Sudden Unexplained Nocturnal Death Syndrome (SUNDS)

Sudden unexplained nocturnal death syndrome (SUNDS) is a sudden death that happens during sleep in people who seemed healthy and whose autopsy shows no clear cause. Over the last few decades, doctors learned that many of these deaths are actually due to hidden electrical problems in the heart (called channelopathies), especially Brugada syndrome, which can trigger dangerous heart rhythms at night. SUNDS has been described most often in young adult men in Southeast Asia, but it can occur in other regions too. The pattern—night-time death, a normal-looking heart, and no other clear cause—led scientists to look closely at the heart’s electricity and genes. Many victims or their relatives show the type-1 Brugada ECG pattern or carry SCN5A or other ion-channel gene variants that can cause fatal rhythms in sleep. jacc.org+3ahajournals.org+3JAMA Network+3

Sudden Unexplained Nocturnal Death Syndrome (SUNDS) is a sudden death during sleep in an otherwise healthy person where no structural heart disease is found at autopsy. Many cases are now thought to be caused by inherited electrical problems in the heart (cardiac channelopathies), especially Brugada syndrome, which can trigger dangerous heart rhythms (ventricular fibrillation) at night or with fever, certain medicines, or big swings in the body’s nervous system. People often have a normal heart ultrasound, but the electrocardiogram (ECG) can show a “type-1 Brugada pattern,” sometimes only during fever or after certain drug challenges. Because SUNDS is sudden, prevention is the main goal: identifying at-risk people, avoiding triggers, treating fevers quickly, and using proven therapies like an implantable cardioverter-defibrillator (ICD) for those at high risk. ahajournals.org+2OUP Academic+2

Other names

SUNDS has different local names in Asia: “bangungut” in the Philippines, “Lai Tai” in Thailand, and “pokkuri” in Japan. In many medical papers and clinics, SUNDS overlaps with or is considered part of Brugada syndrome–related sudden death. You may also see terms like sudden arrhythmic death syndrome (SADS) or idiopathic ventricular fibrillation when an electrical cause is suspected but the heart looks normal. Wikipedia+3PMC+3orphananesthesia.eu+3

Types

Doctors do not use rigid “types,” but it helps to think of SUNDS in three practical groups:

1) SUNDS linked to Brugada syndrome.
These are cases where the victim or family members show a type-1 Brugada ECG (spontaneous or drug-provoked) or carry a pathogenic ion-channel variant (often SCN5A). Night-time lethal rhythm is typical. jacc.org+1

2) SUNDS probably due to another inherited rhythm disorder.
A smaller portion is associated with long-QT syndromes (LQT1–3), catecholaminergic polymorphic ventricular tachycardia (CPVT), early repolarization or other channelopathies. These can also present with a normal-looking heart at autopsy. OUP Academic

3) SUNDS with no marker found yet.
Some victims have no recognizable ECG pattern or gene change even after careful testing. Doctors still suspect an electrical cause, but the exact defect is unknown with current methods. Ongoing genetic studies continue to find new variants. sciencedirect.com+1

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Causes

Below are causes and contributors doctors consider in SUNDS. The core idea is a vulnerable heart-electrical system (often genetic), plus triggers that make a dangerous rhythm more likely during sleep.

1. Brugada syndrome (channelopathy).
   In Brugada syndrome, tiny gates (ion channels) in heart cells do not work properly, especially sodium channels. This can create a short-circuit in the lower chambers (ventricles) and cause ventricular fibrillation at night. Many SUNDS cases fall here. jacc.org

2. SCN5A gene variants.
   SCN5A encodes the main cardiac sodium channel (NaV1.5). Some variants reduce sodium current, making Brugada-type rhythms more likely in sleep. Families of SUNDS victims sometimes carry these variants. NCBI+1

3. Other ion-channel genes.
   Changes in CACNA1C, CACNB2, KCND3, KCNE3, KCNQ1, KCNH2, RYR2 and others can affect calcium or potassium currents, raising risk for fatal rhythms without structural heart disease. OUP Academic

4. Long-QT syndromes (especially LQT3).
   Some SUNDS cases are tied to prolonged repolarization (long QT), which can degenerate into torsades de pointes and VF, sometimes during rest or sleep. OUP Academic

5. Early repolarization / J-wave syndromes.
   Prominent J-waves and early-repolarization patterns can be linked to malignant nocturnal arrhythmias in a subset of patients. jacc.org

