ICD
The Implantable Cardioconverter device (ICD) is effectively a portable defibrillator device which is surgically implanted pectoraly. Two wires are surgically placed transvenously across the superior Vena Cava which are used to input the cardiac stroke rate to the device. During Cardio tachyrhythmia or fibrillation the heart rate is very irregular as it produces spasmodic movements instead of its usual smooth, repetative cycle. This makes the heart very ineffective at pumping blood around the circulatory system and as result cardiac arrest occurs which can be lethal. The input wires will detect the potentially dangerous heartrate during its irregular electrical signal stage and emit an electrical pulse across the heart, aimed at reseting the heartrate to its usual tempo. It is very useful for patients at risk of sudden cariac arrest as they effectively have a "defibrillator on tap" however it has been reported that they sometimes emit unneccesary shocks which cause great discomfort to fully conscious patients. Medical companys are working on making the device smaller, the wires stronger to prevent wire fracture, and reprogramming to prevent unneccesary shocks.