text: It depends on the type of arrhythmia. Usually arrhythmias result from problems with the way electricity flows through the heart, and electrophysiology studies (EPS for short), which map the current flow in the heart, are more helpful.\n\nA nuclear stress test shows pictures of the blood flow to various parts of the heart. They take one set of pictures when you are resting, and another set when the heart is under stress--either from running on a treadmill, or injecting a chemical to stress the heart. \n\nIf your arrhythmia is from part of your heart not getting enough blood, then the nuclear stress test might help figure it out.\n\nVery few doctors will order tests without a sound reason, but if you have reservations, you should get a second opinion from a Cardiologist. If your first doc has a problem with you getting a second opinion, you need a new doctor.\n\nGood luck.