This study contained 34965 participants (40% men and 60% women). The baseline characteristics of the participants are summarized in Table 1. The mean ages of men and women were both 44.8 years old. There were no significant differences comparing the age between men and women. Men had significantly higher prevalences of overweight, obese, presence of smoking history, hypertension, diabetes and presence of one or more CVD risk factors (Table 1).
Table 1
Characteristics of the 34965 participants in this study
Characteristics | Men | Women | P values# |
Age, y [mean (95% CI)] | 44.8 (44.7–44.9) | 44.8 (44.7–44.8) | 0.765 |
Age group |
20–29 years old, % | 17.2 | 17.7 | 0.396 |
30–39 years old, % | 23.8 | 24.0 | 0.738 |
40–49 years old, % | 22.5 | 22.3 | 0.777 |
50–59 years old, % | 18.6 | 17.9 | 0.245 |
60–69 years old, % | 10.5 | 9.8 | 0.123 |
≥ 70 years old, % | 7.5 | 8.3 | 0.310 |
BMI, kg/m2 [mean (95% CI)] | 24.1 (24.0-24.2) | 23.5 (23.4–23.5) | ༜0.001 |
Overweight, % | 34.9 | 29.4 | ༜0.001 |
Obese, % | 14.0 | 10.8 | ༜0.001 |
Smoking, % | 58.2 | 3.6 | ༜0.001 |
Hypertension, % | 31.5 | 25.3 | ༜0.001 |
Prediabetes, % | 16.2 | 15.4 | 0.244 |
Diabetes, % | 10.9 | 8.9 | ༜0.001 |
FPG, mmol/L [mean (95% CI)] | 5.4 (5.3–5.4) | 5.3 (5.2–5.3) | 0.073 |
PG2h, mmol/L [mean (95% CI)] | 6.9 (6.8-7.0) | 7.0 (6.9–7.1) | 0.328 |
Hypercholesterolemia, % | 11.1 | 10.5 | 0.244 |
Rural, % | 47.7 | 47.6 | 0.955 |
Urban, % | 52.3 | 52.4 | 0.955 |
With cardiovascular/cerebrovascular diseases, % | 3.1 | 2.5 | 0.121 |
CVD risk groups | | | |
Without CVD risk factors, % | 22.2 | 60.2 | ༜0.001 |
With one CVD risk factor, % | 43.9 | 25.1 | ༜0.001 |
With two CVD risk factors, % | 22.5 | 10.8 | ༜0.001 |
With three or more CVD risk factors, % | 11.3 | 4.0 | ༜0.001 |
The percentages shown above were compared by Chi-square test. # The underlined numbers indicated the significant differences (p༜0.05). The quantitative values of age, BMI, FPG and PG2h were indicated as mean (95% CI) and compared by two-tailed t test. CVD risk factors include hypertension, diabetes, obesity, hypercholesterolemia and smoking history. Older age was not included in the CVD risk factors for analysis because age was mentioned and analyzed separately. BMI, body mass index; FPG, fasting plasma glucose level; PG2h, plasma glucose level of 2 hours after oral glucose tolerance test; CVD, cardiovascular disease; CI, confidence interval. |
The weighted prevalences of arrhythmias in men, women and all participants with different ages are summarized in Table 2. Major arrhythmias accounted for 1.70% of all participants. The weighted prevalence of major arrhythmias in men was higher than in women (2.37% vs 1.04% in men vs women) (Table 2). The weighted prevalences of major arrhythmias in the young (20–44 years old), middle (45–59 years old) and older age (≥ 60 years old) groups were 1.30%, 2.37% and 5.56% in men, and 0.58%, 1.06% and 2.38% in women, respectively. Specifically, atrial fibrillation/flutter (MC 8 − 3) accounted for 0.28%, 0.35% and 0.20% in the whole population, men and women respectively. Complete RBBB (MC 7 − 2) had the highest prevalence among all major arrhythmias, with the weighted prevalence of 0.85%, 1.16% and 0.55% in the whole population, men and women respectively. Minor arrhythmias accounted for 9.92% in all participants. In the young, middle and older age groups, the weighted prevalences of minor arrhythmia were 11.05%, 10.82% and 14.26% in men, and 6.58%, 7.85% and 14.17% in women, respectively. Individuals in the older age group had higher prevalences of atrial fibrillation/flutter, complete RBBB and atrial/junctional/ventricular premature beats in both men and women, compared with those in the young age group. In addition, gender had an important impact on some specific types of arrhythmia. Complete LBBB, complete RBBB, nonspecific IVCD, sinus bradycardia, incomplete RBBB and Mobitz type I AV conduction defect were more common in men than in women, while sinus tachycardia was more frequent in women than in men (Table 2).
