Atrial Flutter - Science topic

Hi Wasim,

As mentioned above this is usually easy to diagnose by a 12 lead ECG during the episode. If the episodes are intermittent but relatively frequent then a holter or event monitor may help. 

If the episodes are quite infrequent and usually last a few minutes then there are now mobile phone covers which function as ECG electrodes.  An associated app in the phone can save as pdf which can also be emailed to a physician. 

An implantable loop recorder is not usually needed for atrial flutter.

I hope this is helpful to you.

"For non invasive modality such as ECG, ECHO, CT, MRI or PET, how could we differentiate that the atrial remodeling process already occur or not? Any atrial size enlargement was associated with atrial remodeling?"

It is possible to compare the volume of the atria, typically normalized by the body surface area, to various studies that have compared normal versus diseased populations.  However, you raise a significant point about how to differentiate between arrhythmia induced remodeling, and remodeling caused by other comorbidities, such as mitral valve regurgitation, hypertension, etc.  Because of the complex manner in which all of these factors intertwine, I don't think post-hoc attribution of causality is possible for any feature of atrial structural remodeling.  Fortunately, measurement of these features, e.g. fibrosis, or atrial volume, can help determine the best treatment options to pursue.

If you are looking for tools that can help you measure atrial volumes from image data, check out Seg3D.  It is a free image segmentation package that is quite stable and has releases for most major operating systems.  

"For CARTO 3, how could we differentiate between scarred tissue and true atrial remodeling?"

I am not certain what you are looking for here.  If a patient has an atrial arrhythmia (AF), and no prior ablation therapy, I would assume that any abnormal tissue is atrial remodeling.  If the patient has previously undergone an ablation procedure, then there may be a difference between scarred tissue, and remodeled tissues.  If you are interested in trying to classify these tissue types, I would look at work that has been done with voltage mapping.   Marchlinski et al. looked at the amplitude of intracardiac electrograms as a means of classifying different types of cardiac pathology.  Their work has largely focused on ventricular scarring, but I would start there anyway.

Good luck!