Why am i having heart palpitations jut sitting at my desk at work? it happens about once a day for about 30 seconds.

Need info: Palpitations are universal. There sometimes is a reason for them, often not. Consider: are you using stimulants (caffeine, nicotine, decongestants?) are you well rested? Are you under particular stress? Generally, an evaluation would include and echocardiogram to exclude structural heart disease, lab tests for potassium, magnesium and thyroid hormone, and a 24 hr rhythm recording as a minimum.