Resting ECGs (section: physical state) were taken in Lifelines participants aged 13 years and older during:
The 12-lead resting ECG measures electrical activity of the heart during rest, summarized in 12 leads.
The ECG provides many (>400) different variables at once, both quantitative and qualitative traits. These include duration, voltage and configuration characteristics. For example, information is provided of the cardiac rhythm, heart rate, the function of the sinoatrial and the atrioventricular node, atrial size, left ventricular mass, and repolarisation time (e.g. QT time).
Welch Allyn CardioPerfekt Workstation ecg_manual.pdf
Welch Allyn CardioPerfect Workstation Software ecg_software_manual.pdf
DT100 vacuum units (suction electrode system).
Electrodes were placed with conduction spray on ten clean spots at the abdomen and left side of the chest of lying participants (see illustration). In case of dextrocardia, the electrodes were mirrored.
All ECGs were checked by the research nurse and the Welch Allyn algorithm using CardioPerfekt software (see flow chart). ECG deviations (atrium fibrillation, atrium flutter, bradycardia, tachycardia, infoaction, acute ischemia, ST elevation, Wolff Parkinson White Syndrome, bigemenia, Left Bundle Branch Block, >1 premature ventricular contraction, second or third grade AV-block, pacemaker) were reported to a cardiologist.
The ECG resulted in the following variables:
| Label English | Code | Variable | Assessment | Age |
| ecg performed | ecg_performed_all_m_1 | ecgond_1 | 1A | 13+ |
| ecg performed | ecg_performed_all_m_2 | ecgond_2 | 2A | 13+ |
| if not, reason: / ecg performed | ecg_performed_all_m_2_a | ecg_reden | 2A | 13+ |
| ecg device code | ecg_devicecode_all_m_1 | ecgdevice | 2A | 13+ |
| is ecg to be manually reviewed by a doctor? | ecg_toreview_all_e_1 | review | 1A 2A | 13+ |
| system evaluation ecg | ecg_toreview_all_e_3 | systeem | 3A 4A | 13+ |
| is the ecg manually reviewed by a doctor? | ecg_reviewed_all_e_1 | reviewed | 1A 2A | 13+ |
| automatic interpretation by welch allyn | ecg_welchallyn_all_m_1 | means | 1A 2A | 13+ |
| type of lead set used for analysis of paedriatic ecg | ecg_paediatric_all_m_1 | afleidingenset | 3A | 13+ |
| ecg technician - category of ECG review | ecg_category_all_e_1 | ecg_functieanalist_ecg_category | 3A 4A | 13+ |
| ecg technician - technical review | ecg_conclusion_all_e_3 | ecg_functieanalist_ecg_conclusion | 3A 4A | 13+ |
| ecg technician - advise to GP based on ecg review | ecg_gpadvise_all_e_1 | ecg_functieanalist_ecg_feedback_gp | 3A 4A | 13+ |
| heart rate | ecg_heartrate_all_m_1 | hr | 1A 2A 3A 4A | 13+ |
| overall p-axis (degrees) | p_axis_all_m_1 | p_axis | 1A 2A 3A 4A | 13+ |
| overall duration of p-wave (ms) | p_wave_all_m_1 | p | 1A 2A 3A 4A | 13+ |
| overall pq time (ms) | pq_time_all_m_1 | pq | 1A 2A 3A 4A | 13+ |
