Nawshin Dastagir - Presenter Profile

Orchestral Cacophony in the Heart: Targeting the Conductor of Atrial Fibrillation Rhythms

In this article, Nawshin Dastagir describes how her research will support more effective treatment of atrial fibrillation.

About My Research

Colour Histograms
Colour histograms are developed to show how fast each region of the heart is beating and so help surgeons identify the area in need of treatment
Atrial fibrillation (AF) is an irregular heart rhythm caused by abnormal, chaotic electrical impulses in the heart’s upper chambers, the atria. These electrical impulses, which interfere with the heart’s natural pacemaker, fire so rapidly the atria cannot beat with a regular rhythm or squeeze out blood effectively. Instead, they merely quiver while the ventricles, the heart’s lower chambers, beat rapidly. Healthy atria contract 60-80 times per minute, whereas a fibrillating atria quiver at 300-400 times per minute.

One effective treatment for AF is catheter ablation, whereby areas in the atria and/or nearby locations are targeted and ablated (or “burned”). However, results are variable, with a number of patients requiring repeated procedures if AF recurs in the short term. Long term results are even less encouraging. One of the main issues with ablation is the decision on where to ablate for maximum efficacy and safety. Therefore the research is focusing on improving understanding of the precise electrical mechanisms underlying AF and therefore coming up with strategies that would help in minimising the amount of “burning” with ablation and maximizing the improvement.

It is important that information is available to aid ablation decision and strategy either before or during the ablation procedure. It is also important that techniques and technologies to characterize and map candidate locations for ablation are developed up to the stage when they can be implemented in real-time. For this research, initially, we collect signals from AF patient’s heart using a thin flexible wire with small electrodes known as catheter. This unique tool simplifies the electrical phenomena of the heart by collecting more than 3,000 points of electrical data in a single heartbeat. The research analysis then emphasise on signal processing of these electrical signals, with particular interest in identifying the abnormal electrical activation of the heart, especially the atria in AF. For the off-line aspects of the research we use MATLAB programming. To recognise the abnormal electrical activation in AF, the research has used frequency analysis to determine how fast AF conductor forces the heart to beat. This is called the dominant frequency of AF. The locations of dominant frequency in the atria are looked into in multiple time points and colour histograms are developed to show the regions which are beating the fastest or vice versa.

My Research Findings

In the UK, more than 1 million people are affected by a heart rhythm disease. This type of disease can have a severe impact on life quality. It can also lead to death. The expenses for heart rhythm diseases cost the NHS £1 billion each year. Hence, it is very important to have a correct diagnosis and treatment of heart rhythm disease patients.

Although heart rhythm disturbance in AF is not life threatening, there is an increased risk of stroke or heart failure for some patients. AF is present in one of every five cases of stroke, according to the American Heart Association. A study also noted an increased risk for sudden cardiac death in patients with AF. There are medicines to control AF known as anti arrhythmics. They help by restoring the normal heart rhythm or by controlling the rate at which the heart beats. However they might have side effects and also may not respond well to AF. Some patients need to need to undergo catheter ablation to terminate AF where the clinicians destroy the tissue by using energy source such as high frequency radio waves. It is also very important to identify the reasons or methods that are sustaining AF. Therefore this part of research on AF is very important as it contributes to knowledge and progress on AF and also to identify the fastest and safest way to find treatments that would lead to higher success rate in terminating AF.

So far the results of this research show clinicians the best areas to perform their ablation and removing the AF conductor. This research is expected to improve the success of current AF treatment while reducing the risk of patients to lose healthy heart regions and also to reduce the chances of having stroke. The research is also combining the different parameters to identify AF and also finding their relationships in order to develop an effective ablation strategy.

Therefore the main goals of this research are to understanding the electrophysiology mechanisms of the heart muscles during AF and also to help with its treatment by providing the an idea and technique that will help the clinicians to identify and remove the arrhythmia "triggers" causing the heart to fibrillate, and thus maintain normal a heart rhythm of the patients.

About Nawshin Dastagir

NawNawshin Dastagir - PhD Student at the University of Leicester (2015)shin Dastagir is a research student working towards completion of her doctoral degree in the Department of Cardiovascular Sciences. Nawshin is supervised by Professor G Andre Ng and Dr Fernando S Schlindwein.

Nawshin will present her work at the Festival of Postgraduate Research 6 July 2015 - see Nawshin's Festival poster.

The Festival is open to all members of the University community and the public - book your place here.

Contact Nawshin

Department of Cardiovascular Sciences

University of Leicester

University Road

LEICESTER

LE1 7RH

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