Sinus arrhythmia is a normal physiological process and most of the time it is an indication of good health.
Sinus tachycardia is the normal tachycardia in sinus rhythm, which is normal.
What is your highest rate of tachycardia? It should be indicated on the results page. Were you at rest? Moving? Exercising?
You should make some more tests (echo and stress) to see if your heart is structurally normal and to exclude coronary heart disease. If your heart is normal, nothing to worry about, reduce stress, coffee, cigarettes and sweets. Walk and ride a bike to strengthen your heart and you'll live long...
look up innapprorite sinus tachycardia