Premature Ventricular Conduction
Right Ventricular PVC
Left Ventricular PVC
Pacemaker Lead Placement
Atrial Pacing
The pacing lead is inserted into the atrium to cause atrial depolarization
Ventricular Pacing
The pacing lead is inserted into the ventricle to cause ventricular depolarization
AV Sequencial
Pacing The pacing lead is inserted into the both the atrium and ventricle stimulating at set intervals
ST Segment Depression
The J point occurs at the end of the QRS complex. The ST segment begins at the J point and extends to a user-defined interval.
Downsloping ST
Upsloping ST
Horizontal ST
Ventricular Rhythms
Premature Ventricular Complex - PVC
Heart Rate - Rhythm - PWave - PR Interval (in seconds) - QRS (in seconds)
N/A - Irregular with PVCs - N/A - N/A - ≥ 0.12
Unifocal PVCs: Identical shapes
Multifocal PVCs: More than one shape
Paired PVCs (Couplet)
R on T Phenomenon: PVC occurs at the peak of the of T wave of the preceding beat
Ventricular Bigeminy: Every other beat is a PVC
Ventricular Trigeminy: Every third beat is a PVC
Ventricular Quadrigeminy: Every fourth beat is a PVC
Ventricular Fusion Beat
Heart Rate - Rhythm - PWave - PR Interval (in seconds) - QRS (in seconds)
N/A - N/A - Present Same as sinus rhythm or shorter - ≥ 0.12
Ventricular Escape Beat
Heart Rate - Rhythm - PWave - PR Interval (in seconds) - QRS (in seconds)
< 40 bpm - Irregular - Absent - Absent - ≥ 0.12
Idioventricular Rhythm
Heart Rate - Rhythm - PWave - PR Interval (in seconds) - QRS (in seconds)
20 - 40 bpm - Regular - Absent or not related - N/A - ≥ 0.12
Accelerated Idioventricular Rhythm (AIVR)
Heart Rate - Rhythm - PWave - PR Interval (in seconds) - QRS (in seconds)
40 - 100 bpm - Regular - Absent, not related or retrograde conduction - N/A - ≥ 0.12
Ventricular Tachycardia (3 or more consecutive ventricular complexes)
Heart Rate - Rhythm - PWave - PR Interval (in seconds) - QRS (in seconds)
> 100 bpm - Regular - Absent, not related or retrograde conduction 1:1. 1:2, or VA Wencheback - N/A ≥ - 0.12
Ventricular Fibrillation
Heart Rate - Rhythm - PWave - PR Interval (in seconds) - QRS (in seconds)
300 - 600bpm - Extremely irregular - Absent - Absent - Absent
Ventricular Asystole
Heart Rate - Rhythm - PWave - PR Interval (in seconds) - QRS (in seconds)
Absent - Absent - Absent or present - Absent - Absent
Pacemaker Rhythms
Electronic Pacemaker Spikes
Electrical stimuli delivered by the electronic pacemaker to the endocardium are seen as a spike on the surface ECG.
Ventricular Pacemaker (single chamber)
Single spike producing a wide QRS complex (ventricular capture).
Atrial Pacemaker (single chamber)
Single spike producing paced P wave (atrial capture) followed by an intrinsic QRS complex.
AV Sequential Pacemaker (dual chamber)
First spike followed by a paced P wave (atrial capture) followed by a second spike producing a wide QRS complex (ventricular capture).
Paced Fusion Beat
The electronic pacemaker and the patient’s own cardiac rhythm occurs simultaneously producing a combination of a paced beat and an intrinsic beat.
Full Compensatory Pause vs. Noncompensatory Pause
To measure a Full Compensatory Pause:
- Mark off three normal cycles
- Place the first mark on the P wave of the normal cycle preceding the premature complex
- The third mark should fall exactly on the P wave following the premature complex to be called a compensatory pause.
Failure to Capture
The pacemaker generates a pacemaker spike but does not cause an intrinsic beat (P wave or QRS).
Failure to Sense
The pacemaker does not recognize the intrinsic beats and generates an unnecessary pacemaker spike.
Failure to Fire
The pacemaker does not generate a pacemaker spike when it is needed.
ECG Artifact
Any waveform on the ECG that is not related to the patient’s cardiac events
Calibration Pulses
Deliberate artifact caused to show the interpreter the relationship of the complexes with a known ele
AC Interference (60 cycle)
Sixty even, regular spikes in a one-second interval caused by electrical current near the patient.
Muscle Tremor (Somatic)
Electrical interference caused by the patient’s tensed muscles.
Wandering Baseline (Draft)
An undulating baseline with waveform present.
This is part two of two posters to assist healthcare professionals in recognizing basic arrhythmias. According to the Practice Standards for Electrocardiographic Monitoring in Hospital Settings (Circulation. 2004;110;2721-2746) in general, the mechanisms of arrhythmias are the same in both adults and children. However, the ECG appearance of the arrhythmias may differ due to development issues such as heart size, baseline heart rate, sinus and AV node function, and automatic Innervation.
ECG terminology and diagnostic criteria often vary from text to text and from one teacher to another. There are often several terms describing similar findings (for example: Premature Atrial Contraction, Atrial Premature Complex, Atrial Extrasystole, Supraventricular Ectopic Beat, etc.) It is important to correlate the ECG interpretation with the clinical observation of the patient.
This poster includes Premature Ventricular Conduction, Pacemaker Lead Placement, ST Segment Depression, Ventricular Rhythms, Pacemaker Rhythms, Full Compensatory Pause and ECG Artifact. The ECG rhythm Strips display lead II as the top waveform and lead V1 as the bottom waveform. Classic examples are shown for each rhythm to provide basic visualization and avoid complexities. The intended use of this poster is to complement a text and/or course – in addition to a reference guide for arrhythmia recognition
The most common ECG rate, interval, and duration measurements are from the following publications:
- Clinical Electrocardiography (Post Graduate Institute for Medicine).
- Understanding Electrocardiography (Mary Boudreau Conover).
- How to Quickly and Accurately Master Arrhythmia Interpretation (Dale Davis). • Principles of Clinical Electrocardiography (M. J. Goldman).
- Basic Dysrhythmias Interpretation and Management (Robert Huszar).
- An Introduction to Electrocardiography (Leo Shamroth).
- Interpretation of Arrhythmias (Emanual Stein)