6. Catecholaminergic polymorphic VT (CPVT).
   Mutations (often RYR2) cause stress-triggered arrhythmias. While typically exercise-related, some events can occur at rest, and CPVT belongs to the SADS spectrum relevant to autopsy-negative sudden death. OUP Academic

7. High vagal tone during sleep.
   At night, the body’s vagus nerve activity rises, slowing the heart and unmasking Brugada ECG changes, which can trigger dangerous rhythms. melbourneheartrhythm.com.au

8. Fever.
   Fever further reduces sodium-channel function in Brugada syndrome and can trigger VF, including at night. Cleveland Clinic

9. Electrolyte disturbances (e.g., low potassium).
   Shifts in potassium, sodium, or calcium can destabilize heart electricity and precipitate life-threatening rhythms. melbourneheartrhythm.com.au

10. Medications that block cardiac sodium channels.
    Some antiarrhythmics and other drugs can worsen Brugada pattern and provoke arrhythmia; that’s why drug-challenge tests (under monitoring) can reveal the pattern. jacc.org

11. Certain recreational drugs and alcohol.
    Alcohol binges and some substances can enhance night-time vulnerability and trigger arrhythmia in predisposed people. melbourneheartrhythm.com.au

12. Large meals or heavy drinking before sleep (speculative trigger).
    In Brugada syndrome, post-prandial and resting states (high vagal tone) have been linked to events; culturally, several SUNDS clusters included evening feasts. Mechanism is likely vagal predominance. melbourneheartrhythm.com.au

13. Sleep-disordered breathing.
    Studies show Brugada patients can have breathing irregularities and ST-segment changes during sleep, which may contribute to arrhythmia. PMC

14. Male sex (biologic susceptibility).
    Men are affected far more often, possibly because testosterone modulates ion currents in the right ventricle, favoring the Brugada substrate. JAMA Network

15. Genetic ancestry (Southeast Asian clusters).
    Historical clusters in Thailand, the Philippines, Japan, and among Southeast Asian refugees point to shared genetic and environmental factors. JAMA Network+1

16. Family history of sudden death.
    Unexplained sudden deaths in relatives suggest a heritable electrical disorder in the family. jacc.org

17. Early-morning sleep stage vulnerability.
    Many events occur late at night/early morning, when autonomic balance shifts—this timing pattern is well described in Brugada syndrome. melbourneheartrhythm.com.au

18. Hidden myocarditis or subtle scar (rare in SUNDS).
    SUNDS by definition lacks structural cause at autopsy, but microscopic or transient changes may occasionally act as co-factors; advanced imaging is used mainly to exclude structural disease. Cleveland Clinic

19. Temperature or electrolyte shifts with infections.
    Even mild illness can tip a borderline electrical system into dangerous rhythms during sleep via fever or dehydration effects. Cleveland Clinic

20. Unknown or multifactorial triggers.
    Some cases remain unexplained despite testing. Ongoing genome-wide studies continue to discover new variants and mechanisms. sciencedirect.com

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Symptoms and warning signs

Note: many people have no symptoms before a fatal event. Still, these warning clues deserve urgent medical attention, especially if they happen at night or at rest.

1. Fainting (syncope).
   Sudden blackout without warning can mean a brief dangerous heart rhythm that stopped by itself. This is a major red flag in Brugada and related conditions. Cleveland Clinic+1

2. Nocturnal gasping or “agonal” breathing.
   A partner may notice abnormal gasps in sleep. This can happen when the heart goes into ventricular fibrillation. PMC+1

3. Palpitations.
   A feeling that the heart is racing or pounding can signal arrhythmia, sometimes preceding fainting. Cleveland Clinic

4. Seizure-like episodes.
   Brief shaking can occur from lack of blood flow to the brain during an arrhythmia and may be misdiagnosed as epilepsy. jacc.org

5. Chest discomfort at rest.
   Not specific, but some people report tightness or discomfort before an episode, especially at night. Cleveland Clinic

6. Night-time shortness of breath.
   Trouble breathing in sleep may reflect arrhythmia or sleep-disordered breathing in susceptible patients. PMC

7. Dizziness or near-fainting.
   Lightheaded spells, particularly without exertion, can be an arrhythmic warning. Cleveland Clinic

