Real Time Non-Invasive Hemodynamic Assessment of Ventricular Tachycardia

Abstract

Hemodynamically unstable ventricular tachycardia (VT) is a critical cardiac arrhythmia associated with hemodynamic compromise that requires immediate cardioversion to prevent sudden cardiac death. Since unnecessary cardioverter defibrillators shocks damage the heart and increase the risk of mortality, the discrimination between unstable (i.e. requiring cardioversion) and stable (i.e. not requiring cardioversion) VT is of paramount importance. The aim of this study was to propose and assess non-invasive identification of hemodynamically unstable VT using photoplethysmography (PPG). Seventy-five (n=75) episodes of VT were recorded in 14 patients undergoing invasive electrophysiological studies for VT catheter ablation. Invasive continuous arterial blood pressure (ABP), PPG and electrocardiogram (ECG) were simultaneously recorded. VTs were classified as unstable if during the first 10 seconds from onset, the mean ABP (PVT) was PVT<60 mmHg or if PVT dropped more than 30% with respect to a 10 seconds baseline (i.e. ratio RABP<0.70). Five PPG morphological features were derived and compared to the heart rate from the ECG. PPG markers detected hemodynamically unstable VT with accuracy as high as 86% and were more accurate than the heart rate. The mean absolute slope was the best PPG parameter for classification of PVT<60 mmHg (AUC=0.85, Sensitivity=72%, Specificity=86%) and RABP<0.70 (AUC=0.90, Sensitivity=83%, Specificity=89%) and it was automatically selected in the best two-variables logistic regression, for which AUC=0.94. In conclusion, PPG analysis can accurately identify haemodynamically unstable VTs and has potential to enable optimization of VT therapy and reduce unnecessary and harmful cardioversion shocks.

"Association between photoplethysmography pulse upslope and cardiovascular events in over 170,000 UK Biobank participants"

“…breathing rate [6] or arterial stiffness, and then using these to predict outcomes [7]. In this study, we focused on the PPG upslope because we previously found that it was closely related to significant hemodynamic changes, such as mechanical alternans [8] and life-threatening ventricular tachycardia [9]. The main strength of this study is the large sample size, over 170 thousand participants, and the long follow-up for multiple outcomes.…”

Techniques to aid prediction of pacing dependence at 30 days in patients requiring pacemaker implantation after cardiac surgery

“…Other studies used blood pressure waveforms together with ECG for a better accuracy. Besleaga et al [131] used invasive ABP waveforms, PPG and ECG signals to distinguish between stable and unstable ventricular tachycardia events. Most of the used features consisted of PPG parameters, while ECG signals were used to extract the heart rate and the ABP signals were used to extract mean ABP and the drop in mean ABP.…”