Practical Handbook for Hypertension One

“Practical Handbook for Hypertension” consists of two parts written for references of medical students, hypertensive patients and people who conscious about their health. These two series of the handbooks deal with some fundamentals, concepts and treatments of hypertension as a useful guide in an attempts to deal with hypertension.

It is indeed a tough and tiring job to understand the mechanism of some medically termed, terminologies, concepts; treatments wrote academically from multiple sources that you might feel no interest to read. Therefore, I have summarized the facts in the simplest form to make your reading easy, so that you may grasp the concepts better and understand them perfectly.

I hope that this guide may help you obtain the knowledge of hypertension. More importantly, I hope that you will learn to find this handbook a pleasurable knowledge instead of a dreaded one.

Introduction

Cardio-cerebral vascular disease has known as the main culprit for hypertension. Back in the 1920s, people have realized that parents with hypertension will always pass on to the generations. It is not always true, as factors other than genetic factors, such as dietary, smoking, drinking, obesity, environmental and occupational mental and psychological and climate factors may give rise to hypertension.

The occurrences of hypertension can be complicated; the rate of the occurrences is high, coupling with the longer treatment phases, so earlier prevention is always the best solution to cure such disease. The causes are due to congenital factor resulted in longer and twisted carotid artery, the deformity of artery on the base part of the skull, the blood pressure is too high in the arterial systemic over a long time which finally develops into chronic hypertension. The symptoms of hypertension are a result of the central nervous system dysfunction, mental stimulation, emotional fluctuations, increased sympathetic nervous system excitability, and increased secretion of adrenal medulla. This in turns causes the contraction of small arteries, cramps, and hardening resulting in vascular stenosis, and blood pressure continues to increase.

Chapter 1: Foundation of hypertension

Clinical terminology of hypertension

High blood pressure or hypertension in its clinical terminology refers to the abnormal or unusual circumstances of the arterial blood pressure.

The standard measurement released by the World Health Organization (WHO) in 1999 explained that systolic blood pressure greater than 140 mmHg/ or diastolic blood pressure greater than 90 mmHg is regarded as hypertension.

The Category of hypertension

The first category of high blood pressure is also known as hypertension and its occurrences may due to genetic, smoking, drinking and excessive salt consumption, mental stress, lack of exercise and other underlying factors. More than 90% of the hypertensive patients are accounting for this type of hypertension. At present, it is difficult to cure, but medicinal drugs can control its outbreak.

The second category of hypertension has a clear reason for its outbreak, accounting for 5% to 10%. Its common causes are as follow:

1. Kidney diseases (such as acute and chronic glomerulonephritis, pyelonephritis and renal artery stenosis)
2. Vascular lesions (such as vascular malformations or congenital aortic shrink Narrow Syndrome)
3. Other types of vascular arteritis
4. Pregnancy-induced hypertension (occurs in the late pregnancy, and in serious cases, the termination of pregnancy is required)
5. Endocrine diseases (such as pheochromocytoma, primary aldosteronism syndrome)
6. Brain disorders (such as brain tumors and brain trauma)
7. Drug-induced factors (such as long-term oral contraceptives and long-term use of hormone).

Characteristics of Hypertension

Currently, China has 160 millions of hypertensive patients and according to China’s Health Ministry; hypertension has become the “first killer” in China. Medical experts have rated hypertension as the world’s most scary killers that take away many human lives each year. Hypertension is a silent killer and it shows no symptoms at all. Some may have dizziness, headaches or nasal bleeding and other related symptoms. Even though many patients who have suffered from high blood pressure for many years and no matter how high their blood pressures are, they will not experience any discomfort feelings. Therefore, hypertension does more harm than good to our health as it can take away somebody’s life in any time. Regardless of its severity, one should seek for treatment as soon as possible as way to prolong life span.

Persons who are 35 or above, smokers, obese, high blood lipids, or with a family record of hypertension should get their blood pressure checked once each year. For those who have been suffering from hypertension, regardless of age, they should go for blood pressure diagnosis at least once a month in order to monitor and to maintain the normal blood pressure.

