What Causes Chest Discomfort, Fluttering Sensation With Leaky Valve And Bradycardia Episodes?

I have been unwell since the last three months of my pregnancy, my baby is nearly six months old. I have severe discomfort in chest, both arms, upper body mainly although sometimes the fluttering sensation can go into my groin and legs. I also have occasional spells where I feel short of breath and have an irritating cough too at this time. I have a leaky valve, an enlarged left atrium and a new heart murmer. I have episodes of bradycardia at night. Echo normal with EF of 55%. ECG normal sinus rhythm. Any help would be appreciated. I am forty years of age and very overweight .Regards