Frances, 57, was diagnosed with paroxysmal atrial fibrillation and keeps her heart rate under control with flecainide.

“I went to bed as normal one day and woke in the early hours feeling very strange. 

"My heart was beating heavily and I had a feeling similar to stomach rumbling, but it was in my chest. I could feel this across the upper part of my chest, including the top of my arm. I wasn’t worried as it didn’t hurt, and I drifted in and out of sleep.

“By 11am the next day, it was still going on, so I phoned the doctor. He told me to get a taxi to the surgery straight away, but I walked instead. Halfway there, I started to feel unwell and thought I was going to pass out.

“Once I’d made it to the doctor's, I didn’t feel too bad. My GP took my pulse and straight away said that I had an arrhythmia, which is an irregular heartbeat.

"He wired me up to an electrocardiogram (ECG) and managed to capture my arrhythmia on the printout. Apparently, this can come and go quite quickly.

“I was given a high dose of aspirin, to lower my risk of getting a stroke, and was referred to hospital immediately. By the time I reached hospital, my symptoms had stopped. Luckily, the doctors could see from my previous ECG that I had an arrhythmia and diagnosed me with paroxysmal atrial fibrillation.

"They made an appointment for me to have a 24-hour ECG, which records heart symptoms as you go about your normal daily activities, and then I was discharged.

“In the meantime, I had two more episodes of atrial fibrillation and had to come back to hospital. I was given an intravenous infusion of flecainide, which corrects an abnormal heartbeat. I was only on the drip for 10 minutes when the monitor showed my heartbeat going back to normal. I’ve been on low-dosage tablets of flecainide ever since.

“When my appointment came for the 24-hour ECG, I felt perfectly well. Since I’ve been on the tablets, I haven’t had anything like those three episodes.

"I also take aspirin daily to protect me from a stroke. Every day I experience extra heartbeats called ectopic beats, but they’re nothing to worry about.”