Faint or unconscious. Case my critical?

Hi.. Few days back I climbed stairs (two rounds) in my second floor house with some heavy stuff. Just after completing stairs, I was feeling some giddiness.. But instead of lie down on bed , I preferred to go washroom.. After sitting on WC for one minutes, I fell unconscious. When I opened my eyes I was on floor with two broken teeth, my specs was damaged, a round on my forehead... Was it a stroke / attach.. Should I consult a heart specialist/ general physician / get ECG etc. done. My father had heart attack in 2007 when he was 62; open heart surgery was done.. in 2010 he had another heart failure, which he could not survive.. Does it make my case my critical? I have hypo thyroid since 2005 and taking 100 mg eltroxin daily... My thyroid is within range for last 6 month.