Beyond the life saving capabilities, pacemakers and other cardiac devices have forensic importance as well, scientists have revealed at the EHRA EUROPACE – CARDIOSTIM 2017.
According to scientists, these devices have revealed the time and cause of death in some cases where autopsy failed to do so. With more and more sophisticated cardiac devices being used as implants, scientists thought of interrogating these devices to determine the information they can reveal. Currently, device interrogation is not routinely performed after autopsy.
The study was conducted in cooperation with the Department of Forensic Medicine at Charité – Medical University of Berlin where more than 5 000 autopsies were performed in a five year period. Of these, 150 cases had an implantable cardiac device which was removed from the body during the autopsy.
The explanted devices included 107 pacemakers, 22 implantable cardioverter defibrillators (ICDs), 14 cardiac resynchronisation therapy (CRT) systems, and six implantable loop recorders. The devices were interrogated by two electrophysiologists to determine time and cause of death, and device failure.
Time of death could be determined in 76 per cent of cases using data from the device. It could be identified precisely (to the minute) when the patient had tachycardia (fast heart rate) at the end of life. In other cases, changes in seven parameters were used to assign the time of death. These included lead impedance and pacing threshold.
Cause of death was determined in 24 per cent of cases. This included bradycardia, tachycardia, ventricular fibrillation, and device malfunctions.
Device malfunction occurred in 7 per cent of cases. This included hardware failure such as a broken lead, algorithm issues meaning the device did not recognise an arrhythmia or deliver a shock when it occurred, or a programming issue where the shock setting was insufficient to terminate an arrhythmia.
Dr Philipp Lacour, a cardiologist at Charité – Medical University of Berlin, Germany, lead author of the study said: “We think device interrogation should be routinely performed after autopsy in all forensic cases,” continued Dr Lacour. “It helps determine the time and cause of death and identifies device malfunctions that might otherwise have gone unnoticed and should be highlighted to manufacturers and health departments.”
He concluded: “To ensure that accurate data is extracted from cardiac devices, the time between autopsy and device interrogation should be kept as short as possible and we try to do it within two weeks. This avoids the memory of the device filling up with artefacts that can be generated after the leads are cut.”