Acute hypertensive damage of arterial vessels of the heart.
Experimentally-induced acute angiotensin hypertension has been shown to increase the permeability of cardial arteries and arterioles to plasma components within a few hours. Only in one of the coronary arteries was an increased and focal permeability for plasma components demonstrated, the penetration taking place into the entire thickness of the vessel wall. However, the permeability observed in intramyocardial small arteries and arterioles showed a distinct deposition of plasma components, both in the tunica intima and the tunica media and usually in the entire circumference of the vessels. The results support the view that an increased arterial permeability of the myocardial vessels for plasma components is an important initial stage in the development of hypertensive vascular disease of the heart.