High Blood Pressure
• Definitions
· High Blood Pressure is the disease of hypertension.
· High blood pressure is a disease because elevated blood pressure damages organs and leads to increases 
in mortality.
· Systolic blood pressure is the maximum pressure within the circulatory system occurring while the left ventricle of the heart is contracting and pushing blood into the aorta and the systemic arteries.
· Diastolic blood pressure is the lowest pressure in the cardiac cycle, this happens when the aortic valve has closed and the heart is no longer pushing blood into the systemic circulation and is being filled with blood returning from the venous systems of the body and lungs.
· Hypertension is defined as a systolic blood pressure above 140 mm Hg and a diastolic blood pressure above 90 mm Hg.
· Optimal blood pressure is controversial. Physicians tend to start blood pressure medications for patients with blood pressure greater than 140/90.
· Normal blood pressure is much less than 140/90 and many clinical studies have shown that blood pressures less than 120/80 are beneficial in protecting against vascular disease, heart disease and stroke.
• Overview:
· Hypertension affects over fifty million Americans and only half are receiving treatment for the disease.
· Only 37% of American patients with hypertension currently have their blood pressures under adequate control.
· Blood pressure should be measured with a well-calibrated blood pressure machine or sphygmomanometer placed around the arm at about the same level as the heart.
· Blood pressure readings should be taken after the patient has been resting comfortably, back supported in the sitting or supine position, for at least 5 minutes.
· Smoking and coffee may temporarily elevate readings for at least 30 minutes.
· A single elevated blood pressure reading is usually not enough to diagnose hypertension and physicians usually will wait for 3 separate elevated readings before diagnosing hypertension. In some cases a single reading that is excessively elevated can be enough to make the diagnosis or when organ damage is present.
• Types:
· There are two types of hypertension: primary hypertension and secondary hypertension.
· Primary/ Essential Hypertension:
· Primary hypertension also referred to as essential hypertension is the most common form of hypertension.
· Primary hypertension is the most common form. 95% of people with hypertension have primary hypertension.
· Primary hypertension onset is usually between the ages 25 and 55 years.
· Primary hypertension is caused by slight abnormalities in the normal physiology used to maintain circulatory blood pressures. These abnormalities include excesses in the enzyme Renin, excesses in adrenaline and stiff arteries.
· Other factors contributing to primary hypertension are obesity, excessive alcohol intake, excessive salt intake, sedentary status and smoking.
· There is a strong genetic predisposition for this form of hypertension.
· There are usually other family members with hypertension.
· Secondary Hypertension:
· Secondary hypertension is much less common, only about 5% of cases.
· Secondary hypertension usually results from a specific disease such as:
· obstruction of the artery to the kidney
· diseases leading to excesses in cortisol
· tumors of the adrenal gland
· kidney disease
· obstruction of blood flow through the aorta
· disease of the thyroid gland
• Symptoms:
· Hypertension usually does not produce symptoms and is therefore sometimes referred to as the “silent killer”.
· Hypertension may cause:
· headaches, usually described as a pulsating discomfort or an aching discomfort in the back of the head. This is usually worse in the morning.
· Hypertension with excessively elevated pressures can cause confusion, changes in vision, and nausea and vomiting.
• Complications
• Complications of uncontrolled hypertension include
· heart muscle hypertrophy
· heart failure
· arrhythmias
· heart attack
· dementia
· stroke
· kidney failure
· sudden death
• Treatment
· Lifestyle modifications for all patients with newly diagnosed hypertension include:
· Diet that are high in fruits, vegetables, and low-fat dairy foods and as well as low in saturated and total fats.
· Weight reduction
· Decreased alcohol consumption can help lower blood pressure.
· Dietary salt restriction
• Medications:
· Medications are started if:
· Inadequate lowering of blood pressure in response to behavior modifications
· Sign of organ damage from hypertension
Drug Therapy:
• There are six classes of medications for hypertension:
· diuretics (water pills that decrease blood volume by increasing urine output)
· alpha blockers(not commonly used for blood pressure)
· ACE (Angiotensin converting enzyme) inhibitors inhibit the activation of an angiotensin enzyme responsible for increasing blood pressure. While ACE Inhibitors are used to control blood pressure, they often have additional health benefits and are often the first choice medication
· Calcium channel blockers (lower blood pressure by dilating arteries)
· Angiotensin Receptor Blockers (block the affects angiotensin an enzyme that causes constriction of arteries.
· Renin blockers (New class of blood pressure medication that block renin-a precursor to angiotensin
• Goals of treatment:
· There is no consensus for optimal blood pressure control.
· In general physicians treat patients much more aggressively if there are signs of hypertension induced organ damage.
REFERENCES
Curr Probl Cardiol. 2007 Apr;32(4):201-59 PMID: 17398315
Bolli P et al; Canadian Hypertension Education Program: Applying the 2005 Canadian Hypertension Education Program recommendations: 1. Diagnosis of hypertension. CMAJ 2005;173:480. [PMID: 16129865]
Chobanian AV et al: The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure: the JNC 7 Report. JAMA 2003;289:2560. [PMID: 12748199]
Forette F et al: The prevention of dementia with antihypertensive treatment. Arch Intern Med 2002;162:2046. [PMID: 12374512]
J Hypertens 2003;21:1983. [PMID: 14597836]
Posted on September 24, 2008
