What Causes Chest Discomfort Along With Palpitations And Muscle Spasms?

Hi there. Ive had a very disturbed night, having been woken a few times with a funny sensation in my chest: I d say palpitations, flutterings or muscle spasm in my solar plexus kind of area, below where I d think my heart was, right in the middle of my breast plate at the bottom. It s been on about a five minute loop, although I have kept falling back to sleep. Im a 41 year old female, very healthy, on no medication an not under any stress ( unless you can count 3 kids on summer vacation...