Nurses have to do this at least once every eight hours and sometimes once every four hours depending on Dr.'s orders. It is then up to the nurse to identify the heart rhythm and if something is wrong notify the physician. And it is also a nurse's duty to make sure that if the alarm sounds on the machine monitoring the patient's heart: they check on the patient to get vital signs and assess heart, lungs, and other important body system before and during speaking with the doctor. Also during this process a nurse is expected to know the patient's medications, and I/O (input and output), and labs.
Overall, its a sinus rhythm. Possibly ST depression in Lead II, and inverted T wave in whichever V lead is shown, I'd worry about some ischemia. I'd recommend a 12-lead, with minimal artifact, and cardiac labs to confirm the ischemia and possible infarct.