Human heart aneurysm: biochemical and morphological characteristics

The microscopic structure of left ventricular wall aneurysms and akinetic zones differs markedly. In samples obtained from akinetic zones, dystrophic changes and marked hypertrophy of muscle cells were observed with dispersed myofibrosis. In 1 case of left ventricular wall aneurysm, a pronounced nonspecific inflammatory reaction in the subepicardial layer was present. In all samples investigated, there were marked morphological signs of activated proteosynthesis, mainly aggregations of ribosomes, both in the muscle cells and in the fibroblasts. Utilization of glucose-14C was highest in samples with a predominant content of muscle cells. Pentose-phosphate shunt activity was highest in samples consisting mainly of fibrous scar tissue. The ability of the tissue homogenate to incorporate glycine-14C into the trichloracetic acid-precipitated protein was higher in samples containing predominantly connective tissue. The highest activity of the pentose-phosphate shunt, together with the highest rate of proteosynthesis, was observed in the sample from the left ventricular wall aneurysm with marked inflammatory infiltration of the tissue.