Systemic hypertension in children and adolescents: causes and treatment

Renovascular Hypertension

Hypertension constitutes a major health problem and the challenge is to identify patients having ‘surgically’ curable renal vascular disease among the majority with so-called essential hypertension. The best of unsatisfactory diagnostic tests are renography and plasma renin activity both before and during angiotensin II blockade. The necessity of better screening tests has increased because of the recent advances in surgical techniques and especially percutaneous transluminal renal angioplasty. The latter has definitely become the method of choice for correction of suspected hemodynamically significant artery stenoses whenever technically feasible. With improved angioplasty techniques the risk of treating renal artery stenosis without hemodynamic and clinical importance (so-called cosmetic repair) has increased. Unfortunately randomized trials including surgery versus angioplasty are not available. It should be kept in mind that only after correction of the stenosis is achieved and the blood pressure has become normal, can the diagnosis of renovascular hypertension be made with certainty.

Secondary hypertension: evaluation and treatment

Most patients with hypertension in the United States have essential (primary) hypertension (95%), the cause of which is unknown. The remaining 5% of adults with hypertension have the secondary form of hypertension, the cause and pathophysiologic process of which are known. Internists and other primary care physicians refer to this as treatable or curable hypertension, because the hypertension can be managed or even controlled with medications. Similarly, the condition is called surgical hypertension by surgeons in the belief that once the cause is determined and identified, surgical intervention will result in cure of hypertension. Secondary causes of hypertension include renal parenchymal disease, renovascular diseases, coarctation of the aorta, Cushing's syndrome, primary hyperaldosteronism, pheochromocytoma, hyperthyroidism, and hyperparathyroidism. Occasionally included in this category are alcohol- and oral contraceptive-induced hypertension and hypothyroidism, but these conditions are not discussed herein. The evaluation of secondary hypertension is of interest and can bring together different facets of anatomy, physiology, pharmacology, and radiology in the medical and surgical treatment of these disorders. Despite enthusiasm that can be generated in the evaluation of these conditions, evaluation can be expensive and should not be conducted for all patients with hypertension. Features that aid in the diagnosis of secondary hypertension include the following: 1. Onset of hypertension before the age of 20 or after the age of 50 years. The presence of hypertension at a young age may suggest coarctation of the aorta, fibromuscular dysplasia, or an endocrine disorder. Hypertension found for the first time after the age of 50 years may suggest the presence of renovascular hypertension caused by atherosclerosis. 2. Markedly elevated blood pressure or hypertension with severe end-organ damage, as in grade III or IV retinopathy. These findings suggest the presence of renovascular hypertension or pheochromocytoma. 3. Specific body habitus and ancillary physical findings. For example, truncal obesity and purple striae occur with hypercortisolism, and exophthalmos is associated with hyperthyroidism. 4. Resistant or refractory hypertension (poor response to medical therapy usually necessitating use of more than three antihypertensive medications from three different classes). 5. Specific biochemical test that suggest the existence of certain disorders, such as hypercalcemia in hyperparathyroidism, hyperglycemia in Cushing's syndrome and pheochromocytoma, and unprovoked hypokalemia with renin-producing tumors, primary hyperaldosteronism, or renin-mediated renovascular hypertension. 6. Other characteristics that may suggest secondary hypertension such as abdominal diastolic bruits (renovascular hypertension), decreased femoral pulses (coarctation of the aorta), or bitemporal hemianopias (Cushing's disease). A combination of a good history and physical examination, astute observation, and accurate interpretation of available data usually are helpful in the diagnosis of a specific causation.

Epidemiological survey of blood pressure of pre-school children

An epidemiological survey of blood pressure was carried out in 2301 pre-schoolers aged 2-6 years in 11 kindergartens of Guangzhou during 1984. Judging from the chart of selected percentile of blood pressure in relation to age plotted according to the mean blood pressure, the authors suggest that the upper limit of pre-schoolers' blood pressure is 115/75 mmHg. The blood pressure of growing children rises with increases in age, weight and height. Ponderosity Index (W/H3) reflects more precisely the influence of body weight and height on blood pressure. The results show that the percentage of children with high normal pressure is obviously higher in those with a family history of hypertension than in those without such a history. It is of great importance, in the prevention of primary hypertension, to practise medical surveillance and health care in children with high normal blood pressure, especially in those with a family history of hypertension.

