The club launched an initiative over the weekend after conversations with the general secretary of the Federation of Hearts supporters, Steven Kilgour.
It allowed fans to buy a virtual ticket for the Championship encounter due to be played on Friday, February 26.
With the match being shown live on BBC Scotland, it has denied Inverness the chance to make money from PPV.
Hearts and Inverness fans have responded in incredible fashion.
The Highlanders' previous record attendance of 7,753 at the Caledonian Stadium was set back in 2008 with the visit of Rangers.
At time of writing 7,820 virtual tickets have been sold.
A club statement said: “Everyone at ICTFC is both astonished and full of gratitude to the fans of all clubs who have bought tickets so far. Virtual tickets for our Championship match v Hearts only went on sale on Saturday morning and with very little fanfare, as were preparing for our scheduled and subsequently postponed game v Dundee. We had no target. We had no expectation.
"That however, did not deter our own loyal Caley Jags fans, nor the football public in general from rallying to support our initiative over the weekend. Incredibly, fans from across four continents have bought tickets since Saturday.
“But one group of fans in particular, the supporters of Heart of Midlothian FC, have made the most incredible financial effort and subsequently, they have not only made a huge difference to us in this stressful and onerous season, they have shown a collective level of goodwill seldom seen in football.
“Unless we build a new stand in the future, of which there are understandably no plans to do, they will forever hold the record (and it is still rising!) attendance at Inverness Caledonian Thistle Football Club and it has been achieved in the most philanthropic of circumstances.
“It is a unique record, achieved in unique circumstances and given the circumstances, entirely appropriate. And it is still rising.
“Thank you everyone, whoever you support, the generosity and warmth you have each shown towards a fellow football club is hugely appreciated.”