An 80-year-old woman, who had previously had a few attacks of dizziness, fell and broke her hip. She was found to have a slow pulse, and this is her ECG. The surgeons want to operate as soon as possible but the anaesthetist is unhappy.
What does the ECG show and what should be done?
The ECG shows:
- P wave rate 130/min
- Complete heart block
- Ventricular (QRS complex) rate 23/min
- The ventricular ‘escape’ rhythm has wide QRS complexes and abnormal T waves
No further interpretation of the ECG is possible.
In complete heart block there is no relationship between the P waves (here with a rate of 120/min) and the QRS complexes.
What to do
In the absence of a history suggesting a myocardial infarction, this woman almost certainly has chronic heart block: the fall may or may not have been due to a Stokes–Adams attack. She needs a permanent pacemaker, ideally immediately. If permanent pacing is not possible immediately, a temporary pacemaker will be needed preoperatively.
Complete (third degree) heart block.