St Andrew’s among first in Australia to use S-ICD implantable defibrillator system for patients at risk of sudden cardiac arrest
In a first for Queensland, St Andrew’s War Memorial Hospital cardiologists recently implanted the world’s first and only implantable heart defibrillator system that is placed under the skin without any direct contact with the heart to treat arrhythmia.
St Andrew’s cardiologist and Queensland Cardiovascular Group Director Dr John Hayes said this new evolution in defibrillation therapy, which provides protection for patients who are at risk of sudden cardiac arrest, is less invasive and carries lower risk than other such defibrillators.
“The new heart defibrillator is designed to provide the same defibrillation protection as a traditional transvenous implantable cardioverter defibrillator (ICD). However, the advantage of the S-ICD system is that it sits just below the skin and uses a lead wire implanted along the bottom of the rib cage and breastbone. The lead is placed under the skin rather than through a vein into the heart, leaving the heart and blood vessels untouched, making it low-risk and less invasive,” Dr Hayes said.
Recent estimates show approximately 80,000 people in the Australia are at risk of sudden cardiac arrest. Genetic conditions or a history of heart disease can put patients at a high risk of such arrests.
“Sudden cardiac arrest can occur with very little warning and may result in death if not treated quickly. It is an abrupt loss of heart function and is caused by rapid and/ or chaotic electrical activity of the heart known as ventricular tachycardia or ventricular fibrillation,” Dr Hayes said.
The S-ICD system consists of two components: a pulse generator and an electrode. The pulse generator is a small battery-powered device that constantly monitors the heart’s rhythm and provides a small electrical shock to restore the heart to normal rhythm when it is beating dangerously fast (tachycardia) or chaotically. The electrode enables the device to sense the cardiac rhythm and serves as a pathway for electric shock delivery when needed.The S-ICD system is suitable for a large population of patients at risk of sudden cardiac arrest. However, it is not intended for patients who have symptomatic bradycardia (a slow heartbeat) and who require a pacemaker.
The S-ICD system is commercially available in many countries in Europe as well as New Zealand and the US. The Australian TGA granted regulatory approval for the S-ICD system in 2014. To date, more than 8,000 of these devices have been implanted in patients around the world.