Flexibility in Medical Writing

catheterization. Echocardiography would tend to overlook obstruction on the right side since the right ventricular outflow tract is not readily apparent and seldom evaluated under inotropic stimulation. This finding helps to further the concept that this disease involves the myocardium as a whole and it manifests itself as an obstruction where the anatomic features allow the changing size and shape to impede ejection at rest or with inotropic stimulation. Recent pathologic studies6 have shed some light on the ultrastructural characteristics of the myocardium in this disease. These studies were obtained on septal biopsies from patients operated on. The changes noted were 1 ) intracellular abnormalities (disarray of myofibrils and myofilaments), 2 ) cellto-cell abnormalities (disorganization of muscle cells, abnormal cell contacts). On biopsies of other portions of the myocardium (left ventricular apex and left ventricular posterior wall) cell hypertrophy was present in all cases. In patients with obstruction, no cell-to-cell alterations were present and intracellular abnormalities were observed in only three of eight patients. In patients with obstruction, changes as described in 1) and 2) were noted. They conclude that most changes occur in the septum. Nevertheless, comprehensive studies of other areas of the myocardium are not available. Some of the changes seen in operative cases are from patients with severe disease who have undergone secondary changes, and may not reflect the original situation. Much remains to be learned about this disease, but if a disease involves the myocardium, it can be associated with any congenital or acquired anomaly.