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Clinical Profiling: Natural History of Essential Hypertension

by Gary D. Goldberg, PhD
Clinical Professor of Medical Education
Angeles College of Nursing, Los Angeles, Ca.

Hypertension is a major cardiovascular risk factor that directly contributes to myocardial episodes such as abnormal wall motion, hypertrophies, and subsequently an infarction (MI).  Also noted, are cerebrovascular accidents (CVA), congestive heart failure (CHF), peripheral arterial insufficiency (PAI), and premature mortality.  Optimal and cost-effective management of the condition depends on careful diagnosis, treatment minimization, and optimized adherence to the selections of tests and treatment plans.  In addition, full patient commitment and adherence toward the medical and environmental regiment.

Background –

     Of all the known cardiovascular risk factors, hypertension is the most prevalent:  it occurs in up to 40% of the United States population (approximately 60 million Americans), when using a threshold of 140/90 mmHg. ¹ Hypertension is indeed the most common reason cited for office visits to American internists, and the most common indication for the use of prescription medication in the United States. ²  In 2008, direct costs of American anti-hypertensive management and treatment of its complications totaled near $30 billion. ³

     Recent analysis suggests that hypertensive patients fall in two groups:  Approximately one-fourth consists of individuals under the age of 50 who are predominantly male and have a diastolic hypertension.  The remaining three-fourths are older than the age of 50, are slightly more than half (59%) women, and often display isolated systolic hypertension.  From Framingham’s data, the best predictors of coronary heart disease differ in the three age clusters:  <50 years old to 59 years old, and > 60 years old.  Among patients <50 years old, DBP predicted subsequent coronary heart disease better than SBP.  Among patients 50 to 59, SBP, DBP, and pulse pressure served equally well as predictors.  At age 60 years and older, pulse pressure was the best predictor followed by SBP. ⁴   

     Based on its high prevalence within our societies today, “essential hypertension“ diagnosis with responsiveness to treatment plans, and its financial impact just within the United States alone, deserves everyone’s attention.  

A Short Historical Perspective –

     The first repot of direct B/P measurement dates back to 1726, when Stephen Hales, cannulated a horse’s crural artery and assessed the height of the blood column before and after hemorrhage.  The monaural stethoscope appeared in the early nineteenth century; the binaural stethoscope came to America in 1852, and the introduction of the sphygmomanometer cuff in 1896. Dr. Nikolai Korotkoff (Russian physician), reported the auscultatory method of measuring arterial pressure in 1905, showing the measurement of diastolic pressure and systolic levels for the first time. ⁵ 

     Early efforts to reduce extreme hypertension by adrenalectomy or sympathectomy frequently led to disastrous results.  Some early authorities concluded that such hypertension was not merely “primary” but “essential,” because brusque pressure reductions were deleterious (e.g., harmful to health).    A big breakthrough came on experimental hypertension through Dr. Harry Goldblatt, (U.S. pathologist, in 1896-1977).  His description of the renal artery clip model was revealed and pantone in 1934.  Thus began a series of discoveries of one intriguing complexity after another:  renin, angiotensin, atrial natriuretic factor, cation fluxes, endothelial factors, vascular remodeling, central monoaminergic, and hypothalamic factors, and others. ⁶  

     In 1960 Dr. Irvine H. Page, (chemist, biomedical leader in academic medicine), formed hypotheses and proposed his “mosaic theory” of hypertension:  a disease of regulation in which abnormal regulatory systems fail to reduce B/P once it is elevated.  More precisely, the control of arterial pressure was likened to a kaleidoscope of interlocking, dynamic equilibria that determined the net effect while continually shifting from one set of relations to another.  Although the regulatory factors were limited, their changing interplay was not.  The strength of the model lies in its adaptability to new data.  Based on the premise that there is likely to be no unique cause for most cases of hypertension but many potentially contributing factors, one struggles to integrate all the possible components.    His “mosaic concept” offers a way to combine diverse factor from genetic and physiologic to emotional and environmental.  ⁷ Many of the medications that were originally developed during the late 1960’s and early 1970’s for other purposes rather then hypertension, were later applied using Professor Page’s theorem as an afterthought or via serendipity (i.e., discoveries by accident). 

     Despite the many modern advances, hypertension still largely remains a “triple paradox” by which firstly, the condition, easy to diagnose but often remains undetected. Secondly, relatively simple to treat, but too often remains untreated, and lastly, for which despite available and potent drugs, treatment plans for many are all too often ineffective. 

Pathophysiology – 

     There are numerous factors affecting B/P control and they are complex in themselves with their interrelationships.   Striking examples of the interdependencies include observations that insulin resistance precedes hypertension in individual patients genetically predisposed to it.  In addition, hyperinsulinemia, salt sensitivity, obesity, and increased sympathetic drives are covariant. 

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