What should I do now?
Call 911
Call 911 if racing occurs with chest pressure, severe trouble breathing, fainting, or severe weakness or dizziness. Do not drive yourself.
Contact your care team
Contact your care team if episodes are new, more frequent, longer, or interfere with daily life. Follow your personal plan when an episode will not stop.
Keep your care plan
Keep your treatment and follow-up plan. Bring questions, readings, and your medication list.
SECTION 2
What symptoms can SVT cause?
SVT often feels like your heartbeat suddenly switches to a much faster speed. It can happen while you are resting or being active.
Common symptoms
- A racing heartbeat: Your pulse suddenly becomes much faster than usual.
- Pounding in your chest or neck.
- Lightheadedness: Feeling dizzy, unsteady, or close to passing out.
- Shortness of breath: Including difficulty keeping up with your usual activities.
- Weakness or fatigue: During an episode or afterward.
- Chest pressure or tightness.
- Fainting.
Can it feel like anxiety?
A sudden racing heartbeat can feel frightening or similar to a panic attack. Symptoms alone cannot reliably distinguish anxiety from an abnormal heart rhythm. Recording the rhythm during an episode helps identify what is happening.
When should I seek emergency care?
Call 911 if a racing heartbeat occurs with chest pain or pressure, severe shortness of breath, fainting, or severe weakness or a feeling that you may pass out. Do not drive yourself.
For other episodes, follow the action plan you develop with your care team.
Updated October 2026. Educational information; your own care plan may differ.