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Figure 2 Left: Sample of the electrocardiogram of a 9-year-old girl during the maximal load of the exercise stress test (leads II, aVF, V2–5). Middle: Electrocardiogram of the same girl during exercise stress test three years later showing multifocal ventricular ectopic beats. Right: Electrocardiogram obtained during an exercise stress test of a 42-year-old woman demonstrating sustained polymorphic ventricular tachycardia (leads V_1–6).