Quantitative Evaluation of the Relationship between T-Wave-Based Features and Serum Potassium Level in Real-World Clinical Practice

Table 1

Baseline characteristics of the subjects.

Variable	Total	Normal ECG subgroup
No. of patients, n	330	231
Age (years), mean±SD	47.6±17.2	45.9±15.1
Male sex, n (%)	140 (42.4)	89 (38.5)
Potassium level (mmol/L), mean±SD	4.17±0.39	4.35±0.59
No. of normal sinus rhythms, n (%)	254 (77.0)	191 (82.7)
No. of normal ECG, n (%)	231 (70.0)	231 (100.0)
Amplitude of T-wave (mV), mean±SD
Lead II	0.23±0.11	0.24±0.10
Lead V3	0.43±0.24	0.42±0.23
Lead V4	0.40±0.22	0.39±0.20
Lead V5	0.38±0.19	0.37±0.17
Lead V6	0.32±0.16	0.32±0.14
Gradient of T-wave (mV/s), mean±SD
Lead II	-3.06±1.51	-3.1±1.39
Lead V3	-5.13±3.18	-5.02±3.07
Lead V4	-5.02±3.13	-4.93±2.88
Lead V5	-4.81±2.78	-4.78±2.49
Lead V6	-4.21±2.30	-4.24±2.07

SD: standard deviation; no.: number; ECG: electrocardiogram. Normal ECG or otherwise normal ECG.