Cardiol Res

Cardiology Research, ISSN 1923-2829 print, 1923-2837 online, Open Access

Article copyright, the authors; Journal compilation copyright, Cardiol Res and Elmer Press Inc

Journal website https://www.cardiologyres.org

Original Article

Volume 12, Number 1, February 2021, pages 37-46

Evaluation of Index of Cardio-Electrophysiological Balance in Patients With Atrial Fibrillation on Antiarrhythmic-Drug Therapy

Figure 1. Tp-e and cTp-e intervals in drug and control groups. Tp-e: T wave peak-to-end; cTp-e: corrected Tp-e.

Figure 2. Tp-e/QT and Tp-e/QTc rates in drug and control groups. Tp-e: T wave peak-to-end; Tp-e/QTc: corrected Tp-e/QT.

Figure 3. iCEB and iCEBc values in drug and control groups. iCEB: index of cardio-electrophysiological balance; iCEBc: corrected iCEB.

**Table 1.** Demographic Features, Comorbidities, Drug Use and Some Laboratory Parameters of the Amiodarone, Propafenone and Control Groups
	Amiodarone (n = 68)	Propafenone (n = 40)	Control (n = 50)	P value
^aDepending on the expected count, Pearson Chi-square, Fisher exact or Fisher-Freeman-Halton test was used. Descriptive statistics were presented as number (%). ^bOne-way ANOVA was used. Descriptive statistics were presented as mean ± standard deviation. ^cMann-Whitney U test was used. Descriptive statistics were presented as median (IQR). ACE: angiotensin-converting enzyme; ARB: angiotensin receptor blocker; NOAC: new oral anticoagulants; TSH: thyroid-stimulating hormone; IQR: interquartile range.
Sex (%)
Female, n (%)	30 (44.1)	21 (52.5)	26 (52.0)	0.600^a
Male, n (%)	38 (55.9)	19 (47.5)	24 (48.0)
Age (years)	65.3 ± 7.3	62.9 ± 5.5	62.7 ± 4.4	0.051^b
Smoking (%)	16 (23.5)	6 (15.0)	8 (16.0)	0.445^a
Duration of drug use (median (IQR))	20.5 (16.0 - 29.0)	19.0 (13.8 - 23.0)	-	0.034^c
Type of atrial fibrillation
Paroxysmal	57 (83.8)	34 (85)	-	0.087^a
Persistent	11 (16.2)	6 (15)	-	0.088^a
Comorbidities
Heart failure (%)
Ischemic heart failure	25 (36.8)	0 (0.0)	-	< 0.001^a
Non-ischemic heart failure	10 (14.7)	1 (2.5)	-	0.043^a
Hypertension (%)	48 (70.6)	20 (50.0)	-	0.053^a
Coronary artery disease (%)	38 (55.9)	8 (20.0)	-	0.001^a
Stroke (%)	12 (17.6)	1 (2.5)	-	0.029^a
Diabetes mellitus (%)	23 (33.8)	15 (37.5)	-	0.859^a
Concurrent medication use
Beta-blocker (%)	55 (80.9)	37 (92.5)	-	0.174^a
Calcium channel blocker (%)	7 (10.3)	3 (7.5)	-	0.742^a
ACE inhibitor/ARB (%)	59 (86.8)	22 (55.0)	-	0.001^a
Spironolactone (%)	13 (19.1)	0 (0.0)	-	0.002^a
NOAC (%)	30 (44.1)	16 (40)	-	0.676^a
Warfarin (%)	14 (20)	5 (12)	-	0.286^a
Aspirin (%)	20 (29)	9 (22.0)	-	0.434^a
Clopidogrel (%)	6 (8.8)	2 (5)	-	0.707^a
Laboratory parameters
Serum calcium (mg/dL)	9.5 ± 0.6	9.8 ± 0.5	9.7 ± 0.5	0.158^b
Serum potassium (mEq/L)	4.2 ± 0.3	4.2 ± 0.3	4.2 ± 0.3	0.783^b
Aspartate aminotransferase (U/L)	22.2 ± 5.3	24.7 ± 5.8	23.9 ± 6.6	0.068^b
Alanine aminotransferase (U/L)	23.3 ± 6.2	25.0 ± 5.9	24.0 ± 7.2	0.374^b
TSH (µU/mL) (median (IQR))	2.4 (1.6 - 3.5)	2.5 (1.9 - 3.5)	2.3 (1.7 - 3.1)	0.493
Risk score
CHA₂DS₂-VASc score (median (IQR))	3.0 (2.8 - 4.0)	2.0 (1.0 - 3.0)	-	< 0.001^c

