Histological examination of the resected aneurysm revealed myocardium which was almost totally replaced by dense fibrous tissue and numerous caseating granulomata.
Abnormalities of the coronary circulation were not apparent grossly in the specimens with hypertrophied right ventricular myocardium and imperforate pulmonary valves.
Other fetal organs can be involved such as the fetal heart (cardiomegaly with a thick myocardium which may contain punctuate calcifications) or the fetal lung.
While it commonly involves many organs, direct involvement of the myocardium is rare.
Apart from these changes in specific focuses, large areas of the myocardium can be normal.
The ventricular conduction tissues then extend on the septal surfaces as insulated subendocardial tracts before ramifying into the ventricular myocardium at the apexes.
Early treatment leads to the preservation of ischaemic myocardium, reduction of infarct size and maintenance of cardiac function.
Macroscopically visible myocardium may be confined to the base of the heart in the region of the tricuspid orifice.
