flutter is a very general term used to explain many feelings in the chest. I had strange feelings for three months after my last procedure, but I described them as a twitching. It was as though my heart gave a solid THUMP and then speeded up with less intense pumping. Sometimes this occurred several times a day, sometimes just once. I think mine was the sensations of Vasospasm. During the procedure my Artery went into spasm which could be seen on the monitor, but after three months it seemed to stop. I believe vasospasm can start at any age, but there are medications which can help it. If the spasms are not too great, then there is no discomfort, as there were none with mine. It was just very annoying.
Just another idea.
Arrhythmias can be a symptom of coronary artery disease or appear in healthy hearts. I she continues to complain of these "flutters" she should mention this to her doctor.
Another term for heart flutter is PALPITATION. Regardless it is the subjective feeling and awareness of one's heart beat. It can be slow, regular or fast. It can be regular or irregular. And most important, it can be sustained or terminate on its own.
Without health history, prior symptoms, medication, etc. it would be difficult to help you assess the problem. If there has been previous heart attacks, there may be scar tissue that interferes with electrical conductivity. . Scar tissue in the heart from a heart attack or other injury can lead to palpitations, as can valve problems such as mitral valve prolapse.
Due to having a history of a heart attack, it may be advisable to have your mother's doctor to evaluate the arrhythmia...more than likely it is an innocent event, but your doctor advice can give you and your mother peace of mind.
Thanks for sharing, and if you have any followup questions, you are welcome to respond. Take care.