Table 2
Prevalences of arrhythmias in men, women and all participants.
ECG abnormalities | All participants, No. (percentage) | men | | women | P value# (men vs women) |
20-44y | 45-59y | ≥ 60y | All ages | | 20-44y | 45-59y | ≥ 60y | All ages |
Major arrhythmias | 550 (1.70%) | 1.30% | 2.37% | 5.56%*** | 2.37% | | 0.58% | 1.06% | 2.38%*** | 1.04% | ༜0.001 |
Atrial fibrillation or flutter (MC 8 − 3) | 77 (0.28%) | 0.14% | 0.23% | 1.20%** | 0.35% | | 0.08% | 0.05% | 0.80%* | 0.20% | 0.130 |
Complete LBBB (MC 7 − 1) | 28 (0.12%) | 0.06% | 0.20% | 0.61% | 0.20% | | 0.01% | 0.03% | 0.15%* | 0.05% | 0.037 |
Complete RBBB (MC 7 − 2) | 289 (0.85%) | 0.51% | 1.21% | 2.97%*** | 1.16% | | 0.35% | 0.59% | 1.10%** | 0.55% | 0.001 |
Nonspecific IVCD (MC 7 − 4) | 59 (0.20%) | 0.29% | 0.43% | 0.59% | 0.38% | | 0.00% | 0.06% | 0.03% | 0.02% | ༜0.001 |
Mobitz Type II or III AV conduction defects (MC 6 − 1, 6 − 2) | 16 (0.04%) | 0.01% | 0.07% | 0.04% | 0.03% | | 0.00% | 0.17% | 0.02% | 0.05% | 0.536 |
Supraventricular or ventricular rhythm/tachycardia (MC 8-4-1, 8-4-2, 8 − 2) | 28 (0.09%) | 0.14% | 0.14% | 0.12% | 0.14% | | 0.01% | 0.10% | 0.07% | 0.05% | 0.084 |
WPW (MC 6 − 4) | 44 (0.09%) | 0.14% | 0.04% | 0.02%** | 0.09% | | 0.12% | 0.04% | 0.05% | 0.09% | 0.926 |
artificial pacemaker (MC 6–8) | 9 (0.03%) | 0.01% | 0.04% | 0.00% | 0.02% | | 0.00% | 0.01% | 0.16% | 0.03% | 0.117 |
Minor arrhythmias | 3046 (9.92%) | 11.05% | 10.82% | 14.26%* | 11.58% | | 6.58% | 7.85% | 14.17%*** | 8.29% | ༜0.001 |
Sinus bradycardia (MC 8–8) | 703 (2.81%) | 3.99% | 4.29% | 3.22% | 3.94% | | 1.62% | 2.03% | 1.39% | 1.70% | ༜0.001 |
Sinus tachycardia (MC 8 − 7) | 540 (1.68%) | 0.94% | 1.07% | 2.06%* | 1.18% | | 1.78% | 1.38% | 4.52% | 2.14% | 0.004 |
Atrial or junctional or ventricular premature beats (MC 8-1-1, 8-1-2, 8-1-3) | 544 (1.57%) | 0.91% | 1.04% | 4.33%*** | 1.58% | | 0.87% | 1.73%** | 3.41%*** | 1.57% | 0.945 |
Incomplete RBBB (MC 7 − 3) | 285 (0.97%) | 1.53% | 1.47% | 0.94% | 1.40% | | 0.34% | 0.85%* | 0.67% | 0.55% | ༜0.001 |
Mobitz Type I AV conduction defect (MC 6 − 3) | 141 (0.47%) | 0.43% | 0.85%* | 0.79% | 0.62% | | 0.15% | 0.17% | 1.08% | 0.32% | 0.045 |
Short PR interval (MC 6 − 5) | 241 (0.70%) | 0.84% | 0.26%* | 0.13%* | 0.54% | | 1.02% | 0.89% | 0.34%*** | 0.86% | 0.084 |
Other minor arrhythmias (MC 7 − 6, 7–7, 8-1-4, 8 − 5, 8 − 6, 8–9) | 592 (1.73%) | 2.40% | 1.84% | 2.80% | 2.31% | | 0.81% | 0.79% | 2.75% | 1.15% | ༜0.001 |
The percentages shown above were compared by Chi-square or Fisher’s test. *, * and *** indicated the p values comparing the percentages of ECG findings in the middle/older age group with those in the young age group (* p༜0.05, ** p༜0.01, *** p༜0.001). # The p values revealed the differences comparing the percentages of ECG findings between men and women. The underlined p values indicated the significant differences (p༜0.05). MC, Minnesota coding; LBBB, left bundle branch block; RBBB, right bundle branch block; IVCD, intravascular conducting delay; AV, atrial-ventricular; WPW, Wolff-Parkinson-White. |
