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
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

7.2 Heart rate

Can be found for be, be2, ie, and ie2.

Feature id is heart_rate.

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)