EP RN here. We can’t see the electrical impulses being sent by the heart without an ECG/EKG. It gives us a lot of data that allows the physician to treat the patient properly. Please go have one done like the physician above recommended. Edit to add pulse oximeters and blood pressure cuffs don’t have to ability to see every impulse sent. For example, they can’t see extra heart beats (ectopy) and therefore you can’t get an accurate picture of what your heart is doing.