Enhancing SVT Discrimination in Implantable Cardioverter Defibrillators Using MEMS Accelerometers

Sudden cardiac death (SCD) accounts for over 325,000 deaths in the United States per year. Implantable cardioverter defibrillators (ICDs), about 100,000 of which are implanted each year, are used to diagnose and treat cardiac arrhythmias in patients that are at risk for sudden cardiac death due to ventricular fibrillation. Upon detection of an arrhythmia, the ICD has several treatment options, all of which deliver varied amounts of electric current to the myocardium. Detection of ventricular tachycardia (VT) or ventricular fibrillation (VF) prompts the ICD to administer high-energy defibrillation shocks, which can exceed 30J. The current method for sensing arrhythmias is the use of electrodes implanted in the myocardium which are capable of detecting electric potentials. The extensively studied algorithms that analyze electrogram sensor data have allowed ICD’s to achieve a 0% false negative rate for detection of fibrillation. The drawback, however, is the high false positive rate of over 22%. False positives result in inappropriate shocks which have detrimental effects on patient health and quality of life [1].