shaking on Saturday,
Sinus tachycardia can be caused by a multitude of different conditions, most of them non cardiac. Im not sure the reason your physician wants you to see a cardiologist unless there are some factors that he/she is concerned with that lends the specific etiology to the heart. Overall, a good history and physical will often point to the primary cause of the symptoms. Without being the physician performing this, I cant comment on why he/she thinks you need a cardiologist.
good luck
Hi I think your PCP wanting you to see a cardio should be reason enough for you to do so.
I would see a cardio under your circumstances if anything you will feel better knowing you did.
Do you trust your PCP? If so, go to the cardiologist. If you don't trust your PCP, you should look for another one.