A 17-year-old male with loss of consciousness during a febrile illness

The case

A 17-year-old male with a history of asthma presented with loss of consciousness during a febrile illness. He reported being in his usual state of health until the previous day, when he developed a fever associated with nasal congestion, cough, sore throat, and fatigue. His symptoms worsened throughout the morning, prompting him to leave school early. Later that evening, after sleeping, he experienced syncope while getting up to use the bathroom and was found on the floor in front of the shower by his sibling. The syncopal episode reportedly lasted less than a minute.

Prior to the syncopal event, he noted nausea and palpitations, but denied chest pain, dyspnea, lightheadedness, dizziness, or seizure-like activity. There was no postictal confusion, headache, or bleeding from the ears, nose, or throat. Family history was notable for the absence of sudden cardiac death or known Brugada syndrome. Emergency medical services transported him to the emergency department.

On examination, the patient was alert and oriented. Vital signs were significant for fever with a temperature of 38.4 °C and an elevated blood pressure of 152/86 mm Hg. He had copious nasal secretions, but respiratory and cardiac examinations were otherwise unremarkable. Neurologic examination was also normal.

An ECG performed in the emergency department revealed a type 1 Brugada pattern (Figure), prompting cardiology consultation. Transthoracic echocardiography demonstrated normal right ventricular size and systolic function, with mild thickening of the left ventricular posterior wall, attributed to increased body habitus. Left ventricular ejection fraction was 69.2%, and troponin and BNP levels were within normal limits.

He was admitted to the pediatric intensive care unit, where a viral respiratory panel returned positive for influenza A, and he was started on oseltamivir. Repeat ECGs during febrile episodes continued to demonstrate a type 1 Brugada pattern, and the patient remained hemodynamically stable throughout hospitalization, requiring only a single dose of hydralazine for systolic blood pressure above 150 mm Hg. Cardiac MRI and coronary CT angiography were normal. After the patient became afebrile, ECG findings showed resolution of the Brugada pattern and normalization of T-wave inversions.

Following discharge, his genetic testing revealed a pathogenic variant in the SCN5A gene consistent with Brugada syndrome.

Diagnosis

Brugada syndrome

Etiology and clinical findings

Brugada syndrome is a cardiac channelopathy that is diagnosed when patients have ECG findings in keeping with the Brugada pattern (usually type 1/coved type ST elevation in right precordial leads) in conjunction with clinical symptoms such as syncope, palpitations from an arrhythmia, or sudden cardiac death.^1,2

Brugada syndrome is rare in the pediatric population, with only 4.3% of patients experiencing their first ventricular arrhythmia before age 16; the first arrhythmic episode generally occurs between the fourth and fifth decades of life.^1,3 

Pediatric Brugada syndrome presents across a spectrum from asymptomatic (identified through family screening in most cases) to life-threatening arrhythmias. Symptomatic presentations include syncope, aborted sudden cardiac death, or ventricular tachycardia and are more frequently observed at night, suggesting an association with increased parasympathetic tone. ^1,3

The relationship between sodium channel dysfunction and ST-segment elevation is not fully understood. However, defective myocardial sodium channels are thought to reduce inward sodium current, shortening the action potential and contributing to abnormal depolarization or repolarization, particularly in the right ventricular outflow tract, resulting in the characteristic ECG findings.²

First genetically characterized in the late 1990s, SCN5A remains the most commonly implicated gene in Brugada syndrome. Genetic testing demonstrates variable diagnostic yield in pediatric populations, and the condition is increasingly recognized as genetically heterogeneous and likely polygenic rather than attributable to a single mutation.^2,4

In children, Brugada syndrome is frequently unmasked by fever, which exacerbates sodium channel dysfunction and increases the risk of ventricular arrhythmias, making aggressive antipyretic management crucial.^1,5

Differential diagnosis

The diagnosis of Brugada syndrome requires careful differentiation from other conditions that may present with syncope (Table).

Febrile seizures are a common cause of transient loss of consciousness in children and may be misinterpreted as arrhythmic syncope. However, the presence of characteristic electrocardiographic findings and the absence of postictal features may help distinguish cardiac from neurally mediated causes.⁶ Febrile seizures are also more common in the 6-month to 5-year age range.

