Hypertension Blog

Systolic hypertension is more common in elderly patients. Elevated systolic blood pressure readings are usually caused by increased CO, systemic vascular resistance, or both. The main vascular cause of systolic hypertension is rigidity of the aorta, which develops from arteriosclerosis and increases total peripheral vascular resistance. Normally, the elastic aorta stretches as blood is pumped from the heart, but with decreased elasticity and compliance, systolic pressure increases significantly.

Aging also causes hyaline degeneration of the tunica media of arterioles, reducing lumen size. Further, decreased baroreceptor sensitivity may contribute to increased sympathetic nervous system activity and elevated levels of norepinephrine.

About 45% of the elderly in the United States have systolic blood pressures of 160 mm Hg or higher and diastolic pressures of less than 90 mm Hg-a condition known as isolated systolic hypertension. Generally, this condition reflects a disease process resulting in lost elasticity of the aorta and its large branches. Other than advanced age, this condition is the greatest risk factor of endocrine disease in elderly patients.

Endocrine Disorders

Pheochromocytoma, an abnormal growth of new tissue on the adrenal medulla, produces excessive catecholamines, causing hypertension. These tumors occur most commonly in patients ages 40 to 60, and about 90% of them are benign.

A patient with pheochromocytoma may experience severe headaches, profuse sweating, palpitations, and pronounced pallor caused by a sudden release of catecholamines resulting in a hypertensive crisis. These attacks can be triggered by physical activity, postural changes, emotional distress, hypoglycemia, and surgical trauma. An attack may also be provoked when the tumor is palpated.

If left untreated, a patient with pheochromocytoma can develop diabetes, cardiomyopathy, and hypertension, any of which can result in death. The usual treatment is surgical removal of the tumor, which relieves hypertension in about 75% of patients. The remaining 25% can usually manage their hypertension with antihypertensive drug therapy.

Caused by excessive aldosterone secretion of the adrenal gland, primary hyperaldosteronism is another endocrine disorder that causes hypertension. This condition is more common in women ages 20 to 50. Suspect it in hypertensive patients who have hypokalemia and don’t take diuretics.

The three causes of primary hyperaldosteronism are unilateral adrenocortical adenoma, adenomatous hyperplasia, and adrenocortical carcinoma. Unilateral adrenocortical adenoma alone causes 80% to 85% of the cases of primary hyperaldosteronism.

Physicians typically treat primary hyperaldosteronism by surgically removing the tumor. Unfortunately, surgery generally doesn’t cure hypertension resulting from adenomatous hyperplasia.

Cushing’s syndrome, another cause of hypertension, results from either prolonged treatment with large doses of glucocorticoids or excess cortisol production by the adrenal cortex, which is most commonly caused by a pituitary tumor. In either case, hypertension results from the mineralocorticoid effects of the hyperfunctioning adrenal tissue. When a pituitary tumor causes Cushing’s syndrome, the usual treatment consists of surgical removal. Hypertension can also be caused by acromegaly-a chronic metabolic condition resulting from excessive production of growth hormone in the anterior pituitary. The condition is characterized by enlargement and elongation of the bones of the face, jaw, and extremities. Although one­third of patients with acromegaly have hypertension, it’s usually not severe, and the treatment of acromegaly-surgery, radiation, and drugs-usually alleviates the hypertension.

Hypertension is sometimes called the “silent killer” because many people don’t know they have it. If left untreated, chronic systolic and diastolic hypertension damages the walls of systemic blood vessels and organs such as the heart, brain, kidneys, and retina. Eventually, this organ damage can result in coronary artery disease (CAD), CVA, renal failure, and blindness .

Coronary Artery Disease

Hypertension is the main risk factor for developing CAD from atherosclerosis. With hypertension, atherosclerotic plaque forms in the inner lining of the artery at an accelerated rate. As the artery narrows, more force is needed to pump blood through it, creating an even further elevation in blood pressure.

Cerebrovascular Accident

Hypertension is also a serious risk factor of CVA. In fact, hypertension is a leading cause of transient ischemic attacks and CVAs resulting from cerebral thrombosis, intracerebral hemorrhage, and emboli.

