I Have Vt And Nicm---diagnosed Feb, 2014--- I Have ICD

i have vt and nicm---diagnosed Feb, 2014--- I have ICD since that date. I am active and exercise daily (25 minutes--fast walking at small incline). and BMI of 21. I take 100 amerodine daily and 6.25 coreg and 3.25 lisiniprol 2X daily. Should I have a higher doseage of coreg?---I hear the more the better. I am age 72