Effects of exercise training on LV performance and mortality in a murine model of dilated cardiomyopathy

Dilated cardiomyopathy (DC) is a leading cause of cardiovascular morbidity, and nonpharmacological therapies, such as exercise training, have been sug gested. The effects of exercise on left ventricular (LV) function and morta lity remain controversial. Using a recently described murine model of DC, w hich involves a dominant-negative form of the cAMP response element binding protein (CREB) transcription factor (CREBA133) under the control of the ca rdiac myocyte-specific alpha-myosin heavy chain promoter, we sought to asse ss the effects of moderate-intensity exercise training on LV performance an d mortality. Thirty-two transgenic mice were subjected to exercise training and compared with sedentary controls. There was progressive enlargement in LV dimensions in both the sedentary and exercise-trained mice. LV performa nce was progressively impaired, and exercise training did not prevent this decline. The sedentary CREBA133 mice displayed a significantly increased ra te of death, and exercise training did not prevent or delay this excess mor tality. The CREBA133 murine model of inherited DC demonstrated progressive ventricular dilatation and dysfunction with increased mortality, which was not altered with 12 wk of moderate-intensity exercise training.