Meningitis presenting as hypertension

A 21 month old girl who presented with what seemed to be hypertensive encephalopathy is described. Although her encephalopathy resolved with antihypertensive treatment, subsequent investigations revealed haemophilus meningitis.

Emotional and familial determinants of elevated blood pressure in black and white adolescent males

The relationships between blood pressure and several personality and traditional risk factors were examined in a sample of black and white adolescent males who were enrolled in a health science course in Tampa, Florida. Although a number of personality and traditional risk factors significantly predicted elevated blood pressure for both groups of adolescent males, suppressed anger and weight were the major independent predictors. Among black and white males, those who generally harbored grudges and suppressed their anger had higher systolic blood pressure; diastolic blood pressure was higher only for the white males who frequently held in their angry feelings. Weight and excessive salt usage significantly predicted both elevated systolic and diastolic pressures for white males, while these variables significantly predicted systolic pressures for black males. Familial factors were found to be independent predictors of systolic and diastolic blood pressure only for the white adolescent males. A further examination of the relationship between the frequency that anger is suppressed shows that the shape of the curves relating anger-in scores to blood pressure appears to have a 'threshold'. These findings indicate that adolescent males who are at increased risk for elevated systolic and diastolic blood pressure can be identified by how often angry feelings are held-in and suppressed.

Renal vein renin measurement and arteriography in the investigation and management of severe childhood hypertension

Forty-two children aged one to sixteen years with persistent and severe hypertension were investigated by renal vein renin measurements. There were no serious complications in the 49 procedures performed and technical failure occurred on three occasions. Arteriography was performed in 35. Asymmetrical renin release was found in 22 patients and of these 15 underwent surgery. This was successful in 12 patients (80%) who became normotensive. Ten had unilateral disease (100% cure rate) but only 2 (40%) with bilateral disease became normotensive. Renal vein renin studies combined with arteriography have a useful role in the investigation and management of childhood hypertension.

Correlates of adolescent blood pressure at five-year follow-up

In 1973, standardized measurements of blood pressure (BP), height, and weight were obtained on all adolescents attending high school in a rural Kentucky county. In 1978, a 5-year follow-up BP study was undertaken of all adolescents who were 14-15 years old at the time of the initial survey (n = 310), and of selected 16-19 year olds who were in the high, intermediate, and low ranges of the initial sex-specific BP distributions (n = 198). Follow-up measurements included height, weight, and BP on all subjects and, in addition, overnight sodium (Na) excretion, serum cholesterol, glucose, triglyceride, and uric acid concentrations on the older group. Our findings indicate that BP in young adults is related to BP in adoleslcence, change in relative weight since adoleslcence, and current relative weight. Relative rank order of initial BP levels were maintained over the 5-year period in both the younger and older groups. Additional cardiovascular disease risk factors were found to cluster in young adults with high BP, and clustering of risk factors may, in part, be related to high relative weight.

A survey of patterns of nonpharmacologic care for hypertensive patients, including recommendations for their children

To ascertain current approaches of physicians to nutritional-hygienic management of hypertensive patients and their children, a survey was done among a random sample of Chicago-area generalists, internists, and cardiologists. Thirteen items related to advice for patients; two for their children. Of 713 physicians holding M.D. degrees in the sample, 573 (80%) responded. For hypertensive patients, the great majority of physicians indicated that they advise weight loss, avoidance of salt use at table, no smoking, regular exercise, limitation of alcohol intake, and avoidance of stressful situations. Although 98% advised weight loss, a minority responded positively to reduction of carbohydrate and/or fat intake. Only 25% recommended limiting the salt use of children, and only 19% recommended taking the blood pressure of children of hypertensive patients. These data indicate that the majority of Chicago-area practitioners advocate nutritional-hygienic measures for their hypertensive patients. Only a minority, however, apparently advocate primary preventive approaches for the children of hypertensive patients.

