3 The technologies
3.1 Implantable cardioverter defibrillators (ICDs) are small, battery-powered devices that are implanted under the skin just below the collarbone, with leads (tiny wires) inserted into the heart. The devices operate by sensing and analysing the electrical activity of the heart, thereby monitoring for arrhythmia, and delivering electrical pulses or shocks to restore normal rhythm if necessary. Based on average selling prices aggregated across all manufacturers of ICDs sold in the UK to the NHS in the financial year of 2011, the cost of a complete ICD system was estimated at £9692.
3.2 Cardiac resynchronisation therapy with pacing (CRT‑P), also known as biventricular pacing, involves implanting a pulse generator in the upper chest. Three leads connect this to the right atrium and both ventricles, and the device resynchronises the contraction of the ventricles, thereby improving the heart's pumping efficiency. Based on average selling prices aggregated from devices sold in the UK to the NHS across all manufacturers in the financial year of 2011, the cost of a complete CRT‑P system is estimated to be £3411.
3.3 Cardiac resynchronisation therapy with a defibrillator device (CRT‑D) combines CRT‑P and ICD devices. A CRT‑D device defibrillates the heart internally in the event of an acute arrhythmic event and improves ventricular efficiency and blood flow. Based on average selling prices aggregated from devices sold in the UK to the NHS across all manufacturers in the financial year of 2011, the cost of a complete CRT‑D system is estimated to be £12,293.
3.4 Costs may vary in different settings because of negotiated procurement discounts.
3.5 Adverse events from implantable devices are mostly related to implantation-related complications and include coronary vein dissection, coronary vein perforation, lead dislodgement, infection and death. Patients with defibrillator devices (ICD and CRT‑D) who experience defibrillator shocks may have adverse psychological symptoms (notably anxiety).