X Factor star Katie Waissel has updated her fans after she suffered a heart attack.Katie has been resting since the shock medical scare and posted a photo from her home as she relaxed to update her Instagram followers on her condition.In the photo Katie, 35, is seen wearing a Holter Monitor – a wearable device that monitors your heart rate and rhythm.She wrote: "Currently wearing the Holter Monitor as part of my ongoing cardiac testing.