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 15, Number 2, April 2024, pages 99-107

Optimizing Patient Selection for Physiological Pacing in Bradyarrhythmia: Factors Associated With High Ventricular Pacing Burden

Figure 1. Box and whisker chart demonstrating the progression of VP% burden over 3 years in group 1 and group 2 individually. “X” represents the average value, while the box and the additional line contained within the box represent median and interquartile range. VP: ventricular pacing.

**Table 1.** Past Medical History and Medication
Variable	VP% < 20% (n = 82), frequency (%) or median (IQR)	VP% ≥ 20% (n = 154), frequency (%) or median (IQR)	P-value
*P < 0.05. ACEi: angiotensin-converting enzyme inhibitor; ARB: angiotensin receptor blocker; CABG: coronary artery bypass grafting; DOAC: direct oral anticoagulant; IQR: interquartile range; MRA: mineralocorticoid receptor antagonist; PCI: percutaneous coronary intervention; PVD: peripheral vascular disease; TIA: transient ischemic attack; VP: ventricular pacing.
Past medical history
Sex
Male	42 (52.2%)	102 (66.2%)	0.021*
Female	40 (47.8%)	52 (32.8%)
Age at implant	77 (68 - 82)	77.5 (72.5 - 84)	0.059
Hypertension	52 (63.4%)	87 (56.5%)	0.12
Diabetes	16 (19.5%)	32 (20.8%)	0.24
PCI	21 (25.6%)	32 (20.8%)	0.87
CABG	4 (4.9%)	16 (10.4%)	0.048*
Stroke/TIA	19 (23.2%)	22 (14.3%)	0.40
PVD	4 (4.9%)	11 (7.1%)	0.25
Dyslipidemia	55 (67%)	81 (52.6%)	0.95
Atrial fibrillation	29 (35.4%)	59 (38.3%)	0.052
Medication
Antiplatelet	54 (65.9%)	72 (46.7%)	0.44
Beta-blocker	43 (52.4%)	62 (40.3%)	0.96
Antiarrhythmic (class 1)	0 (0%)	1 (100%)	0.40
Antiarrhythmic (class 3)	9 (11%)	13 (8.4%)	0.99
Calcium channel blocker	22 (26.8%)	35 (22.7%)	0.73
DOAC/warfarin	26 (31.7%)	50 (32.5%)	0.14
ACEi/ARB	41 (50%)	61 (39.6%)	0.93
MRA	6 (7.3%)	16 (10.4%)	0.08
Statin	63 (76.8%)	91 (59.1%)	0.95

Table 1. Past Medical History and Medication

Variable

VP% < 20% (n = 82), frequency (%) or median (IQR)

VP% ≥ 20% (n = 154), frequency (%) or median (IQR)

P-value

*P < 0.05. ACEi: angiotensin-converting enzyme inhibitor; ARB: angiotensin receptor blocker; CABG: coronary artery bypass grafting; DOAC: direct oral anticoagulant; IQR: interquartile range; MRA: mineralocorticoid receptor antagonist; PCI: percutaneous coronary intervention; PVD: peripheral vascular disease; TIA: transient ischemic attack; VP: ventricular pacing.

Past medical history

Sex

Male

42 (52.2%)

102 (66.2%)

0.021*

Female

40 (47.8%)

52 (32.8%)

Age at implant

77 (68 - 82)

77.5 (72.5 - 84)

0.059

Hypertension

52 (63.4%)

87 (56.5%)

0.12

Diabetes

16 (19.5%)

32 (20.8%)

0.24

PCI

21 (25.6%)

32 (20.8%)

0.87

CABG

4 (4.9%)

16 (10.4%)

0.048*

Stroke/TIA

19 (23.2%)

22 (14.3%)

0.40

PVD

4 (4.9%)

11 (7.1%)

0.25

Dyslipidemia

55 (67%)

81 (52.6%)

0.95

Atrial fibrillation

29 (35.4%)

59 (38.3%)

0.052

Medication

Antiplatelet

54 (65.9%)

