HYPOTENSION

BYPROF.DR.KAMAL

MAHMOUDAHMAD

HEAD OF

THE CARDIOLOGY&

ANGIOLOGY UNITMEDICAL RESEARCH

INSTITUTEALEXANDRIA UNIVERSITY

DEFINITION

• Blood pressure: How low can you go?

• Current guidelines identify normal blood pressure as lower than 120/80

• Many experts think 115/75 is optimal. • Some experts define low blood pressure as readings

lower than 90 systolic or 60 diastolic

Normal physiology

• Blood pressure is continuously regulated by the autonomic nervous system, to balance the effects of the

• 1- sympathetic nervous system, which tends to raise blood pressure,

&• 2-parasympathetic nervous system, which lowers it.

• The vast and rapid compensation abilities of the autonomic nervous system allow normal individuals to maintain an acceptable blood pressure over a wide range of activities and in many disease states.

PATHOPHYSIOLOGY

1 Reduced blood volume

Hypovolemia, is the most common mechanism producing hypotension. This can result from

Hemorrhage. Insufficient fluid intake, as in starvation; Excessive fluid losses from diarrhea or

vomiting. Hypovolemia is often induced by excessive use

of diuretics.

2- Decreased cardiac output

Severe congestive heart failure, Large myocardial infarction, Bradycardia, often produces hypotension and can

rapidly progress to cardiogenic shock. Arrhythmias often result in hypotension by this

mechanism. Beta blockers can cause hypotension both by

slowing the heart rate and by decreasing the pumping ability of the heart muscle.

3-Excessive vasodilation

• Excessive vasodilation, or insufficient constriction of the resistance blood vessels (mostly arterioles), This can be due to;

injury to the brain or spinal cord . dysautonomia, an intrinsic abnormality in autonomic functioning. sepsis, acidosis, medications, such as nitrate preparations, calcium channel blockers,

ARBS or ACE inhibitors.

Many anesthetic agents and techniques, including spinal anesthesia and most inhalational agents, produce significant vasodilation.

Causes of low blood pressure

Causes of low blood pressure Athletes and people who exercise regularly tend to have lower BP than do people who aren't as fit. So, in general, do nonsmokers and people who eat well and maintain a normal weight. But in some instances, low blood pressure can be a sign of serious, even life-threatening disorders.

Causes of low blood pressure The American Heart Association considers the

following as possible causes of low blood pressure:

1-Pregnancy. • Because a woman's circulatory system

expands rapidly during pregnancy, blood pressure is likely to drop. In fact, during the first 24 weeks of pregnancy, systolic pressure commonly drops by five to 10 points and diastolic pressure by as much as 10 to 15 points.

Pregnancy. Hypotension during pregnancy can be as serious as

hypertension.

Low systolic pressure may lead to low birth weight, death of the foetus or low intelligence quotient scores at the age of about four years.

Low diastolic pressure can also increase the risk of premature birth.

Pregnancy.

90/66

Causes of low blood pressure

• 2-Medications. Many drugs can cause low blood pressure,

including diuretics and other drugs that treat high blood pressure; heart medications such as beta blockers;

Drugs for Parkinson's disease; tricyclic antidepressants;

Sildenafil (Viagra), particularly in combination with nitroglycerine; narcotics; and alcohol.

3- Heart problems..

Causes of low blood pressure

• 4-Endocrine problems. hypothyroidism , adrenal insufficiency (Addison's disease), low blood sugar

(hypoglycemia), and in some cases, diabetes, can trigger low blood pressure.

• 5-Dehydration. • Even mild dehydration can cause weakness, dizziness and fatigue. Fever,

vomiting, severe diarrhea, overuse of diuretics and strenuous exercise can all lead to dehydration.

• Far more serious is hypovolemic shock, a life-threatening complication of dehydration. It occurs when low blood volume causes a sudden drop in blood pressure and a corresponding reduction in the amount of oxygen reaching your tissues.

• If untreated, severe hypovolemic shock can cause death within a few minutes or hours.

