I’d strongly suggest that she visit a GP for a formal consultation.
As pointed out, she has clear risk factors for heart disease, especially in the context of experiencing symptoms such as a heavy heart and fatigue.
It’s worth noting that certain ECG abnormalities can be non-specific.
I’d still suggest for you to bring the actual recording of the old ECG down for the consultation (as well as all her other old medical notes/laboratory results) – it’s very helpful for the doctor to compare any current ECG readings against the old one that was taken.
He may go on to suggest an exercise treadmill test, which is a commonly used screening test for patients with risk factors for heart disease.
Cheers
