AGT and Ventriculomegaly: However, after challenging the animals by administration of AngII to increase cardiac afterload iCMp38αKO hearts developed a highly impaired systolic pump function (EF: 29 ± 7.6%) as well as an extensive left ventricular dilation (EDV: 109.7 ± 14.6 μl, ESV: 78.4 ± 16.5 μl) within 48 h after onset of AngII treatment.