Normally, you can expect the following

• You may be given medicine to help you relax.
• A local anaesthetic, which induces numbness in the area, will be given to your skin near a vein in your groyne, neck, or forearm.
• Your healthcare provider will make a needle puncture through your skin and into your blood vessel.
• A small straw sized tube called a sheath will be inserted into your artery or vein.
• Several specialised EP catheters will be carefully guided into the blood vessel through the sheath and advanced into your heart by your doctor.
  
• To help progress the catheters to the heart, fluoroscopy (a special type of X-ray that is displayed on a TV monitor) is utilised.
• Small electrical impulses will be sent through the catheters by your doctor to cause your heart to beat at varied speeds. Your heartbeat may become faster or stronger.
• Electrical signals produced by your heart will be picked up by special catheters and recorded. This is known as cardiac mapping, and it allows the clinician to pinpoint the source of arrhythmias.
• Your doctor may do an ablation if a specific part of the heart is determined to be producing a rhythm problem.
• Your doctor will remove the catheter after an EP study is done,
• EP study usually takes 1 to 4 hours.

Reference - Health Encyclopedia. (n.d.). Retrieved from https://johnshopkinshealthcare.staywellsolutionsonline.com/Library/Encyclopedia/92,P07971