ECG of the Week: ECG of the Week - 22rd January 2018

Wednesday 24 January 2018

ECG of the Week - 22rd January 2018 - Interpretation

The following ECG is from a 78 yr old female who presented to the Emergency Department with a history of progressively worsening dysponea and peripheral oedema. Her past medical history includes ischaemic heart disease and hypertension.

Click to enlarge

Things to think about

What are the key ECG abnormalities ?
How could you improve the quality of the patient's ECG ?

Rate:

60 bpm

Rhythm:

Regular
Sinus rhythm

Axis:

Normal

Intervals:

PR - Normal (~200ms)
QRS - Prolonged (120ms)

Additional:

RBBB Pattern
Baseline wander in limb leads ? U waves
Significant high frequency artefact obscuring majority of details in precordial leads

Interpretation:

Sinus rhythm with RBBB
Significant artefact obscuring rest of ECG interpretation

Troubleshooting artefact

There are multiple factors that can generate artefact during the ECG recording / printing process including:

Patient factors

Implanted devices
PPM - Pacing Spikes
Nerve stimulators
Movement disorders e.g. Parkinson's, essential tremor
Rigors
Muscle tremor / activity can be related to pain, hypothermia etc.
CPR
Habitus - very thin or obese patients, paediatric patients
Poor pad contact due to hair
Poor pad contact due to moisture - sweating, immersion etc.

Lead factors

Poor pad contact
Pad misplacement
Damaged lead or lead connection

ECG Machine Factors

Inappropriate settings of gain or filtering modes
Electrical artifact from power supply

Printing factors

Low ink
Print head tracking
Paper alignment

External factors

Interference from surrounding electronic devices. Relatively rare using newer ECG machines and environmental interference is usually compounded by incorrect machine filter settings.

An awareness of these factors and a systemic approach to addressing each point in the recording process, from patient to printer, is important in addressing recording problems such as artifact and lead mal-positioning.

References / Further Reading

Life in the Fast Lane