Case 4: An 81-Year-Old Man in Pacemaker Clinic
History
Diagnosis
History
An 81-year-old man with a pacemaker is in the operating room for shoulder surgery. Pacemaker device was “reprogrammed” just prior to surgery:
Diagnosis
- Sinus rhythm with VOO pacing (asynchronous mode with no ventricular sensing) – this mode was likely chosen to prevent inappropriate pacemaker inhibition during shoulder surgery.
- T-wave inversion – consider inferior ischemia
- Fusion beats (red arrow) – see Comment
- Pseudofusion beats (blue arrow) see Comment
Comment: Fusion beats represent an intermediate QRS complex between two sources within the same chamber – in this case, the fusion beats are intermediate between a conducted QRS complex and a paced QRS complex. Pseudofusion beats represent a native conducted QRS complex with a superimposed pacemaker “spike” from the pacing lead of the same chamber, which does not alter the QRS complex.
ECG ID: E783