Supraventricular tachycardia (SVT): symptoms, triggers, and treatment

Have you ever felt your heart slam into a fast, steady beat out of nowhere? That could be supraventricular tachycardia (SVT). SVT is a rapid heart rhythm that starts above the heart’s ventricles and often comes on suddenly. People describe it as pounding, fluttering, or a racing pulse that can last seconds to hours.

Typical symptoms are strong palpitations, lightheadedness, shortness of breath, chest tightness, sweating, or fainting in more severe cases. Some people feel anxious or tired after an episode. If you ever pass out, have chest pain, or struggle to breathe, get emergency help right away.

How SVT starts and common triggers

SVT usually happens because electrical signals take a shortcut in the upper chambers of the heart. Types include AVNRT and AVRT, but you don’t need the jargon to act. Common triggers are caffeine, energy drinks, alcohol, nicotine, intense stress, fever, lack of sleep, and certain medications or illegal stimulants. Thyroid problems can also make SVT more likely.

Sometimes episodes have no obvious trigger. If yours come after a specific food, drink, or activity, tracking that pattern helps your doctor find the cause and reduce future attacks.

What to do during an episode and when to seek care

If an episode is mild, try to stay calm and sit down. Some people can stop SVT with a vagal maneuver, like bearing down (Valsalva) or splashing cold water on the face. These techniques affect the autonomic nerves and can slow the heartbeat, but they don’t always work and aren’t safe for everyone. Don’t try forceful maneuvers if you feel faint or have heart disease—call your provider instead.

Emergency care is needed if you have chest pain, severe shortness of breath, fainting, or if the fast heartbeat doesn’t slow down. In the ER, doctors may give medicines like adenosine or use electricity (cardioversion) to reset the rhythm.

For recurring SVT, expect tests such as an ECG, a Holter monitor, and sometimes an echocardiogram or exercise test. These help your team see how often episodes happen and whether another heart issue is present.

Treatment options range from daily medications (beta-blockers, calcium channel blockers, or antiarrhythmics) to a minimally invasive procedure called catheter ablation. Ablation targets the faulty electrical pathway and often prevents future episodes—many people feel better long term after it. Talk to a cardiologist or electrophysiologist to weigh risks and benefits.

Simple lifestyle changes help too: cut back on stimulants, manage stress, get regular sleep, and treat conditions like hyperthyroidism. Keep a record of episodes—what you were doing, what you ate, and how long it lasted. That checklist speeds up diagnosis and treatment.

PillPack Supplies has more articles and medication info if you want to read up or find prescriptions. If you’re worried about SVT, reach out to your healthcare team. A quick check now can prevent bigger problems later.