The medication capaptin 40 and telema 40 which you are right now taking is mainly for controlling your blood pressure.
The pproblem which you are describing is mainly the problem with the electrical activity of the heart and in medical term it is known as arrythemia. It can be of many types and because of many problems.
It is important to have a proper controlled rate of heart to maintain the cardiac function. In case of arrrythemia the abnormality in the heart rate
can lead to disturbed heart function and present in various sign and symptoms.
I would suggest you to have a consultation with some cardiologist and try to investigate this problem of racing heart beat and in the mean time keep taking our blood pressure medication
and also try to find if this is related to some event which you face and your heart rate start racing. I mean to ask you if any precipatating factor is there which is causing this problem.
Thanks and take care.