COMPAS© Holter Bin

The Holter Bin method compares the QT values for matched narrow “bins” of heart rate. It does not rely on a mathematical heart rate correction method. Holter data is necessary because the method requires a large number of cardiac beats. The COMPAS Holter bin method relies on beat-to-beat measurements of the QT interval for all cardiac beats selected in a given RR bin. It does not depend on a representative or median beat because in some cases a representative beat may not adequately reflect the QT values in a single RR bin. This occurs, for example, if a drug changes the morphology of the T-wave or if a bin includes beats at different plasma concentrations of the drug. When analyzing data from drugs with fast acting profiles, this functionality is critical.

Note on Signal Averaging

Sequential beat-to-beat reading of all QT intervals on Holter monitoring is difficult and very labor-intensive if a reasonable accuracy is to be achieved. For that reason, some older Holter bin methods used signal-averaging of the waveform patterns in each bin, and only subsequently measure the QT interval on the “representative” beat. It should be cautioned that this approach may introduce bias, as the same RR interval may occur during different underlying heart rates. Further, different QRS-T patterns are classified into the same bin, and averaging may potentially distort the accuracy of the signal.