Your health care provider may advise a CRT for the following reasons :

• If you are experiencing symptoms of heart failure that range from mild to severe.
• When the lower chambers of your heart do not synchronize to work together.
• If your heart is weak and enlarged as detected during the testing.
• When your heart failure is not well controlled by medicines and lifestyle changes.

Reference : Cardiac Resynchronization Therapy. (n.d.). Retrieved from https://www.azheartarrhythmia.com/contents/ep-procedures/cardiac-resynchronization