8. Episodes triggered by fever.
   Symptoms that appear during a fever (palpitations, fainting) are concerning in Brugada syndrome. Cleveland Clinic

9. Events after alcohol or heavy meal.
   Some report nighttime symptoms after drinking or late feasts, consistent with vagal triggers in Brugada. melbourneheartrhythm.com.au

10. Unexplained collapses in relatives.
    Family stories of sudden night-time death or fainting raise suspicion for an inherited rhythm problem. jacc.org

11. Documented abnormal ECG (even transient).
    An ECG once showing a type-1 Brugada pattern is a major warning, even if later tracings look normal. jacc.org

12. Nocturnal nightmares with awakening gasps in at-risk men.
    Historical SUNDS descriptions (“bangungut”—to rise and moan) reflect abrupt nocturnal distress before death in otherwise healthy young men. ahajournals.org

13. Syncope during rest or while sitting.
    Arrhythmic syncope often occurs without exertion in Brugada phenotype. melbourneheartrhythm.com.au

14. Previous cardiac arrest with no structural cause.
    People resuscitated from VF with a normal heart often have an inherited electrical disorder. ahajournals.org

15. Night-time events clustered in hot climates or during infections.
    This pattern fits the fever/sodium-channel sensitivity that can unmask Brugada at night. Cleveland Clinic

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Diagnostic tests

Goal: look for an electrical disorder (especially Brugada syndrome), exclude structural heart disease, find triggers, and protect family members.

A) Physical examination (at the bedside)

1. General physical exam and vitals.
   Doctors check blood pressure, pulse, temperature, and oxygen level to look for fever, low blood pressure, or clues to other illness. In SUNDS work-ups, the physical exam is often normal, which pushes attention to electrical testing. Cleveland Clinic

2. Focused cardiac and respiratory exam.
   Listening for murmurs, extra sounds, or lung crackles helps exclude structural or heart-failure causes of collapse. SUNDS usually lacks these findings. Cleveland Clinic

3. Family history review.
   A detailed interview about night-time sudden deaths, fainting, seizures, or known channelopathies in relatives helps reveal a hereditary pattern. jacc.org

4. Medication and substance review.
   Doctors look for sodium-channel–blocking drugs, QT-prolonging drugs, alcohol use, or other triggers that can unmask Brugada patterns. jacc.org

5. Fever screen and illness check.
   Because fever can bring out the Brugada ECG and trigger arrhythmia, temperature and infection symptoms are carefully assessed. Cleveland Clinic

B) Manual / bedside provocation & functional tests

6. Orthostatic blood pressure/heart-rate testing.
   A simple stand test can reproduce lightheadedness and helps separate reflex syncope from arrhythmic causes. In SUNDS suspicion, abnormal orthostatics push doctors to broader rhythm testing. Gimsi

7. Tilt-table test (supervised).
   Tilting the table can provoke reflex syncope in a controlled lab. A negative tilt in a patient with dangerous night-time events keeps concern high for an arrhythmic cause like Brugada. Gimsi

8. Fever provocation (clinical observation only).
   Doctors do not induce fever, but when a patient with suspected Brugada develops fever from any illness, ECGs are repeated because fever can unmask diagnostic changes. Cleveland Clinic

9. Gentle vagal maneuvers education.
   Patients are taught Valsalva-type maneuvers for certain benign tachycardias; importantly, if symptoms are at rest or at night or include fainting, urgent rhythm evaluation is preferred. (This is supportive care, not a diagnostic endpoint.) melbourneheartrhythm.com.au

10. Sleep evaluation cues.
    Bed partners are asked about gasping, pauses, or snoring. If suspected, doctors may order a sleep study because disordered breathing can co-occur with Brugada and may influence risk. PMC

C) Laboratory and pathological tests

11. Electrolytes and metabolic panel.
    Low potassium, sodium, or calcium, thyroid problems, or acidosis can worsen electrical instability; correcting them reduces triggers. melbourneheartrhythm.com.au

12. Toxicology screen.
    Looks for drugs that block sodium channels or prolong QT, or substances (including alcohol/cocaine) that can trigger arrhythmias. jacc.org

13. Cardiac enzymes (troponin) during acute events.
    Helps exclude heart attack when someone presents with collapse; SUNDS/Brugada events usually have no ischemic injury, which directs work-up to electrophysiology. Cleveland Clinic

