Question

A 40-year-old woman was seen at our outpatient clinic because of episodes of palpitations that lasted several hours. She reported no syncopal episodes or family history of sudden cardiac death and was not on any medication. The resting ECG and ECG recorded during the palpitations are shown in Fig. 1a and b. What is the (differential) diagnosis?

Fig. 1
figure 1

a ECG at baseline. b ECG during symptoms

Answer

You will find the answer elsewhere in this issue.