Impaired Skeletal Muscle Fatigue Resistance in Rats with Pressure Overload-induced Left Ventricular Hypertrophy

In rats with left ventricular (LV) hypertrophy, we investigated whether abnormalities of skeletal muscle could result in reduced exercise tolerance in the absence of reduced cardiac function. LV pressure overload was induced by partial constriction of the abdominal aorta (AC) with controls subjected to sham operation. Cardiac and skeletal muscle function and blood flow were assessed in vivo3 and 6 weeks later. AC induced LV hypertrophy of 41 % and 37 % at 3 and 6 weeks post-operation. In AC rats, cardiac index was 31 ±8 and 35 ±4 ml /min /100 g at 3 and 6 weeks compared to 38 ±4 and 34 ±2 ml /min /100 g in controls ( n.s.). Fatigue index of the soleus (type-I rich) muscle in AC rats was reduced by 14 % ( P