Evaluation and management of patients after implantable cardioverter-defibrillator shock

Context There has been a tremendous increase in the use of implantable cardioverter-defibrillators (ICDs) after several large clinical trials demonstrated their ability to effectively reduce mortality in selected populations of patients with cardiac disease. Thus, the nonelectrophysiologist will often encounter patients who have received an ICD shock. Objective To assess options for the evaluation and management of patients who have received an ICD shock. Evidence Acquisition Literature search using the PubMed and MEDLINE databases to identify articles published from January 1990 to September 2006, using the Medical Subject Headings defibrillators, implantable; defibrillators, implantable/ adverse effects; anti-arrhythmic agents; electric countershock; quality of life; tachycardia therapy; algorithm; ventricular tachycardia/diagnosis; and supraventricular tachycardia/ diagnosis. Case reports were excluded and articles were limited to those published in English. Scientific statements and guidelines from the American College of Cardiology, the American Heart Association, and the Heart Rhythm Society were also reviewed, as were the reference lists of retrieved articles, to identify any additional articles for inclusion. Evidence Synthesis There are multiple causes of both appropriate and inappropriate ICD shocks. Irrespective of appropriateness, receiving ICD shocks substantially impairs a patient's quality of life. A variety of techniques are available using ICD programming to reliably limit the occurrence of appropriate or inappropriate ICD shocks. Antiarrhythmic medications can also effectively reduce the occurrence of shocks. Conclusions Through the use of effective ICD programming and antiarrhythmic medications, the occurrence of ICD shocks can be reduced while maintaining the lifesaving ability of the ICD. A basic understanding of the range of available options is fundamental for evaluation and management of the patient who has received an ICD shock.