| overall qrs-axis (degrees) | qrs_axis_all_m_1 | qrs_axis | 1A 2A 3A 4A | 13+ |
| qt-interval (ms) | qt_interval_all_m_1 | qt | 1A 2A 3A 4A | 13+ |
| overall duration of the qrs-complex (ms) | qrs_complex_all_m_1 | qrs | 1A 2A 3A 4A | 13+ |
| qt-interval (ms) corrected for heart frequency (hodges) | qtc_interval_all_m_1 | qtc | 1A 2A 3A 4A | 13+ |
| overall t-axis (degrees) | t_axis_all_m_1 | t_axis | 1A 2A 3A 4A | 13+ |
| negative amplitude of p-wave (microvolt) - lead I - II - III - aVR - aVL - aVF - V1 - V2 - V3 - V4 - V5 - V6 - x - y - z | pnegamp_i/ii/iii/avr/avl/avf/v1-6/x/y/z_all_m_1 | pnegamp_1-6/15-20/23-25 | 1A 2A 3A 4A | 13+ |
| negative amplitude of p-wave (microvolt) - lead v3r | pnegamp_v3r_all_m_1 | pnegamp_13 | 1A 3A | 13+ |
| negative amplitude of p-wave (microvolt) - lead v7 | pnegamp_v7_all_m_1 | pnegamp_21 | 1A 3A | 13+ |
| posittive amplitude of p-wave (microvolt) - lead I - II - III - aVR - aVL - aVF - V1 - V2 - V3 - V4 - V5 - V6 - x - y - z | pposamp_i/ii/iii/avr/avl/avf/v1-6/x/y/z_all_m_1 | pposamp_1-6/15-20/23-25 | 1A 2A 3A 4A | 13+ |
| positive amplitude of p-wave (microvolt) - lead v3r | pposamp_v3r_all_m_1 | pposamp_13 | 1A 3A | 13+ |
| positive amplitude of p-wave (microvolt) - lead v7 | pposamp_v7_all_m_1 | pposamp_21 | 1A 3A | 13+ |
| amplitude of the q-wave (microvolt) - lead I - II - III - aVR - aVL - aVF / V1 - V2 - V3 - V4 - V5 - V6 - x - y - z | qamp_i/ii/iii/avr/avl/avf/v1-6/x/y/z_all_m_1 | qamp_1-6/15-20/23-25 | 1A 2A 3A 4A | 13+ |
| amplitude of the q-wave (microvolt) - lead v3r | qamp_v3r_all_m_1 | qamp_13 | 1A 3A | 13+ |
| amplitude of the q-wave (microvolt) - lead v7 | qamp_v7_all_m_1 | qamp_21 | 1A 3A | 13+ |
| duration of the q-wave (ms) - lead I - II - III - aVR - aVL - aVF / V1 - V2 - V3 - V4 - V5 - V6 - x - y - z | qduration_i/ii/iii/avr/avl/avf/v1-6/x/y/z_all_m_1 | qduration_1-6/15-20/23-25 | 1A 2A 3A 4A | 13+ |
| duration of the q-wave (ms) - lead v3r | qduration_v3r_all_m_1 | qduration_13 | 1A 3A | 13+ |
| duration of the q-wave (ms) - lead v3r | qduration_v7_all_m_1 | qduration_21 | 1A 3A | 13+ |
| amplitude of the r'-wave (microvolt) - lead I - II - III - aVR - aVL - aVF / V1 - V2 - V3 - V4 - V5 - V6 - x - y - z | raccamp_i/ii/iii/avr/avl/avf/v1-6/x/y/z_all_m_1 | raccamp_1-6/15-20/23-25 | 1A 2A 3A 4A | 13+ |
| amplitude of the r'-wave (microvolt) - lead v3r | raccamp_v3r_all_m_1 | raccamp_13 | 1A 3A | 13+ |
| amplitude of the r'-wave (microvolt) - lead v7 | raccamp_v7_all_m_1 | raccamp_21 | 1A 3A | 13+ |
| duration of the r'-wave (ms) - lead I - II - III - aVR - aVL - aVF / V1 - V2 - V3 - V4 - V5 - V6 - x - y - z | raccduration_i/ii/iii/avr/avl/avf/v1-6/x/y/z_all_m_1 | raccduration_1-6/15-20/23-25 | 1A 2A 3A 4A | 13+ |
| duration of the r'-wave (ms) - lead v3r | raccduration_v3r_all_m_1 | raccduration_13 | 1A 3A | 13+ |
