I am a 59 year old woman who has a mechanical mitral valve as of 2005.  Occasionally I have felt palpations in my chest, and once in awhile the fluttering palpations in my wrist and throat.  However, in the last three days I have had several instances of strong palpations in my neck, always in the same spot.  No pain.  Every time they have checked my carotid artery, it is fine.  I am on Warfarin, Lopressor, Synethroid, Prilosec, and anti-inflammatories.  I have not changed medication in several months.  My blood pressure is normal to low, with pulse at 60-70 beats per minute.  I do have stuffy sinuses and my right ear and throat (on that side) feel a little swollen.  Otherwise, no other heart symptoms at all.  Should I be concerned?