There is evidence that in most cases the heart damage of trastuzumab tends to be manageable, even temporary, and reversible in some cases. In fact, many patients have been re-challenged with trastuzumab after initial evidence of heart damage and have been able to tolerate it. However, this issue should not be taken lightly, and you should be on regular cardiac monitoring. If you have a pre-existing heart condition or borderline poor heart function, you may or may not be a candidate for trastuzumab. You should discuss this with your doctor.