Herceptin and heart function


I had my 3rd herceptin injection today. I had it infused since March with chemo so I've had 6 altogether. I had a heart MRI in January and they said my injection fraction (whatever that means) was 64%. I had another MRI in may and they told me today it had gone down to 61%. I asked if it was ok and they said it was still in range. Has this happened to anyone else? I'm worried it will keep falling 

Julie x

  • Hi Julie /  

    Normal LVEF (left ventricular ejection fraction) is between 55% and 70%. The test is a measure the heart muscles strength and the figure is the % ammount of blood in the left chamber that is pumped by the heart in one heartbeat in real time. I was allowed in with J when she had her MUGA scan and onscreen I was actually watching the scan of her heart working - clever stuff eh...

    Herceptin can gradually lower this % figure - the cut off figure is around 50% to 52%. If it gets this low they will usually give you a break from Herceptin for a few weeks to allow the levels to rise back a bit.  The reason the cut off level is just over 50% is any lower than 45% and the heart may not recover fully leaving you with lifelong damage.

    When J started Herceptin her 18 x herceptin her level was 67%. Halfway through this had dropped to 52% and she was given a 3 week break - Her levels came back up to 58% and stayed around this level until her last Herceptin. I'm not sure if they lowered her dosage slightly after her break though ?

    It is fairly common the need a break towards the end or not fully complete the course.

    Hope this puts your mind at rest a bit - G n' J

  • Hello

    Thanks for your reply, I see that they are saying 6 months herceptin is as effective as 12 months now so if I get to the 6 month mark I will feel better about it.

    Thanks again 

    Julie x