there are some forms of cardiac arrhythmia - including pat (paroxysmal atrial tachycardia) and supraventricular tachycardia - that can cause those symptoms; they can be diagnosed by a cardiologist using a holter monitor test and there are other conditions including high blood pressure all of which might have been brought to light by hormonal changes following your recent pregnancy. the best place to start is with your primary care provider. it could be that you may need to take a mild dose of a beta-blocker such as metoprolol tartrate which i take. once your doctors have ruled out anything more serious something along those lines could be of great help. if there is an endocrine imbalance your doctor might decide to send you to an endocrine specialist but because of the recent pregnancy be sure to keep your ob/gyn in the loop. good luck! in the meantime be sure to sleep with your head elevated slightly and it might help a little if you don't lie on your back it puts a little more stress on your mitral valves.
my heart pounds at night my ears burn and head pressure all the time and i feel dizzy most the time had for 5 weeks. had baby 4 months ago head pressure is in top temples forehead and back of head cannot sleep at night because of heart pounding