With respect to other ECG abnormalities except arrhythmias, ST depression and T abnormalities and tall R wave left had higher prevalences than other specific ECG types (Table 3). The ST depression and T abnormalities accounted for 10.96%, 7.54% and 14.32% in the whole population, men and women respectively. Tall R wave left accounted for 4.42%, 5.83% and 3.05% in the whole population, men and women respectively. Participants in the older group had higher prevalences of ST depression and T abnormalities, tall R wave left and left axis deviation, compared with those in the young group. In addition, gender played an important role in these ECG abnormalities as well. Compared with women, men had significantly higher prevalences of Q wave abnormalities, ST elevation, tall R wave left, left axis deviation and right axis deviation. Women had higher prevalences of ST depression and T abnormalities and low voltage, compared with men (Table 3).
Table 3
Prevalences of other ECG abnormalities (except arrhythmias) in men, women and all participants
ECG abnormalities | All participants, No. (percentage) | men | | women | P value# (men vs women) |
20-44y | 45-59y | ≥ 60y | All ages | | 20-44y | 45-59y | ≥ 60y | All ages |
ST depression and T abnormalities (MC 4 − 1, 4 − 2, 4 − 3, 4–4, 5 − 1, 5 − 2, 5 − 3 or 5 − 4) | 4192 (10.96%) | 5.26% | 9.30%*** | 11.44%*** | 7.54% | | 8.36% | 18.46%*** | 25.19%*** | 14.32% | ༜0.001 |
Q wave abnormalities (MC 1–1 or 1–2) | 416 (1.28%) | 1.35% | 1.77% | 1.86% | 1.55% | | 0.78% | 1.23% | 1.31% | 1.00% | 0.003 |
Q wave abnormalities plus ST-T ischemic abnormalities (MC ‘1–1 or 1–2’ plus ‘4 − 1, 4 − 2, 4 − 3, 4–4, 5 − 1, 5 − 2, 5 − 3 or 5 − 4’) | 75 (0.16%) | 0.14% | 0.05% | 0.55% | 0.19% | | 0.07% | 0.17% | 0.30%* | 0.14% | 0.414 |
ST elevation (MC 9 − 2) | 239 (0.92%) | 2.81% | 0.88%*** | 0.20%*** | 1.78% | | 0.06% | 0.16% | 0.02% | 0.08% | ༜0.001 |
Tall R wave left (MC 3 − 1 or 3–3) | 1042 (4.42%) | 4.94% | 7.16%* | 6.28% | 5.83% | | 1.21% | 3.40%*** | 7.89%*** | 3.05% | ༜0.001 |
Tall R wave right (MC 3 − 2) | 54 (0.22%) | 0.23% | 0.13% | 0.41% | 0.23% | | 0.28% | 0.06% | 0.22% | 0.20% | 0.765 |
Left/right atrial hypertrophy (MC 9 − 3 or 9 − 6) | 64 (0.31%) | 0.21% | 0.43% | 1.05% | 0.43% | | 0.06% | 0.27%* | 0.52%* | 0.21% | 0.063 |
Left axis deviation (MC 2 − 1) | 698 (2.13%) | 1.41% | 3.31%*** | 4.36%*** | 2.48% | | 0.98% | 2.22%*** | 3.35%*** | 1.78% | 0.003 |
Right axis deviation (MC 2–2) | 254 (0.67%) | 0.99% | 0.72% | 0.80% | 0.88% | | 0.67% | 0.31%* | 0.15%*** | 0.47% | 0.008 |
Low voltage (MC 9 − 1) | 325 (0.97%) | 0.45% | 0.81% | 1.16% | 0.68% | | 1.14% | 1.18% | 1.67% | 1.24% | 0.001 |
