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Normal Regulation of Blood Pressure (BP)

• Normal Systolic BP (SBP) is less than 120mmHg
• Normal Diastolic BP (DBP) is less than 80 mmHg
• Blood pressure is the force exerted by the blood against the walls of the blood vessel
• Adequate blood pressure is required to maintain tissue perfusion during activity and rest
• Maintaining blood pressure involves integrating systemic factors and local peripheral vascular effects
• Arterial BP = Cardiac Output (CO) x Systemic Vascular Resistance (SVR)
• Mechanisms that regulate BP can affect CO, SVR, or both
• Blood pressure regulation involves nervous, cardiovascular, renal, and endocrine functions
• BP is regulated by short-term (seconds-hours) and long-term (days-weeks) mechanisms

Factors Influencing Blood Pressure

• Cardiac factors include heart rate, contractility, and conductivity
• The sympathetic nervous system influences BP through α₁- and α₂-Adrenergic receptors (vasoconstriction) and β₂-Adrenergic receptors (vasodilation)
• Local regulation involves vasodilators like prostaglandins and nitric oxide, and vasoconstrictors like endothelin
• Renal fluid volume control involves the renin-angiotensin-aldosterone system and natriuretic peptides
• Neurohormonal factors that influence blood pressure include vasoconstrictors like Angiotensin and Norepinephrine

Cardiac Output (CO)

• Cardiac output is the amount of blood pumped by the ventricle in one minute and reflects the heart's mechanical ability
• Cardiac Output (CO) = Stroke Volume (SV) x Heart Rate (HR)/min
• Factors that affect heart rate (HR) or stroke volume (SV) impact cardiac output
• Preload is blood volume in ventricles at the end of diastole, before the next contration
• Contractility refers to the force of contraction, more fibre stretching equals stronger contraction
• Afterload is peripheral resistance against which the left ventricle must pump
• Atrial kick occurs during the final phase of atrial systole, when atria contract and eject a bolus of blood into ventricles
• Cardiac reserve describes the heart's ability to respond to demands by increasing cardiac output

Systemic Vascular Resistance (SVR)

• SVR is the force opposing blood movement within vessels
• SVR is mainly determined by the radius of small arteries and arterioles
• A small change in vessel radius creates a major change in SVR
• If SVR increases while cardiac output remains constant or increases, arterial BP will increase

Hypertension (HTN)

• Hypertension is a sustained elevation in systemic arterial blood pressure
• Hypertension is a major modifiable risk factor for cardiovascular disease and mortality in Canada
• Increased blood pressure increases the risk for myocardial infarction (MI), heart failure (HF), stroke, and renal disease
• The World Health Organization (WHO) identifies hypertension as a silent killer
• Increased awareness and early detection are crucial for hypertension management
• Blood pressure should be measured in all adult patients at all appropriate visits to determine cardiovascular risk and monitor the effectiveness of antihypertensive treatment
• Stage 1 hypertension is defined as systolic BP of 140-159 mmHg or diastolic BP of 90-99 mmHg
• Stage 2 hypertension is defined as systolic BP of 160 mmHg or diastolic BP of 100 mmHg
• The target BP for individuals with both hypertension, and diabetes mellitus is less than 130 mmHg systolic and less than 80 mmHg diastolic

Primary (Essential) Hypertension

• Primary (Essential) Hypertension accounts for the majority of hypertension cases
• It has no exact identified cause, but results from a complex interaction of genes and environmental factors
• Contributing factors include increased sympathetic nervous system (SNS) activity, increased sodium intake, overproduction of sodium-retaining hormones and vasoconstrictors, increased body weight, diabetes mellitus (DM), and excess alcohol intake

Secondary Hypertension

• Secondary Hypertension accounts for 5-10% of hypertension cases in adults and over 80% in children
• Secondary Hypertension has a specific cause identified and corrected
• Clinical findings include unprovoked hypokalemia, abdominal bruit, variable pressures, tachycardia, sweating, tremor, and family history of renal disease
• Possible causes include congenital conditions of the aorta, renal disease, endocrine or neurological disorders, sleep apnea, medications, and pregnancy
• Treatment focuses on eliminating the underlying cause

Primary Hypertension: Etiology and Risk Factors

• Risk factors include older age and sedentary lifestyle
• Risk factors include a high dietary sodium intake
• Risk factors include psychosocial stress and elevated serum lipids
• Risk factors include gender, being of an ethnicity with increased risk, or a family history of hypertension
• Risk factors include glucose intolerance or obesity
• Risk factors include heavy alcohol consumption or cigarette smoking

