Chapter 7 Electrocardiograms
There are two identifiers for baseline and index electrocardiograms
Baseline electrocardiogram identifiers are [be] and [be2]
Index electrocardiogram identifiers are [ie] and [ie2]
Although there are 2 identifiers for each, they refer to the same EKG (e.g. ie and ie2 are the same EKG).
The duplicates were created to have a standard interpretation of EKGs in addition to the interpretation provided by the reporter.
Benay Ozbay reviewed all uploaded EKG files up to November 2022, and reported data into be2 and ie2. This means that be2 and ie2 features should be preferred over be and ie ones, when both are available.
Subsequent EKG during follow-up are in the index hospitalization instrument ih_ekg or in the follow-up instrument fu_ekg. (no expert review)
7.1 Analysis
All these four EKGs (be, ie, ih, fu) have an analysis feature. Below is the correspondence of each checkbox number.
Analysis feature exists for both be/be2 and ie/ie2.
| analysis_num | Feature |
|---|---|
| 1 | Normal Sinus Rhythm |
| 2 | Accelerated Idioventricular Rhythm |
| 3 | Accelerated Junctional Rhythm |
| 4 | Asystole |
| 5 | Atrial Fibrillation |
| 6 | Atrial Flutter |
| 30 | AV Nodal Reentrant Tachycardia |
| 7 | Bundle Branch Block, Nonspecific |
| 46 | Bundle Branch Block, Left Bundle (defined as QRS ≥120ms + broad notched or slurred R wave in I, aVL, V5 & V6) |
| 48 | Bundle Branch Block, Right Bundle (defined as QRS ≥120ms; RSR’ pattern in V1-V3; and slurred S wave in I, aVL, V5-6) |
| 9 | Escape Rhythm, Ventricular |
| 10 | Escape Rhythm, Junctional |
| 47 | Fasicular Block, Left Anterior |
| 49 | Fasicular Block, Left Posterior |
| 8 | Heart Block, First Degree |
| 23 | Heart Block, Second Degree Type I |
| 24 | Heart Block, Second Degree Type II |
| 31 | Heart Block, Third Degree |
| 11 | Junctional Tachycardia |
| 52 | Left Ventricular Hypertrophy (defined as sum of S wave in V1 + R wave in V5 or V6 ≥35 mm or R wave in aVL ≥11 mm) |
| 53 | Low QRS Voltage (defined as QRS voltage < 5 mm in the limb leads and/or < 10mm in precordial leads.) |
| 12 | Multifocal Atrial Tachycardia |
| 54 | PR-segment Depression (defined as ≥0.5 mm PR depression from TP segment) |
| 56 | P wave abnormality suggesting left atrial enlargement |
| 57 | P wave abnormality suggesting right atrial enlargement |
| 17 | Premature Atrial Complex |
| 20 | Premature Ventricular Complex Bigeminy |
| 21 | Premature Ventricular Complex Quadrigeminy |
| 22 | Premature Ventricular Complex Trigeminy |
| 39 | Pulseless Electrical Activity |
| 51 | Q Waves, Pathological |
| 26 | Sinus Arrest / Sinus Pause |
| 27 | Sinus Arrhythmia |
| 28 | Sinus Bradycardia |
| 58 | Sinus Dysfunction |
| 29 | Sinus Tachycardia |
| 40 | ST segment elevation, diffuse (defined as ≥1 mm unless in leads V2 to V3 where defined as ≥2 mm in men ≥40 years, ≥2.5 mm in men < 40 years, and ≥1.5 mm in women) |
| 41 | ST segment elevation, regional (defined as ≥1 mm unless in leads V2 to V3 where defined as ≥2 mm in men ≥40 years, ≥2.5 mm in men < 40 years, and ≥1.5 mm in women) |
| 42 | ST segment depression, diffuse (defined as ≥0.5 mm below the baseline) |
| 45 | Tall T waves (defined as >10 mm in precordial leads or >5 mm in the limb leads) |
| 44 | T wave inversions |
| 55 | T wave notching in ≥ 3 leads (defined as bifid T-wave with a notch duration between the 2 peaks ≥40 ms and an amplitude ≥0.5 mm) |
| 32 | Ventricular Fibrillation |
| 50 | Ventricular Tachycardia, Non-sustained (defined as 3 or more premature ventricular contractions for < 30 seconds at a rate of >100 beats per minute without hemodynamic collapse) |
| 33 | Ventricular Tachycardia Unspecified Morphology, Sustained |
| 34 | Ventricular Tachycardia Monomorphic, Sustained |
| 35 | Ventricular Tachycardia Polymorphic, Sustained |
| 36 | Ventricular Tachycardia Torsade de Pointes, Sustained |
| 37 | Wandering Atrial Pacemaker |
| 38 | Wolff-Parkinson-White Syndrome |
7.3 Durations, voltages
Additional data on mainstream durations and voltages can be found for be, be2 and ie2 (not for ie, don’t ask me why).
| var | EKG measure |
|---|---|
| pr_duration | PR |
| qrs_duration | QRS |
| qt_duration | QT Also qtcb_duration__c and qtcf_duration__c that are both calculated |
| sokolow_lyon_voltage | QRS voltage (only be2, ie2) |
| cornell_voltage | QRS voltage (only be2, ie2) |