The Rhythm of Hypertension

The blood pressure shows significant cyclical changes within a day. It increases in a day and decreases at night. In other words, the blood pressure will decline while one sleeps at night and it rises again by the following morning when one gets up. Therefore, one should take medication in the morning but does not exercise at this time particularly for those with significant and chronic hypertension records. One should do exercise before dinner.

Blood pressure too, shows cyclical changes. The changes in the characteristics being high in cold weather, low in the summer, nevertheless, it increases during fall, winter and spring.

The Rhythm of Hypertension Within a Day

Common terminologies of hypertension

Blood pressure: Blood vessels within the unit area of the lateral pressure vessel wall that commonly known as pressure. As blood pressure is grouping into arterial blood vessels, capillaries and veins, and thus blood pressure is termed as arterial blood pressure, capillary pressure and venous blood pressure. Nevertheless, doctors usually refer blood pressure as arterial blood pressure. When the blood vessels dilate, the blood pressure decreases; but when blood vessels contracts, the blood pressure increases.

Factors affecting blood pressure: Factors include changes in blood volume, vascular contraction or expansion, and myocardial contractility. When speaking of normal “blood pressure” actually refers to artery blood pressure in the upper arms, or brachial artery vascular blood pressure as the direct assessment of the main artery blood pressure.

Casual blood pressure: a measured pressure taken without any preparations of the patients

Ambulatory blood pressure: a measured pressure taken 24hours a day by the monitoring device, including systolic blood pressure, diastolic blood pressure, mean arterial pressure, heart rate, as well as the highest value and the minimum value of blood pressure within a day

Hypertension: the abnormal increase of blood pressure than that of the normal arterial blood pressure

Systolic blood pressure (SBP): the force of blood in the arteries as the heart beats and it is the top number in a blood pressure reading. When the systolic blood pressure is 140mmHg and higher, this condition is isolated systolic hypertension (ISH) or commonly known as “high-pressure.”

Diastolic blood pressure (DBP): when the heart is at rest, between beats, the blood pressure falls and it is the bottom number in a blood pressure reading, or commonly known as “low pressure.”

Pulse pressure: the different value between systolic blood pressure and diastolic pressure, or in its mathematical sentence: SBP – DBP.

Mean arterial pressure (MAP): average arterial pressure during a single cardiac cycle and its mathematical sentence: MAP = (CO x SVR) + CVP, where CO is cardiac output, SVR is systemic vascular resistance and CVP (always ignored in the calculation as its value is relatively small) is central venous pressure. Generally, MAP is equivalent to DBP plus about 1/3 of pulse pressure.

kPa: unit measurement for the blood pressure

mmHg: measure the blood pressure mercury sphygmomanometer to represent the level of blood pressure. 1mmHg = 0,133 kPa and 7.5mmHg = 1kPa.

Ideal blood pressure: SBP is <120 mmHg and DBP is <80 mmHg.

Normal blood pressure: SBP should be <130 mmHg and DBP <85 mmHg.

Pre-hypertension: SBP is 130 to 139 mmHg and / or DBP 85 to 89 mmHg.

Hypertension: SBP is ≥ 140 mmHg and (or) DBP is ≥ 90 mmHg.

Borderline hypertension: SBP is at 140 – 160 mmHg (18.6 – 21.3kPa), while DBP is at 90 – 95 mmHg (12.0 – 12.6kPa).

Essential hypertension: high blood pressure with no identifiable cause, accounting for more than 90 per cent, control with medication but hardly cured.

Secondary hypertension: an elevated blood pressure that results from genetics, lifestyle, and diseases include kidney disease, endocrine diseases such as adrenal hyperplasia and cancer or other causes.

Plateau-type hypertension: more common in people who live in plateau region or highlands with obvious high blood pressure, particularly in the increase in DBP.

Sleep-type hypertension: blood pressure increases while sleeping and after sleeping.

Aggressive-type malignant hypertension: high blood pressure that causes swelling of the optic nerve behind the eye (also called papilledema) as well as organ damage in the brain, lung and / or kidneys. SBP and DBP is usually greater than 200 and 140, respectively.