14. Genetic testing panel for channelopathies.
    Panels include SCN5A and other ion-channel genes. A positive result supports the diagnosis and guides family screening, though not all patients have an identifiable variant. NCBI

15. Post-mortem molecular autopsy (families of victims).
    If a relative died suddenly at night with a negative autopsy, DNA testing can find a familial variant, allowing living family members to be tested and protected. SpringerOpen

D) Electrodiagnostic tests (core of SUNDS work-up)

16. 12-lead ECG with right-precordial leads (including higher intercostal spaces).
    A type-1 Brugada pattern—coved ST elevation in V1–V2—is the key marker. Recording the leads one or two spaces higher increases sensitivity. A spontaneous type-1 pattern is diagnostic. jacc.org

17. Pharmacologic sodium-channel blocker challenge (ajmaline, flecainide, procainamide) under monitoring.
    In patients without a spontaneous pattern, carefully giving one of these drugs in a lab can provoke the type-1 pattern and confirm Brugada susceptibility (interpretation follows consensus/ESC guidance). jacc.org+1

18. Ambulatory ECG (Holter/event recorder).
    Worn for days to weeks to catch intermittent arrhythmias or dynamic ST-segment changes, which are common in Brugada patients—especially at night. PMC

19. Electrophysiology study (EPS) in selected cases.
    An invasive test maps heart electricity and tries to induce arrhythmias. Its role in risk prediction for Brugada is debated, but it can aid decisions in experienced centers. ahajournals.org

20. Exercise test (to exclude other causes / characterize response).
    Exercise may suppress Brugada ST elevation (vagal opposite), but the test helps rule out ischemia, assess QT behavior, and clarify the diagnosis in the broader SADS work-up. jacc.org

E) Imaging tests (to exclude structural disease)

21. Transthoracic echocardiogram.
    An ultrasound of the heart looks for structural problems. In SUNDS/Brugada, the echo is usually normal, supporting an electrical cause. Cleveland Clinic

22. Cardiac MRI (CMR).
    CMR looks for scar, myocarditis, or right-ventricular abnormalities (e.g., ARVC) that can mimic Brugada. A normal CMR again points toward a pure electrical problem. PMC

23. Coronary imaging (as indicated).
    CT angiography or invasive angiography is used when ischemia is suspected; in SUNDS cases, normal coronaries are common, which supports the channelopathy pathway. Cleveland Clinic

24. Sleep study (polysomnography) with ECG channels when indicated.
    If bed partners report gasping or apneas, a sleep study can document breathing problems and nocturnal ECG changes, offering an avenue to reduce co-triggers. PMC

Non-pharmacological treatments (therapies & “other” measures)

Each item includes: an easy description, purpose, and simple mechanism. (These measures reduce risk; they are not guarantees. Always work with a cardiologist/electrophysiologist.)

1. Family screening and genetic evaluation
   What it is: If a relative died suddenly in sleep or has a known Brugada pattern, screen first-degree relatives with history, ECG, and referral to inherited arrhythmia clinic; consider genetic testing where appropriate.
   Purpose: Find silent carriers or people with the ECG pattern early, so triggers can be avoided and lifesaving therapy planned.
   Mechanism: Identifies channelopathies that increase risk of ventricular fibrillation; enables tailored prevention and ICD decisions. Frontiers+1

2. Rapid fever control
   What it is: Treat fever promptly with cooling and antipyretics; seek urgent care if fever with fainting or palpitations.
   Purpose: Fever can unmask the Brugada ECG and precipitate dangerous rhythms.
   Mechanism: Lowering temperature stabilizes sodium/calcium channel function and sympathetic tone, reducing arrhythmic triggers. PMC+1

3. Avoid drugs known to aggravate Brugada
   What it is: Carry and follow a “red/orange list” (e.g., local anesthetics, certain antiarrhythmics, some psychotropics) from BrugadaDrugs.org; show it to every clinician and pharmacist.
   Purpose: Prevent drug-induced ECG changes and arrhythmias.
   Mechanism: Many “red list” medicines block cardiac sodium channels and can provoke malignant rhythms in susceptible people. brugadadrugs.org+2brugadadrugs.org+2

