Is a heart scan safe?

i mean ,i had a heart scan last week after they put a stent inside of me a year ago.The person giveing me the scan held the scanning probe with gel on it for ages on one spot on my chest,it did hurt as it was pressed quite hard agianst my chest, but what i would like to know is ,is holding the probe for so long on one area harmfull?? as i am thinking like a person haveing a many x rays of a certain part of thier body.Can some one please re-ure me. Many Thanks