Hello and thank you for the question! To diagnose your condition and determine the specific type of tachycardia, your doctor will evaluate your symptoms, conduct a physical examination and order several heart tests. 1.An electrocardiogram, also called an ECG or EKG, is a primary tool for diagnosing tachycardia.Your doctor may also ask you to use portable ECG devices at home to provide more information about your heart rate. These include:Holter monitor and Event recorder. 2.Electrophysiological test Your doctor may recommend an electrophysiological test to confirm the diagnosis or to pinpoint the location of problems in your heart s circuitry. During this test, a doctor inserts thin, flexible tubes (catheters) tipped with electrodes into your groin, arm or neck and guides them through your blood vessels to various spots in your heart. 3.Tilt table test This test helps your doctor better understand how your tachycardia contributes to fainting spells. Under careful monitoring, you ll receive a medication that causes a tachycardia episode.etc I would advice you to consult your doctor Best regards!