4. Implantable cardioverter-defibrillator (ICD) when indicated
   What it is: A small device placed under the skin with a lead to the heart to shock life-threatening rhythms.
   Purpose: Definitive protection for survivors of cardiac arrest or high-risk patients per guidelines.
   Mechanism: Detects ventricular fibrillation/tachycardia and delivers therapy within seconds. PubMed+1

5. Catheter ablation (specialist centers)
   What it is: Minimally invasive procedure to eliminate the arrhythmogenic epicardial substrate in Brugada; considered in recurrent events or ICD shocks, or when an ICD is refused.
   Purpose: Reduce arrhythmic episodes and ICD shocks; in selected patients, may be disease-modifying.
   Mechanism: Ablation removes abnormal electrical tissue that maintains ventricular fibrillation. PMC+2OUP Academic+2

6. CPR and AED access at home for high-risk families
   What it is: Family members learn CPR; consider a home AED when advised by your specialist.
   Purpose: Immediate response buys time before EMS arrival.
   Mechanism: Chest compressions maintain blood flow; AED can stop VF if it occurs. (Standard resuscitation science; specific SUNDS trials are impractical.) PubMed

7. Sleep-apnea evaluation and treatment (e.g., CPAP where indicated)
   What it is: Screen for snoring, witnessed apneas, daytime sleepiness; treat confirmed obstructive sleep apnea.
   Purpose: Sleep apnea increases nocturnal arrhythmia risk; treatment improves overall rhythm stability in several cardiac settings.
   Mechanism: CPAP reduces hypoxia and sympathetic surges that can trigger arrhythmias during sleep. ahajournals.org+1

8. Electrolyte balance and hydration
   What it is: Prevent low potassium or magnesium (from vomiting, diarrhea, extreme diets, or diuretics) and address promptly.
   Purpose: Electrolyte deficits can encourage ventricular arrhythmias.
   Mechanism: Adequate K⁺/Mg²⁺ supports stable cardiac repolarization. PubMed

9. Trigger management: alcohol, very heavy late meals, extreme exertion at night
   What it is: Moderate alcohol; avoid binge drinking and late heavy meals; schedule high-intensity workouts earlier.
   Purpose: Reduce vagal surges and metabolic stress at night that can unmask Brugada patterns.
   Mechanism: Certain autonomic states (high vagal tone) and GI distention may accentuate Brugada ECG changes during sleep. Life in the Fast Lane • LITFL

10. Structured symptom plan
    What it is: A written “if-then” for palpitations, fainting, fever, or shocks (call emergency services, present Brugada card, list of avoided drugs).
    Purpose: Shortens time to correct care.
    Mechanism: Standardized actions reduce delays and exposure to contraindicated medications. brugadadrugs.org

11. Workplace/School safety note
    What it is: Share a one-page Brugada/SUNDS alert with staff (especially for adolescents/young adults).
    Purpose & Mechanism: Ensures rapid recognition and proper first aid; reduces harmful medication exposure. brugadadrugs.org

12. Fever first-aid kit at home
    What it is: Thermometer, antipyretic, guidance on when to go to the ED.
    Purpose & Mechanism: Early fever treatment reduces arrhythmia triggers. PMC

13. Regular follow-up with electrophysiology (EP) clinic
    What it is: Scheduled visits, ECGs, and risk reviews.
    Purpose & Mechanism: Ongoing surveillance updates risk and therapy choices. HRS

14. Medication reconciliation at every visit
    What it is: Review all medicines, including OTC and herbal products.
    Purpose & Mechanism: Avoid inadvertent sodium-channel blocking or QT-affecting drugs. brugadadrugs.org

15. Illness plan for gastrointestinal fluid loss
    What it is: Oral rehydration and medical review during gastroenteritis.
    Purpose & Mechanism: Prevents electrolyte-triggered arrhythmias. PubMed

16. Temperature precautions with exertion/sauna
    What it is: Avoid excessive heat exposure; cool down gradually.
    Purpose & Mechanism: Prevents temperature-related ECG changes. MDPI

17. Education for primary care and emergency staff
    What it is: Share BrugadaDrugs.org and local EP contact.
    Purpose & Mechanism: Reduces exposure to risky drugs in urgent settings. brugadadrugs.org

18. Psychological support
    What it is: Counseling for anxiety after a family event or ICD implant.
    Purpose & Mechanism: Lowers stress-related autonomic swings; improves adherence. PubMed

19. Travel checklist
    What it is: Medical summary, device card, avoid-drug list, fever plan.
    Purpose & Mechanism: Keeps care consistent abroad. brugadadrugs.org

20. Community awareness in high-prevalence areas
    What it is: Public education in Southeast/South Asia and migrant communities.
    Purpose & Mechanism: Earlier recognition, family screening, and trigger avoidance reduce events. ahajournals.org

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Drug treatments

Notes: Drugs do not “cure” SUNDS; they reduce triggers or treat specific arrhythmic scenarios. Some antiarrhythmics used in Brugada may be off-label. Always follow a specialist’s plan.

