Shamir Rai BSC, Presenter: Nothing to Disclose

Chesnal Dey Arepalli MD, Abstract Co-Author: Nothing to Disclose

Patrick McLaughlin FFR(RCSI), Abstract Co-Author: Nothing to Disclose

Savvas Nicolaou MD, Abstract Co-Author: Nothing to Disclose

Detailed anatomic imaging of the cardiac structures is challenging in atrial fibrillation (AF) patients. Computerized tomography (CT) prospective ECG triggered absolute delay based on fixed time interval from R wave are least subjected to mis-registration and motion artifacts. A new absolute prospective ECG triggered Atrial fibrillation (AFb) algorithm with a fixed delay of 250 ms after the R wave was developed at our institute. The purpose of our study was to assess diagnostic quality of cardiac (coronary and non-coronary) and extra cardiac structures utilizing AFb algorithm.

15 consecutive atrial fibrillation patients who had AFb algorithm prior to their LAA ablation procedure were identified retrospectively. Images were acquired on a second generation dual source 128 slice scanner with 110 ml of Omnipaque 350. Cardiac structures evaluation included the four chambers, mitral and aortic valves; coronary arteries (CA) and extra cardiac structures included pulmonary veins, lung parenchyma and fissures and thoracic aorta. CA evaluation was based on 17-segment model as defined by American Heart Association. Each anatomic structure was graded for image quality by two blinded independent radiologists (1, non-diagnostic; 2, decreased image quality, unlikely to be diagnostic; 3, decreased image quality with potential to be diagnostic; 4, decreased image quality but diagnostic; 5, diagnostic study).

The mean heart rate (HR) for the studies analyzed was 70 ± 19; maximum HR was 94 ± 41. Both reader 1 and reader 2 had an excellent interobserver agreement with a median score of 5 ± 0 and 5 ± 1 for cardiac structures and median scores of 5 ± 0.for non-cardiac structures.

AFb algorithm based on prospective ECG triggered absolute delay method at 250 ms from R wave assess the essential anatomical cardiac structures relevant to AF ablative procedure. Further, diagnostic quality coronary arteries assessment is also feasible with the AFb algorithm.

In atrial fibrillation patients, optimized prospective ECG triggered absolute delay protocol can simultaneously evaluate cardiac structures including coronary arteries. This algorithm has the potential to replace the prospective ECG gated diastolic phase study that is utilized to assess the coronary arteries.

Rai, S, Arepalli, C, McLaughlin, P, Nicolaou, S, Clinical Utility of Prospective ECG Triggered Absolute Fixed Delay in Atrial Fibrillation Patients in the Assessment of Cardiac Structures and Coronary Anatomy.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14018802.html