The following ECGs are from a 89 yr old male who presented with worsening dizziness and light-headedness. Clinical examination revealed postural hypotension. He is on no medication.

Key features:  ECG1

• Mean ventricular rate ~48 bpm
• Mean atrial Rate ~84bpm
• 2:1 AV block
• LBBB Morphology
  • Sgarbossa negative

Key features:  ECG 2

• Mean ventricular rate 30 bpm
• Mean atrial rate 102 bpm
• Complete heart block
  • AV Dissociation
  • Atrial rate > ventricular rate
• Complexes #1 & #4
  • LBBB Morphology – same as ECG above
• Complexes #2, #3, & #5
  • RBBB Morphology
  • Deep T wave inversion leads V1-3
  • ? Cardiac T wave memory

Pacemaker Insertion Indication

This patient has a clear indication for PPM insertion given the AV block seen on the ECGs. However, even in the absence of AV block the second ECG also has another indication for PPM insertion. The second ECG also shows bilateral bundle branch block, evidence of both RBBB and LBBB, this is clear evidence of disease in all 3 fascicles and is a Class I recommendation for PPM insertion.

What happened?

The patient was admitted under the cardiology team and placed on an isoprenaline infusion. He underwent subsequent single chamber pacemaker insertion and was discharged following a brief in-patient stay.

Thank you Dr. J Larkin for the ECGs and interpretations.