The percentages shown above were compared by Chi-square or Fisher’s test. *, * and *** indicated the p values comparing the percentages of ECG findings in the middle/older age group with those in the young age group (* p༜0.05, ** p༜0.01, *** p༜0.001). # The p values revealed the differences comparing the percentages of ECG findings between men and women. The underlined p values indicated the significant differences (p༜0.05). |
Figures 1A, 1B, 1C and 1D indicated the odds ratios for the effects of multiple factors on major arrhythmias, minor arrhythmias, ST depression and T abnormalities and tall R wave left, respectively, by multivariate logistic regression analysis. Male gender, older age and living in rural area were positively associated with major arrhythmias. It is worth noting that the likelihood of having major arrhythmias in the 60-year-older group was nearly 4 times higher than that in the reference group (20–44 years old). The risk of having minor arrhythmias was significantly higher in males, the middle age group, the older age group, the smoking group, hypertensive participants, and residents living in rural area. Factors independently influenced the odds ratios of having ST depression and T abnormalities included female gender, older age, hypertension, overweight, obesity and hypercholesterolemia. In addition, male gender, older age and hypertension significantly increased the odds ratios of having tall R wave left.
To identify the factors that influence each arrhythmia ECG type, multivariate logistic regression analysis was conducted, and the results are displayed in Table 4. Older age (at least 60 years old) significantly increased the risk of having atrial fibrillation/flutter, complete LBBB, complete RBBB, nonspecific IVCD, sinus tachycardia, atrial/junctional/ventricular premature beats and Mobitz Type I AV conduction defect. Smoking was positively associated with supraventricular or ventricular rhythm/tachycardia and incomplete RBBB. Hypertension increased the risk of having sinus tachycardia and Mobitz Type I AV conduction defect. Diabetes, obesity and hypercholesterolemia were not positively associated with any arrhythmia ECG type. Residents living in rural area had higher risk of obtaining complete LBBB, nonspecific IVCD, sinus bradycardia and incomplete RBBB, compared to those living in urban area (Table 4).
Table 4
The odds ratios of the effects of multiple factors on arrhythmias
ECG abnormalities | Gender(male vs female) | 45–59 years old | ≥ 60 years old | smoking | hypertension | Pre-diabetes | Diabetes | overweight | Obese | Hyper-cholesterolemia | Rural (vs urban) |
Major arrhythmias | 2.14 (1.56–2.95) | 1.83 (1.29–2.58) | 4.90 (3.48–6.92) | 1.22 (0.89–1.69) | 1.29 (0.95–1.77) | 1.40 (0.99–1.96) | 0.86 (0.57–1.29) | 1.13 (0.82–1.55) | 1.20 (0.77–1.87) | 1.37 (0.93–2.04) | 1.39 (1.06–1.81) |
