My ECG report shows 'Sinus Tachycardia & RBBB'. Is that a serious problem?

Need more. Information s/t is hr > 100 so it could be 101 or 150 serious depends upon higher rate and if it is at rest and because it's always due to some underlying condition like fever dehydration heart disease so it is serious and be clarified by a cardiologist RBBB Not serious .