Low blood pressure could in theory cause chest pain
due to an inadequate blood supply to the heart muscle (angina) but this would be rare.
A heart attack
in a 22 year old would be VERY rare unless it was caused by a clot that occurred as a result of trauma to the heart area (stab wound etc). Heart attacks generally occur in older people who have arteriosclerosis
(hardening of the artery walls). Plaque can build up in the arteries over time and break away forming a clot in the artery. This would then block off the blood supply to the heart and result in heart muscle death. Occasionally this can happen to very young people, but it's rare. Other complications are vasculitis
and 'bridging' coronary arteries, and other supply and demand issues which are very rare.
Low blood pressure is generally a normal healthy variant. It can sometimes indicate other endocrine and cardiac problems but that's quite rare. Lower than average BP is only ever a problem if its so low that it's unable to push blood around the body sufficiently. If this happened you would be symptomatic with dizziness