Causes of low blood pressure

• 6-Blood loss. • Losing a lot of blood from major injury or severe internal bleeding reduces the amount of blood in our

body, leading to a severe drop in blood pressure. • 7-Severe infection (septicemia).

• Septicemia can happen when an infection in the body enters the bloodstream. Lung, abdomen or urinary tract infections are usually the cause of septicemia. These conditions can lead to a life-threatening drop in blood pressure called septic shock.

Causes of low blood pressure

• 8-Allergic reaction (anaphylaxis).• Anaphylaxis is a severe and potentially life-

threatening allergic reaction. Common triggers of anaphylaxis include foods, certain medications, insect venoms. Anaphylaxis can cause breathing problems, hives, itching, a swollen throat and a drop in blood pressure.

• 9-Nutritional deficiencies.• In addition to making patients feel tired because you're not getting enough oxygen, anemia can lead

to low blood pressure.

SYNDROMES OF HYPOTENSION

Orthostatic hypotension,• Also called "postural hypotension",• is a common form of low blood pressure. It occurs after a

change in body position, typically when a person stands up from either a seated or lying position. It is usually transient and represents a delay in the normal compensatory ability of the autonomic nervous system.

• It is commonly seen in hypovolemia and as a result of various medications. In addition to blood pressure-lowering medications, many psychiatric medications, in particular antidepressants, can have this side effect.

DIAGNOSIS OF ORTHOSTATIC HYPOTENSION

• Simple blood pressure and heart rate measurements while lying, seated, and standing (with a two-minute delay in between each position change) can confirm the presence of orthostatic hypotension.

• Orthostatic hypotension is indicated if there is a drop in 20 mmHg of systolic pressure (and a 10 mmHg drop in diastolic pressure and a 20 beat increase in heart rate.

Neurocardiogenic syncope

• is a form of dysautonomia characterized by an inappropriate drop in blood pressure while in the upright position. Neurocardiogenic syncope is related to vasovagal syncope in that both occur as a result of increased activity of the vagus nerve, the mainstay of the parasympathetic nervous system.

Carotid sinus syndrome

Carotid sinus syndrome (CSS) is diagnosed when carotid sinus hypersensitivity is documented in a patient with otherwise unexplained dizziness, falls, presyncope or syncope, in whom carotid sinus massage reproduces presenting symptoms.

Carotid sinus syndrome

• The cardioinhibitory subtype is diagnosed if carotid sinus massage produces asystole exceeding 3 seconds,

• the vasodepressor subtype if there is a fall in systolic blood pressure (SBP) exceeding 50mmHg in the absence of significant bradycardia

• Mixed subtype if both are present.

Postprandial hypotension It occurs 30–75 minutes after eating meals. When a

great deal of blood is diverted to the intestines to facilitate digestion and absorption, the body must increase cardiac output and peripheral vasoconstriction in order to maintain enough BP to perfuse vital organs, such as the brain.

It is believed that postprandial hypotension is caused by the autonomic nervous system not compensating appropriately, because of ageing or a specific disorder

SYMPTOMS OF

HYPOTENSION

Symptoms

• The cardinal symptom of hypotension is lightheadedness or dizziness.

• If the blood pressure is sufficiently low, fainting and often seizures will occur.

• Other symptoms• Lack of concentration • Blurred vision • Nausea • Cold, pale skin • Rapid, shallow breathing • Fatigue • Depression • Thirst

Screening and diagnosis

The doctor must ask questions, including:

• What is your normal blood pressure? • What medications do you take? • Have you been eating and drinking normally? • Have you have any recent illness, accident, or

injury? • What other symptoms do you have? • Did you faint or become less alert? • Do you feel dizzy or light-headed when standing or

sitting after lying down?

Screening and diagnosis

• Blood tests.