Refractory hypertension: blood pressure that hardly to control even the patients have make their endeavors in life changes and even the doctor has prescribed medicines in their full doses. DBP continues to rise and maintain at 115mmHg (15.2kPa) or above.

Elderly hypertensive: more commonly among people with age greater than 65 years old. Their blood pressure is more than three times more than the standard blood pressure diagnosis, that is, SBP is ≥ 140 mmHg and (or), DBP is ≥ 90 mmHg.

Isolated systolic hypertension (ISH): a DBP is not high, but SBP is out of normal range. The SBP reading is at or above 140mmHg and DBP reading is under 90mmHg.

Renovascular hypertension (or “renal hypertension”): a syndrome that consists of elevated blood pressure due to narrowing of the arteries that carry blood to kidneys. It is a form of secondary hypertension as its cause is identifiable. Other diseases such as renal artery stenosis, acute and chronic glomerulonephritis, pyelonephritis (polycystic kidney disease) may also lead to this type of hypertension.

Iatrogenic hypertension: is resulting from inappropriate medication that leads to high blood pressure, also known as hypertension drugs.

White coat hypertension: a phenomenon in which patients have elevated blood pressure during a clinic visit though they have normal blood pressure at all times. This condition may lead to flawed conclusion regarding the causative association of hypertension and sleep apnea.

Hypertensive encephalopathy: blood pressure suddenly surges up to 200 – 260 mmHg /140 -180 mmHg and may lead to cerebral edema and intracranial hypertension

Stroke: called cerebrovascular disease in medical term, divided into cerebral thrombosis and brain hemorrhage. Hypertension accounts for 86% of stroke.

Transient ischemic attack (TIA) or transient ischemic encephalopathy: a “mini stroke” causes short-term (one-time) insufficiency of basilar artery system, resulting in the blood of the brain tissue ischemia and a focal neurological dysfunction in the corresponding symptoms and signs.

Cerebral infarction/cerebral thrombosis: blockage of human brain artery happens due to certain reasons, vascular disruption that causes the vascular brain tissue necrosis and loss of blood supply and a corresponding clinical symptoms and signs, such as hemiplegia, and aphasia.

Cerebral hemorrhage: sudden, severe headache is common in hemorrhagic stroke, and is especially indicative of that if accompanied by stiff neck, facial pain, and pain between the eyes, vomiting, or modified consciousness (Weibers, 2001). Other signs of hemorrhagic stroke include those that indicate increased intracranial pressure, caused by swelling or collection of blood. These include increased blood pressure, unequal pupils, especially when one pupil is dilated and does not react to light, headache, vomiting, visual disturbances, and decorticate or decerebrate posturing (Yamamoto, 1996).

Hypercholesterolemia: consist of pure cholesterol (TC) and low-density lipoprotein (LDL) levels.

Hyperlipidemia: an elevation of lipids (fats) in the bloodstream. These lipids include cholesterol, cholesterol esters, phospholipids and triglycerides that transported in the blood as part of large molecules called lipoproteins.

Mixed hyperlipidemia: have both higher cholesterol and triglycerides

Renal failure: known as renal dysfunction, refers to a variety of reasons including hypertension caused by progressive renal damage, which could not sustain its basic renal function.

Myocardial infarction: commonly known as a heart attack, a condition that occurs when there is an interruption of the blood transportation to a part of the heart due to rupture of a vulnerable plaque. This may result in ischemia (oxygen shortage) that causes damage and potential death of a certain segment of the heart muscle (myocardium) and tissue.

Antihypertensive drugs: also known as the anti-hypertension drugs, and can be divided into six categories: (1) Diuretics (2) Angiotensin-converting enzyme inhibitor (3) II angiotensin receptor (AT1) antagonist (4) β receptor antagonist (5) calcium antagonist (6) α receptor antagonist.

Calcium antagonist: block the cell membrane Ca2 + on the voltage-dependent calcium channels into the cell, reduce the intracellular Ca2 + concentration, thus affecting cell function in drug, also known as calcium channel blockers. They assist in reducing blood pressure and may cure angina syndrome.