Cerebral arterial hemorrhage can occur when progressive atherosclerotic changes take place and blood pressure increases in the affected vessels. Eventually, smooth blood vessel tissue is replaced with fibrous tissue, causing vessel walls to become thicker and more rigid. But the vessels also weaken because of intense constriction of the cerebral arterioles and arteries, resulting in the development of microaneurysms that tend to rupture easily.

Renal Disease

Hypertension also leads to end-stage renal disease. During the early stage of hypertension, the capillary basement membrane of the glomeruli becomes thickened by atherosclerosis. Hypertension then causes a gradual destruction of the glomeruli, tubules, and nephrons. At first, a patient’s glomerular filtration rate may remain normal, but scarring eventually occurs, causing renal failure. Although most hypertensive patients have some degree of renal dysfunction, African-American hypertensive patients have the greatest risk of developing end-stage renal disease.

Retinopathy

Hypertension can also cause retinopathy. The resulting retinal changes are categorized in four stages of increasingly severe vessel damage.

Usually, the early stages go undetected because the patient has no significant signs or symptoms to report and no apparent reason to seek medical attention. However, if his hypertension is left untreated and his condition progresses into the later stages of retinopathy, he may develop retinal lesions, which can cause blurred vision, or papilledema and retinal hemorrhaging, which can result in blindness.

Diagnostic testing for heart failure includes chest X-ray, ECG, echocardiography, and pulmonary artery catheterization.In a patient with heart failure, a chest X-ray reveals an enlarged heart, indicating hypertrophy or dilation. If the patient is in the early stages of heart failure, the chest X-ray may show congested pulmonary veins in the upper lobes. If he is in the late stages, the X-ray may show interstitial pulmonary edema and pulmonary effusion. If the patient has biventricular failure, the chest X-ray may show a pleural effusion.

A physician uses an ECG to detect left ventricular hypertrophy. An ECG also detects signs of arrhythmias, such as irregular QRS complexes and F waves, and signs of myocardial ischemia, such as T-wave inversion and ST-segment elevation.

Used to measure the size of the heart chambers, echocardiography may reveal an enlarged right or left atrium. This test also is used to assess ventricular function and to detect ventricular hypertrophy. With normal ventricular function, echocardiography shows concentric contractility, a lack of abnormal wall movement, and a left ventricular ejection fraction of 55% to 60%. With left ventricular hypertrophy, it displays a ventricular wall thickness that exceeds 1.2 cm during diastole.

Pulmonary artery catheters are used to measure cardiac pressures. In right ventricular heart failure, the patient’s right atrial pressure may be elevated. In left ventricular heart failure, his pulmonary artery pressure and pulmonary artery wedge pressure are elevated, and CO is reduced.

The diagnostic tests for aortic dissection include chest X-ray, ECG, and CT scan. When a patient has a dissecting aortic aneurysm, a chest X-ray may reveal a left pleural effusion. An ECG helps in differentiating aortic insufficiency from ascending aortic dilation and aortic dissection. A CT scan provides information on the location and severity of the dissection.

Some More Facts

Before your patient undergoes surgery, explain the procedure and outline what he can expect in the ICU, including cardiac and PAWP monitoring and I.V. fluid administration. Also, tell him that he may need an arterial line, indwelling urinary catheter, and endotracheal tube.After surgery, explain the need for frequent assessments of vital signs and peripheral pulses to determine the patency of the graft. Also, explain the need for early ambulation to prevent postoperative complications. Instruct the patient on coughing, deep breathing, and splinting the incision and have him perform return demonstrations.

Whether your patient had surgery or was successfully treated with drug therapy, he may be prescribed one or more antihypertensive drugs. Before he goes home, teach him the name of any prescribed drug, the dosage, and its therapeutic and adverse effects. Teach him how to take his blood pressure at home. And demonstrate how to take a pulse.

Discuss the signs and symptoms of a recurring dissection. Stress the pressing need for him to return to a health care facility if the signs and symptoms recur.

The diagnostic tests used to detect cerebrovascular disease include computed tomography, Cn scans, magnetic resonance imaging (MRI), cerebral angiography, and digital subtraction angiography.By using a contrast medium to enhance the view of cerebral vessels, a CT scan helps deter­mine whether a patient’s neurologic changes resulted from an ischemic or hemorrhagic CVA. In an ischemic CVA, the CT scan will show areas of decreased absorption or density. In a hemorrhagic CVA, it will show areas of increased absorption or density. If the patient has had an ischemic CVA, a CT scan can help determine the size and location of a thrombus or embolus. A CT scan also can be used to monitor the effects of a patient’s treatment.

