Today's featured BHF Heart Runner in the 2008 Flora London Marathon is Tessa Dollar (pictured right).
Many runners take part and raise money for us in the Marathon because they have lost family and friends to a heart condition, or know those who are living with the effects of heart disease.
Tessa's experience of a heart conditions is an extremely personal one however.
She says: "By pure coincidence, I am under investigation for a heart condition. Luckily physical exertion doesn't seem to be an issue!
"So I have first hand knowledge what an amazing charity this is."
More than 600 Heart Runners will pound the streets of London on Sunday, raising hundreds of thousands of pounds for the BHF's vital and life-saving research work into heart disease.
Tessa will be among them, so if you'd like to sponsor her online please visit her page now