Table 1. Demographic Features, Comorbidities, Drug Use and Some Laboratory Parameters of the Amiodarone, Propafenone and Control Groups

Amiodarone (n = 68)

Propafenone (n = 40)

Control (n = 50)

P value

^aDepending on the expected count, Pearson Chi-square, Fisher exact or Fisher-Freeman-Halton test was used. Descriptive statistics were presented as number (%). ^bOne-way ANOVA was used. Descriptive statistics were presented as mean ± standard deviation. ^cMann-Whitney U test was used. Descriptive statistics were presented as median (IQR). ACE: angiotensin-converting enzyme; ARB: angiotensin receptor blocker; NOAC: new oral anticoagulants; TSH: thyroid-stimulating hormone; IQR: interquartile range.

Sex (%)

Female, n (%)

30 (44.1)

21 (52.5)

26 (52.0)

0.600^a

Male, n (%)

38 (55.9)

19 (47.5)

24 (48.0)

Age (years)

65.3 ± 7.3

62.9 ± 5.5

62.7 ± 4.4

0.051^b

Smoking (%)

16 (23.5)

6 (15.0)

8 (16.0)

0.445^a

Duration of drug use (median (IQR))

20.5 (16.0 - 29.0)

19.0 (13.8 - 23.0)

0.034^c

Type of atrial fibrillation

Paroxysmal

57 (83.8)

34 (85)

0.087^a

Persistent

11 (16.2)

6 (15)

0.088^a

Comorbidities

Heart failure (%)

Ischemic heart failure

25 (36.8)

0 (0.0)

< 0.001^a

Non-ischemic heart failure

10 (14.7)

1 (2.5)

0.043^a

Hypertension (%)

48 (70.6)

20 (50.0)

0.053^a

Coronary artery disease (%)

38 (55.9)

8 (20.0)

0.001^a

Stroke (%)

12 (17.6)

1 (2.5)

0.029^a

Diabetes mellitus (%)

23 (33.8)

15 (37.5)

0.859^a

Concurrent medication use

Beta-blocker (%)

55 (80.9)

37 (92.5)

0.174^a

Calcium channel blocker (%)

7 (10.3)

3 (7.5)

0.742^a

ACE inhibitor/ARB (%)

59 (86.8)

22 (55.0)

0.001^a

Spironolactone (%)

13 (19.1)

0 (0.0)

0.002^a

NOAC (%)

30 (44.1)

16 (40)

0.676^a

Warfarin (%)

14 (20)

5 (12)

0.286^a

Aspirin (%)

20 (29)

9 (22.0)

0.434^a

Clopidogrel (%)

6 (8.8)

2 (5)

0.707^a

Laboratory parameters

Serum calcium (mg/dL)

9.5 ± 0.6

9.8 ± 0.5

9.7 ± 0.5

0.158^b

Serum potassium (mEq/L)

4.2 ± 0.3

0.783^b

Aspartate aminotransferase (U/L)

22.2 ± 5.3

24.7 ± 5.8

23.9 ± 6.6

0.068^b

Alanine aminotransferase (U/L)

23.3 ± 6.2

25.0 ± 5.9

24.0 ± 7.2

0.374^b

TSH (µU/mL) (median (IQR))

2.4 (1.6 - 3.5)

2.5 (1.9 - 3.5)

2.3 (1.7 - 3.1)

0.493

Risk score

CHA₂DS₂-VASc score (median (IQR))

3.0 (2.8 - 4.0)

2.0 (1.0 - 3.0)

