Fig 1.
The T/QRS ratio is the quotient of T amplitude and QRS amplitude.
Table 1.
Patient characteristics.
Fig 2.
Receiver operating characteristic (ROC) curve of relative ST analysis.
The ROC curve was calculated under non-parametric assumption. The two highlighted points (red dot) represent the cut-offs closest to (0,1) at a relative T/QRS ratio rise of 0.64 (sensitivity 100%, specificity 90%) and 0.70 respectively (sensitivity 90%, specificity 100%).
Fig 3.
Panel A shows an example of an ECG in a control (pH>7.20) at the beginning of the registration (black) and during an absolute (episodic) ST event (grey). The absolute rise in T/QRS ratio here exceeds 0.10, whereas the relative T/QRS rise does not exceed 0.70 (no event). Panel B shows an ECG in a case (pH<7.05) at the beginning of the registration (black) and during a relative ST event (relative rise from baseline is 1.25) (grey). The absolute T/QRS rise is here below 0.05 (no absolute ST event).
Table 2.
Crosstable of relative and absolute ST analysis.
Table 3.
Test performance of absolute and relative ST analysis to detect impending cord acidaemia (pH < 7.05).