ECG edition in dual source CT

The following question has been sent by Sofiane Hadjadj, MD, clinical research, Canada:

hi, we have just aquired the dual source ct, and I am very impressed by the quality of images for coro ct even with high calccium scoring, my question is regarding the EKG editing, are their any rules regarding this process for arythmias, which complex has to be deleted, which phase is the best for short rr, etc….
thank in advance for your help.

Stephan Achenback, MD, Professor of Medicine, University of Erlangen-Nuremberg:

There are no specific “rules” as to how to edit the ECG in arrhythmias. Here are some hints:
Usually it is best to exclude the premature, ectopic beat. Since this will change the cycle length of the accepted beats, “ms” triggering (e.g., 300 ms before the R-wave) makes more sense than “%” triggering.
Sometimes a very long interval without any acceptable data can occur if an ectopic pbeat is excluded. (because the table keeps moving, and there may be a gap in the data if too much data is excluded). In this case, two possibilities:
1) You may try to insert an additional synchronization signal just before the next accepted beat, so that TWO image reconstruction windows will be used in the long diastole after the ectopic beat.
2) If you know before the scan that a lot of arrhythmia s to be expected, you may want to enter a heart rate that is substantially lower than the actual heart rate. This slows down table movement and you are less likely to encounter this interpolation problem.
Also, systolic triggering can be useful (e.g., 350 ms after the R wave).

Kind regards
Stephan Achenbach

See another answer to this question by Dr. Juergens

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