Pathophysiology for sure about the development of hypertensive crisis is unknown. Progressive malignant hypertension may be a nonspecific process that causes increased blood pressure is extreme. Humoral factors (especially the renin-angiotensin axis) and local products produced by blood vessels (eg prostaglandins and free radicals) may also be involved in increasing blood pressure very quickly.
However, the progressive increase in blood pressure is an important first step. There are three major organ systems are affected by high blood pressure is the central nervous system, cardiovascular system, renal system.
Central Nervous System
Cerebral autoregulation is an important ability of the cerebral blood vessels to maintain cerebral blood flow remained constant in addition to changes in blood pressure. When the average arterial pressure - mean (MAP) increased, disturbed and endhotelium cerebral brain barrier can become loose. Fibrinoid material deposited in the brain blood vessels and cause lumen narrowed. Then the blood vessels of the brain trying to vasodilatation in the lumen was narrowed. This could be the beginning of cerebral udem and mikrohemoragik. Patients with chronic hypertension may tolerate a high MAP before an interruption in autoregulasi system.
Enselopati Hypertension is one of the clinical manifestations of cerebral edema and mikrohemoragi, which occur dysfunction of cerebral autoregulation. Without immediate treatment, enselopati hypertension can lead to cerebral hemorrhage, coma and eventually died.
Cardiovascular system
Hypertension affects the structure and function of coronary arteries and left ventricle. Hypertension also activate the renin-angiotensin system, aldosterone, which causes systemic vasokonstriktif. This resulted in increased oxygen demand of the heart muscle because of increased left ventricular wall stress that can lead to hipertropi left ventricle and compression of the coronary blood vessels. When hypertension emergency occurs, the left ventricle can not compensate for systemic vascular resistance. This will ultimately lead to left ventricular failure and pulmonary edema, or ischemic heart muscle.
renal system
Chronic hypertension causes pathological changes in small arteries of kidney. This continued on endothelial dysfunction and a weak vasodilatation, which will affect renal autoregulation. When disturbed renal autoregulation, intraglomerular pressure is directly related to systemic arterial pressure, this makes the lack of protection of renal changes in fluctuating blood pressure. When the crisis of hypertension, such interference can cause ischemia in acute renal.
No comments:
Post a Comment