1. Isoproterenol (IV)
   Class: Non-selective β-agonist (catecholamine).
   Dose/Time (acute, under monitoring): Continuous IV infusion titrated by specialist for VF storm.
   Purpose: First-line acute therapy for Brugada electrical storm.
   Mechanism: Increases L-type Ca²⁺ current and heart rate, suppressing phase-2 reentry and VF.
   Side effects: Tachycardia, arrhythmias, hypotension, tremor. FDA label: ISUPREL® injection. PMC+2sciencedirect.com+2

2. Quinidine (oral)
   Class: Class Ia antiarrhythmic (Na⁺/K⁺ channel blocker).
   Dose/Time: Individualized dosing (e.g., quinidine gluconate/sulfate in divided doses) per EP specialist.
   Purpose: Prevent recurrent VF/ICD shocks; alternative when ICD declined/not available.
   Mechanism: Inhibits Ito current, restoring action-potential dome and reducing phase-2 reentry in Brugada.
   Side effects: GI upset, cinchonism, QT prolongation, torsades risk; drug interactions. FDA labels: quinidine gluconate; (quinidine content also in dextromethorphan/quinidine). jacc.org+2FDA Access Data+2

3. Acetaminophen (paracetamol)
   Class: Analgesic/antipyretic.
   Dose/Time: Follow OTC label; avoid overdose and duplicate products.
   Purpose: Fever control, a key trigger-reduction strategy in Brugada/SUNDS.
   Mechanism: Central prostaglandin synthesis inhibition reduces temperature.
   Side effects: Hepatotoxicity with overdose or liver disease; heed label warnings. FDA sources. FDA Access Data+1

4. Ibuprofen (NSAID)
   Class: Non-steroidal anti-inflammatory/antipyretic.
   Dose/Time: Per OTC label; avoid late pregnancy; use lowest effective dose.
   Purpose: Fever reduction when acetaminophen is unsuitable/insufficient.
   Mechanism: COX inhibition lowers prostaglandins and fever set-point.
   Side effects: GI upset/bleeding, kidney effects, CV warnings on label. FDA sources. FDA Access Data+1

5. Magnesium sulfate (IV, monitored)
   Class: Electrolyte.
   Dose/Time: IV replacement per label (e.g., for documented hypomagnesemia or torsades-like contexts).
   Purpose: Stabilize repolarization when magnesium is low or polymorphic VT present.
   Mechanism: Modulates Ca²⁺ influx and suppresses early afterdepolarizations.
   Side effects: Flushing, hypotension, respiratory depression at high levels. FDA label. FDA Access Data

6. Potassium chloride (oral/IV per label)
   Class: Electrolyte.
   Dose/Time: Replace documented hypokalemia; dosing per label and labs.
   Purpose: Correct low K⁺ that predisposes to ventricular arrhythmias.
   Mechanism: Restores membrane excitability and repolarization stability.
   Side effects: GI irritation (oral), hyperkalemia/arrhythmia (over-replacement). FDA labels. FDA Access Data+1

7. Isoproterenol alternatives where isoproterenol unavailable (specialist use)
   Class: Other β-agonists (e.g., orciprenaline—availability varies).
   Purpose/Mechanism: Similar β-stimulation to suppress Brugada storm acutely.
   Evidence base: Case reports/series. (Use only under EP guidance.) OUP Academic

8. Short-acting sedation/analgesia (ED/ICU context)
   Class: Per protocol (e.g., fentanyl/midazolam) to facilitate ablation or acute stabilization.
   Purpose/Mechanism: Reduce adrenergic swings and pain that can worsen instability.
   Note: Drug selection must avoid Brugada “red list” interactions. brugadadrugs.org