Other inherited cardiac channelopathies should also be considered. Long QT syndrome may present with syncope or sudden cardiac arrest, particularly in pediatric patients, but is distinguished by prolonged QT intervals on ECG. Catecholaminergic polymorphic ventricular tachycardia is another important consideration, typically triggered by exercise or emotional stress rather than fever, and characterized by a normal resting ECG with arrhythmias induced during exertion.³

Vasovagal syncope remains the most common cause of syncope in pediatric patients and should be considered, particularly in the absence of abnormal electrocardiographic findings. However, the presence of a spontaneous type 1 Brugada pattern, especially when unmasked by fever, strongly supports a diagnosis of Brugada syndrome over benign causes.^1,5

Micturition syncope is a transient loss of consciousness occurring immediately before, during, or after urination, often triggered by a sudden drop in blood pressure and heart rate, particularly when standing. It more commonly affects older individuals and is generally considered a benign form of reflex syncope.³

In the setting of febrile syncope, an infectious etiology must also be considered. Viral myocarditis can present with arrhythmias and electrocardiographic changes during febrile illness, potentially mimicking Brugada syndrome. This diagnosis is less likely in the absence of characteristic findings on cardiac magnetic resonance imaging, such as increased myocardial T2 signal or late gadolinium enhancement in a nonischemic pattern, and of normal cardiac biomarkers, including troponin.^3,7 Flu-related pericarditis may also result in ST segment elevation, though this may be more widespread rather than just involving the right precordial leads.

Orthostatic syncope is a likely differential in cases of febrile illness. This patient had inadequate fluid intake, which may then lead to volume depletion and orthostatic hypotension. Patients with viral illnesses who present with vomiting and diarrhea may be further at risk.

A thorough evaluation, including serial ECGs, laboratory studies, and cardiac imaging, is essential for distinguishing these entities and ensuring an accurate diagnosis.¹

Management

Management of pediatric Brugada syndrome should be individualized based on clinical presentation, family history, and genetic data. Fever-related syncope or febrile seizures should prompt 12-lead ECG evaluation, particularly in children with a family history of Brugada syndrome.^1,5

Cardiac imaging is integral, as Brugada syndrome is diagnosed in the absence of structural heart disease. Recommended evaluation includes transthoracic echocardiography and, when indicated, cardiac MRI.¹

Once structural heart disease has been excluded and clinical criteria are met, the diagnosis can be established. Although genetic testing may support the diagnosis, negative results do not exclude Brugada syndrome.^2,4

Management is primarily supportive and includes aggressive antipyretic therapy with acetaminophen or nonsteroidal anti-inflammatory drugs. Antiarrhythmic therapy such as quinidine may be considered in select cases, whereas sodium channel–blocking agents should be avoided.^1,2

In the acute setting, patients may require cardiac monitoring. High-risk patients, including those with a history of cardiac arrest, may benefit from implantable cardioverter-defibrillator (ICD) placement. Among pediatric patients with Brugada syndrome who undergo ICD implantation, appropriate therapies occur in a substantial proportion, though device-related complications, including inappropriate shocks, are common.^3,8

In the outpatient setting, patients should be counseled to avoid hyperthermia, as elevated body temperature may precipitate arrhythmic events.¹ They should also be educated regarding medications that may exacerbate Brugada syndrome, with resources such as BrugadaDrugs.org serving as a useful clinical reference.

Adolescents should be advised to avoid alcohol and illicit substances such as cocaine, which may act as sodium channel blockers and precipitate arrhythmias. Importantly, Brugada syndrome does not universally preclude participation in sports, as symptoms are not typically exercise-induced.³

References

1. Marsman EMJ, Postema PG, Remme CA. Brugada syndrome: update and future perspectives. Heart. 2022;108(9):668-675. doi:10.1136/heartjnl-2020-318258

2. Narasimhan B, Na J, Monasky MM, et al. Brugada syndrome. Nat Rev Dis Primers. 2025;11(1):38. doi:10.1038/s41572-025-00622-5

3. Moore BM, Roston TM, Laksman Z, Krahn AD. Updates on inherited arrhythmia syndromes. Prog Cardiovasc Dis. 2025;91:130-143. doi:10.1016/j.pcad.2025.06.002

4. Pannone L, Bisignani A, Osei R, et al. Genetic testing in children with Brugada syndrome: results from a large prospective registry. Europace. 2023;25(5):euad079. doi:10.1093/europace/euad079

5. Michowitz Y, Milman A, Andorin A, et al. Characterization of patients with fever-induced Brugada syndrome. Heart Rhythm. 2021;18(11):1871-1878. doi:10.1016/j.hrthm.2021.06.019

6. Gonzalez Corcia MC, Chandler SF. Cardiac channelopathies in the pediatric patient: Brugada syndrome. Card Electrophysiol Clin. 2025;17(4):663-672. doi:10.1016/j.ccep.2025.07.014

7. McBenedict B, Alphonse B, Devan JN, et al. Advances and challenges in the management of Brugada syndrome. Cureus. 2024;16(6):e61837. doi:10.7759/cureus.61837

8. Writing Committee Members; Shah MJ, Silka MJ, Silva JNA, et al. 2021 PACES expert consensus statement on cardiovascular implantable electronic devices in pediatric patients. Heart Rhythm. 2021;18(11):1888-1924. doi:10.1016/j.hrthm.2021.07.038