Pounding heart palpitations. resting heart rate 72-74bpm. palps as high as 90-100bpm. fatigued and dizzy. blood work was normal. is this concerning?

Mitral valve prolaps: Your episodic palpitations and rapid heart rate could be mitral valve prolapse, and an echocardiogram can determine if this is present, or another entity is causing this. See a cardiologist to get a precise diagnosis. While probably benign, some entities can be life threatening, and are treatable. Make an appointment ASAP.