Hypertension is an obscure diagnosis for it is only a sign, not a disease. It is just as much a sign of some basic condition as is a fever, a rash, a headache, or nausea.
The causes in childhood and adolescence are numerous, most usually renal or vascular. As I write this introduction a few examples readily come to mind, such as essential hypertension, renal insufficiency, polycystic kidneys, pyelonephritis, thrombosis of the renal arteries, coarctation of the aorta, and chronic lung disease. There are, of course, numerous other less frequent causes that will be covered in the articles of this symposium.
With the numerous diagnostic possibilities it is inevitable that all practicing pediatricians are from time to time faced with the problem of determining the specific etiology of hypertension among their patients. All of us, I am sure, have special cases that remain in our memory.
In my own experience I remember one little girl I cared for since birth. As a newborn she had a cardiac murmur but otherwise seemed perfectly normal. The murmur was systolic and could be heard not only on the anterior chest but posteriorly in the intrascapular region. The electrocardiogram was normal. But blood pressure in the upper extremities was considerably elevated, whereas in the lower extremities it was greatly diminished. The diagnosis was at once evident - coarctation of the aorta. This was in the 1940s and there was one man, Dr. Robert Gross, Pediatric Surgeon at the Children's Hospital in Boston, who had reported on the successful operation for this condition.
The child, then 6 years of age, was sent to the Children's Hospital and underwent the operation for the coarctation. If I recall correctly she was the 1.0th patient successfully treated by this master surgeon. This little girl is now a grown woman and in perfect health. She has had several children of her own.
I mention this case because not only were the treatment and cure spectacular in those days, but because it represents one of the few causes of hypertension that can be cured immediately by operation. A few others are pheochromocytoma and neuroblastoma.
All well-trained pediatricians realize today that routine blood pressure readings should commence when children are 3 years of age. Proper sized cuffs are essential as well as testing when the child is relaxed.
The importance of pediatric care for children cannot be overemphasized, as increased blood pressure of long duration can be extremely damaging. This brings up the question of therapy for children and adolescents with hypertension. Are drugs always necessary or can many cases be satisfactorily treated by dietary means alone? This subject will be fully covered in the articles presented in this symposium.
The following papers are under the Guest Editorship of Dr. Glenn H. Bock, Vice Chairman of the Department of Pediatric Nephrology at the Children's Hospital National Medical Center, and Associate Professor of Pediatrics at the George Washington University Medical College, Washington, DC.
Dr. Bock introduces the symposium with his article "Pediatric Hypertension: Still More Art than Science." In this paper he emphasizes the importance of early detection of elevation in blood pressure. There appears to be a relationship between hypertension in childhood and the end-organ damage in adult life. The need for adequate cuff selection is emphasized. Also discussed is the potential risk of higher likelihood for the development of acquired sustained hypertension.
The next paper, "A Pediatrician's Approach to the Evaluation of Hypertension," follows sequentially and has been written by Dr. John K. Hurley. Dr. Hurley is also on the staff of the Children's Hospital National Medical Center where he serves as Attending Nephrologist as well as Associate Clinical Professor of Pediatrics at the George Washington School of Medicine.
Dr. Hurley states at the outset that hypertension is a risk factor rather than a disease, and that it is just one of the factors responsible for the development of cardiovascular, brain, and kidney damage in the adult. He notes that whereas a great deal of information has been gathered on the risks and treatment in the adult, the same is not as yet available for children. A large and important section of this article is devoted to the history, physical examination, and diagnostic testing of children with hypertension. The child's pediatrician, Dr. Hurley states, is the best person to evaluate these children, for not only has he or she the background but enjoys the confidence of both the patients and their families.
The third contribution to the symposium is titled "The role of Noninvasive Evaluation of Pediatric Hypertension" and has been authored by Dr. Julie R. Ingelfinger. Dr. Ingelfinger is Associate Professor of Pediatrics at Harvard Medical School and Director of the Hypertension Clinic at Children's Hospital, Bt)ston, Mass.
This is a clear and very well organized discussion of noninvasive diagnosis in hypertensive children. Dr. Ingelfinger refers to the suggestions of the Second Task Force for Blood Pressure Control in Children in 1987 for the evaluation of hypertensive children. These evaluations are broken up into phased stages with the noninvasive diagnostic features being presented for use before resorting to invasive methods. The various diagnostic techniques are described, such as ultrasound, radionuclide renal scans, and digital subtraction angiography. Various therapeutic trials using pharmacologic agents are also discussed.
The next article covers the subject of "Hypertension in Infants" and is contributed by Dr. Raymond D. Adelman. Dr. Adelman, who is a recognized authority on the subject, is Professor and Chairman of the Department of Pediatrics at the Eastern Virginia Medical School and Vice President for Medical Affairs of the Children's Hospital of the King's Daughters, Norfolk, Va.
The author notes that much of pediatric hypertension occurs in the neonatal period. His article discusses the means of identifying the elevation in pressure at this early age. He emphasizes that these values are affected by birthweight, postnatal age, level of activity, and cuff size. The numerous causes of hypertension in the neonate are listed and carefully discussed, as are the clinical signs and symptoms. Dr. Adelman states that most neonates with hypertension respond well to medical management. Occasionally surgery is required - but surgery has been associated with increased morbidity and mortality. Generally, in the author's experience, most of the medicated children remain normotensive after medication is withdrawn.
The following paper dealing with "The Hypertensive Adolescent" is written by Dr. Bonita Falkner, Professor of Pediatrics and Director of Pediatric Nephrology and Hypertension at Hahnemann University, Philadelphia. It is of interest to note that Dr. Falkner was a member of the Second Task Force on Blood Pressure Control in Children, 1987.
Adolescence is the age period when essential hypertension usually becomes recognizable and can be diagnosed, although secondary causes continue to occur. Dr. Falkner points out that essential hypertension in adolescents is usually mild. If the hypertension is severe it is generally secondary to renal or renal-vascular disease. The article clearly evaluates the characteristics of juvenile essential hypertension and its risk factors. As to treatment, the author states, this does not necessarily indicate a lifetime of drug therapy. Mild hypertensives, as a rule, can be treated without medication. To quote from Dr. Falkner: "Adolescents have enough problems getting through their own growing up," and "It is better to avoid conveying to the young patient the notion of hypertension as a disease."
The final paper discusses "What's New in the Antihypertensive Armamentarium?" The author is Dr. Mary Ellen Turner, Attending Pediatric Nephrologist at the Children's Hospital National Medical Center and Assistant Professor of Pediatrics at the George Washington University School of Medicine, Washington, DC.
Dr. Turner states at the outset of her article that the Second Task Force on Blood Pressure Control in Children recommended that nonpharmacologic therapy should be used as the first step in treating hypertension. Later, if medications are used, they usually have been thiazide diuretics, with the addition of an adrenergic blocking agent and then a vasodilator. This present article reviews two new classes of drugs that have proven not only efficacious but well tolerated. These new drugs are the angiotensin converting enzyme inhibitors and the calcium channel blockers. A number of these drugs, such as Captopril and enalapril, are beginning to be widely used. The calcium channel blockers, although being used for years in Europe, are just being introduced into the United States. This review presents us with the latest information on a new and important group of antihypertensives for children.