Supraventricular Tachycardia
1 medicine
Supraventricular tachycardia (SVT) is a fast heart-rhythm disorder starting above the ventricles, causing sudden episodes of racing heartbeat treated with verapamil when needed.
Key facts
- Supraventricular tachycardia (SVT) is an umbrella term for fast heart rhythms starting above the ventricles; episodes begin and end abruptly.
- During an episode the heart suddenly races to 150-250 beats per minute, then returns to normal just as quickly, lasting seconds to hours.
- SVT usually is not life-threatening, but frequent or prolonged episodes are exhausting; verapamil slows conduction through the AV node to stop the re-entrant circuit that drives most episodes.
- Seek urgent care for an episode lasting more than 30 minutes, fainting, or severe chest pain.
What happens during an episode
During an episode, most people feel a sudden pounding or fluttering in the chest, often with lightheadedness, breathlessness, or mild chest discomfort. Some notice an urge to urinate as the rapid rate triggers hormonal changes. Episodes can last seconds or hours and may happen once in a lifetime or many times a week.
How SVT is treated
SVT is not usually life-threatening, but frequent or prolonged episodes can be exhausting and disruptive. When a doctor decides treatment is needed, verapamil is a well-established option: it slows conduction through the atrioventricular node, terminating the re-entrant circuit that drives most SVT. It sits within the broader range of heart and blood pressure medicines used to manage cardiac rhythm and rate.
When to seek urgent care
Seek urgent care if an episode lasts longer than 30 minutes, if you feel faint or lose consciousness, or if chest pain becomes severe. A first episode, or one that behaves differently from previous ones, is worth a same-day medical review even after it settles.
This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.