| duration of the r'-wave (ms) - lead v7 | raccduration_v7_all_m_1 | raccduration_21 | 1A 3A | 13+ |
| amplitude of the r-wave (microvolt) - lead I - II - III - aVR - aVL - aVF / V1 - V2 - V3 - V4 - V5 - V6 - x - y - z | ramp_i/ii/iii/avr/avl/avf/v1-6/x/y/z_all_m_1 | ramp_1-6/15-20/23-25 | 1A 2A 3A 4A | 13+ |
| amplitude of the r-wave (microvolt) - lead v3r | ramp_v3r_all_m_1 | ramp_13 | 1A 3A | 13+ |
| amplitude of the r-wave (microvolt) - lead v7 | ramp_v7_all_m_1 | ramp_21 | 1A 3A | 13+ |
| duration of the r-wave (ms) - lead I - II - III - aVR - aVL - aVF / V1 - V2 - V3 - V4 - V5 - V6 - x - y - z | rduration_i/ii/iii/avr/avl/avf/v1-6/x/y/z_all_m_1 | rduration_1-6/15-20/23-25 | 1A 2A 3A 4A | 13+ |
| duration of the r-wave (ms) - lead v3r | rduration_v3r_all_m_1 | rduration_13 | 1A 3A | 13+ |
| duration of the r-wave (ms) - lead v7 | rduration_v7_all_m_1 | rduration_21 | 1A 3A | 13+ |
| amplitude of the s'-wave (microvolt) - lead I - II - III - aVR - aVL - aVF / V1 - V2 - V3 - V4 - V5 - V6 - x - y - z | saccamp_i/ii/iii/avr/avl/avf/v1-6/x/y/z_all_m_1 | saccamp_1-6/15-20/23-25 | 1A 2A 3A 4A | 13+ |
| amplitude of the s'-wave (microvolt) - lead v3r | saccamp_v3r_all_m_1 | saccamp_13 | 1A 3A | 13+ |
| amplitude of the s'-wave (microvolt) - lead v7 | saccamp_v7_all_m_1 | saccamp_21 | 1A 3A | 13+ |
| duration of the s'-wave (ms) - lead I - II - III - aVR - aVL - aVF / V1 - V2 - V3 - V4 - V5 - V6 - x - y - z | saccduration_i/ii/iii/avr/avl/avf/v1-6/x/y/z_all_m_1 | saccduration_1-6/15-20/23-25 | 1A 2A 3A 4A | 13+ |
| duration of the s'-wave (ms) - lead v3r | saccduration_v3r_all_m_1 | saccduration_13 | 1A 3A | 13+ |
| duration of the s'-wave (ms) - lead v7 | saccduration_v7_all_m_1 | saccduration_21 | 1A 3A | 13+ |
| amplitude of the s-wave (microvolt) - lead I - II - III - aVR - aVL - aVF / V1 - V2 - V3 - V4 - V5 - V6 - x - y - z | samp_i/ii/iii/avr/avl/avf/v1-6/x/y/z_all_m_1 | samp_1-6/15-20/23-25 | 1A 2A 3A 4A | 13+ |
| amplitude of the s-wave (microvolt) - lead v3r | samp_v3r_all_m_1 | samp_13 | 1A 3A | 13+ |
| amplitude of the s-wave (microvolt) - lead v7 | samp_v7_all_m_1 | samp_21 | 1A 3A | 13+ |
| duration of the s-wave (ms) - lead I - II - III - aVR - aVL - aVF / V1 - V2 - V3 - V4 - V5 - V6 - x - y - z | sduration_i/ii/iii/avr/avl/avf/v1-6/x/y/z_all_m_1 | sduration_1-6/15-20/23-25 | 1A 2A 3A 4A | 13+ |
| duration of the s-wave (ms) - lead v3r | sduration_v3r_all_m_1 | sduration_13 | 1A 3A | 13+ |
| duration of the s-wave (ms) - lead v7 | sduration_v7_all_m_1 | sduration_21 | 1A 3A | 13+ |
| deviation from the st segment at 0 ms from the j point (mm) - lead I - II - III - aVR - aVL - aVF / V1 - V2 - V3 - V4 - V5 - V6 - x - y - z | st0_i/ii/iii/avr/avl/avf/v1-6/x/y/z_all_m_1 | st0_1-6/15-20/23-25 | 1A 2A 3A 4A | 13+ |
| deviation from the st segment at 0 ms from the j point (mm) - lead v3r | st0_v3r_all_m_1 | st0_13 | 1A 3A | 13+ |
