An 89-year-old woman, with a past history of arterial hypertension, Graves disease, and paroxysmal atrial fibrillation, with preserved ventricular function on her last echocardiogram, presented to the emergency department with palpitations, with good hemodynamic tolerance. On arrival, ECG 1 was perfomed (Figure 1). Shortly after, the tracing of ECG 2 was recorded (Figure 2).

Figure 1

(0.57MB).

Figure 2

(0.62MB).

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