9. Antibiotics/antivirals when infection causes fever
   Class: As indicated by infection source and culture.
   Purpose/Mechanism: Removing fever source reduces arrhythmic trigger burden.
   Caution: Cross-check chosen agents against BrugadaDrugs.org lists. brugadadrugs.org

10. Electrolyte oral solutions
    Class: ORS (regulated as drugs/medical foods depending on product).
    Purpose/Mechanism: Prevent dehydration-induced electrolyte loss during illness.
    Note: Follow label and clinician guidance. PubMed

(Further antiarrhythmics are not broadly recommended in Brugada/SUNDS, and some are unsafe. Evidence-based mainstays are ICD, isoproterenol for storm, quinidine for prevention, plus ablation in selected patients.) PubMed+1

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Dietary molecular supplements

Use only after your clinician checks interactions/electrolytes. Evidence ranges from suggestive to limited; the priority is still fever control, drug avoidance, ICD/ablation where indicated.

1. Magnesium (oral) – supports stable repolarization; helpful if dietary intake is low; avoid excess in kidney disease. PubMed

2. Potassium-rich diet – fruits/vegetables/legumes to maintain normal K⁺; do not self-supplement tablets without labs. PubMed

3. Omega-3 fatty acids (EPA/DHA) – may modestly affect arrhythmic substrate in some settings; overall effects on malignant ventricular arrhythmias remain mixed. PubMed

4. Coenzyme Q10 – supports myocardial energetics; evidence for preventing malignant arrhythmias is limited; consider only as adjunct. PubMed

5. Vitamin D (correct deficiency) – general cardiovascular support; deficiency correction advisable for overall health. PubMed

6. B-complex (for nutrition gaps) – aids general metabolism; no direct anti-VF proof. PubMed

7. Electrolyte powders without stimulants – use during heat/illness to maintain hydration. PubMed

8. Taurine – theoretical membrane-stabilizing effects; human anti-VF evidence is limited; avoid high doses. PubMed

9. Melatonin (sleep timing aid) – may improve sleep regularity; avoid interacting sedatives; not anti-arrhythmic. PubMed

10. Fiber-rich diet pattern – overall cardiometabolic benefit; indirect risk reduction. PubMed

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Immunity-booster / regenerative / stem-cell drugs

There are no proven “immunity boosters,” regenerative, or stem-cell drugs that prevent SUNDS/Brugada events. The evidence-based path is identification, trigger control, ICD, and ablation. Below are contextual clarifications, not recommendations:

1. Stem-cell therapies – Not established for Brugada/SUNDS; should be avoided outside approved trials. Mechanism claims do not match channelopathy pathophysiology. PubMed

2. Antioxidants (e.g., CoQ10) – Adjunctive wellness only; no evidence for preventing VF in Brugada/SUNDS. PubMed

3. Immunomodulators (steroids, biologics) – Not disease-directed; may be used for other illnesses but must be vetted for interactions. PubMed

4. Gene therapy – Experimental; not available for routine care in channelopathies tied to SUNDS. PubMed

5. Beta-agonists (isoproterenol) – Acute anti-arrhythmic effect via ion-channel physiology, not “immunity.” PMC

6. Quinidine – Substrate-level electrophysiology effect, not regenerative. jacc.org

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Surgeries/procedures (what is done and why)

1. ICD implantation – Outpatient/minimally invasive procedure placing a defibrillator to treat VF/V-tach automatically. Why: Proven lifesaving therapy in survivors of arrest or high-risk Brugada/SUNDS profiles per consensus statements. PubMed

2. Epicardial substrate catheter ablation – EP lab procedure accessing the heart’s outer surface to remove abnormal electrical tissue in Brugada. Why: Reduces recurrent VF/ICD shocks; for symptomatic or ICD-refusing patients at expert centers. PMC+1

3. Temporary transvenous pacing (rare/ICU) – Short-term pacing support in severe bradyarrhythmias or during storm while stabilizing. Why: Bridge to definitive therapy. PubMed

4. Coronary/structural evaluations (as indicated) – To exclude other causes when presentation is unclear. Why: SUNDS requires ruling out structural disease. ahajournals.org

5. Electrophysiology study (EPS) with drug challenge – Controlled testing (e.g., ajmaline/procainamide challenge) at expert centers to unmask Brugada pattern. Why: Risk clarification; not a treatment itself. PubMed

