Supraventricular tachycardia (SVT) is an abnormally fast heart rhythm arising from improper electrical activity in the upper part of the heart.

There are four main types:

  • Atrial fibrillation
  • Paroxysmal Supraventricular Tachycaria (PSVT)
  • Atrial flutter
  • Wolff–Parkinson–White syndrome.

Symptoms may include palpitations, feeling faint, sweating, shortness of breath, or chest pain.

They start from either the atria or atrioventricular node.

They are generally due to one of two mechanisms: re-entry or increased automaticity.

The other type of fast heart rhythm is ventricular arrhythmia—rapid rhythms that start within the ventricle.

Diagnosis is typically by electrocardiogram (ECG), Holter monitor, or event monitor.

Blood tests may be done to rule out specific underlying causes such as hyperthyroidism or electrolyte abnormalities.

Specific treatments depend on the type of SVT. They can include medications, medical procedures, or surgery.

Vagal maneuvers or a procedure known as catheter ablation may be effective in certain types.

For atrial fibrillation, calcium channel blockers or beta-blockers may be used.

Long term some people benefit from blood thinners such as aspirin or warfarin.

Atrial fibrillation affects about 25 per 1000 people

Paroxysmal supraventricular tachycardia affects about 2.3 per 1000.

Wolff-Parkinson-White syndrome affects about 2 per 1000,

Atrial flutter affects about 0.8 per 1000.