Electrophysiologic Testing, Defibrillators and Ablation


Certain forms of heart disease are associated with electrical instability that may result in unusually fast heart rhythms, or “arrhythmias”. Fast arrhythmias may result in dizziness or fainting and may be potentially life-threatening. Patients with suggestive symptoms or certain abnormal cardiac tests may be candidates for electrophysiologic stimulation (“EPS”) testing to confirm whether or not such arrhythmias exist. During EPS, electrical catheters are passed through the veins into the heart, and a physician assesses cardiac electrical stability with computer assistance. Areas of instability can be “mapped” and potentially targeted for further treatment.

Patients with congestive heart failure and reduced pump function are particularly prone to more serious arrhythmias and may also be candidates for EPS. Some fast arrhythmias are best prevented and treated using a technically sophisticated device known as an implantable cardioverter defibrillator, or “ICD.” Like conventional pacemakers, ICDs have the ability to detect and treat arrhythmias instantly, with the patient often being entirely unaware. Most patients who are appropriate candidates for an ICD do not require prior EPS testing but can easily be identified by Echocardiography, Exercise Echocardiography, Myocardial Perfusion Imaging, or Cardiac Catheterization. In addition, many patients who require an ICD are also appropriate candidates for resynchronization therapy.

Not all fast arrhythmias, such as supraventricular tachycardia (SVT) and atrial fibrillation, are live-­threatening but can result in severe symptoms despite appropriate medical therapy. Most of these arrhythmias may be cured in the cardiac electrophysiology suite using various ablation procedures. During an ablation procedure, catheter-­based delivery of radiofrequency energy is used to destroy, or “ablate”, the small tissue regions responsible for the arrhythmia origin or circuit. Although complex or multiple combinations of arrhythmias may require repeat procedures, many patients can be cured of their arrhythmias for life and no longer require any drug therapy.

The diagnosis and treatment of cardiac arrhythmias is a complicated subject that requires careful consideration of all appropriate options before choosing the one that best meets your needs and desires. Our cardiologists will guide you through these decisions and help you identify the best course of action.

Patient Instructions Before Testing and Procedures