Blood pressure in a high school population. II. Clinical profile of the juvenile hypertensive

One-hundred-fourteen hypertensive high school students were evaluated to determine whether a distinctive clinical profile could be identified; 71 normotensive students served as controls. Selected blood chemistry determinations, urinalysis, and chest roentgenograms were done to help rule out secondary causes of hypertension. Left ventricular function was assessed by echocardiography and systolic time intervals. The hemodynamic response to exercise was also evaluated. A significant number of the subjects 14 to 18 years of age with persistent systolic and/or diastolic pressure 1.65 SD above the mean for age and sex showed the following: obesity; elevated serum triglyceride concentration; basilar hypertrophy by electrocardiogram/vectorcardiogram; electromechanical systole and pre-ejection period shorter, and the ratio of the pre-ejection period over the left ventricular ejection time lower, than mean for age and sex as determined by systolic time intervals; volume indices depressed and cardiac contractile functions elevated as determined by echocardiography; higher blood pressure at start of exercise stress test and higher peak systolic and diastolic pressures during test, and a slower return of heart rate to base line level after the test. The above findings should be useful in following the course of a young individual with essential hypertension and may provide a means of evaluating therapeutic intervention.

Clinical evaluation and comparison of the Infrasonde, Arteriosonde, and mercury sphygmomanometer in measurement of blood pressure in children

Both systolic and diastolic pressures can be measured in children with the mercury sphygmomanometer, the Arteriosonde and the Infrasonde. Estimates made blindly with these instruments were compared with directly measured intra-arterial blood pressures in 50 children aged between 4 days and 14 years. Systolic and diastolic estimates with the three techniques showed highly significant correlations with simultaneous intra-arterial measurements (P less than 0.001). The Infrasonde diastolic estimates were least satisfactory and the slope of the regression line against the intra-arterial pressure differed significantly from unity (y=0.54x+29.53). In 11 small children a satisfactory diastolic estimate could not be obtained with the mercury sphygmomanometer. While the mercury sphygmomanometer should remain the standard hospital equipment, an Arteriosonde would be valuable if it is difficult to hear Korotkoff's sounds on auscultation and if a diastolic pressure is required. For research investigations into childhood blood pressure an Arteriosonde or mercury sphygmomanometer, coupled with a device to exclude observer bias, is probably most suitable. Although the Infrasonde is not sufficiently accurate for research purposes, it is acceptable for routine ward use.

A survey of 164 Finnish children and adolescents with hypertension

A retrospective analysis was performed on 164 children and adolescents with persistent hypertension. Among the unselected 115 patients with hypertension seen within the last three years 47 (41%) exhibited renal disease, 37 (32%) coarctation of the aorta, 10 (9%) miscellaneous associated causes and 21 (18%) no associated cause (essential hypertension). A substantial number, 53/164, had a primary disease potentially curable by surgery, and in 37 patients the blood pressure was normalized postoperatively. The outcome depended mostly on the basic disease and the availability of chronic hemodialysis. 11/164 children have died, all because of terminal basic disease, and one with simultaneous hypertensive crisis. We thus recommend a thorough investigation in the case of a child with persistent hypertension.

Hemodynamics of essential hypertension in young subjects

Cardiac output was determined in 42 young essential hypertensives (15 to 25 yrs); values ranged from 3.86 to 10.30 L./minute. These differences were not related to magnitude of volemia. Correlation of output to weekly blood pressure average (BPav) was not significant; its relationship to intraarterial pressure (BPia) was not significant in 21 patients aged 20 to 25 and of borderline significance in 13 aged 15 to 19. Blood pressure changes associated with the study (BPia--BPav) were also not consistently related to cardiac output. Six patients had systolic hypertension; only one had elevated stroke volume. These results outline as complex a picture in young essential hypertensives as in older subjects.

Nonrenovascular renal hypertension in children

Hypertension in children has been reported with increasing frequency because of increased awareness of its occurrence by clinicians. Renovascular lesions have been stressed in the past. However, in recent years, a number of nonrenovascular renal lesions have received attention and form the basis for this report. Unilateral chronic atrophic pyelonphritis, segmental unilateral pyelonephritis, the Ask-Upmark kidney, and unilateral renal hypoplasia have been associated with curable hypertension. The subject of juxtaglomerular cell hyperplasia, which has variably been reported in these cases, is reviewed. Ureteral obstruction, in the form of uretero-pelvic or ureterovesical junction obstruction, solitary renal cysts, the unilateral multicystic kidney, renal trauma, and renal tumors (Wilms' tumor and juxtaglomerular cell tumors) may also be associated with hypertension in children. Pheochromocytoma must be ruled out in all cases. Because of renewed interest, these nonrenovascular renal causes of hypertension are now likely to be diagnosed with increased frequency.