Atrial fibrillation/flutter | 1.91 (0.83–4.42) | 1.23 (0.37–4.05) | 9.39 (3.63–24.29) | 1.01 (0.42–2.46) | 1.64 (0.74–3.65) | 1.42 (0.59–3.45) | 0.68 (0.25–1.82) | 1.35 (0.61–3.01) | 0.72 (0.19–2.69) | 2.21 (0.86–5.68) | 1.91 (0.95–3.86) |
Complete LBBB | 3.06 (0.77–12.19) | 2.84 (0.53–15.07) | 11.08 (2.43–50.49) | 2.10 (0.53–8.31) | 0.95 (0.33–2.72) | 1.66 (0.47–5.83) | 1.57 (0.25–9.94) | 0.95 (0.28–3.26) | 0.98 (0.30–3.15) | 2.41 (0.61–9.50) | 3.72 (1.25–11.06) |
Complete RBBB | 1.92 (1.23–3.01) | 2.04 (1.22–3.41) | 5.27 (3.19–8.70) | 1.23 (0.78–1.94) | 1.36 (0.87–2.13) | 1.32 (0.81–2.17) | 1.07 (0.66–1.74) | 1.10 (0.69–1.76) | 1.45 (0.76–2.77) | 1.22 (0.70–2.11) | 1.02 (0.69–1.50) |
Nonspecific IVCD | 18.43 (5.44–62.44) | 1.88 (0.79–4.47) | 2.89 (1.03–8.09) | 1.04 (0.47–2.33) | 1.02 (0.41–2.50) | 1.69 (0.67–4.31) | 0.23 (0.05–1.02) | 1.33 (0.56–3.15) | 0.95 (0.25–3.59) | 1.25 (0.40–3.92) | 2.53 (1.29–4.96) |
Mobitz Type II or III AV conduction defects | 0.96 (0.26–3.58) | 12.09 (3.11–47.04) | 2.74 (0.49–15.26) | 0.55 (0.13–2.34) | 2.88 (0.58–14.32) | 6.40 (1.69–24.20) | 0.69 (0.13–3.62) | 0.75 (0.10–5.43) | 1.14 (0.12–10.88) | 0.54 (0.12–2.38) | 1.62 (0.47–5.59) |
Supraventricular or ventricular rhythm/tachycardia | 1.40 (0.54–3.65) | 1.69 (0.54–5.30) | 1.66 (0.45–6.17) | 3.23 (1.22–8.57) | 1.60 (0.50–5.12) | 0.98 (0.37–2.58) | 0.53 (0.12–2.42) | 0.85 (0.26–2.73) | 0.70 (0.18–2.80) | 0.56 (0.14–2.16) | 1.20 (0.41–3.53) |
WPW | 1.27 (0.55–2.93) | 0.46 (0.16–1.36) | 0.58 (0.12–2.77) | 0.75 (0.28-2.00) | 0.31 (0.10-1.00) | 0.29 (0.04–2.22) | 0.39 (0.10–1.44) | 1.63 (0.69–3.89) | 2.50 (0.67–9.33) | 0.74 (0.16–3.36) | 1.24 (0.58–2.65) |
Minor arrhythmias | 1.34 (1.13–1.59) | 1.19 (1.03–1.38) | 2.08 (1.69–2.57) | 1.20 (1.02–1.41) | 1.29 (1.08–1.52) | 1.10 (0.89–1.34) | 0.99 (0.77–1.28) | 0.76 (0.63–0.91) | 0.62 (0.50–0.77) | 0.82 (0.63–1.07) | 1.19 (1.04–1.37) |
Sinus bradycardia | 2.21 (1.66–2.93) | 1.47 (1.13–1.90) | 1.41 (0.97–2.04) | 1.29 (0.97–1.72) | 0.71 (0.53–0.96) | 0.77 (0.53–1.13) | 0.65 (0.42-1.00) | 0.77 (0.60–0.98) | 0.67 (0.44–1.01) | 0.64 (0.42–0.97) | 2.03 (1.64–2.50) |
Sinus tachycardia | 0.64 (0.40–1.02) | 0.84 (0.59–1.20) | 2.10 (1.15–3.83) | 0.75 (0.46–1.22) | 2.78 (1.82–4.24) | 1.64 (0.89–3.05) | 1.50 (0.78–2.88) | 0.60 (0.31–1.16) | 0.32 (0.21–0.50) | 0.60 (0.37–0.97) | 0.95 (0.62–1.44) |
Atrial or junctional or ventricular premature beats | 0.96 (0.64–1.43) | 1.75 (1.24–2.46) | 5.74 (3.81–8.66) | 1.17 (0.75–1.81) | 1.25 (0.89–1.75) | 1.02 (0.67–1.54) | 0.79 (0.49–1.27) | 0.90 (0.64–1.27) | 0.87 (0.57–1.33) | 0.89 (0.54–1.48) | 1.11 (0.83–1.49) |
Incomplete RBBB | 2.04 (1.33–3.15) | 1.40 (0.97–2.03) | 1.17 (0.65–2.10) | 1.67 (1.12–2.49) | 0.88 (0.60–1.30) | 1.30 (0.81–2.09) | 1.20 (0.68–2.10) | 0.69 (0.47-1.00) | 0.80 (0.50–1.29) | 1.00 (0.56–1.76) | 1.72 (1.26–2.35) |
Mobitz Type I AV conduction defect | 1.79 (0.74–4.33) | 1.75 (0.93–3.28) | 3.43 (1.73–6.80) | 1.12 (0.63–2.01) | 1.92 (1.05–3.50) | 1.68 (0.68–4.13) | 1.01 (0.51–2.02) | 1.05 (0.53–2.06) | 0.63 (0.30–1.36) | 0.39 (0.15–1.03) | 0.42 (0.22–0.82) |
