T wave alternans (TWA), signal averaged electrocardiography (SAECG, one or two criteria), and combination of TWA and SAECG as predictors of inducible ventricular arrhythmias at electrophysiological testing
| n | Sensitivity | Specificity | PV+ | PV− | RR | Accuracy | p value | |
|---|---|---|---|---|---|---|---|---|
| TWA | 43 | 70% | 88% | 64% | 90% | 6.8 | 84% | < 0.0001 |
| SAECG-I | 35 | 50% | 62% | 21% | 86% | 1.5 | 60% | < 0.29 |
| SAECG-II | 35 | 50% | 76% | 30% | 88% | 2.5 | 71% | < 0.10 |
| TWA+SAECG-I | 43 | 60% | 94% | 75% | 89% | 6.6 | 86% | < 0.0001 |
| TWA+SAECG-II | 43 | 60% | 97% | 86% | 80% | 7.7 | 88% | < 0.0001 |
n, number of cases with a determinate test result; PV+, positive predictive value; PV−, negative predictive value; RR, relative risk.