CBC FASTING SUGAR: Cortisol, 6-8 AM Levels less than 3 indicate adrenal insufficiency. Levels greater than 18 are normal. Levels in the middle can be sorted out with a dynamic cortisol test e.g. ACTH stimulation

Screening and diagnosis

• Electrocardiogram (ECG). IT detects irregularities in heart rhythm, structural

abnormalities in the heart, and IHD.. • 24-hour Holter monitor to record heart's electrical activity during daily

routine. • Echocardiogram. Echocardiogram may show abnormalities in heart

muscle or valves or function

Screening and diagnosis

• Tilt-table test. If the subject have low blood pressure on standing, or from faulty brain signals (neurally mediated hypotension), the doctor may suggest a tilt-table test, which evaluates how your body reacts to changes in position.

• During the test, the subject lie on a table that's tilted to raise the upper part of your body, which simulates the movement from a prone to a standing position.

•

Key features

Complications OF HYPOTENSION

• Shock • Injury from falls due to fainting • Falls are particularly dangerous for older adults. Fall-

related injuries, such as a broken hip, can dramatically impact a person's quality of life.

• Severe hypotension starves your body of oxygen, which can damage the heart, brain, and other organs. This type of hypotension can be life threatening if not immediately treated.

TREATMENT OF

HYPOTENSION

Prevention

• Steps to prevent or reduce symptoms may include:

• Drinking plenty of fluids • Getting up slowly after sitting or lying down • Using compression stockings to increase

blood pressure in the legs • Avoiding standing for a long time

Treatment

1) The treatment for hypotension depends on its cause. 2) Asymptomatic hypotension in healthy people usually does

not require treatment. 3) If it's not clear what's causing low blood pressure or no

effective treatment exists, the goal is to raise our blood pressure and reduce signs and symptoms

4) Severe hypotension needs to be aggressively treated because reduced blood flow to critical organs including the brain, heart and kidneys may cause organ failure and can ultimately lead to death.

Treatment

5) Use more salt. Sodium can raise blood pressure, sometimes

dramatically, for people with low blood pressure, that can be a good thing.

But because excess sodium can lead to heart failure, especially in older adults, it's important to check patients individually before upping salt intake.

Treatment

6) Drink more water. Although nearly everyone can benefit from drinking

enough water, this is especially true more for hypotensives. Fluids increase blood volume and help prevent dehydration, both of which are important in treating hypotension.

7) Follow a healthy diet. Get all the nutrients you need for good health by focusing on

a variety of foods, including whole grains, fruits, vegetables, and lean chicken and fish.

Treatment

8) Use compression stockings. The same elastic stockings and

leotards commonly used to relieve the pain and swelling of varicose veins may help reduce the pooling of blood in your legs

9) Medications.

Several medications, either used alone or together, can be used to treat low blood pressure For example,

1- Fludrocortisone is often used to treat low blood pressure. This drug helps boost our blood volume, which raises blood pressure.

2- Midodrine to raise standing blood pressure levels in people with chronic orthostatic hypotension. It works by restricting the ability of our blood vessels to expand, which raises blood pressure.

Other drugs, such as 3- Pyridostigmine, 4-Nonsteroidal anti-inflammatory drugs (NSAIDs), 5-Caffeine 6-Erythropoietin these are sometimes used, either alone

or with other drugs.

PREGNANCY

• EFFORTIL May impair utero-placental perfusion, can cause uterine relaxation.

• Should not be used in pregnancy especially in 1st trimester

• Midodrine has been assigned to pregnancy category C by the FDA.

• Animal studies have failed to reveal evidence of teratogenicity.

• There are no controlled data in human pregnancy. Midodrine is only recommended for use during pregnancy when benefit outweighs risk.

• .

Midodrine Lactation Warnings

There are no data on the excretion of midodrine into human milk.

The manufacturer recommends that caution

be used when administering midodrine to nursing women

Postprandial hypotension

. Ibuprofen (or indomethacin (may be beneficial

Vasovagal Syncope can be treated with

• Beta blockers [for example, propanolol• Fludrocortisone • A pacemaker can also be helpful when a

patient fails drug therapy