Supra Ventricular Tachycardia

Fig 6 SVT monitor

Supraventricular tachycardia (SVT) is a type of rapid heartbeat that originates above the ventricles (the lower chambers of the heart) and is characterized by a heart rate greater than 100 beats per minute (often 150-200 BPM). Supraventricular Tachycardia is caused by abnormal electrical impulses in the heart’s upper chambers. SVT is caused by either an extra electrical pathway (connection) in their heart (some people are born with it) or by a small focus that starts firing rapidly in the upper chambers. The episode of fast heart rate may be triggered by various factors such as stress, caffeine, alcohol, stomach swelling, or even certain positions. Some people may have no symptoms or may experience only occasional episodes of SVT, while others may have frequent or persistent episodes that require treatment.

Symptoms of Supraventricular tachycardia may include:





difficulty breathing1

shortness of breath



chest 1

Chest discomfort

The condition may be diagnosed through an ECG, which records the heart’s electrical activity. It is important to record the ECG at the time of symptoms to establish the diagnosis as the ECG will often look completely normal in between the episodes of Supraventricular tachycardia. Episodes which are too short to be picked up by an ECG can be documented on long-term monitoring devices (Holter) or smart watches.

Fig 5 SVT Converted 1

Treatment for Supraventricular tachycardia may depend on the severity and frequency of the symptoms and underlying causes. Some cases which are mild, infrequent or short lived may require medication, while others which are very severe may require urgent electrical cardioversion, a procedure that involves using a shock to reset the heart’s rhythm. Catheter ablation, is a simple key-hole procedure that uses small catheters (special electrical wires) advanced through the veins to destroy the abnormal heart tissue causing the Supraventricular Tachycardia. It is often a curative procedure with a very high success rate reaching above 95% and excellent procedural safety (risk <1%).

If you have Supraventricular Tachycardia, it’s important to understand that although the symptoms are disturbing and can affect the quality of life, it is rarely life threatening if managed properly. Make sure you keep records of the ECGs documenting the Supraventricular tachycardia as it helps your electrophysiologist in making the accurate diagnosis.