If the patient has experienced a hemorrhagic CVA, the physician may order an MRI to precisely locate the lesion.

Cerebral angiography helps identify the location of a hemorrhagic or ischemic CVA. This test also helps determine the extent of damage to the surrounding cerebral tissue, while allowing direct visualization of the cerebral vascular system. However, cerebral angiography may induce a cerebral embolism, cerebral hemorrhage, or spasm.

Digital subtraction angiography commonly is used with cerebral angiography to better visualize the cerebral arteries by computerized fluoroscopy.

Many types of diuretics are used to mobilize edematous fluid, reduce pulmonary vein pressure, and reduce preload. Usually, a physician first prescribes a thiazide diuretic. These drugs reduce hypertension and treat edema by inhibiting sodium reabsorption in the distal renal tubule and promoting sodium and water excretion. If your patient has pulmonary edema, his physician also may prescribe morphine to reduce preload and control anxiety.By acting on the loop of Henle, loop diuretics also promote sodium and water excretion. With thiazide or loop diuretics, the patient may need potassium supplements. Or the physician may prescribe potassium sparing diuretics if the patient is prone to hypokalemia.

The only class of drugs that improves survival in patients with heart failure, vasodilators reduce systemic vascular resistance and pulmonary and peripheral vein pressures, increase left ventricular stroke volume and CO, and enhance myocardial function by reducing myocardial oxygen demand. Sodium nitroprusside, a potent vasodilator, commonly is administered for acute heart failure.

A physician also may prescribe an ACE inhibitor. These drugs prevent the conversion of angiotensin I to angiotensin II, thus increasing CO by reducing systemic vascular resistance.

The current system for classifying blood pressure in people over age 18 defines normal and high normal blood pressure and four categories of increasingly severe hypertension . A patient who has a reading of 130/85 mm Hg or less and who doesn’t take antihypertensive drugs has normal blood pressure. However, a patient in this category still has some cardiovascular risk unless his blood pressure is less than 120/80 mm Hg. If a patient has unusually low readings, he should be evaluated further.

A patient in the high normal category has a systolic reading between 130 and 139 mm Hg and a diastolic reading between 85 and 89 mm Hg. A patient in this category has an increased risk of developing hypertension and should frequently have his blood pressure monitored. He should also be counseled on lifestyle changes that can reduce his blood pressure.

The four stages of hypertension indicate a patient’s increased risk of developing hypertension ­related complications or diseases such as a cerebrovascular accident (CVA), cardiovascular disease, and renal disease.

All stages of hypertension require treatment, though the specific treatment will vary. If left untreated, hypertension results in damage to organs such as the brain, heart, and kidneys. When noting the stage of a patient’s hypertension, you should also identify any organ disease and additional risk factors. For example, a patient with a blood pressure of 142/94 mm Hg and left ventricular hypertrophy plus diabetes should be classified as having stage 1 hypertension with organ disease (left ventricular hypertrophy) and a major risk factor (diabetes).

If a patient’s systolic and diastolic blood pressures fall into two different categories, he should be classified based on the more severe pressure reading. For example, 160/92 mm Hg should be classified as stage 2 hypertension based on the systolic pressure reading. However, a reading of 205/125 mm Hg should be classified as stage 4 hypertension based on the diastolic reading.

Stages 1 and 2 hypertension

Patients with stage 1 (mild) hypertension have systolic blood pressure readings of 140 to 159 mm Hg and diastolic blood pressure readings of 90 to 99 mm Hg. Stage 2 (moderate) hypertensive patients have systolic blood pressure readings between 160 and 179 mm Hg and diastolic readings between 100 and 109 mm Hg. Of the four stages of hypertension, stage 1 is the most common in adults.

The typical treatment of stages 1 and 2 hypertension involves lifestyle modification and, initially, a single antihypertensive drug, such as a diuretic or a beta-blocker. Some physicians may with­hold drugs from patients with diastolic pressures in the 90 to 94 mm Hg range. However, such patients should be examined in 3 to 6 months to determine if their blood pressure has risen or if they’ve experienced cardiac and vascular changes.

