ICDs are commonly tested for device performance and battery life. This way, you'll know that your device is programmed correctly and when it's ready for replacement. Your device may first be tested during the implant surgery using what is called Defibrillation Threshold Testing (DFT). This test is to ensure that the device is functioning properly and will respond appropriately to a life-threatening arrhythmia. Since the reliability of ICDS has become so high, DFT testing is not always performed at implant and is rarely performed at follow-up appointments unless there is a suspected problem with the device. Besides DFT testing, follow-up appointments at your doctor's office will use a 'programmer' device to pull information from your implant to ensure everything else is working properly. This process is painless and can also be accomplished from home using a remote monitor.