Is a weak/shallow heart beat a sign of heart problems? do i need to seek attention right away?

Heart Beat abnormal: If you have had the onset of a change in your heart beat or rate, the way to see if there is a serious problem with your heart rhythm is with an electrocardiogram (ECG or EKG). If this is sudden or has any associated symptoms such as chest pain, breathing difficulty, lightheadedness or other worrisome symptom, this should be evaluated promptly.

Need be examined: First we need to know if this is something new and how long this has been happening. In the absence of any illness or symptoms (fatigue, shortness of breath, weakness etc), I suspect that this is just your own perception. If you are concerned and this is something new, you should consult your doctor about it. If you have symptoms, you need to seek attention immediately.