Stages 3 and 4 hypertension

A patient with stage 3 (severe) hypertension has a systolic blood pressure reading between 180 and 209 mm Hg and a diastolic blood pressure reading between 110 and 119 mm Hg. And the patient with stage 4 (very severe) hypertension has a systolic blood pressure reading of 210 mm Hg or more and a diastolic reading of 120 mm Hg or more.

Treatment of stages 3 and 4 hypertension also includes lifestyle modification. However, the patient may also need a second or third antihypertensive drug .

At first, many patients with hypertension have no symptoms. As the disease progresses, some patients actually become accustomed to its symptoms-headaches, dizziness, and blurred vision­and view them as insignificant. Thus, diagnosing and treating hypertension may require a thorough patient assessment. This usually includes obtaining and interpreting a patient’s health history, performing a physical examination, taking blood pressure readings, and monitoring the results of diagnostic tests.You also may use your assessment skills to help identify someone who may develop hypertension. And you may use them to evaluate a patient who has just been diagnosed with hypertension, to monitor a hypertensive patient’s treatment, and to detect complications resulting from hypertension.

By guiding a hypertensive patient through the initial phases of detection and education about his condition, you playa leading role in his plan of care. For the first step in this process, obtain the patient’s health history, which should include risk factors, medical history, and any social characteristics that might influence his response to the disease or its treatment.Hypertension seems to be hereditary. If a patient’s parents have hypertension, he has twice the risk of developing it as someone whose parents don’t have it. When obtaining a hypertensive patient’s family history, ask about his parents, grandparents, siblings, and children. Record their ages and general states of health. If one of these family members is dead, find out the cause of death and the age at the time of death.

Note episodes of hypertension and coronary artery, cerebral, peripheral, or renal vascular disease among family members. If a family member has any of these diseases, the rest of the family has an increased risk of developing them.

Also, ask him if he knows of any complications that occurred during his fetal development.

Hypertension affects about 20% of adults and occurs increasingly with age. Typically, the disease is more common:

• among African-Americans than whites
• among less educated people of both races
• in lower socioeconomic groups
• in men from young adulthood to age 55
• in postmenopausal women
• among African-Americans and whites living in the southeastern United States.

About 58 million Americans have hypertension. And although hypertension control has improved considerably over the past 20 years, mostly because of large-scale education programs to increase public awareness, many people with this dangerous disease still don’t know they have it.

Typically, hypertension is detected during routine physical examinations or at health fairs. After the condition has been diagnosed, treatment usually consists of lifestyle modifications and antihypertensive drug therapy, depending on the severity of the hypertension.

Blood Pressure: Normal and Abnormal

The term blood pressure refers to the force exerted by the blood against the arterial wall, usually the brachial artery wall. A blood pressure of 120/80 mm Hg is considered normal. The “120 mm Hg” is the systolic pressure-the force exerted against the arterial wall when the heart’s ventricles contract. During systole of the cardiac cycle, the elastic walls of the aorta and arteries stretch as more blood enters the ventricles. Ventricular pressure builds, causing the ventricles to contract and the aortic valve to open. The peak pressure of blood being forced through the aorta is the systolic pressure.

The “80 mm Hg” of a normal blood pressure is the diastolic pressure-the force exerted against the arterial walls when the ventricles are relaxed. During diastole of the cardiac cycle, the aortic valve closes, followed by a passive elastic recoil of the arterial walls, with a minimum amount of pressure being exerted against them. The pressure in the arteries continues to decrease during diastole, which allows the ventricles to fill with blood in preparation for the next ventricular contraction.

Patients with hypertension have either high systolic pressure, high diastolic pressure, or both. High systolic pressure is 140 mm Hg or more; high diastolic pressure is 90 mm Hg or more.

A single elevated blood pressure reading doesn’t necessarily indicate hypertension because factors such as stress, anxiety, or pain can temporarily elevate blood pressure. A physician diagnoses hypertension when a patient’s blood pressure is elevated at two different examinations. During each, readings should be taken when the patient is seated and resting comfortably. During the initial evaluation, blood pressure readings should be obtained in both arms. On subsequent evaluations, they should be taken from the arm with the higher reading.