Hi there. I know how that first appointment feels, so much information, so many words that it's hard to absorb it all. I too am HER2+ and the way my onc explained it to me was that HER2 cells are like excellerants on cancer cells, good news is that is what Herceptin is for. I am doing a year of herceptin (18 infusions I think) which I started when I started Docetaxol. I have it every three weeks until November this year. I dont have any side effects from it but yes you do have your heart tested every 12 weeks as herceptin can affect heart function, it hasn't affected mine and I believe it's only a small percentage that it does. I have an ECG every three months which is non invasive, it's a couple of pads on your chest and ultrasound. I hope this info helps you a little, I am more than happy to answer any other questions if I can relate to it. Good luck with your treatment, things do settle down a bit with time so go easy on yourself. Take care. Tash xx