Diuretics or water pills: help kidneys to excrete more sodium in urine. Three main examples of diuretics are thiazide (Zaroxolyn and Esidrix), loop (Lasix, Bumex, Demadex) or potassium-sparing (Aldactone).

Angiotensin-converting enzyme inhibitors (ACEI): an inhibitor of angiotensin-converting enzyme (ACE) used to treat hypertension and congestive heart failure. It may reduce the formation of angiotensin II.

Antihypertensive drug-peak ratio (T / P ratio): the effects of drug-hour antihypertensive effect of lowering the largest numerical divided by the lower value.

Chapter 2: Essential knowledge of hypertension

Hypertension-related diseases

Hypertension and hypercholesterolemia

Hypertension and hyperlipidemia (elevated level of lipids) has high correlation with the development of atherosclerosis (the hardening of artery). The acute or high blood pressure may lead to vascular endothelial dysfunction, followed by an increased vascular permeability and the accumulation of excessive lipoprotein cholesterol and fatty substances clogging the blood vessels that finally causing atherosclerosis. The build up of excessive fat and cholesterol attached to the blood vessel walls causing the lumen becomes smaller and simultaneously increasing the vascular resistance and thereby increasing heart load pressure. Finally, there is the rise of blood pressure due to the blockage in the heart that contributes to cardiovascular and cerebrovascular damage, further indulging the occurrence of cardiovascular disease.

Hypertension and diabetes

Hypertension and type 2 diabetes are two closely dependent variables, accounting for nearly 40% of patients who have suffered from type 2 diabetes and at the same time they are also sufferers for hypertension. Approximately 5% to 10% of hypertensive patients have to dwell with type 2 diabetes. In general, the relationship between hypertension and diabetes sometimes can be very complicated. Some people may suffer from diabetes first and later hypertension or vice versa. Some patients who have suffered from diabetes for more than ten years, their diagnosis test showed an obvious albumin in urine, which leads to the gradual increase of their blood pressures. Among the hypertensive patients, they have hyperinsulinemia and abnormal glucose (also known as “insulin resistance” state) in their blood pressure more significant than that of people with normal blood pressure. Over the time, some of these patients may gradually develop into type 2 diabetes. Hence, hypertensive patients should pay more attention to protect their kidneys as the combination of hypertension and high blood glucose contributes to proteinuria (describes a condition in which urine contains an abnormal amount of protein) that may easily cause the damage of kidneys. This situation not only worsens the existing health’s condition, but also deteriorates the renal function. In addition to the protection of kidney hypoglycemia (hypoglycemia means low blood sugar in people without diabetes and it is an indicator of a health problem), more importantly, patients should pay attention to control their blood pressure.

Diagnostic standards for hypertension

World Health Organization / International Union Hypertension (WHO-ISH) has formulated a diagnostic standard and classification for those who are above 18 years old for hypertension diagnosis in 1999. (See table 1 below).

Table 1 shows WHO-ISH guidelines and classification of the level of blood pressure in 1999.

In addition to standards described in table 1, United States has come out the formulation to assess the prevention and treatment of hypertension documented in the seventh report of the National Commission (JNC7) (see table 2) in 2003. This table explicitly states the concept of “pre-hypertensive”, noting that systolic blood pressure of 120mm Hg to 139mmHg or diastolic blood pressure of 80mmHg to 89mmHg as the phase of pre-hypertension.

Table 2 shows definition and classification of blood pressure levels as documented in JNC7 by United States in 2003.

In 2004, basic guidelines for hypertension in China based upon the guidelines released by WHO in terms of the standard diagnosis of hypertension. The results of epidemiological data have determined 120mmHg to 139mmHg / 80mmHg to 89mmHg as standard normal high value. Patients with blood pressure in this context should have endeavor to change their dietary patterns and early prevention should be taken to avoid the development of hypertension (see table 3). Another guideline towards prevention and treatment of hypertension has documented in the report in Europe in 2003 (see table 4).

