ICD follow-up and troubleshooting
The implantable cardioverter-defibrillator (ICD) is an effective therapy for reducing the risk of sudden death in survivors of cardiac arrest and in patients with significant left ventricular systolic dysfunction and heart failure. A brief examination should focus on the ICD wound and signs of heart failure. Pertinent medications, such as anti-arrhythmic drugs and oral anticoagulants, should be reviewed. Amiodarone, for example, slows the ventricular tachycardia cycle length, and this should be factored into device programming. Physicians should also be aware of the potential for antiarrhythmic agents to alter the defibrillation threshold. Knowledge of the anticoagulation status is helpful in the event that atrial fibrillation is detected. In contrast to the fixed sensing of a traditional pacemaker, ventricular sensing in an ICD is dynamic. It auto-adjusts to the R-wave amplitude and decays to reach the maximum programmed sensitivity, while avoiding T-wave sensing.
