Clinical Complications Of Systemic Hypertension
Chronic hypertension can have adverse effect to the other parts of the body or other systems. Most often the organs/systems most susceptible are the” Cardiovascular system, nervous system, retina and Kidneys.
- The left ventricle undergoes hypertrophy and dilatation and later on cardiac failure sets in.
- Ischemic heart disease is more common in them. This may present as angina pectoris, myocardial infarction or sudden death.
- Atherosclerosis is accelerated. Atherosclerosis of the aorta may lead to dissecting aneurysm. Atherosclerosis of the coronary, cerebral, renal and peripheral arteries lead to their progressive occlusion.
Central nervous system
Strokes are among the most common complications in hypertension. The lesion may be an ischemic infarct resulting from thrombosis or a hemorrhage resulting from rupture of an artery.
Hypertensive encephalopathy: It is a specific complication seen in hypertensive patients when there is rapid rise of blood pressure. The incidence is higher in acute glomerulonephritis, pheochromocytoma and malignant hypertension. The cerebral arteries go into spasm in response to a rapid rise in blood pressure. Edema and ischemia of the brain develop. Clinically, it is characterized by intense headache, visual disturbances, convulsions, loss of consciousness and varying degrees of focal neurological deficits. Prompt reduction of blood pressure completely reverts the attacks and restores the normal state. This feature distinguishes hypertensive encephalopathy from cerebral infarction or hemorrhage in which the neurological deficit persists.
Atheroma of the renal arteries results in reduction of blood supply to the kidney and progressive loss of renal function in malignant hypertension. Renal function deteriorates rapidly, ending in renal failure.
The retinal arterioles undergo changes. These have been graded as follows:
- Grade 1: Arteriolar narrowing and increase in light reflex over the arterioles.
- Grade 2: Marked arteriolar narrowing and arteriovenous nicking
- Grade 3: Grade 2 + flame-shaped hemorrhages and fluffy (soft) exudates.
- Grade 4: Grade 3 + Papilledema.
The retinal changes give an indication of the progress of hypertension and help in determining the prognosis. Grades 1 and 2 are seen in the early phases of hypertension. Grade 3 is suggestive of the accelerated phase and grade 4 indicates transition to the malignant phase.
Malignant and accelerated hypertension
If hypertension is allowed to progress unchecked, many cases may go into the malignant phase. Its exact mechanism is not still clear. Secondary hypertension occurring in renal disease and pheochromocytoma shows a greater tendency to progress to the malignant phase. It is characterized by further elevation of blood pressure and grade 4 retinal changes. At this state, there is widespread fibirnoid necorsis of arterioles. Retinopathy may lead to visual impairment. The diagnosis of the malignant phase and the accelerated phase depends on the evidence of vascular damage in a patient with severe hypertension. Malignant hypertension is characterized by papilledema whereas accelerated hypertension shows only grade 4 retinopathy. Once the malignant phase sets in, death occurs within two years as a result of cardiac failure, renal failure or cerebral hemorrhage. Prompt treatment arrests the malignant phase and its complications.
Hypertension leads to reduction of lifespan and also considerable morbidity. Death is caused by cardiac failure, cerebrovascular accidents or renal failure. Reduction of blood pressure to normal levels significantly reduces mortality and morbidity and improves lifespan. Hypertension is the most frequent cause of ischemic and hemorrhagic strokes in the middle-aged and elderly. Maintenance of lower blood pressure levels considerably reduces the risk of strokes.
© 2014 Funom Theophilus Makama