Posts Tagged: electrocardiography

Ventricular tachycardia (VT) is a life-threatening arrhythmia. In patients with myocardial infarction, it is caused by a reentrant circuit, formed by conduction blocks and a slow conducting zone within the infarcted area. Catheter interventions consist of identifying those circuits and breaking them by radiofrequency ablation. Here a novel method is presented for identification of ablation targets. It consists of pacing the heart from various sites of the ventricle. As the catheter is moved, changes of the activation wavefront can be detected by analysis of surface electrocardiograms. Areas of abrupt changes thereby correspond to critical zones likely to sustain VT circuits.

Wearable technologies will play an important role in advancing precision medicine by enabling measurement of clinically-relevant parameters that define an individual’s health state. The lifestyle and fitness markets have provided the driving force for the development of a broad range of wearable technologies that can be adapted for use in healthcare. Here we review existing technologies currently used for measurement of the four primary vital signs along with other clinically-relevant parameters. We review the relevant physiology that defines the measurement needs, and evaluate the different methods of signal transduction and measurement modalities for use in healthcare.

ECGi is an emerging non-invasive technique that computes unipolar electrograms (EGMs) at the epicardial surface from ECG recordings and torso anatomy. We propose a new method that uses estimates of delays between neighboring points on top of local estimates. It improves the activation maps, yielding a 19% reduction in relative error compared to our reference clinical data.

We describe a QRS detection algorithm that is suitable for clean clinical ECGs as well as poorer quality telehealth ECG. A data repository of annotated telehealth ECGs has been made available on-line for future algorithmic development and testing.