Continuous monitoring for prediction and prevention of ventricular arrhytmias and sudden cardiac death

An sudden increase in STV (short term variability of repolarization) above the daily variance has been shown to predict the occurrence of a ventricular arrhythmia. An automatic algorithm that can measure STV 24/7 (STV QTarea) was developed, patented and downloaded in existing ICDs. It was shown that the new ICD+ with 24/7 detection of STV was able to recognize the increase in STV that precedes a Torsade de pointes arrhythmia and by activating the pacemaker the ICD+ was capable of preventing these life threatening arrhythmias in animals. Anti-arrhythmic effect was associated with a decrease in STV by the increased paced heart rate.

This project has been finished in 2021. An added project concerns the STV behavior during ischemia induced Ventricular Fibrillation (VF). The pig was used to induce VF after LAD occlusion (75 min) and reperfusion. Again STV showed a clear increase from 0.8±0.26 ms at baseline to 3.0±1.67 ms just prior to VF.  Novel ICD treatment clinically In the STV-ARI study (n=5+10 patients), 3 goals were tested: 1. Using different vectors in the electrode recording the ARI (activation recovery interval), the optimal vector to determine STV on the EGM was determined. 2. The patented STV-QTarea methodology was tested on human signals and failed to detect STV accurately under SR conditions. 3. The effect of pacing (higher heart rate) on the physiological behavior of STV was confirmed on human signals. In the currently running STV-ARI 2.0 study, the number of patients receiving a replacement ICD will be increased to ascertain the testing of the above 3 goals. A dynamic window to measure STV will be added to the algorithm to allow proper STV detection during higher heart rates.