- Sinus rhythm initially 55/min, with ventricular extrasystoles
- The third extrasystole occurs on the peak of the T wave of the preceding sinus beat
- After three or four beats of ventricular tachycardia, ventricular fibrillation develops
- In the sinus beats there is a Q wave in lead III; and there are raised ST segments in leads II and III, and ST segment depression and T wave inversion in lead I
Although only leads I, II and III are available, it looks as if the chest pain was due to an inferior myocardial infarction. This was probably the cause of the ventricular extrasystoles, and an ‘R on T’ extrasystole caused ventricular tachycardia, which rapidly decayed into ventricular fibrillation.
It might be argued that in lead III, and perhaps also in lead I, ‘torsade de pointes’ ventricular tachycardia is present, but this is not apparent in lead II.
What to do ?
Immediate defibrillation, but if no defibrillator is at hand then cardiopulmonary resuscitation should be performed, and the usual procedure for the management of cardiac arrest instituted.
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