Hi. The doctor at my university just recommended Lexapro for me (I've had anxiety for over two years now) and I just did a quick search on it and noticed that some side-effects can be heart palpitations or a lengthening of the QT interval... Seeing as I have a minor ventricular septal defect, should I be concerned about taking this medication given my heart condition? She's prescribed 10mg daily. Also, and I don't know how useful this info is for you but, I'm an 18 year old female, 5 foot 4, around 135 lbs.