Short PR interval | 0.57 (0.38–0.86) | 0.76 (0.44–1.30) | 0.42 (0.21–0.85) | 1.35 (0.58–3.15) | 0.67 (0.38–1.19) | 0.76 (0.42–1.35) | 1.00 (0.46–2.20) | 1.24 (0.60–2.55) | 0.79 (0.36–1.77) | 0.81 (0.41–1.60) | 0.84 (0.51–1.41) |
Note: All factors indicated in the table above were simultaneously adjusted to calculate the odds ratios. The upper limit and the lower limit of the 95% confidence intervals (CIs) were written in the brackets. Normal ECG was used as the reference. The middle age (45–59 years old) group and the older age (≥ 60 years old) group were compared with the young group (20–44 years old). The underlined odds ratios indicated the significant associations between the factors and the ECG findings. LBBB, left bundle branch block; RBBB, right bundle branch block; IVCD, intravascular conducting delay; AV, atrial-ventricular. |
With regard for the factors influencing other ECG abnormal types except arrhythmias, the results of multivariate logistic regression analysis are displayed in Table 5. Older age (at least 60 years old) was positively associated with ST depression and T abnormalities, tall R wave left, left/right atrial hypertrophy, left axis deviation and low voltage. Smoking was positively associated with Q wave abnormalities, tall R wave right and low voltage. Hypertension significantly increased the risk of having ST depression and T abnormalities, Q wave abnormalities, tall R wave left and left axis deviation. Obesity significantly contributed to ST depression and T abnormalities and left axis deviation. Hypercholesterolemia was positively associated with ST depression and T abnormalities (Table 5).
Table 5
The odds ratios of the effects of multiple factors on ECG abnormalities except arrhythmias
ECG abnormalities | Gender(male vs female) | 45–59 years old | 60 ~ years old | smoking | hypertension | Pre-diabetes | Diabetes | overweight | Obese | Hyper-cholesterolemia | rural |
ST depression and T abnormalities | 0.51 (0.44–0.58) | 1.78 (1.58-2.00) | 2.45 (2.07–2.89) | 1.04 (0.89–1.22) | 1.92 (1.69–2.18) | 1.32 (1.12–1.56) | 1.17 (0.98–1.39) | 1.20 (1.05–1.37) | 1.24 (1.05–1.47) | 1.28 (1.09–1.51) | 0.97 (0.87–1.09) |
Q wave abnormalities | 1.15 (0.84–1.58) | 1.28 (0.88–1.86) | 1.49 (0.97–2.28) | 1.62 (1.14–2.29) | 2.04 (1.48–2.81) | 0.75 (0.48–1.18) | 1.04 (0.65–1.66) | 1.01 (0.74–1.39) | 1.25 (0.81–1.94) | 1.41 (0.87–2.28) | 0.84 (0.62–1.14) |
Q wave abnormalities plus ischemic ST-T abnormalities | 1.38 (0.57–3.34) | 1.00 (0.41–2.45) | 4.13 (1.60-10.69) | 0.99 (0.38–2.59) | 1.39 (0.65–2.96) | 1.69 (0.70–4.09) | 0.89 (0.32–2.47) | 1.35 (0.60–3.04) | 0.86 (0.28–2.63) | 1.83 (0.77–4.32) | 0.79 (0.39–1.61) |
ST elevation | 20.03 (8.26–48.62) | 0.45 (0.26–0.77) | 0.13 (0.06–0.26) | 1.60 (0.98–2.62) | 0.77 (0.47–1.27) | 1.19 (0.52–2.72) | 0.15 (0.07–0.34) | 0.78 (0.49–1.25) | 0.51 (0.23–1.12) | 0.52 (0.19–1.44) | 1.15 (0.75–1.77) |
