Can and ECHO scan be wrong?

[Multikatie]

I have recently been experiencing palatations , dizzyness , chest pain , headaches and near pass out , and high pulse of 160 BPM even if I stand up , move position and walk about for 20 seconds and it's annoying so can anyone have any ideas of what that could be .

I am 16 , female , I have been to see a cardiologist and he thought it could be a arrythmia , so he sent me for ECHO , 24 hour ecg they were done 8th August and in November I went back but I seen a different cardiologist witch was a locam one and he was very obnoxious and obedient , he said my ecg was fine , and the echo showed mild LV systolic impairment , but in his words it's Probley wrong as the ECHO people said they couldn't do it Properly and the palpitations are just stress , and my heart races to 160 BPM when I walk about 10-20 seconds and I don't have stress .

Also my mum has servere LV dysfunction as we'll so don't know if it could be related and also Sunday 15th December I had a MRI cardiac monopoly or something like that done , also before the MRI went to my doc and she said exactly what the result said and the cardiologist I seen at first wrote it , so the locam was undermining his judgement. Also it said they couldn't get a proper picture of the right side not the left and she said some people are born that way , but surely if I was born I would have know from scans I had when I was a baby and older and my question is can an echo give you and incorrect result !