Hypertension in acute neurological diseases of childhood

Five children are described who developed hypertension in relation to acute neurological disease. Possible pathophysiological mechanisms for the hypertension are considered. It is thought that the hypertension may have been related to interruption of the ascending tracts in the brain stem, leading to failure of integration between, or independent action of, the baroreceptors and osmoreceptor system. Management and treatment are discussed. Diazoxide (5 mg/kg bodyweight, given intravenously) appears to be the most effective drug for use in the acute episodes.

Analysis of 100 children with severe and persistent hypertension

In 100 children with persistent hypertension seen over the past 5 1/2 years the commonest causes of hypertension were chronic glomerulonephritis, reflux nephropathy, coarctation of the aorta, and obstructive uropathy, accounting for some 70% of cases. 17 children have died, but in the remainder hypertension has been controlled by surgery, chronic haemodialysis, or by the use of pharmacological agents. Methyldopa was the commonest drug used, and the children appeared relatively resistant to the side effects of this and of other drugs, even when large doses were used. The improvment is the prognosis of severe hypertension in childhood indicated in this survey is largely due to the availability of chronic haemodialysis and transplantation for end-stage renal disease, but the advances in diagnositc methods and surgical techniques and the introduction of new drugs have also contributed.

Studies of blood pressures in children, ages 5-14 years, in a total biracial community: the Bogalusa Heart Study

Blood pressure, height, weight, maturation, triceps skinfold thickness, serum lipids, and hemoglobin were measured as risk factors for coronary artery disease in 3,524 children (93% of the eligible population) in Bogalusa, Louisiana. Nine blood pressures were taken on each child by trained observers with mercury sphygmomanometers (Baumanometer) and Physiometrics automatic recorders in a rigid randomized design in a relaxed atmosphere with other children present. The pressures observed were low compared to reported data. Black children had significantly higher blood pressures than white children. This difference, starting before age 10, was largest in the children in the upper five percent of the pressure ranks. Stepwise multiple regression analysis revealed that this racial differnce was significant when measured by an automatic recorder. Body size, expressed by height and by weight/height3 index, was a strong determinant of blood pressure level. Other positive determinants were blood hemoglobin and external maturation.

High blood pressure in children: problems and guidelines for evaluation and treatment

Evidence is presented from studies of the authors and of other investigators that primary hypertension is more common in children than was previously thought. Ninety-five percent of 131 asymptomatic children with incidental hypertension were considered to have primary hypertension after investigation for possible causes. The definition of hypertension was based on normal ranges of blood pressure for each age and sex. However, the definition of juvenile hypertension is still unsettled as is the question of treatment. Investigation of the effect of prolonged antihypertensive therapy on growth and development is needed. Primary hypertension in the young makes possible the study of the disease at its inception.

Aldosteronoma in a child with localization by adrenal vein aldosterone: collective review of the literature

Hyperaldosteronism due to aldosteronoma is a rare but potentially curable form of pediatric hypertension. We have presented a patient who had symptoms of enuresis and fatigue, and in whom the diagnosis was suggested by low serum potassium and persistent hypertension. Diagnosis was confirmed by increased plasma and urinary aldosterone and decreased plasma renin. The tumor was localized with the aid of adrenal venography and catheterization, which showed greatly increased plasma aldosterone levels in the right adrenal vein. The pathologic findings were totally reversed by right adrenalectomy. The clinical picture and results following surgical removal of aldosterone-producing tumors in six children are reviewed.

Hypertension in Nigerian children

A retrospective review of 138 cases of hypertension in Nigerian children attending the University College Hospital, Ibadan, during a 9-year period was undertaken. The main findings were (a) that hypertension occurs more commonly in children aged 5 to 10 years and is seen in both sexes; (b) that nephrotic syndrome is the most frequent clinical condition associated with hypertension in these children; (c) that glomerulonephritis is the most frequent histological finding at biopsy or necropsy; (d) that unlike the experience in Europe and America, pyelonephritis is not a major cause of hypertension in Nigerian children; (e) that the course of hypertension in the majority of the children is rapidly progressive and prognosis is poor.