A patient with a secondary prevention ICD in situ experienced a shock from his device. The download is shown in the strip. It is a single-chamber device and the top trace is from the RV tip to RV ring and the lower trace is from the generator can to the RV shock coil.
A. He has had an appropriate shock for VF
This is a single-chamber device and it is important not to become confused and think that the top trace is from an atrial lead and that the diagnosis is AF. The rate is very fast and irregular with a chaotic morphology demonstrating VF. ATP would have been unsuccessful, but a further clue that this was a shock comes from the notation 24.9J at the bottom of the strip at the point the shock was delivered. Different manufacturers’ interrogation strips can look quite different but close scrutiny of all the information can often give the answer.