72 (46.7%)

0.44

Beta-blocker

43 (52.4%)

62 (40.3%)

0.96

Antiarrhythmic (class 1)

0 (0%)

1 (100%)

0.40

Antiarrhythmic (class 3)

9 (11%)

13 (8.4%)

0.99

Calcium channel blocker

22 (26.8%)

35 (22.7%)

0.73

DOAC/warfarin

26 (31.7%)

50 (32.5%)

0.14

ACEi/ARB

41 (50%)

61 (39.6%)

0.93

MRA

6 (7.3%)

16 (10.4%)

0.08

Statin

63 (76.8%)

91 (59.1%)

0.95

**Table 2.** Admission ECG and Pre-Implant Echo Parameters
Variable	VP% < 20% (n = 82), frequency (%) or median (IQR)	VP% ≥ 20% (n = 129), frequency (%) or median (IQR)	P-value
AS: aortic stenosis; ECG: electrocardiogram; EDD: end-diastolic diameter; LA: left atrial; LV: left ventricular; MR: mitral regurgitation; RA: right atrial; RV: right ventricular; TR: tricuspid regurgitation; VP: ventricular pacing.
Admission ECG
Sinus rhythm	48 (58.5%)	67 (51.9%)	0.63
Atrial fibrillation/flutter	21 (25.6%)	28 (21.7%)	0.71
Other	13 (15.8%)	34 (26.4%)	0.81
Heart rate (bpm), median (IQR)	57.5 (40 - 70)	58 (42 - 65)	0.99
PR interval (ms), median (IQR)	190 (160 - 240)	200 (160 - 236)	0.45
QRS (ms), median (IQR)	108 (94 - 139)	107.5 (95.5 - 128.5)	0.53
QTc (ms), median (IQR)	430 (400 - 451)	420.5 (400 - 442.5)	0.27
Echocardiogram	VP% < 20% (n = 73), frequency (%)	VP% ≥ 20% (n = 115), frequency (%)	P-value
LV function			0.48
Normal LV function	57 (78.1%)	84 (73%)
Mildly impaired	12 (16.4%)	19 (16.5%)
Moderately impaired	1 (1.4%)	7 (6.2%)
Severely impaired	3 (4.1%)	5 (4.3%)
LV EDD			0.82
Normal	66 (90.4%)	101 (87.8%)
Increased	7 (9.6%)	14 (12.2%)
LA size			0.22
Normal	46 (63%)	62 (53.9%)
Enlarged	27 (37%)	53 (46.1%)
RV size			0.22
Normal	62 (84.9%)	90 (78.2%)
Enlarged	10 (15.1%)	24 (21.8%)
RA size			0.09
Normal	61 (83.6%)	83 (72.2%)
Enlarged	12 (16.4%)	31 (17.8%)
Moderate+ TR	6 (8.2%)	18 (15.6%)	0.14
Moderate+ MR	10 (13.7%)	16 (13.9%)	0.95
Moderate+ AS	3 (4.1%)	12 (10.4%)	0.12

Table 2. Admission ECG and Pre-Implant Echo Parameters

Variable

VP% < 20% (n = 82), frequency (%) or median (IQR)

VP% ≥ 20% (n = 129), frequency (%) or median (IQR)

P-value

AS: aortic stenosis; ECG: electrocardiogram; EDD: end-diastolic diameter; LA: left atrial; LV: left ventricular; MR: mitral regurgitation; RA: right atrial; RV: right ventricular; TR: tricuspid regurgitation; VP: ventricular pacing.

