The British Heart Foundation has launched a wide-ranging appeal in the weeks leading up to Valentine's Day on 14 February, urging people to "have a heart" to help raise £1m.
It is hoped that the integrated campaign, which has been timed to peak next Tuesday, will raise enough to fund 30 new BHF nurses.
Marketing has already begun, with advertising rolled out across the country in the form of billboards, posters and press adverts.
The image shows a young girl who has undergone heart surgery alongside the message "Sorry Emma, there's only one BHF heart nurse for every 12,000 patients".
The foundation is aiming to raise awareness of the shortage of specialist nursing care and is asking members of the public to "give a gift that saves lives". The appeal also has a web component.
The homepage of the main BHF website has been taken over by the Valentine Appeal, with the Sorry Emma image appearing before a hand moves across the screen to peel back the page and reveal the message "Underneath, we're all romantics at heart. Have a heart and give a gift that saves lives".
The site, designed by the digital marketing agency Squeeze Digital, pulls together all the facets of the campaign, with links to donate, gifts to buy online and information on the various fundraising events. These include a Flirt Walk in Hyde Park on Sunday, organised in partnership with Parship dating service, which is designed both to raise funds and help people find a partner.
People are also encouraged to donate £1 for the right to put up a love note in a BHF shop window or online. Celebrities who have pledged their support include actress Helen Mirren, who expressed her wish as "One day with my dad, who died of a heart attack. Just one more day".
Community fundraisers have been sent packs with ideas for sales, sweepstakes and promise auctions. The campaign is also being supported by a general direct mailout and a Valentine's Day pack sent to 192,000 of the charity's supporters.
Jackie Skeel, head of fundraising campaigns at the foundation, said: "We have pulled all the stops out for this year's Valentine Appeal. We hope it will encourage people to visit the website and help raise funds for our heart nurses."