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Obesity-associated electrocardiographic changes are also found in healthy young individuals with a normal body mass index (BMI) (18.5–25 kg/m2).
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There were significant differences between the BMI quartiles in terms of maximum P-wave duration, P-wave balance, total P-wave area in lead V1, PR-interval duration, and heart axis.
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Within the normal range, an increased BMI was independently associated with an increased P-wave duration, increased P-wave balance, a leftward shift of the heart axis, and decreased Sokolow-Lyon voltage.
Introduction
Methods
Medical screening
Weight and height measurement
ECG measurements
Variable | Description |
---|---|
Maximum P-wave duration (ms) | Longest P-wave duration sampled from all leads |
P-wave balance in lead V1 (µV) | Difference between the upward and downward deflection of the P‑wave |
P-wave dispersion (ms) | Difference between the longest minus the shortest P-wave duration from all leads |
Total P-wave area in lead V1 (mm*ms) | Sum of the total area under and above the isoelectric line from onset to termination of the P‑wave [27] |
PR interval (ms) | Beginning of the P‑wave until the beginning of the QRS complex |
QRS duration (ms) | First deflection from the isoelectric line following the P‑wave until the J‑point |
Heart axis (degrees) | Net vector of the R wave axis based on the extremity leads |
Sokolow-Lyon voltage (mm) | Sum amplitude of the S wave in lead V1 and the amplitude of the R wave in lead V5 or V6 (whichever is larger) [28] |
Cornell product (ms*mm) | |
Maximum T‑wave duration (ms) | Longest T‑wave duration sampled from all leads |
Minimum T‑wave duration (ms) | Shortest T‑wave duration sampled from all leads |
T-wave dispersion (ms) | Difference between the longest and shortest T‑wave duration selected from all leads |
QTcF duration (ms) | QTcF duration is calculated using the Fridericia formula, which divides the QT interval by the cube root of RR interval [30]. QT interval is the interval between the start of the Q wave and the end of the T wave. RR interval is the interval between the onset of one QRS complex to the onset of the next QRS complex, measured in seconds, derived from the heart rate (HR) as 60/HR |
Validation cohort
Statistical analysis
Results
Body mass index (kg/m2) | |||||
---|---|---|---|---|---|
18.5–20.7 (n = 323) | 20.8–22.0 (n = 334) | 22.1–23.4 (n = 324) | 23.5–25.0 (n = 309) | 25.1–30.0 (n = 255) | |
Corresponding group |
α
|
ß
|
γ
|
δ
|
ε
|
Age (years) | 22.2 ± 2.93 γ δ ε | 22.6 ± 3.02 | 23.0 ± 2.93 α | 23.1 ± 3.05 α | 23.1 ± 2.89 α |
Gender (% male) | 70.0 | 72.8 | 76.5 | 75.4 | 77.5 |
Temperature (°C) | 36.7 ± 0.35 | 36.7 ± 0.40 | 36.7 ± 0.40 | 36.7 ± 0.39 | 36.8 ± 0.39 |
Systolic blood pressure (mm Hg) | 117 ± 10.2 γ δ ε | 119 ± 10.5 ε | 120 ± 9.63 α ε | 121 ± 10.0 α | 123 ± 10.0 α ß γ |
Diastolic blood pressure (mm Hg) | 67.9 ± 7.77 | 68.3 ± 7.74 | 68.6 ± 7.68 | 68.4 ± 7.50 | 69.1 ± 8.34 |
Ventricular rate (beats/min) | 64.4 ± 9.99 | 62.7 ± 9.69 | 62.5 ± 10.6 | 62.6 ± 9.83 | 64.7 ± 10.6 |
Serum Sodium (mmol/l) | 141 ± 1.82 | 141 ± 1.90 | 141 ± 1.92 | 141 ± 1.85 | 141 ± 1.91 |