Tall R wave left | 1.95 (1.48–2.58) | 1.51 (1.21–1.89) | 1.85 (1.38–2.47) | 1.02 (0.80–1.30) | 4.03 (3.25-5.00) | 1.32 (0.95–1.83) | 0.68 (0.47–0.99) | 0.65 (0.50–0.83) | 0.32 (0.22–0.45) | 1.16 (0.83–1.61) | 1.03 (0.83–1.30) |
Tall R wave right | 0.58 (0.23–1.48) | 0.33 (0.14–0.78) | 1.29 (0.50–3.35) | 2.83 (1.16–6.89) | 2.02 (0.91–4.49) | 0.94 (0.26–3.38) | 0.92 (0.36–2.32) | 1.60 (0.58–4.41) | 0.93 (0.29–2.98) | 0.46 (0.17–1.22) | 0.42 (0.19–0.96) |
Left/right atrial hypertrophy | 2.72 (1.04–7.08) | 3.27 (1.57–6.79) | 8.47 (3.73–19.22) | 0.75 (0.30–1.88) | 0.56 (0.21–1.47) | 1.27 (0.60–2.73) | 1.36 (0.33–5.61) | 0.38 (0.15–0.95) | 0.33 (0.08–1.30) | 2.41 (0.76–7.67) | 1.11 (0.50–2.51) |
Left axis deviation | 1.36 (1.04–1.79) | 2.12 (1.63–2.76) | 3.38 (2.43–4.69) | 1.08 (0.81–1.45) | 1.40 (1.09–1.79) | 1.30 (0.98–1.73) | 1.13 (0.81–1.56) | 1.51 (1.17–1.95) | 2.04 (1.54–2.72) | 1.26 (0.95–1.66) | 0.69 (0.55–0.87) |
Right axis deviation | 1.64 (0.98–2.75) | 0.82 (0.45–1.50) | 0.98 (0.51–1.88) | 1.60 (0.93–2.77) | 0.80 (0.48–1.32) | 0.72 (0.31–1.64) | 0.79 (0.32–1.93) | 0.58 (0.36–0.93) | 0.32 (0.15–0.66) | 0.72 (0.36–1.44) | 0.60 (0.38–0.96) |
Low voltage | 0.44 (0.26–0.72) | 1.72 (1.15–2.58) | 3.26 (1.90–5.60) | 1.73 (1.00–3.00) | 0.45 (0.28–0.75) | 1.02 (0.59–1.76) | 1.52 (0.85–2.71) | 0.54 (0.36–0.81) | 0.52 (0.24–1.10) | 0.63 (0.36–1.09) | 0.90 (0.63–1.26) |
Note: All factors indicated in the table above were simultaneously adjusted to calculate the odds ratios. The upper limit and the lower limit of the 95% confidence intervals (CIs) were written in the brackets. Normal ECG was used as the reference. The middle age (45–59 years old) group and the older age (≥ 60 years old) group were compared with the young group (20–44 years old). The underlined odds ratios indicated the significant associations between the factors and the ECG findings. |
The weighted prevalences of major arrhythmias in participants with none, one, two and at least three CVD risk factors were 1.19%, 1.76%, 1.95% and 2.17% respectively (Table 6). The presence of CVD risk factors significantly increased the risk of obtaining ST depression and T abnormalities, Q wave abnormalities and tall R wave left, after gender and age were adjusted (Table 6). A history of cardiovascular/cerebrovascular diseases significantly increased the risk of having major arrhythmias, atrial fibrillation/flutter, atrial/junctional/ventricular premature beats, ST depression and T abnormalities, Q wave abnormalities, tall R wave left and left axis deviation, with gender and age adjusted (Table 6). The weighted prevalence of major arrhythmias in participants with a history of cardiovascular/cerebrovascular diseases was as high as 5.72%, while the prevalence in those without the history was only 1.61% (Table 6).