Table 3 shows guideline towards prevention and treatment of hypertension in China in 2004 in terms of its definition and classification of the blood pressure levels. Note: If the systolic and diastolic blood pressure is of different levels, the value should base upon the high value.

Table 4 shows guideline towards prevention and treatment of hypertension in Europe in 2003 in terms of its definition and classification of the blood pressure levels.

Chapter 3: Treatment concepts, first aids and hypertension

Regardless of whether or not to accept medical treatment, every hypertensive patients are required to undergo medicinal treatment to improve the way of life. Nevertheless, when deals with patients with light degree of hypertension, doctor usually recommends patients to non-medication treatment for a period to maintain their blood pressure. The non-medication treatments include salt restriction (less than 6g per day), weight control, stop smoking, low fat dietary menu, and alcohol limitation; avoid mood fluctuations and over exertion with healthy living adjustment to ensure adequate sleep and exercise.

The aims for hypertension treatment

The main purpose is to reduce cardiovascular disease, blood pressure, incidence of other complications related to human organs such as heart, brain, kidneys and so forth effectively but more importantly to reduce the rate of mortality. Another aim is to achieve the therapeutic effects for the treatment of hypertension.

For most of the patients, the systolic and diastolic blood pressure should keep below 140/90mmHg, elderly should ensure their systolic blood pressure be well below 140 mmHg or 150mg if the target of 140mmHg is hardly achieved. Hypertensive patients with diabetic and nephropathy or nephrosis (damage and disease of the kidney) should maintain their blood pressure below 130/80 mmHg.

First aids for hypertension

When encountering patients with a sudden elevated blood pressure, how would you deal with it? The following measures are for your reference:

A sudden elevated blood pressure accompanying by nausea, vomiting, severe or chronic headache, palpitation and even blurred vision, indicating that patients have suffered from hypertensive encephalopathy. In this case, patients should rest immediately on bed while serving with antihypertensive drug. Besides this drug, they should have other medications such as diuretics and sedatives to calm down their mentality disturbances. Do not panic when dealing with these patients, otherwise the condition may get worse than expected. If after this measure had taken but patients did not show any promising recoveries, then you should notify the emergency first aid centre of your local hospital immediately for the real time treatments.

Patients who experience sudden palpitation, shortness of breath, lips cyanosis (bluish lips), loss of limbs ability in physical activities, accompanying with pink bubble phlegm may indicate the occurrence of acute left ventricular failure. In this case, patients should have their legs hang down immediately by taking a sitting posture. If bags filled with oxygen is available, you should get the patients be oxygenated with this bag while waiting the arrival of the ambulance from the Emergency centre of your local hospital.

After going through a great deal of tiredness and mental exhaustion, patients may have experienced sudden pain on their hearts and chests and sometimes the pain may extend to the left shoulder or upper left extremity (consists of a large rounded head joined to the body by a constricted portion called the neck, and two eminences). This can result in pale or whitish facial appearance and cold sweating. In this case, make sure the patient rests with calm and tranquility by placing a piece of nitroglycerin on his lower tongue and subsequently ask him to breathe in oxygen. Notify the Emergency center of your nearby hospital immediately for further treatments.

If hypertensive patients experience headache, vomiting, limbs numbness or paralysis, unconscious, you should let the patients rest on bed immediately but avoid side position, make sure their heads placing towards the side to prevent the vomit substances from reentering the airway that causes patients to breathe difficultly. Notify the Emergency center of your local hospital promptly for further treatments.

Note:

Hypertensive encephalopathy is a neurologic syndrome that occurs in patients with acutely elevated blood pressure, as may be seen in association with preeclampsia, cyclosporine therapy, and renal disease. Symptoms most commonly include headache, seizures, and cortical visual disturbances.

Cyanosis is a bluish coloration of the skin due to the presence of deoxygenated hemoglobin in blood vessels near the skin surface. It occurs when the oxygen saturation of arterial blood falls below 85%. Lips cyanosis is often due to a circulatory or ventilatory problem that leads to poorer blood oxygenation in the lungs or greater oxygen extraction due to slowing down of blood circulation in the skin’s blood vessels.