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 14, Number 2, April 2023, pages 106-114

Triggers of Atrial Fibrillation in the Geriatric Medical Intensive Care Unit: An Observational Study

Figure 2. Comparison between relevant medications used in the sinus and the AF groups. AF: atrial fibrillation.

**Table 1.** Demographic Data, Comorbidities and Clinical Presentation
	Stay sinus (n = 124)	Converted to AF (n = 18)	P value
*P ≤ 0.05. No difference is found between the two groups except for pneumonia. AF: atrial fibrillation; BMI: body mass index; COPD: chronic obstructive pulmonary disease.
Age (years)	69.3 ± 7.2	71.6 ± 8.4	0.2
Sex, n (%)
Male	63 (51%)	9 (50%)	1
Female	61 (49%)	9 (50%)
BMI	24.2 ± 7.2	25.2 ± 7.8	0.8
Smoking, n (%)	25 (20%)	3 (16.6%)	0.87
COPD	36 (29%)	6 (33%)	0.85
Pneumonia	12 (9.6%)	9 (50%)	0.00*
Pulmonary embolism	1 (0.8%)	1 (5.5%)	0.23
Diabetes	63 (50%)	8 (44%)	0.8
Renal impairment	19 (15%)	2 (11%)	1
Hemorrhage	10 (8%)	0 (0%)	0.3
Heart failure	16 (13%)	3 (16.6%)	0.7
Pulmonary edema	2 (1.6%)	0 (0%)	1
Hypertension	72 (58%)	8 (44%)	0.3
Obstructive sleep apnea	1 (0.8%)	0 (0%)	0.87

Table 1. Demographic Data, Comorbidities and Clinical Presentation

Stay sinus (n = 124)

Converted to AF (n = 18)

P value

*P ≤ 0.05. No difference is found between the two groups except for pneumonia. AF: atrial fibrillation; BMI: body mass index; COPD: chronic obstructive pulmonary disease.

Age (years)

69.3 ± 7.2

71.6 ± 8.4

0.2

Sex, n (%)

Male

63 (51%)

9 (50%)

Female

61 (49%)

9 (50%)

BMI

24.2 ± 7.2

25.2 ± 7.8

0.8

Smoking, n (%)

25 (20%)

3 (16.6%)

0.87

COPD

36 (29%)

6 (33%)

0.85

Pneumonia

12 (9.6%)

9 (50%)

0.00*

Pulmonary embolism

1 (0.8%)

1 (5.5%)

0.23

Diabetes

63 (50%)

8 (44%)

0.8

Renal impairment

19 (15%)

2 (11%)

Hemorrhage

10 (8%)

0 (0%)

0.3

Heart failure

16 (13%)

3 (16.6%)

0.7

Pulmonary edema

2 (1.6%)

0 (0%)

Hypertension

72 (58%)

8 (44%)

0.3

Obstructive sleep apnea

1 (0.8%)

0 (0%)

0.87

**Table 2.** Clinical Characteristics According to the Onset of Atrial Fibrillation
	Stay sinus (n = 124)	Converted to AF (n = 18)	P value
There is no difference between the two groups. APACHE II: Acute Physiology and Chronic Health Evaluation II; SIRS: systemic inflammatory response syndrome; SD: standard deviation.
Systolic blood pressure (mm Hg), mean ± SD	119.6 ± 33.6	111.6 ± 25	0.3
Diastolic blood pressure (mm Hg), mean ± SD	72.4 ± 20	68.8 ± 17	0.4
Pulse (beats/min), mean ± SD	92 ± 17.6	93 ± 13.6	0.8
Temperature (°C), mean ± SD	37.5 ± 0.6	37.6 ± 0.7	0.5
Respiratory rate, mean ± SD	22.6 ± 7	25.3 ± 7.8	0.1
APACHE II, mean ± SD	14 ± 6.7	14.7 ± 6.4	0.7
SIRS
Negative	86 (69%)	11 (61%)	0.5
Positive	38 (30.6%)	7 (39%)
Septic shock
Negative	111 (89%)	13 (72%)	0.8
Positive	13 (8%)	5 (27.7%)

Table 2. Clinical Characteristics According to the Onset of Atrial Fibrillation

Stay sinus (n = 124)

Converted to AF (n = 18)

P value

There is no difference between the two groups. APACHE II: Acute Physiology and Chronic Health Evaluation II; SIRS: systemic inflammatory response syndrome; SD: standard deviation.

Systolic blood pressure (mm Hg), mean ± SD

119.6 ± 33.6

111.6 ± 25

0.3

Diastolic blood pressure (mm Hg), mean ± SD

72.4 ± 20

68.8 ± 17

0.4

Pulse (beats/min), mean ± SD

92 ± 17.6

93 ± 13.6

0.8

Temperature (°C), mean ± SD

37.5 ± 0.6

37.6 ± 0.7

0.5

Respiratory rate, mean ± SD

22.6 ± 7

25.3 ± 7.8

0.1

APACHE II, mean ± SD

14 ± 6.7

14.7 ± 6.4

0.7

SIRS

Negative

86 (69%)

11 (61%)

0.5

Positive

38 (30.6%)

7 (39%)

Septic shock

Negative

111 (89%)

13 (72%)

0.8

Positive

13 (8%)

5 (27.7%)

