A 52-year-old man known to suffer from dilated cardiomyopathy due to a mutation of the LMNA gene was admitted to the cardiac intensive care unit in cardiogenic shock. He had a cardiac resynchronisation device (CRT-D) programmed at a paced atrioventricular delay of 200 ms and a lower rate set at 80 beats/min. The electrocardiogram at admission is shown in Fig. 1.

Fig. 1
figure 1

Electrocardiogram at presentation

What rhythm is seen and how can the pacing activity be explained?

Answer

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