Started minoxidil 5% recently and experienced chest tightness. ekg test came back perfect. how can i use minoxidil without chest side effects?

It would be REALLY: unusual to have chest tightness as a side effect of topical minoxidil, suggested by the 5% label. It is, however, a strong blood vessel dilator, and when taken orally can affect the heart/heart rate. You may be an unusually sensitive reactor. All I can say is...if you are sure the chest pain is associated with application of topical Minoxidil (try, stop, etc), then you must avoid the minoxidil.