An EP study may be recommended by your doctor for the following reasons:

• To evaluate symptoms such as dizziness, fainting, weakness, palpitation or others to check if they might be caused by heart rhythm problem.
• If you have an abnormal heart rhythm (arrhythmia).
• If you are undergoing catheter ablation.
• If you have a risk of sudden cardiac death.
• To check how well medicines given to treat a heart rhythm problem are working. 
• If you are undergoing heart surgery.
  

Reference : Articles. (n.d.). Retrieved from https://www.cedars-sinai.org/health-library/tests-and-procedures/e/electrophysiological-studies.html