In summary, using a murine model of ischemic cardiomyopathy with marked cardiac remodeling and severely impaired LV function, we show that short-term T3 therapy together with β1-AR blockade remuscularizes the heavily scarred LV PW, which results in an enduring improvement in LV structure and contractile function. This evidence concerns the gene ADRB1 and ischemic cardiomyopathy.