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. 2010 Jun 16;10:28. doi: 10.1186/1471-2261-10-28

Table 3.

Accuracies and Predictive Values of Pooled Conventional versus A-ECG Criteria in the Test Set

Disease
(N = 208)
Healthy
(N = 107)
TP FN TN FP Sensitivity(CLs) Specificity(CLs) Accuracy(CLs)
Conventional ECG status
Abnormal (optimized pooled criteria) 163 45 91 16 78%(72-84%) 85%(77-91%) 81%(76-85%)
Best individual parameter status*
Abnormal QTVI in lead II (>-1.64 units) 161 47 87 20 77%(71-83%) 81%(73-88%) 79%(74-83%)
Best 1° A-ECG scores status*
"Full Disclosure" (5-min) A-ECG:
Abnormal 9-parameter score 185 23 98 9 89%(84-93%)‡ 92%(85-96%) 90%(86-93%)†
Abnormal 7-parameter score 194 16 101 6 92%(88-96%)‡ 94%(88-98%)† 93%(90-96%)†
"Snapshot" (10-sec) A-ECG:
Abnormal 7-parameter score 192 16 92 15 92%(88-96%)‡ 86%(78-92%) 90%(86-93%)†
Disease
+LVSD
(N = 41)
Disease
no LVSD
(N = 44)
TP FN TN FP PPV (CLs) NPV (CLs) +LR -LR
Conventional ECG status
Abnormal (optimized pooled criteria) 39 2 10 34 53%(41-65%) 83%(51-98%) 1.23 0.21
Best individual parameter status*
Abnormal Z integral (>12.4 mV*ms) 28 13 31 13 68%(52-82%) 70%(55-83%) 2.31 0.45
Best 2° A-ECG scores status*
Abnormal 5-parameter score 34 7 41 3 92%(78-98%)‡ 85%(72-94%) 12.16 0.18

A-ECG, advanced ECG; LVSD, left ventricular systolic dysfunction; TP and FP, true and false positives; TN and FN, true and false negatives; CLs, exact 95% binomial confidence limits; PPV and NPV, positive and negative predictive values; +LR and -LR, positive and negative likelihood ratios; QTVI, the QT interval variability index; Z integral, the total integral of the Z-lead QRS complex above 5 Hz.

*The best individual parameters and their cut-off values and the best A-ECG scores are all carried over from the training set and are not necessarily fully optimized with respect to the test set.

†P < 0.05 and ‡P < 0.0001 versus the optimized pooled conventional ECG criteria.