Nitroglycerin itself is the reason of your blood pressure fall, as it will dilate your arteries your diastolic blood pressure falls, avoid it if there is no chest heaviness Or exertional breathlessness. However I will suggest you to get an ekg done particularly when your when your heart rate is on lover side. Likewise if your are on beta blocker group of drugs that will result in lowering of pulse rate in most of the patient s. Do re titrate your medication when your Gp returns. Regards. Dr Priyank mody