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Detection and measurement and of repolarisation features in atrial fibrillation and healthy subjects

Al-Karadi, Marwa Saeb


Marwa Saeb Al-Karadi


Philip (Engineer) Langley

Antony Wilkinson


Major cardiac organisations recommended U wave abnormalities should be reported during ECG interpretation. However, U waves cannot be measured in patients with atrial fibrillation (AF) due to the obscuring fibrillatory wave.

The first aim of the research was to provide a validated algorithm to clean the ECGs of AF patients by removing the atrial fibrillatory waves so that the characteristics of ventricle repolarisation components, U and T waves, could be detected and measured accurately without fibrillatory wave contamination.

Having established a validated algorithm to measure the waveform features, the second aim was to use this algorithm to investigate the effect of beat interval dependency on the repolarisation waves, especially U waves, during AF and to compare them to those in sinus rhythm (SR) of healthy subjects. The research could provide mechanistic insight into the origin of U waves since AF is unique in its rapidly changing ventricular beat intervals. The preceding beat interval has a direct impact on ventricular filling dynamics and hence also on mechano-electrical coupling, one of the leading hypotheses of U wave genesis.

Algorithms were developed to remove the contaminating fibrillatory waves in AF recordings and to measure features of the ventricular repolarisation waves.

The ventricular repolarisation features, U and T waves, are measurable and dependent on preceding beat interval in AF and SR. The beat interval dependency of repolarisation features, especially the U wave, supported the mechano-electrical hypothesis during AF and SR.

The research provides tools to facilitate the detection and reporting of U waves and their abnormalities in AF patients and provides mechanistic insight into rate dependency of ventricular repolarisation features.


Al-Karadi, M. S. (2019). Detection and measurement and of repolarisation features in atrial fibrillation and healthy subjects. (Thesis). University of Hull. Retrieved from

Thesis Type Thesis
Deposit Date Feb 24, 2020
Publicly Available Date Feb 23, 2023
Keywords Medical engineering
Public URL
Additional Information Department of Medical Engineering, The University of Hull
Award Date Jul 1, 2019


Thesis (11.1 Mb)

Copyright Statement
© 2019 Al-Karadi, Marwa Saeb. All rights reserved. No part of this publication may be reproduced without the written permission of the copyright holder.

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