@StevenGerrard, in your case, I strongly advise against using oral minoxidil. You have a heart condition, and you also say that topical minoxidil gave you "terrible chest pains plus arrhythmia". Goodness knows what oral minoxidil could do to you. You're already using dutasteride, aren't you, and dutasteride is a highly effective treatment in itself. I think you need to think for a minute, is it really worth putting your health (and, worst case scenario, your life) in serious danger just for the sake of growing some extra hairs in addition to whatever results you're already achieving with dutasteride?