Year of Publication


Degree Name

Master of Science in Biomedical Engineering

Document Type

Master's Thesis




Biomedical Engineering

First Advisor

Dr. Abhijit Patwardhan


T-wave Alternans (TWA) in an electrocardiogram (ECG) has received considerable interest as a potential predictor of sudden cardiac death (SCD). However, large clinical trials have shown that while TWA has a very high negative predictive value, its positive predictive value is poor. Results of previous studies suggest that arrhythmia onset can be affected by the phase relationship of alternans of the depolarization and repolarization phase of the action potentials of the ventricles. To assess this relationship, one would first need to establish that depolarization alternans can be detected and then develop methods to determine its relationship with repolarization alternans, which is TWA. The objective of this thesis was to determine whether depolarization phase alternans can be detected in clinical grade ECGs. To accomplish this, an algorithm was developed to quantify R-Wave alternans (RWA) in patients who display TWA in their ECGs. Using both the morphology and amplitude of the R-wave, our results show that RWA can be seen in clinical ECGs. This suggests that RWA has the potential to help quantify occurrence and incidence of depolarization alternans, and supports further exploration of the link between depolarization and repolarization alternans which has the potential to improve clinical utility of TWA.

Digital Object Identifier (DOI)