The singer, who recently relaunched the group on U.K. Tv series The Big Reunion, suffers from an irregular heartbeat and needs surgery to determine whether she requires a pacemaker.
Heaton has asked doctors to postpone the procedure until she wraps up her plans with Liberty X, and admits she finds the prospect daunting as she will be awake throughout the operation.
She tells Britain's Ok! magazine, "After the Big Reunion gig, I'm going to have an operation, where they'll put electrical wires into my heart. It doesn't sound nice and I'll be awake... They'll measure my heartbeat and see where the arrhythmia (irregularity) is coming from. Then, depending on the prognosis, I could have a pacemaker fitted. I don't want a pacemaker, but if it fixes my problem of course I will (have it fitted)."
The operation will come just months after Heaton underwent a double mastectomy to prevent her developing breast cancer.
Heaton and her Liberty X bandmates are one of six U.K. pop groups to have reformed for The Big Reunion, a Tv show which will conclude with a comeback concert in London and a nationwide tour.