| deviation from the st segment at 0 ms from the j point (mm) - lead v7 | st0_v7_all_m_1 | st0_21 | 1A 3A | 13+ |
| deviation from the st segment at 20 ms from the j point (mm) - lead I - II - III - aVR - aVL - aVF / V1 - V2 - V3 - V4 - V5 - V6 - x - y - z | st20_i/ii/iii/avr/avl/avf/v1-6/x/y/z_all_m_1 | st20_1-6/15-20/23-25 | 1A 2A 3A 4A | 13+ |
| deviation from the st segment at 20 ms from the j point (mm) - lead v3r | st20_v3r_all_m_1 | st20_13 | 1A 3A | 13+ |
| deviation from the st segment at 20 ms from the j point (mm) - lead v7 | st20_v7_all_m_1 | st20_21 | 1A 3A | 13+ |
| deviation from the st segment at 40 ms from the j point (mm) - lead I - II - III - aVR - aVL - aVF / V1 - V2 - V3 - V4 - V5 - V6 - x - y - z | st40_i/ii/iii/avr/avl/avf/v1-6/x/y/z_all_m_1 | st40_1-6/15-20/23-25 | 1A 2A 3A 4A | 13+ |
| deviation from the st segment at 40 ms from the j point (mm) - lead v3r | st40_v3r_all_m_1 | st40_13 | 1A 3A | 13+ |
| deviation from the st segment at 40 ms from the j point (mm) - lead v7 | st40_v7_all_m_1 | st40_21 | 1A 3A | 13+ |
| deviation from the st segment at 60 ms from the j point (mm) - lead I - II - III - aVR - aVL - aVF / V1 - V2 - V3 - V4 - V5 - V6 - x - y - z | st60_i/ii/iii/avr/avl/avf/v1-6/x/y/z_all_m_1 | st60_1-6/15-20/23-25 | 1A 2A 3A 4A | 13+ |
| deviation from the st segment at 60 ms from the j point (mm) - lead v3r | st60_v3r_all_m_1 | st60_13 | 1A 3A | 13+ |
| deviation from the st segment at 60 ms from the j point (mm) - lead v7 | st60_v7_all_m_1 | st60_21 | 1A 3A | 13+ |
| deviation from the st segment at 80 ms from the j point (mm) - lead I - II - III - aVR - aVL - aVF / V1 - V2 - V3 - V4 - V5 - V6 - x - y - z | st80_i/ii/iii/avr/avl/avf/v1-6/x/y/z_all_m_1 | st80_1-6/15-20/23-25 | 1A 2A 3A 4A | 13+ |
| deviation from the st segment at 80 ms from the j point (mm) - lead v3r | st80_v3r_all_m_1 | st80_13 | 1A 3A | 13+ |
| deviation from the st segment at 80 ms from the j point (mm) - lead v7 | st80_v7_all_m_1 | st80_21 | 1A 3A | 13+ |
| negative amplitude of t-wave (microvolt) - lead I - II - III - aVR - aVL - aVF / V1 - V2 - V3 - V4 - V5 - V6 - x - y - z | tnegamp_i/ii/iii/avr/avl/avf/v1-6/x/y/z_all_m_1 | tnegamp_1-6/15-20/23-25 | 1A 2A 3A 4A | 13+ |
| negative amplitude of t-wave (microvolt) - lead v3r | tnegamp_v3r_all_m_1 | tnegamp_13 | 1A 3A | 13+ |
| negative amplitude of t-wave (microvolt) - lead v7 | tnegamp_v7_all_m_1 | tnegamp_21 | 1A 3A | 13+ |
| positive amplitude of t-wave (microvolt) - lead I - II - III - aVR - aVL - aVF / V1 - V2 - V3 - V4 - V5 - V6 - x - y - z | tposamp_i/ii/iii/avr/avl/avf/v1-6/x/y/z_all_m_1 | tposamp_1-6/15-20/23-25 | 1A 2A 3A 4A | 13+ |
| posittive amplitude of t-wave (microvolt) - lead v3r | tposamp_v3r_all_m_1 | tposamp_13 | 1A 3A | 13+ |
| posittive amplitude of t-wave (microvolt) - lead v7 | tposamp_v7_all_m_1 | tposamp_21 | 1A 3A | 13+ |