(BBC News) A total of 745,000 pacemakers have been confirmed as having cyber-security issues that could let them be hacked.
The Food and Drug Administration revealed that 465,000 pacemakers in the US were affected, in an advisory note about a fix to the problem.
The pacemaker's manufacturer, Abbott, told the BBC there were a further 280,000 devices elsewhere.
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The flaws could theoretically be used to cause the devices to pace too quickly or run down their batteries.