ECG of the Week - 14th August 2017 - Interpretation

The following ECG is from a 74 yr old male who presented with suspected cardiac chest pain.

Click to enlarge

Rate:

• 103 bpm

Rhythm:

• Regular
• Abnormal P wave preceding each QRS
• P wave inversion leads II, III, aVF, V3-6
• Positive P wave in lead aVR and V1

Axis:

• Normal

Intervals:

• PR - Short (~100ms)
• QRS - Normal (80ms)
• QT - 330ms (QTc Bazette 430 ms)

Additional:

• Early R wave transistion
• Very flat T waves through-out

Interpretation:

• Ectopic Atrial Tachycardia

The ECG machine failed to recognize the abnormal P wave axis instead reading the ECG as showing delta waves in leads V5-6 and II due to relatively short pr with superimposed p inversion trailing into the QRS. 
Remember always look at the ECG yourself, don't trust the machine and take the ECG to the bedside.

What happened ?

The patient was admitted under the cardiology team for further investigation of suspected ACS. Coronary angiogram showed diffuse non-obstructive coronary disease for medical management. Following commencement of beta-blocker therapy the patient's ECG reverted to normal sinus rhythm with unchanged QRS morphology. 

References / Further Reading

Life in the Fast Lane

• Ectopic Atrial Tachycardia

Textbook

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