Enhancing Fiber Direction Estimation from Electrograms: A Comparative Study and Method Improvement for Clinical and Research Applications

For the heart to pump blood throughout the body, electrical impulses that trigger the cellular contraction must be generated and spread through the myocardial tissue. These signals propagate faster along the longitudinal cardiac fiber direction than the transverse direction, conferring the heart with anisotropic conduction properties. Therefore,...

Location Estimation of Atrial Activity from Epicardial Electrogram measurements

Atrial Fibrillation (AF) is a cardiac arrhythmia that occurs due to the initiation of electrical impulses in the heart in an uncoordinated manner, giving rise to a disorganized and rapid heartbeat. The progression of AF over time can lead to complications such as stroke and heart failure. Catheter ablation is an established treatment protocol...

Array Processing in Atrial Fibrillation: Application of different signal models and LAT estimation techniques

Atrial fibrillation (AF) is the most commonly occurring arrhythmia in clinical practice and can have a significant impact on the current and future wellbeing of the patient. By placing an unipolar sensor array directly on the epicardium during an open-heart surgery to measure the electrical activity of the atrium, more insight about this disease...

Improving the Estimation of Epicardial Activation Times Using Spatial Information

Atrial fibrillation is a common cardiovascular disease, affecting the regular beating of the heart through chaotic contraction of the heart's upper chambers. On its own, the condition—increasingly prevalent among the elderly—is not life threatening, but it leads to an increased risk of stroke and heart failure. As of yet, there is no consensus...

Estimating atrial activity in epicardial electrograms: a beamforming perspective

The most common serious heart rhythm disease is atrial fibrillation. It is not fatal on its own but does increase the risk of heart failures and strokes. There is little understanding about the mechanisms behind the disease, so more insight is desired. Using an array of electrodes, measurements are being performed of the electrical atrial...

The area of a unipolar electrogram to identify the arrhythmogenic substrate

Background: Unipolar electrograms (U-EGMs) contain additional information about interatrial activation and conduction in their morphology, which may aid towards improved diagnosis and staging of atrial fibrillation (AF).Objective: The primary objective is to investigate regional differences in electrogram area (EA) during SR and AF and to design...

Atrial activation time estimation using cross-correlation between higher order neighboring electrodes: In epicardial electrograms

A common cardiac arrhythmia is atrial fibrillation, which is becoming more widespread worldwide. Currently there is some understanding about the mechanisms behind atrial fibrillation, however more insight into the conduction of the atrial tissue is desired. Therefore, invasive mapping studies have been performed where an array of electrodes is...

Multiway Component Analysis for the Removal of Far Ventricular Signal in Unipolar Epicardial Electrograms of Patients with Atrial Fibrillation

Atrial fibrillation (AF) is one of the more common clinical arrhythmias with a high morbidity and mortality. Despite this, the electrophysiological and pathological mechanisms associated with AF largely remain a mystery, encouraging the use of ever more sophisticated techniques to extract vital information for diagnostic and therapeutic purposes...