Lately i noticed that i would sometimes take a sudden deep breath involuntarily. should i be concerned? whom should i consult?

Ask your doctor!: Did you just describe a sigh or yawn? ...And those certainly are not pathologic! now, if there is pain with it... Or if you've got other symptoms, you might be able to build a case but you should ask yourself whether or not you've been anxious about something... Or particularly bored. If your doctor listened to your lungs, checked some lab, maybe a blood gas, he/she could reassure you further.