There are different indications for the use of a pacemaker or an implanted cardioverter defibrillator (ICD). A thorough evaluation of the patient is required to discover the underlying condition before the decision on which to use can be made.
- The history is important in evaluating the cause of syncope and the ECG is the most important investigation.
- A sudden loss of consciousness with no premonitory symptoms and no features of a convulsion is likely to be due to an arrhythmia.
- The usual indication for a pacemaker is symptomatic bradycardia; patients with asymptomatic bradycardia usually do not need a pacemaker.
- An implanted cardioverter defibrillator (ICD) is usually indicated in patients who have been resuscitated from a cardiac arrest or who are at high risk of a cardiac arrest by the nature of their heart disease.