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Ventricular Fibrillation
Diagnosis

If your doctor suspects that you may have an arrhythmia, he or she will order one or more of the following diagnostic tests to determine the source of your symptoms.

  • Electrocardiogram — The electrocardiogram (ECG or EKG) records the heart's electrical activity. Small patches called electrodes are placed on your chest, arms and legs, and are connected by wires to the ECG machine. Your heart's electrical impulses are translated into a wavy line on a strip of moving paper, enabling doctors to determine the pattern of electrical current flow in the heart and to diagnose arrhythmias and heart damage.
  • Holter Monitor — A holter monitor is a small, portable machine that you wear for 24 hours. It enables continuous recording of your ECG as you go about your daily activities. You will be asked to keep a diary log of your activities and symptoms. This monitor may detect arrhythmias that might not show up on a resting EKG that only records for a few seconds.
  • Exercise Stress Test — The exercise stress (treadmill) test enables physicians to record your heart's electrical activity which may not occur at rest.
  • Event Recorder — An event recorder (loop recorder) is a small portable transtelephonic monitor that may be worn for several weeks. This type of recorder is good for patients who don't experience symptoms very often. The monitor "loops" a two-minute recording into its memory that is continually overwritten. When you experience symptoms, you press a "record" button on the monitor which stores a correlating strip of EKG material. The recordings are telephoned to a 24-hour monitoring station and faxed directly to the requesting physician.
  • Magnetic Source Imaging — Magnetic source imaging (MSI) is used as an overlay to magnetic resonance imaging (MRI). The device senses weak magnetic fields generated by heart muscle tissue and localizes the arrhythmia non-invasively to save time during the invasive study.
  • Tilt Table Test — Tilt table testing is used to diagnose fainting or black-out spells (vasovagal syncope) by trying to reproduce the black-out episodes. You will be tilted upright to about 60 degrees on a special table for a period of time with continuous recording of your ECG and blood pressure.
  • The Electrophysiology (EP) Study — The EP study allows doctors to acquire more accurate, detailed information and, in many cases, provide treatment (i.e. catheter ablation) during the same session.

Reviewed by health care specialists at UCSF Medical Center.