The singer, 35, was rushed to hospital earlier this month, sharing the news with her followers while recovering from the health scare.
She praised paramedics in Watford for their speediness in arriving at her home after calling emergency services.
In a follow-up Instagram post, shared on Wednesday (24 November), Waissel revealed she will be wearing a Holter Monitor as part of her “ongoing cardiac testing”.
“I will be wearing this device for 48 hours as it records my heart activity,” she wrote, adding: “Other testing follows this week, but emotionally, I am taking them just one test at a time.”
She promised her followers she will “share my findings with you”, saying that she hopes to “either give you clarity or peace of mind, to those that are seeking it”.
Following news of her suspected heart attack, Waissel’s spokesperson said: “Wednesday morning [10 November] an ambulance was called to Katie Waissel’s North London home, as she had experienced both signs and symptoms of a heart attack.”
Waissel became famous after appearing on the seventh series of ITV talent show The X Factor in 2010. She finished in seventh place.
Matt Cardle eventually won that year’s series, with Rebecca Ferguson and One Direction the runners up.
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