Ibutilide and novel indexes of ventricular repolarization in persistent atrial fibrillation patients

Table 1 Baseline and clinical charactersistics of the study population

Patients’ characteristics	Value
Age (yr)	67.1 ± 9.9
Men	50%
Duration of atrial fibrillation (d)	94 ± 51
Baseline heart rate (beats per minute)	87 ± 19
Hypertension	65%
Diabetes	30%
Coronary artery disease	25%
Left ventricular ejection fraction	58% ± 7%
Left atrial diameter (mm)	41.7 ± 4.3
Sodium (mEq/L)	139.0 ± 3.0
Potassium (mEq/L)	4.4 ± 0.4

Table 2 Electrocardiographic variables before and after ibutilide infusion

Variables	Before ibutilide	After ibutilide	P value
QTc (ms)	442 ± 29	471 ± 37	0.037
Tpe in lead II (ms)	79 (70-88)	100 (87-104)	< 0.001
Tpe in precordial leads (ms)	96 (80-108)	101 (91-119)	0.021
Tpe dispersion (ms)	25 (23-30)	35 (27-39)	0.012
Tpe/QT in lead II	0.22 (0.18-0.24)	0.24 (0.22-0.28)	0.12
Tpe/QT in precordial leads	0.23 (0.18-0.26)	0.26 (0.23-0.28)	0.028

The parameters are presented as means ± SD or as median values (25^th-75^th percentile). QTc: Corrected QT interval; Tpe: T peak-to-end.