Supraventricular tachycardia (SVT) is a sudden, abnormally fast heart rhythm that starts in the upper chambers of your heart, often pushing your heart rate above 150 beats per minute. Treatment ranges from simple physical techniques you can do at home to stop an episode, to medications given in an emergency room, to a permanent fix through a catheter-based procedure. The right approach depends on how often episodes happen, how severe they are, and how your body tolerates them.
Stopping an Episode at Home
The first line of treatment for SVT is a set of physical maneuvers that stimulate your vagus nerve, which acts like a brake pedal for your heart rate. The most effective of these is the modified Valsalva maneuver. You bear down hard as if straining during a bowel movement for about 15 seconds while sitting up, then immediately lie flat with your legs raised at a 45-degree angle for 15 seconds, and finally return to a semi-reclined position for 45 seconds. That leg-raise step is what makes it “modified,” and it roughly doubles the success rate compared to straining alone. Studies show the modified version converts SVT back to a normal rhythm about 43% of the time, versus around 17% for the standard strain-only technique.
Other vagal maneuvers include splashing ice-cold water on your face or briefly submerging your face in cold water, which triggers a reflex that slows the heart. Coughing forcefully or bearing down can also help. These techniques work best when you start them as soon as you feel the episode begin. If one attempt doesn’t work, you can try again.
What Happens in the Emergency Room
If vagal maneuvers don’t stop the episode and your symptoms are significant, an ER visit is the next step. The standard treatment is an IV medication called adenosine, which briefly interrupts the electrical circuit causing the rapid rhythm. It works within seconds and the effect is almost immediate. The sensation can be intense: many people describe a brief feeling of chest pressure or flushing that lasts only a few seconds before the heart snaps back to its normal rate.
If adenosine doesn’t work, doctors may try other medications that slow the heart’s electrical signals, typically calcium channel blockers or beta blockers given through an IV.
In rare cases where a person is experiencing dangerously low blood pressure, chest pain, difficulty breathing, confusion, or signs of heart strain, the treatment shifts to synchronized cardioversion. This is a controlled electrical shock delivered while you’re sedated. It resets the heart rhythm immediately. This is reserved for situations where the fast rhythm is causing your body to become unstable, not for a typical SVT episode.
Daily Medications to Prevent Episodes
If SVT episodes happen frequently or are disruptive to your life, a daily medication can reduce how often they occur. Beta blockers and calcium channel blockers are the most commonly prescribed options. They work by slowing conduction through the part of the heart where SVT circuits tend to form. These medications don’t cure SVT, but many people find their episodes become less frequent and easier to manage.
For people who are pregnant, medication choices narrow. Certain beta blockers like metoprolol and propranolol are considered safe during pregnancy. Amiodarone, a more powerful rhythm-control drug, is generally avoided because of risks to the developing baby, though it may be considered in very specific, serious situations after careful discussion.
Catheter Ablation as a Permanent Fix
Catheter ablation is the closest thing to a cure for SVT, and it’s increasingly recommended for people who want to stop taking daily medication or who have frequent, bothersome episodes. During the procedure, a thin catheter is threaded through a vein in your groin up to your heart. The tip of the catheter delivers targeted heat (radiofrequency energy) to destroy the tiny patch of tissue responsible for the abnormal electrical circuit.
Success rates are high. In a recent cohort study of 102 patients, 98% had a successful ablation during the procedure itself. At three months of follow-up, 13% experienced a recurrence of their arrhythmia. Recurrence was more likely in patients with higher BMI or diabetes. Notably, patients with Wolff-Parkinson-White syndrome (a specific type of SVT caused by an extra electrical pathway) had zero recurrences.
The procedure typically takes one to three hours, and most people go home the same day or the next morning. Recovery involves a few days of rest and avoiding heavy lifting while the catheter insertion site heals. Many people notice an immediate difference: no more sudden racing episodes.
Common Triggers and How to Manage Them
SVT episodes often have identifiable triggers, and learning yours can significantly reduce how often they happen. The most common culprits include emotional stress, excessive alcohol (generally defined as more than 14 drinks per week for men or 7 for women), smoking, and stimulant drugs including cocaine and methamphetamine. Over-the-counter medications like decongestants and some diet pills contain stimulants that can also provoke episodes.
Caffeine is worth a special mention because it gets blamed more than it deserves. For most people with SVT, moderate caffeine intake does not trigger episodes. Large amounts may increase risk, but you don’t necessarily need to give up your morning coffee. Sleep deprivation and dehydration are commonly reported triggers as well, though they’re harder to study in controlled settings. Keeping a log of what you were doing, eating, or drinking before an episode can help you and your doctor spot patterns and make targeted changes.