< 0.001^c

**Table 2.** Echocardiographic and Electrocardiographic Parameters of Amiodarone, Propafenone and Control Groups
	Amiodarone (n = 68)	Propafenone (n = 40)	Control (n = 50)	P value
*Depending on the expected count, Pearson Chi-square, Fisher exact or Fisher-Freeman-Halton test was used. Descriptive statistics were presented as number (%). Multiple comparisons were marked with superscript letters in the table. As same letters notify no significant difference between the groups, different letters mean a significant difference between the groups. Tp-e: T wave peak-to-end; iCEB: index of cardio-electrophysiological balance; iCEBc: corrected iCEB; LVEF: left ventricular ejection fraction; LA: left atrial; IVS: interventricular septum; PW: posterior wall; VT: ventricular tachycardia; TdP: torsades de pointes; Tp-e: transmural dispersion of repolarisation; cTp-e: corrected Tp-e.
Echocardiographic parameters
Heart rate (beat per minute)	72.1 ± 10.8	73.0 ± 11.4	75.8 ± 13.3	0.278
QRS (ms)	94.8 ± 13.0^a	100.5 ± 13.2^b	90.7 ± 6.7^a	< 0.001
QT interval (ms)	412.1 ± 37.0^a	384.1 ± 30.7^b	377.5 ± 26.8^b	< 0.001
QTc interval (ms)	450.1 ± 27.5^a	421.8 ± 25.3^b	412.1 ± 23.6^b	< 0.001
Tp-e interval (ms)	85.2 ± 18.9^a	69.9 ± 10.3^b	66.5 ± 10.6^b	< 0.001
Tp-e/QT ratio	0.20 (0.18 - 0.22)^a	0.18 (0.16 - 0.20)^b	0.17 (0.15 - 0.20)^b	< 0.001
cTp-e interval (ms)	93.8 ± 20.3^a	78.6 ± 13.7^b	75.1 ± 11.8^b	< 0.001
Tp-e/QTc ratio	0.18 (0.16 - 0.20)^a	0.16 (0.15 - 0.19)^b	0.16 (0.14 - 0.18)^b	< 0.001
iCEB	4.4 ± 0.6^a	3.9 ± 0.5^b	4.2 ± 0.4^a	< 0.001
iCEBc	4.8 ± 0.6^a	4.3 ± 0.6^b	4.6 ± 0.4^c	< 0.001
Echocardiography parameters
LVEF (median (IQR)) (%)	50.0 (35.0 - 55.0)^a	55.0 (53.0 - 55.0)^b	56.0 (55.0 - 60.0)^b	< 0.001
LA diameter (cm)	4.6 ± 0.6^a	4.0 ± 0.3^b	3.7 ± 0.3^c	< 0.001
IVS thickness (mm)	11.7 ± 1.1^a	11.0 ± 0.8^a	10.1 ± 1.0^b	< 0.001
PW thickness (mm)	10.6 ± 1.1^a	10.1 ± 1.0^a	9.0 ± 1.0^b	< 0.001
Advers events
TdP (%)	1 (1.5)	0 (0.0)	-	0.999*
Non-sustained VT (%)	0 (0.0)	1 (2.5)	-	0.370*

Table 2. Echocardiographic and Electrocardiographic Parameters of Amiodarone, Propafenone and Control Groups

Amiodarone (n = 68)

Propafenone (n = 40)

Control (n = 50)

P value

*Depending on the expected count, Pearson Chi-square, Fisher exact or Fisher-Freeman-Halton test was used. Descriptive statistics were presented as number (%). Multiple comparisons were marked with superscript letters in the table. As same letters notify no significant difference between the groups, different letters mean a significant difference between the groups. Tp-e: T wave peak-to-end; iCEB: index of cardio-electrophysiological balance; iCEBc: corrected iCEB; LVEF: left ventricular ejection fraction; LA: left atrial; IVS: interventricular septum; PW: posterior wall; VT: ventricular tachycardia; TdP: torsades de pointes; Tp-e: transmural dispersion of repolarisation; cTp-e: corrected Tp-e.

Echocardiographic parameters

Heart rate (beat per minute)

72.1 ± 10.8

73.0 ± 11.4

75.8 ± 13.3

0.278

QRS (ms)

94.8 ± 13.0^a

100.5 ± 13.2^b

90.7 ± 6.7^a

< 0.001

QT interval (ms)

412.1 ± 37.0^a

384.1 ± 30.7^b

377.5 ± 26.8^b

< 0.001

QTc interval (ms)

450.1 ± 27.5^a

421.8 ± 25.3^b

412.1 ± 23.6^b

< 0.001

Tp-e interval (ms)

85.2 ± 18.9^a

69.9 ± 10.3^b

66.5 ± 10.6^b

< 0.001

Tp-e/QT ratio

0.20 (0.18 - 0.22)^a

0.18 (0.16 - 0.20)^b

0.17 (0.15 - 0.20)^b

< 0.001

cTp-e interval (ms)

93.8 ± 20.3^a

78.6 ± 13.7^b

75.1 ± 11.8^b

< 0.001

Tp-e/QTc ratio

0.18 (0.16 - 0.20)^a

0.16 (0.15 - 0.19)^b

0.16 (0.14 - 0.18)^b

< 0.001

iCEB

4.4 ± 0.6^a

3.9 ± 0.5^b

4.2 ± 0.4^a

< 0.001

iCEBc

4.8 ± 0.6^a

4.3 ± 0.6^b

4.6 ± 0.4^c

< 0.001

Echocardiography parameters

LVEF (median (IQR)) (%)

50.0 (35.0 - 55.0)^a

55.0 (53.0 - 55.0)^b

56.0 (55.0 - 60.0)^b

< 0.001

LA diameter (cm)

