Many people who have Brugada syndrome are undiagnosed because the condition often doesn't cause any noticeable symptoms.

The most important sign of Brugada syndrome is an abnormal pattern on an electrocardiogram (ECG) called a type 1 Brugada ECG pattern. You can't feel a Brugada sign — it's only detected on an ECG.

It's possible to have a Brugada sign, or pattern, without having Brugada syndrome. However, signs and symptoms that could mean you have Brugada syndrome include:

• Dizziness
• Fainting (syncope)
• Gasping, labored breathing, particularly at night
• Irregular heartbeats or palpitations
• Extremely fast and chaotic heartbeat (sudden cardiac arrest)

Brugada syndrome signs and symptoms are similar to some other heart rhythm problems, so it's essential that you see your doctor to find out if Brugada syndrome or another heart rhythm problem is causing your symptoms.

Brugada syndrome is a heart rhythm disorder. Each beat of your heart is triggered by an electrical impulse generated by special cells in the right upper chamber of your heart. Tiny pores, called channels, on each of these cells direct this electrical activity, which makes your heart beat.

In Brugada syndrome, a defect in these channels can cause your heart to beat abnormally and spin electrically out of control in an abnormally fast and dangerous rhythm (ventricular fibrillation).

As a result, your heart doesn't pump effectively and not enough blood travels to the rest of your body. This will cause fainting if that rhythm lasts for only a short time or sudden cardiac death if the heart remains in that bad rhythm.

Brugada syndrome is often inherited, but it may also result from a hard-to-detect structural abnormality in your heart, imbalances in chemicals that help transmit electrical signals through your body (electrolytes), or the effects of certain prescription medications or cocaine use.

Brugada syndrome usually is diagnosed in adults and, sometimes, in adolescents. It's rarely diagnosed in young children.

Risk factors for Brugada syndrome include:

• Family history of Brugada syndrome. If other family members have had Brugada syndrome, you're at an increased risk of having the condition.
• Being male. Adult men are more frequently diagnosed than are women. In young children and adolescents, however, boys and girls are diagnosed at about the same rate.
• Race. Brugada syndrome occurs more frequently in Asians than in other races.
• Fever. While having a fever doesn't cause Brugada syndrome by itself, a fever can irritate the heart and stimulate a Brugada-triggered faint or sudden cardiac arrest, especially in children.

Complications of Brugada syndrome require emergency medical care. They include:

• Sudden cardiac arrest. If not treated immediately, this sudden loss of heart function, breathing and consciousness, which often occurs while sleeping, is fatal. With fast, appropriate medical care, survival is possible.

Administering cardiopulmonary resuscitation (CPR) — rapid compressions to the chest — and an external shock from an automatic external defibrillator (AED) can improve the chances of survival until emergency personnel arrive.

• Fainting (syncope). If you have Brugada syndrome and you faint, seek emergency medical attention.