ECG of the Week - 27th February 2017 - Interpretation

The following ECG is from a 55yr old male who is having episodes of chest pain with increasing frequency. 

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Rate:

• 108 bpm

Rhythm:

• Regular
• Sinus rhythm

Axis:

• Normal

Intervals:

• PR - Normal (160-180ms)
• QRS - Normal
• QT - 300ms

Segments:

• Up-sloping ST segment in lateral precordial leads

Additional:

• Prominent T waves leads II, aVF, V6
• In relation to QRS magnitude
• Low QRS voltage
• No electrical alternans
• Baseline artifact affecting leads V4-6 and end of rhythm strip

Interpretation:

• Prominent T waves in the setting of chest pain are concerning for ACS
• Requires serial ECG's looking for progressive ST segment change
• Combination of low voltage & tachycardia should prompt consideration of pericardial effusion as a cause for the chest pain.
• As with all ECG's the ECG features need to be considered in the patient's specific clinical context

What happened ?

The patient was admitted for investigation under the cardiology team. Serial troponins and D-dimer were negative and an angiogram showed only minor vessel irregularities. 

Causes of Low Voltage ECG

Whilst pericardial effusion / tamponade is the most serious cause of ECG low voltage it is not the only cause or the most common. Causes include:

• Pericardial effusion
• Tamponade
• Pleural effusion
• Obesity
• COPD
• Pneumothorax
• Cardiac infiltrative disease
• Hypothyroidism
• Prior MI
• Dilated cardiomyopathy
• Incorrectly set ECG gain

References / Further Reading

Life in the Fast Lane

• Low QRS Voltage 

Textbook

• Chan TC, Brady WJ, Harrigan RA, Ornato JP, Rosen P. ECG in Emergency Medicine and Acute Care. Elsevier Mosby 2005.