I recently (6 weeks ago) sustained a crushing injury to my knee. The usual swelling, black and blue and pain. All that has gone. I still have slight swelling down to my foot, but no pain. A small area on the left side of my knee has no feeling. There is also a walnut sized blood clot just below the skin that down from egg sized. In the last week I have been getting heart palpatrations, (actually, missing a beat). Just for a short time when I get up in the morning or ready for bed at night. I take medications for low potassium, under active throid and high blood pressure. The question is: How serious does this sound?