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Preventions

1. Treat fever immediately and seek help for fever plus fainting/palpitations. PMC

2. Avoid red/orange-list drugs; carry the Brugada card everywhere. brugadadrugs.org

3. Keep electrolytes normal; address vomiting/diarrhea quickly. PubMed

4. Moderate alcohol; avoid binges and very late heavy meals. Life in the Fast Lane • LITFL

5. Keep a fever kit at home (thermometer, antipyretic). MDPI

6. Screen first-degree relatives; follow EP clinic plans. Frontiers

7. Evaluate/treat sleep apnea if suspected. ahajournals.org

8. Learn CPR; consider home AED if your team advises it. PubMed

9. Communicate your condition in ED/urgent care visits before any meds are given. brugadadrugs.org

10. Keep regular follow-ups and device checks if you have an ICD. HRS

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When to see doctors (or go to emergency care)

• Immediately (Emergency): Fainting, seizure-like episodes, sudden palpitations with dizziness, chest pain, fever with syncope, or any ICD shock. These can signal dangerous rhythms needing urgent care. PubMed

• Soon (Clinic): Family history of SUNDS/Brugada, new nocturnal palpitations, repeated nighttime fainting, or if you were told you have a “Brugada pattern” ECG. Specialized EP evaluation helps tailor prevention. PubMed

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What to eat and what to avoid

• Eat more: Potassium-rich fruits/vegetables (bananas, citrus, leafy greens), legumes, whole grains, fish (omega-3s), nuts/seeds, and enough water through the day—these support electrolytes and overall heart health. PubMed

• Avoid/limit: Binge alcohol, stimulant energy drinks, very heavy late-night meals, crash diets, unregulated “fat burners,” and unsupervised electrolyte tablets. These can shift autonomic tone or electrolytes and raise arrhythmia risk. Life in the Fast Lane • LITFL

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Frequently asked questions

1. Is SUNDS the same as Brugada syndrome?
   Not identical, but many SUNDS cases are explained by Brugada or related channelopathies; care strategies often follow Brugada guidance. ahajournals.org

2. If my daytime ECG is normal, am I safe?
   Not necessarily. The Brugada pattern can be intermittent or appear only with fever/drug challenge. Specialist testing may be needed. revportcardiol.org

3. What’s the single most effective lifesaving therapy?
   For truly high-risk patients, an ICD prevents sudden death by treating VF immediately. PubMed

4. Does catheter ablation replace an ICD?
   In selected symptomatic patients, ablation reduces VF recurrences and shocks; decisions are individualized with your EP team. PMC+1

5. Why is fever so dangerous here?
   Higher temperature can unmask the Brugada ECG and precipitate malignant arrhythmias. Treat fever early. PMC

6. Which pain/fever medicines are reasonable?
   Acetaminophen and ibuprofen per FDA-labeled directions (avoid duplication/overuse; check pregnancy warnings). U.S. Food and Drug Administration+1

7. Are there medicines I must never take?
   Yes—certain sodium-channel blockers and other agents. Always check BrugadaDrugs.org red/orange lists and alert clinicians. brugadadrugs.org

8. Can I exercise?
   Most people can do regular, moderate exercise, but avoid extreme late-night sessions and follow your EP team’s individualized advice. PubMed

9. Is sleep apnea relevant?
   Yes. Treating OSA improves overall arrhythmic risk in several cardiac settings and is reasonable if you screen positive. ahajournals.org

10. Do vitamins or “immunity boosters” prevent SUNDS?
    No supplement prevents malignant arrhythmias. Use diet to maintain electrolytes; focus on proven trigger control and specialist care. PubMed

11. Can children have Brugada patterns?
    Yes; evaluation is family-based. A pediatric electrophysiologist should guide care. PubMed

12. What if I get the flu or dengue with high fever?
    Start fever control immediately and seek medical care; bring your avoid-drug list. MDPI

13. Is isoproterenol something I keep at home?
    No. It’s an IV drug used in hospital for electrical storms under continuous monitoring. FDA Access Data

14. Is quinidine still available?
    Yes in some formulations, but availability varies by country; an EP specialist oversees dosing and safety. FDA Access Data

15. What does success look like?
    No recurrent syncope or shocks, stable ECGs, prompt fever care, and safe medication use—monitored regularly with your EP team. HRS

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The article is written by Team RxHarun and reviewed by the Rx Editorial Board Members

Last Updated: November 03, 2025.

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