A new study suggests that questioning the cardiac implantable electronic device (CIED) following death can provide important information about device malfunctions abnormalities in the premortem as well as the mechanism and timing for death.
Postmortem CIED interrogation is “richly informative” to aid both cardiac and forensic investigations and “should be taken into consideration for certain patients suffering from CIEDs who are undergoing autopsy,” say Elizabeth Paratz, MBBS, Department of Cardiology, Baker Heart and Diabetes Institute, Prahran, Victoria, Australia and colleagues.
Their study results were published online December 22 in JACC: Clinical Electrophysiology.
Cause of Death Revealed in Half of Cases
They looked at CIED interrogations conducted on deceased individuals who were undergoing medical investigation into sudden death (162 patients) or unexplained death (98 patients) by the Victorian Institute of Forensic Medicine between 2005 and 2020.
Two-thirds of the patients were male (68.8%) and their median age was 72.8. The reason for death was cardiac in 79.6% of cases.
Postmortem CIED interrogation was successful in 98.5% of cases and directly informed cause was found in 131 cases (50.4%). There were fatal ventricular arrhythmias in 121 patients.
CIED interrogation helped in the determination of the cause of death in 63.6 percent of cases of sudden death , and 28.6 percent of non-sudden death cases.
In 20 cases (7.7%), CIED interrogation uncovered potential device malfunction. Issues included failure to appropriately treat arrhythmias of the ventricular system in 13 cases, and lead issues in 3 cases including 2 cases resulting in the inability to treat ventricular arrhythmias as well as battery depletion in 6 cases.
The device detected abnormalities in 72 patients (27.7%) within the last 30 days. These included non-sustained ventricular Tachycardia in 26 cases, rapid atrial fibrillation in 17 cases, elective replacement indicator or end-of-life status in 22 intrachoracic impedance alarms or leads issues in 3 cases and therapy administered in one instance.
Paratz and colleagues have reported that “in many cases the absence or arrhythmia could have implications for medicolegal reasons. For instance, in eight instances of fatal motor vehicle accidents, only 1 patient had a ventricular rhythm recorded on their CIED.”
In six instances in where the patient was found dead after a long time, CIED interrogation determined time of death. In one instance, CIED interrogation was used as the primary method for identifying the patient.
The study team notes that postmortem CIED interrogation is not a common practice.
They point to an inquiry conducted in 2007 by Chicago morticians that revealed that around 370 CIEDs were removed each year prior to cremation, however, only 4% morticians ever returned a CIED to the manufacturer for analysis.
“Encouraging postmortem interrogation of CIEDs can aid in the postmarketing surveillance of critical faults, as well in providing an electrophysiological assessment of terminal rhythms and device responses in various physiological situations,” the researchers say.
The study had no commercial funding. Paratz is co-funded by the National Health and Medical Research Council as well as the National Heart Foundation (NHF) Postgraduate Scholarship, Royal Australasian College of Physicians JJ Billings Scholarship and PSA Insurance Cardiovascular Scholarship. The authors have not disclosed any financial affiliations.
JACC: Clinical Electrophysiology. Published online December 22nd, 2021. Abstract
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