Serum Potassium (mmol/l) | 4.31 ± 0.33 | 4.33 ± 0.31 | 4.33 ± 0.29 | 4.36 ± 0.30 | 4.33 ± 0.30 |
Serum Calcium (mmol/l) | 2.42 ± 0.09 | 2.42 ± 0.09 | 2.41 ± 0.09 | 2.42 ± 0.09 | 2.42 ± 0.10 |
Maximum P-wave duration (ms) | 99.09 ± 10.4 δ ε | 100.5 ± 11.5 δ ε | 101.2 ± 10.7 ε | 102.9 ± 10.6 α ß | 103.8 ± 11.1 α ß γ |
P-wave balance in lead V1 (µV) | 0.31 ± 0.45 δ ε | 0.32 ± 0.42 δ ε | 0.33 ± 0.43 | 0.41 ± 0.41 α ß | 0.42 ± 0.35 α ß |
P-wave dispersion (ms) | 51.5 ± 20.8 | 53.6 ± 19.9 | 52.0 ± 21.0 | 51.7 ± 21.3 | 50.9 ± 20.9 |
Total P-wave area in lead V1 (mm*ms) | 47.53 ± 82.6 δ ε | 47.15 ± 76.3 δ ε | 50.50 ± 79.5 δ ε | 67.91 ± 80.0 α ß γ | 70.96 ± 74.0 α ß γ |
PR interval (ms) | 146.9 ± 18.1 γ δ ε | 149.9 ± 21.9 | 152.2 ± 21.0 α | 151.5 ± 20.7 α | 153.1 ± 19.0 α |
QRS duration (ms) | 96.0 ± 10 | 96.4 ± 10 | 97.7 ± 10 | 97.0 ± 10 | 96.9 ± 10 |
Heart axis (degrees) | 68.65 ± 25.8 γ δ ε | 63.90 ± 26.0 δ ε | 59.77 ± 27.0 α ε | 54.57 ± 28.3 α ß | 51.91 ± 28.2 α ß γ |
Sokolow-Lyon voltage (mm) | 28.02 ± 8.28 | 27.30 ± 7.78 | 27.83 ± 8.27 | 26.80 ± 7.69 | 26.77 ± 7.66 |
Cornell product (mm*µV) | 11.45 ± 6.29 | 12.29 ± 6.52 | 12.47 ± 6.21 | 11.74 ± 5.78 | 12.07 ± 6.09 |
Maximum T‑wave duration (ms) | 183 ± 20 | 184 ± 20 | 182 ± 20 | 183 ± 20 | 181 ± 21 |
Minimum T‑wave duration (ms) | 107 ± 54 | 115 ± 52 | 110 ± 49 | 114 ± 51 | 109 ± 50 |
T-wave dispersion (µV) | 75.9 ± 54.7 | 69.4 ± 52.9 | 72.5 ± 54.7 | 68.3 ± 51.8 | 72.4 ± 50.5 |
QTcF duration (ms) | 404.8 ± 17 | 406.7 ± 18 | 405.4 ± 18 | 405.1 ± 19 | 404.0 ± 19 |
BMI and electrocardiographic parameters
Linear regression analysis
Univariate analysis | Multivariate analysis | ||||||
---|---|---|---|---|---|---|---|
Variable | USC | SC | R square | P value | USC | SC | P value |
Age (per year) | 0.079 | 0.139 | 0.019 | <0.001 | 0.061 | 0.108 | <0.001 |
Female gender | −0.211 | −0.054 | 0.003 | 0.056 | Excluded | ||
Temperature (°C) | 0.038 | 0.009 | 0.000 | 0.764 | |||
Systolic blood pressure (mm Hg) | 0.024 | 0.146 | 0.021 | <0.001 | 0.029 | 0.173 | <0.001 |
Diastolic blood pressure (mm Hg) | 0.005 | 0.022 | 0.000 | 0.479 | |||
Ventricular rate (beats/min) | −0.013 | −0.076 | 0.006 | 0.006 | −0.014 | −0.081 | 0.005 |
Serum Sodium (mmol/l) | −0.022 | −0.024 | 0.001 | 0.399 | |||
Serum Potassium (mmol/l) | 0.299 | 0.054 | 0.003 | 0.054 | 0.253 | 0.046 | 0.098 |
Serum Calcium (mmol/l) | −0.735 | −0.038 | 0.001 | 0.178 | |||
Maximum P-wave duration (ms) | 0.020 | 0.130 | 0.017 | <0.001 | 0.018 | 0.112 | <0.001 |
P-wave balance in lead V1 (µV) | 0.003 | 0.077 | 0.006 | 0.006 | 0.003 | 0.072 | 0.010 |
P-wave dispersion (ms) | 0.001 | 0.009 | 0.000 | 0.740 | |||
Total P-wave area in lead V1 (mm*ms) | 0.002 | 0.084 | 0.007 | 0.003 | Excluded | ||
PR interval (ms) | 0.007 | 0.090 | 0.008 | 0.001 | Excluded | ||
QRS duration (ms) | 0.009 | 0.053 | 0.003 | 0.059 | Excluded | ||
Heart axis (degrees) | −0.012 | −0.191 | 0.036 | <0.001 | −0.010 | −0.164 | <0.001 |
Sokolow-Lyon voltage (mm) | 0.000 | −0.048 | 0.002 | 0.084 | 0.000 | −0.097 | <0.001 |
Cornell product (mm) | 5.67 *10−7 | 0.021 | 0.000 | 0.458 | |||
Maximum T‑wave duration (ms) | −0.002 | −0.019 | 0.000 | 0.503 | |||
Minimum T‑wave duration (ms) | 0.001 | 0.038 | 0.001 | 0.171 | |||
T-wave dispersion (ms) | −0.001 | −0.045 | 0.002 | 0.107 | |||
QTcF (ms) | 5.38 *10−5 | 0.001 | 0.000 | 0.982 |