Echocardiography of Gαq mice 16 weeks of age. (A) SS-31 (3mg/kg/d) for 4 weeks (from age 12–16 weeks) significantly ameliorated the decline in systolic function, as indicated by FS in Gαq mice. (B,C) Chamber enlargement and diastolic dysfunction in Gαq mice were slightly attenuated by SS-31 with a statistical trend, p=0.08 and 0.06, respectively. (D) Worsening of myocardial performance index (MPI) in Gαq mice was significantly ameliorated by SS-31. (E) An increase in normalized heart weight in Gαq mice was substantially protected by SS-31, while there was a trend towards protection from increased normalized lung weight by SS-31 (p=0.09), n=3–6.