Evaluate the collective function of references cited together in a given text segment.
Classify their combined role into one of the following categories: 'method', 'background', or 'result'.

Text:While previous computer models had to initiate re-entrant spiral waves artificially through an external stimulus in the repolarizing wave tail (16, 54, 57, 58) or trigger torsades de pointes through external pacing (55, 56), our model naturally predicts the spontaneous transition from a regular rhythm into ventricular tachycardia as a natural consequence of high risk drugs.
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