brady/tachyarrhythmia and urgently address acute MR, VSD, tamponade, aortic catastrophe, or RV infarction. Consider pulmonary artery catheterization and temporary mechanical circulatory support when shock persists despite optimized medical therapy; device choice depends on LV/RV failure, oxygenation, and anatomy. ICU admission is mandatory.

How This One Kills

The dangerous mistake is escalating dobutamine or epinephrine in a hypotensive, ischemic patient before restoring coronary perfusion pressure—creating tachycardia, worsening ischemia, and eventual ventricular fibrillation.

The Atypical Presentation

Patients on β-blockers may be bradycardic without dramatic tachycardia, and chronic heart failure can produce cool extremities and renal dysfunction before frank hypotension. Obesity, early diuretics, or a mixed septic-cardiogenic state can obscure congestion. Use serial lactate, urine output, capillary refill, echo-derived LV/RV function, lung ultrasound, and response to therapy rather than a single blood pressure.

Back to Our Patient

Back to our 72-year-old man: cold extremities, pulmonary edema, JVP elevation, anterior infarction, and BP 74/48 identify cardiogenic shock with both low perfusion and congestion. The team stops further empiric crystalloid, starts norepinephrine at 0.05–0.1 mcg/kg/min, obtains immediate bedside echocardiography, and activates the cath lab. If MAP improves but cardiac output and lactate remain poor, carefully titrated dobutamine may be added; persistent shock triggers mechanical-support consultation. He is transferred directly to the cardiac ICU/cath lab pathway for emergent revascularization and definitive treatment.

Patient Presentation to Attending

“This is a 72-year-old man with acute anterior STEMI physiology, hypotension to 74/48, respiratory distress with pink froth, JVP elevation, diffuse crackles, and cold mottled extremities after an ineffective liter of crystalloid. He is altered and oliguric, with no clear infectious prodrome, and the presentation is most consistent with congested cardiogenic shock rather than isolated hypovolemia. I’m starting norepinephrine at 0.05–0.1 mcg/kg/min through a proximal IV, obtaining immediate bedside echo and lactate, and activating the cath lab. If pressure improves but forward flow remains inadequate, I’ll add low-dose dobutamine while monitoring for tachyarrhythmia and ischemia. He needs emergent revascularization, shock-team evaluation, and ICU-level care.”

Study Directive

Draw a two-axis map of cardiogenic shock: vascular tone versus contractility, then place norepinephrine, dobutamine, vasopressin, epinephrine, milrinone, and nitroglycerin on it. Memorize starting doses and three contraindicating physiologic states for each. Practice interpreting three bedside echoes for LV failure, RV failure, and tamponade. Review your institutional shock pathway and verbalize when you would activate mechanical circulatory support.

Key Medications

Norepinephrine: 0.05–0.1 mcg/kg/min IV infusion, titrate; common range 0.02–1 mcg/kg/min.
Dobutamine: 2–5 mcg/kg/min IV infusion, usual range 2–20 mcg/kg/min; reference dosing in severe renal/hemodynamic instability.
Vasopressin: 0.03 units/min IV infusion; institutional protocols vary.
Epinephrine: 0.05–0.1 mcg/kg/min IV infusion in refractory shock; titrate carefully.
Milrinone: 0.125–0.25 mcg/kg/min IV infusion without loading dose in shock; renal adjustment is essential.
Nitroglycerin: 5–10 mcg/min IV infusion, titrated for hypertensive pulmonary edema.
Pediatric dosing is weight-based and should follow pediatric critical-care protocols; mechanical-support decisions differ substantially.

High-Yield Pearls

A pressor that raises MAP may still worsen flow; reassess lactate, urine output, capillary refill, echo, and rhythm after every titration.
In cardiogenic shock, “more inotrope” is not a substitute for revascularization or correction of a mechanical lesion.
Avoid milrinone loading doses in unstable shock; vasodilation can abruptly collapse perfusion.

The Mimics

Massive pulmonary embolism — acute RV dilation, obstructive physiology, and relatively clear lungs; inotropy alone delays reperfusion therapy.
Tamponade — pericardial effusion with chamber collapse and narrow pulse pressure; pressors cannot substitute for drainage.
Septic shock with myocardial depression — distributive warm/cold mixed physiology and infection source; excessive vasoconstriction worsens tissue perfusion.
Acute aortic regurgitation or VSD — new murmur and echo abnormality; missing mechanical catastrophe delays surgery.

Board Question

A patient with acute MI has cardiogenic shock: MAP 55 mm Hg, cool extremities, pulmonary edema, and no evidence of hypovolemia. Which initial vasoactive agent is preferred?

ADopamine
BNorepinephrine
CDobutamine as sole therapy
DNitroglycerin

Reveal answer

Correct: B

Norepinephrine. Norepinephrine is generally preferred for hypotensive cardiogenic shock because it restores vascular pressure with less tachyarrhythmia than dopamine. Dobutamine can be added after adequate pressure is established when low cardiac output persists; nitroglycerin would worsen hypotension.

Recent Literature

Review or guideline State of Shock: Contemporary Vasopressor and Inotrope Use in Cardiogenic Shock
J Am Heart Assoc, 2023 · cited 86×

Provides a practical cardiogenic-shock framework for choosing vasopressors and inotropes according to blood pressure, perfusion, and hemodynamic phenotype while emphasizing their adverse effects and limited comparative evidence.

Full text · open access

TheDaily Differential

Brugada Updates

When to Think of It

Sick or Not Sick

The First Fifteen Minutes

Definitive Care & Disposition

How This One Kills

The Second-Day Story

Study Directive

Recent Literature

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Vasoactives in Cardiogenic Shock

Abdominal Aortic Aneurysm

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