ECG of the Week - 7th September 2015 - Interpretation

This week's ECG is from a 58 yr old male who presented with abdominal pain and vomiting. 
He is normal fit & well and takes no medication.

Click to enlarge

Rate:

• Atrial rate ~71 bpm
• Ventricular rate ~72 bpm

Rhythm:

• Regular atrial activity
• Some P waves obscured by PVC's
• Bigeminy pattern
• Native QRS followed by PVC's in 1:1 pattern
• Non-conducted P waves due to early PVC's
• 4th PVC subtly different morphology potential fusion complex

Axis:

• Native & PVC's Normal Axis

Intervals - Native QRS Complexes

• PR - Normal (~160ms)
• QRS - Normal (80ms)
• QT - 400ms

Intervals - PVC's

• QRS - Prolonged (160ms)

Segments:

• Native complexes normal ST segments
• Appropriate discordance of ST segments and T waves in PVC's

Interpretation:

• Bigeminy
• Underlying sinus rhythm with blocked P waves

There are multiple causes of PVC's and bigeminy including:

• Anxiety
• Altered sympathetic tone
• Drug toxicity
• Excess caffeine
• Electrolyte disturbance
• Ischaemia
• Myocarditis

Following supportive care and symptom control the patient's ECG showed resolution of the PVC's. Investigations revealed no sinister cause for the presentation and they were discharged.

References / Further Reading

Life in the Fast Lane

• Bigeminy 

Textbook

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