Table 2.

Cutoff QTc interval, sensitivity, specificity, and positive and negative predictive values of using awECG for the diagnosis of prolongation of QTc interval and identification of patients with congenital LQTS.

	Cutoff (ms)	AUC	Sensitivity (%)	Specificity (%)	PPV (%)	NPV (%)
Detection of prolongation of QTc
Male
I	454	0.98	100	88.2	80.0	100
II	467	0.99	100	94.4	85.7	100
V5	451	0.99	100	94.4	87.5	100
Female
I	478	0.97	100	88.3	75.0	100
II	464	0.92	100	80.0	75.0	100
V5	476	0.95	100	87.5	80.0	100
Identification of patients with congenital LQTS
Male
I	454	0.98	100	88.2	80.0	100
II	467	0.89	87.5	94.1	87.5	94.1
V5	451	0.87	85.7	94.1	85.7	94.1
Female
I	463	0.99	100	92.3	91.7	100
II	464	0.97	100	92.3	91.7	100
V5	460	0.98	100	92.3	91.7	100

Abbreviations: AUC, area under receiver operating characteristic curve, awECG, Apple Watch electrocardiogram, LQTS, long QT syndrome, NPV, negative predictive value, PPV, positive predictive value.