Admission ECG

Sinus rhythm

48 (58.5%)

67 (51.9%)

0.63

Atrial fibrillation/flutter

21 (25.6%)

28 (21.7%)

0.71

Other

13 (15.8%)

34 (26.4%)

0.81

Heart rate (bpm), median (IQR)

57.5 (40 - 70)

58 (42 - 65)

0.99

PR interval (ms), median (IQR)

190 (160 - 240)

200 (160 - 236)

0.45

QRS (ms), median (IQR)

108 (94 - 139)

107.5 (95.5 - 128.5)

0.53

QTc (ms), median (IQR)

430 (400 - 451)

420.5 (400 - 442.5)

0.27

Echocardiogram

VP% < 20% (n = 73), frequency (%)

VP% ≥ 20% (n = 115), frequency (%)

P-value

LV function

0.48

Normal LV function

57 (78.1%)

84 (73%)

Mildly impaired

12 (16.4%)

19 (16.5%)

Moderately impaired

1 (1.4%)

7 (6.2%)

Severely impaired

3 (4.1%)

5 (4.3%)

LV EDD

0.82

Normal

66 (90.4%)

101 (87.8%)

Increased

7 (9.6%)

14 (12.2%)

LA size

0.22

Normal

46 (63%)

62 (53.9%)

Enlarged

27 (37%)

53 (46.1%)

RV size

0.22

Normal

62 (84.9%)

90 (78.2%)

Enlarged

10 (15.1%)

24 (21.8%)

RA size

0.09

Normal

61 (83.6%)

83 (72.2%)

Enlarged

12 (16.4%)

31 (17.8%)

Moderate+ TR

6 (8.2%)

18 (15.6%)

0.14

Moderate+ MR

10 (13.7%)

16 (13.9%)

0.95

Moderate+ AS

3 (4.1%)

12 (10.4%)

0.12

**Table 3.** Indications for PPM, Implantation Settings and VP% Burden Over 3 Years
Indication	VP% < 20% (n = 82), frequency (%)	VP% ≥ 20% (n = 154), frequency (%)	P-value
*P < 0.05. AF: atrial fibrillation; AV: atrioventricular; CHB: complete heart block; PPM: permanent pacemaker; RV: right ventricular; SR: sinus rhythm; VP: ventricular pacing.
Tachy-brady syndrome	15 (18.3%)	32 (20.8%)
CHB (sustained)	1 (1.2%)	25 (16.2%)	0.002*
Mobitz-2 (sustained)	8 (9.8%)	16 (10.4%)
Pauses (underlying SR)	6 (7.3%)	5 (3.2%)
Pauses (underlying AF)	26 (31.7%)	41 (26.6%)
Symptomatic bradycardia	14 (17.1%)	9 (5.8%)
Transient high-grade AV block	12 (14.6%)	26 (16.9%)
PPM settings	VP% < 20% (n = 82), frequency (%)	VP% ≥ 20% (n = 121), frequency (%)	P-value
VVI	3 (3.7%)	25 (20.7%)	< 0.001*
DDD	24 (29.3%)	73 (60.3%)
RV pacing mitigation algorithm	55 (67%)	23 (19%)

Table 3. Indications for PPM, Implantation Settings and VP% Burden Over 3 Years

Indication

VP% < 20% (n = 82), frequency (%)

VP% ≥ 20% (n = 154), frequency (%)

P-value

*P < 0.05. AF: atrial fibrillation; AV: atrioventricular; CHB: complete heart block; PPM: permanent pacemaker; RV: right ventricular; SR: sinus rhythm; VP: ventricular pacing.

Tachy-brady syndrome

15 (18.3%)

32 (20.8%)

CHB (sustained)

1 (1.2%)

25 (16.2%)

0.002*

Mobitz-2 (sustained)

8 (9.8%)

16 (10.4%)

Pauses (underlying SR)

6 (7.3%)

5 (3.2%)

Pauses (underlying AF)

26 (31.7%)

41 (26.6%)

Symptomatic bradycardia

14 (17.1%)

9 (5.8%)

Transient high-grade AV block

12 (14.6%)

26 (16.9%)

PPM settings

VP% < 20% (n = 82), frequency (%)

VP% ≥ 20% (n = 121), frequency (%)

P-value

VVI

3 (3.7%)

25 (20.7%)

< 0.001*

DDD

24 (29.3%)

73 (60.3%)

RV pacing mitigation algorithm

55 (67%)

23 (19%)