Table 2.
Arrhythmia episodes
| Total | Asystole | Bradycardia | SRD | HVR | AF | |
|---|---|---|---|---|---|---|
| Number of episodes in Holter‐ECG | 272 | 3 | 105 | 25 | 41 | 98 |
| Number of episodes detected by ICM | 315 | 9 | 108 | 26 | 41 | 131 |
| True positive (TP) episodes | 269 | 3 | 105 | 25 | 41 | 95 |
| False positive (FP) episodes | 46 | 6a | 3a | 1a | 0 | 36b |
| False negative (FN) episodes | 3 | 0 | 0 | 0 | 0 | 3c |
| Sensitivity = TP/(TP+FN) | 98.9% | 100% | 100% | 100% | 100% | 96.9% |
| Positive predictive value = TP/(TP+FP) | 85.4% | 33.3% | 97.2% | 96.2% | 100% | 72.5% |
Note. The analysis included 82 patients with adjudicated Holter findings and ICM data. For details on evaluation methodology, see Appendix 1.
a
Due to undersensing.
b
Due to unstable rhythm caused by ventricular extrasystoles or atrial ectopic activity (mimicking R‐R interval irregularity typical for AF), except for one episode of P‐wave oversensing.
c
Three episodes of AF were evident in the Holter‐ECG but were not detected by the ICM in a single patient having AF alternating with periods of atrial flutter, resulting in too many pseudo‐regular intervals.
Abbreviations: AF = atrial fibrillation; ECG = electrocardiogram; ICM = insertable cardiac monitor; HVR = high ventricular rate; SRD = sudden ventricular rate drop.