4.6 ± 0.6^a

4.0 ± 0.3^b

3.7 ± 0.3^c

< 0.001

IVS thickness (mm)

11.7 ± 1.1^a

11.0 ± 0.8^a

10.1 ± 1.0^b

< 0.001

PW thickness (mm)

10.6 ± 1.1^a

10.1 ± 1.0^a

9.0 ± 1.0^b

< 0.001

Advers events

TdP (%)

1 (1.5)

0 (0.0)

0.999*

Non-sustained VT (%)

0 (0.0)

1 (2.5)

0.370*

**Table 3.** Demographic Features, Electrocardiographic and Echocardiographic Parameters of the Whole Atrial Fibrillation and Control Subjects
	Atrial fibrillation (n = 108)	Control (n = 50)	P value
iCEB: index of cardio-electrophysiological balance; iCEBc: corrected iCEB; LVEF: left ventricular ejection fraction; LA: left atrial; Tp-e: T wave peak-to-end; cTp-e: corrected Tp-e.
Sex (%)			0.698
Female, n (%)	51 (47.2)	26 (52.0)
Male, n (%)	57 (52.8)	24 (48.0)
Age (years)	64.4 ± 6.7	62.7 ± 4.4	0.112
Smoking (%)	22 (20.4)	8 (16.0)	0.515
Electrocardiographic parameters
Heart rate (beats per minute)	72.4 ± 10.9	75.8 ± 13.3	0.121
QRS (ms)	96.9 ± 13.3	90.7 ± 6.7	< 0.001
QT interval (ms)	401.7 ± 37.2	377.5 ± 26.8	< 0.001
QTc interval (ms)	439.6 ± 29.9	412.1 ± 23.6	< 0.001
Tp-e interval (ms)	79.5 ± 17.8	66.5 ± 10.6	< 0.001
cTp-e interval (ms)	88.2 ± 19.5	75.1 ± 11.8	< 0.001
Tp-e/QT ratio	0.20 (0.17 - 0.22)	0.17 (0.15 - 0.20)	0.001
Tp-e/QTc ratio	0.18 (0.15 - 0.19)	0.16 (0.14 - 0.18)	0.001
iCEB	4.2 ± 0.6	4.2 ± 0.4	0.740
iCEBc	4.6 ± 0.7	4.6 ± 0.4	0.602
Echocardiography parameters
LVEF (median (IQR)) (%)	54.0 (44.5 - 55.0)	56.0 (55.0 - 60.0)	< 0.001
LA diameter (cm)	4.4 ± 0.6	3.7 ± 0.3	< 0.001

Table 3. Demographic Features, Electrocardiographic and Echocardiographic Parameters of the Whole Atrial Fibrillation and Control Subjects

Atrial fibrillation (n = 108)

Control (n = 50)

P value

iCEB: index of cardio-electrophysiological balance; iCEBc: corrected iCEB; LVEF: left ventricular ejection fraction; LA: left atrial; Tp-e: T wave peak-to-end; cTp-e: corrected Tp-e.

Sex (%)

0.698

Female, n (%)

51 (47.2)

26 (52.0)

Male, n (%)

57 (52.8)

24 (48.0)

Age (years)

64.4 ± 6.7

62.7 ± 4.4

0.112

Smoking (%)

22 (20.4)

8 (16.0)

0.515

Electrocardiographic parameters

Heart rate (beats per minute)

72.4 ± 10.9

75.8 ± 13.3

0.121

QRS (ms)

96.9 ± 13.3

90.7 ± 6.7

< 0.001

QT interval (ms)

401.7 ± 37.2

377.5 ± 26.8

< 0.001

QTc interval (ms)

439.6 ± 29.9

412.1 ± 23.6

< 0.001

Tp-e interval (ms)

79.5 ± 17.8

66.5 ± 10.6

< 0.001

cTp-e interval (ms)

88.2 ± 19.5

75.1 ± 11.8

< 0.001

Tp-e/QT ratio

0.20 (0.17 - 0.22)

0.17 (0.15 - 0.20)

0.001

Tp-e/QTc ratio

0.18 (0.15 - 0.19)

0.16 (0.14 - 0.18)

0.001

iCEB

4.2 ± 0.6

4.2 ± 0.4

0.740

iCEBc

4.6 ± 0.7

4.6 ± 0.4

0.602

Echocardiography parameters

LVEF (median (IQR)) (%)

54.0 (44.5 - 55.0)

56.0 (55.0 - 60.0)

< 0.001

LA diameter (cm)

4.4 ± 0.6

3.7 ± 0.3

< 0.001