pediatrics
Hypertension in Children
Pathophysiology of Hypertension in Children
As in adults, blood pressure is determined by the balance between cardiac output (affected by myocardial contractility, heart rate, and vascular volume) and vascular resistance (affected by vascular structure and function). The renin-angiotensin-aldosterone system, sympathetic nervous system, sodium transport, and other factors play a role (for further information, see Pathophysiology ). Unlike in older adults, in children and younger adults cardiac output and volume status are more likely to be the prominent driving forces of hypertension, but with aging, vascular structural changes with increased vessel wall thickness and stiffness (which increase vascular resistance) play a more important role. Complications of pediatric hypertension can be Acute Chronic of hypertension in children are relatively uncommon and are usually related to Hypertensive Emergencies in Children , in which end-organ dysfunction or damage is present. Affected organs include the central nervous system (causing encephalopathy, including seizures, lethargy, and/or coma), heart (causing heart failure), eyes (causing papilledema, retinal hemorrhages), and kidneys (causing renal insufficiency). Chronic complicationsof hypertension in children are rare and when present typically do not occur until late adolescence or early adulthood. The complications of chronic hypertension in adults, including coronary artery disease, heart failure, ischemic stroke, and hypertensive end-stage renal disease, rarely, if ever, occur in children. However, there are findings in children that seem to predict later development of these complications. The best-studied and most accurate predictor is the development of left ventricular (LV) hypertrophy (diagnosed by echocardiography). When normalized for height, age, and sex, an LV mass > 51 g/m2is considered excessive. This finding is a clear reason to begin antihypertensive therapy during childhood. Another finding in some hypertensive children that is thought to be a risk factor for cardiovascular disease in adulthood is intima media thickness, as measured by using sensitive ultrasonographic techniques. In children with chronic kidney disease, hypertension has been associated with a steeper decline in kidney function and increased urinaryalbuminexcretion, a marker of kidney damage. Finally, there is preliminary evidence suggesting that hypertension causes deficits in neurocognitive function, but these reports are very limited. 