**Table 3.** Baseline Serum Electrolyte Concentrations
Serum electrolyte concentrations	Stay sinus (n = 124)	Converted to AF (n = 18)	P value
*P ≤ 0.001. Data are presented as mean ± SD. Difference is noted between the two groups regarding serum copper and serum zinc. SD: standard deviation.
Sodium (mmol/L)	134.2 ± 13.5	137 ± 10.4	0.32
Potassium (mmol/L)	4.4 ± 3.7	3.7 ± 0.8	0.84
Magnesium (mEq/L)	1.9 ± 0.4	1.8 ± 0.5	0.186
Phosphorous (mmol/L)	3.4 ± 1.7	3.4 ± 2	0.66
Calcium (mg/dL)	8.6 ± 1	8.8 ± 0.75	0.17
Chloride (mmol/L)	108.7 ± 11	109.5 ± 9	0.580
Copper (µg/dL)	128 ± 64	72.3 ± 37.4	0.000*
Zinc (µmol/L)	132 ± 79	52 ± 27.5	0.000*

Table 3. Baseline Serum Electrolyte Concentrations

Serum electrolyte concentrations

Stay sinus (n = 124)

Converted to AF (n = 18)

P value

*P ≤ 0.001. Data are presented as mean ± SD. Difference is noted between the two groups regarding serum copper and serum zinc. SD: standard deviation.

Sodium (mmol/L)

134.2 ± 13.5

137 ± 10.4

0.32

Potassium (mmol/L)

4.4 ± 3.7

3.7 ± 0.8

0.84

Magnesium (mEq/L)

1.9 ± 0.4

1.8 ± 0.5

0.186

Phosphorous (mmol/L)

3.4 ± 1.7

3.4 ± 2

0.66

Calcium (mg/dL)

8.6 ± 1

8.8 ± 0.75

0.17

Chloride (mmol/L)

108.7 ± 11

109.5 ± 9

0.580

Copper (µg/dL)

128 ± 64

72.3 ± 37.4

0.000*

Zinc (µmol/L)

132 ± 79

52 ± 27.5

0.000*

**Table 4.** Comparison of Laboratory Results
Laboratory investigation	Stay sinus (n = 124)	Converted to AF (n = 18)	P value
Data are presented as mean ± SD. ALT: alanine transaminase; AST: aspartate transaminase; BUN: blood urea nitrogen; CK: creatine kinase; HGB: hemoglobin; INR: international normalized ratio; SD: standard deviation; WBCs: white blood cell counts.
WBCs	15.5 ± 18.6	16 ± 6	0.9
HGB	12 ± 10.4	10.4 ± 2	0.5
Platelets	220.6 ± 119	214 ± 123	0.2
BUN	42.4 ± 34.6	45.7 ± 44.2	0.7
Creatinine	2.4 ± 2	1.9 ± 1.4	0.4
Total proteins	6.4 ± 0.8	6.2 ± 0.8	0.4
Albumin	3 ± 0.7	2.7 ± 0.8	0.2
AST	47 ± 72.4	50.3 ± 63	0.8
ALT	44.6 ± 130.6	33 ± 24	0.7
Total bilirubin	1.7 ± 3.2	1.5 ± 1.4	0.8
Direct bilirubin	0.74 ± 1.7	0.7 ± 0.9	0.9
CK total	475.8 ± 948	469.7 ± 653.4	0.9
CKMB	23 ± 21.7	24.3 ± 16	0.7
INR	1.3 ± 0.3	1.5 ± 0.9	0.25

Table 4. Comparison of Laboratory Results

Laboratory investigation

Stay sinus (n = 124)

Converted to AF (n = 18)

P value

Data are presented as mean ± SD. ALT: alanine transaminase; AST: aspartate transaminase; BUN: blood urea nitrogen; CK: creatine kinase; HGB: hemoglobin; INR: international normalized ratio; SD: standard deviation; WBCs: white blood cell counts.

WBCs

15.5 ± 18.6

16 ± 6

0.9

HGB

12 ± 10.4

10.4 ± 2

0.5

Platelets

220.6 ± 119

214 ± 123

0.2

BUN

42.4 ± 34.6

45.7 ± 44.2

0.7

Creatinine

2.4 ± 2

1.9 ± 1.4

0.4

Total proteins

6.4 ± 0.8

6.2 ± 0.8

0.4

Albumin

3 ± 0.7

2.7 ± 0.8

0.2

AST

47 ± 72.4

50.3 ± 63

0.8

ALT

44.6 ± 130.6

33 ± 24

0.7

Total bilirubin

1.7 ± 3.2

1.5 ± 1.4

0.8

Direct bilirubin

0.74 ± 1.7

0.7 ± 0.9

0.9

CK total

475.8 ± 948

469.7 ± 653.4

0.9

CKMB

23 ± 21.7

24.3 ± 16

0.7

INR

1.3 ± 0.3

1.5 ± 0.9

0.25

**Table 5.** Logistic Regression for Factors Increasing the Incidence of AF in Critically Ill Elderly Patients
Variables	Beta	Standard errors	P	95% confidence interval
AF: atrial fibrillation.
Pneumonia	0.254	0.069	0.00	0.117	0.391
Copper	-0.252	0.000	0.000	-0.002	0.000
Zinc	-0.268	0.000	0.000	-0.002	0.000

Table 5. Logistic Regression for Factors Increasing the Incidence of AF in Critically Ill Elderly Patients

Variables

Beta

Standard errors

95% confidence interval

Lower bound

Upper bound

AF: atrial fibrillation.

Pneumonia

0.254

0.069

0.00

0.117

0.391

Copper

-0.252

0.000

-0.002

0.000

Zinc

-0.268

0.000

-0.002

0.000