Table 6
Prevalences of ECG abnormalities with presence of CVD risk factors and history of cardiovascular/cerebrovascular diseases
ECG abnormalities | CVD risk factors (except age and gender) | | History of cardiovascular/cerebrovascular diseases |
None (%) | One (%) | Two (%) | Three or more (%) | | Without (%) | With (%) # |
Major arrhythmias | 1.19 | 1.76 | 1.95 | 2.17* | | 1.61 | 5.72*** |
Atrial fibrillation or flutter | 0.23 | 0.36 | 0.12 | 0.67 | | 0.21 | 2.70*** |
Complete LBBB | 0.06 | 0.14 | 0.07 | 0.34 | | 0.11 | 0.17 |
Complete RBBB | 0.55 | 0.65 | 1.32** | 0.78 | | 0.84 | 1.99 |
Nonspecific IVCD | 0.16 | 0.25 | 0.16 | 0.27 | | 0.21 | 0.48 |
Mobitz Type II or III AV conduction defects | 0.03 | 0.06 | 0.07 | 0.05 | | 0.05 | 0.01 |
Supraventricular or ventricular rhythm/tachycardia | 0.05 | 0.16 | 0.14 | 0.05 | | 0.09 | 0.10 |
WPW | 0.09 | 0.11 | 0.05 | 0.02 | | 0.08 | 0.20 |
Minor arrhythmias | 9.38 | 11.63 | 8.84 | 10.84 | | 9.95 | 9.28 |
Sinus bradycardia | 2.93 | 3.49 | 2.31 | 2.00 | | 2.84 | 1.98 |
Sinus tachycardia | 1.53 | 1.82 | 1.55 | 1.72 | | 1.72 | 0.70 |
Atrial or junctional or ventricular premature beats | 1.63 | 1.56 | 1.83 | 1.04 | | 1.53 | 2.30** |
Incomplete RBBB | 0.83 | 1.36 | 0.74 | 1.31 | | 0.97 | 0.67 |
Mobitz Type I AV conduction defect | 0.29 | 0.64 | 0.40 | 0.39 | | 0.48 | 0.27 |
Short PR interval | 0.94 | 0.65 | 0.49 | 0.27 | | 0.69 | 1.64 |
Other ECG abnormalities except arrhythmias | | | | | | | |
ST depression and T abnormalities | 9.82 | 10.04*** | 12.56*** | 15.36*** | | 10.59 | 21.83*** |
Q wave abnormalities | 0.94 | 1.19 | 1.67** | 2.99*** | | 1.24 | 1.88** |
Q wave abnormalities plus ischemic ST-T abnormalities | 0.18 | 0.11 | 0.11 | 0.31 | | 0.15 | 2.16** |
ST elevation | 0.51 | 1.78* | 0.43 | 0.73 | | 0.92 | 0.07 |
Tall R wave left | 2.52 | 5.45*** | 6.11*** | 5.52*** | | 4.18 | 7.62** |
Tall R wave right | 0.13 | 0.19 | 0.34* | 0.12 | | 0.21 | 0.54 |
Left/right atrial hypertrophy | 0.22 | 0.39 | 0.33 | 0.05 | | 0.33 | 0.36 |
Left axis deviation | 1.60 | 2.04* | 2.58*** | 3.99*** | | 2.10 | 2.95* |
Right axis deviation | 0.55 | 0.85 | 0.45 | 0.17 | | 0.68 | 2.01 |
Low voltage | 1.46 | 0.84 | 0.49 | 0.51 | | 0.96 | 0.75 |
*, ** and *** refer to p < 0.05, p < 0.01 and p < 0.001 respectively. Gender and age were adjusted to calculate the p values by multivariate logistic regression analysis. The prevalences of ECG findings in participants present with CVD risk factors was compared with those absent of CVD risk factors. |
# The prevalences of ECG findings in participants with history of cardiovascular/cerebrovascular diseases was compared with those without history of cardiovascular/cerebrovascular diseases. |
LBBB, left bundle branch block; RBBB, right bundle branch block; IVCD, intravascular conducting delay; AV, atrial-ventricular; CVD cardiovascular disease. |