-IBIS-1.5.0-
tx
cardiovascular system
hypertension
diagnoses
definition and etiology
definition:
primary or secondary elevation in either systolic and/or diastolic blood pressure
etiology:
Hypertension is characterized by a diastolic reading above 90 mm/Hg., and a systolic reading above 140 m/Hg., or both. There are two types of hypertension: primary (aka essential or idiopathic) and secondary.
primary hypertension (1°): hypertension with no discernible cause; conventionally, about 89% of cases are considered to be in this category. However, many factors are implicated in the development of primary, or essential hypertension. Some of the recognized risk factors include family history, environment (family size, crowding, eating patterns, occupation, obesity), salt ingestion and sensitivity (there is controversy over whether the sodium or chloride part of the salt molecule is the principal factor), race (blacks have more primary hypertension and more morbidity and mortality than whites), hyperlipidemia, smoking, diet
secondary hypertension (2°): This accounts for only a small minority of patients with hypertension, but must be ruled out in all cases, as discovery and treatment of the cause will cure the hypertension. Causes of secondary hypertension include:
sympathetic nervous system compensation in response to pancreatic hypoglycemia: usually will fluctuate; in the morning it will be better and in the afternoon it will be worse
epinephrine compensation in response to severe pancreatic hypoglycemia: the patient will seem like they are calm outside but really tense inside. They will tend to have increasing hypertension as the day goes on.
obese hypertension: may be hormonal, hormonal with adrenal compensation, hormonal with liver compensation, or adrenocortical compensation
renal hypertension: divided into renovascular hypertension (pre-eclampsia and eclampsia), and renal parenchymal hypertension (stenosis of a renal artery causing decreased renal perfusion which results in the kidneys activating the renin-angiotensin pathway)
endocrine hypertension: this includes adrenal hypertension (primary aldosteronism, Cushing's syndrome, and pheochromocytoma), acromegaly, hypercalcemia, and oral contraceptives (probably the most common cause of secondary hypertension).
coarctation of the aorta
signs and symptoms
signs and symptoms:
primary hypertension: patients are often asymptomatic until late in the disease, and frequently hypertension is discovered during routine physical examination.
occipital headache: seen only with severe, advanced disease; worse in the morning on rising, and better as the day goes on
dizziness
palpitations
blurred vision: (+) fundus changes are a late sign
epistaxis
hematuria
(+) bruits over renal arteries: abdominal aorta aneurysm
no fall in BP from supine to standing
secondary hypertension: the same symptoms as primary HT, plus symptoms or history related to whatever is the inciting cause. In addition:
blood pressure falls during orthostatic measurement
sympathetic nervous system compensation may cause BP fluctuations, better a.m., worse p.m.; the individual will appear calm but experiences internal tension (Easley)
lab findings:
chem screen to monitor renal status, blood glucose, potassium levels
microscopic exam of urine for casts
chest x-ray: for aortic aneurysm, coarctation of the aorta
Fantus test for urine chloride: high chloride may indicate NaCl-sensitive HT
specific studies to rule out suspected causes of secondary HT
course and prognosis
It has been estimated that untreated 1° HT decreases lifespan by 10-20 years, principally by increasing atherosclerosis. Death is usually from heart disease, stroke, or kidney failure. Approximately 1% of HT patients will develop malignant HT (extreme HT with papilledema, retinal hemorrhages and exudates, severe headache, vomiting, convulsions, stupor, coma). Malignant HT is a medical emergency. Conventional treatment of 1° HT consists of stress management, dietary modifications (decreased salt intake, decreased calories in overweight patients, decreased cholesterol and saturated fats), regular exercise, control of risk factors that promote atherosclerosis, and drug therapy.
differential diagnosis
primary versus secondary, then differentiate the secondary cause
Cushing's Syndrome
footnotes