After weights workout i experienced muscle spasms in my right pectoral muscles for over 24 hours, no indication of palpitations, increased pulse or heart issues. what is the cause or concerns?

Not unusual: Occam's razor states that the simplest explanation is usually the correct one (my paraphrase). Since you are using your pectoralis muscles vigorously, it seems entirely reasonable for that muscle to give you some feedback with fasiculations, fatigue, and/or spacticity under the right conditions. Common sense would dictate that you should "give it a rest", at least till your're better.

Stamina : It could be that you are over-exerting yourself. Will recommend toning it down and then increase the intensity over next few days . Rarely this could be electrolyte problem. May wanna get it checked by pcp.