Primary Hypertension: Pathophysiology

• Genetic factors play a significant role in familial heritability of hypertension
• Excessive dietary sodium intake is strongly linked to hypertension
• Restricting sodium intake often leads to a decrease in blood pressure
• High plasma renin activity can lead to increased conversion of angiotensinogen to angiotensin I, causing arteriolar constriction, vascular hypertrophy, and increased aldosterone secretion
• Prolonged SNS activity can result in vasoconstriction, increased heart rate, and increased renin release
• Insulin resistance associated with endothelial dysfunction can lead to hyperinsulinemia, simulating SNS and RAAS activity, and impairing nitric oxide-mediated vasodilation
• Endothelial cell dysfunction in hypertension can reduce vasodilator response to nitric oxide and cause pronounced vasoconstriction
• Obesity is linked to hormone abnormalities, contributing to hypertension

Hypertension: Clinical Manifestations

• Hypertension is often asymptomatic until target-organ disease has occurred
• Symptoms of severe hypertension are related to the effect on blood vessels in various organs/tissues or to increased workload of the heart
• Symptoms include fatigue and reduced activity tolerance
• Symptoms include dizziness and palpitations
• Symptoms include Angina and dyspnea
• Extremely high blood pressure may result in headache, nosebleeds, and dizziness

Older Adult with Primary Hypertension

• Blood pressure tends to rise with age because of age-related changes
• Reduced tissue elasticity increases collagen and stiffness of the myocardium
• Increase peripheral vascular resistance can affect the heart's function
• Medications may be altered due to decreased splanchnic flow or the prolonged metabolism/excretion of medications
• BP measurement techniques must account for a potential wide auscultatory gap
• Older adults are extra sensitive to BP changes, where reducing SBP to <120 mmHg with long-standing HTN can lead to inadequate cerebral blood flow
• Older patients are more likely to have orthostatic hypotension because of impaired reflexes, volume depletion, and chronic disease
• Start antihypertensive dose low and increase cautiously

Hypertension: Diagnostic Studies

• Diagnosis is not based on a single elevated reading but requires several elevated readings over several weeks
• Diagnoses involve history and physical examination
• Routine tests include urinalysis and urinary albumin secretion (if patient has diabetes)
• Blood tests can include checking chemistry (potassium, sodium, creatinine, blood urea, nitrogen)
• Fasting blood glucose measures are used in diagnosis
• A Standard 12-lead electrocardiography measures electrical activity of heart

Hypertension: Interprofessional Care

• Regular monitoring of BP, including home monitoring and ambulatory BP monitoring
• Nutritional therapy through reduced sodium and cholesterol intake
• Nutritional therapy also includes increased intake of potassium, calcium and magnesium
• Regular weight management, physical activity is recommended
• Tobacco cessation is recommended, as well as alcohol moderation
• Antihypertensive medications are used in treatment
• Patient should be educated alongside their caregiver(s)

Hypertension: Antihypertensive Therapy

• Medication therapy is recommended for all patients with low risk stage 1 hypertension (140-159/90-99mmHg)
• General goals are BP < 140/90mmHg and BP < 130/80mmHg for patients with chronic kidney disease or diabetes
• There are generally two main actions of medications: reducing SVR & decreasing blood volume
• Full effects of antihypertensive medication may not be apparent for up to 6 weeks
• If BP is not controlled, increase the dosage off first-line medication, and/or substitute or add a second medication from a different class.
• Many patients require at least two medications plus lifestyle changes
• Diuretics, Adrenergic (sympathetic) inhibitors, Direct vasodilators, Angiotensin inhibitors, and Calcium channel blockers are all types of medicine used to treat Hypertension

Primary Hypertension: Nursing Management

• Overall goals include achieving and maintaining a personally determined target BP
• The patient must understand, accept, and implement a therapeutic plan
• An understanding of therapy's minimal adverse effects is needed, alongside confidence to manage effects
• Maintain a thorough assessment and healthcare history to ensure that therapy is applicable
• Health promotion through public awareness and risk factor reduction is key
• Initial assessment is multiple BP measurements a few minutes apart, and average readings
• Ensure size and placement of BP cuff are correct, and the patient is supine or sitting during the test

Hypertension: Patient and Family Teaching

• Sedentary lifestyle, diet, abdominal obesity, DM, smoking, dyslipidemia, stress or lack of adherence to the treatment plan are all modifiable risk factors
• Both over-the-counter and prescribed medications can be a factor
• Minimizing sexual dysfunction caused by dry mouth can be a factor
• Monitoring for frequent voiding through diuretics can be a factor
• Reducing overall cardiovascular risk factors, diet changes, limiting alcohol, regular physical activity, avoiding tobacco, managing stress
• Frequency varies, every 3-6 months once stabilized
• Educating that Hypertension can be controlled but not cured is key
• Checking cooking labels and hidden sodium sources can be useful in treatment

Hypertension: Complications

• Most hypertension issues are located in target organs
• Heart: hypertensive heart disease
• Brain: cerebrovascular disease
• Kidneys: nephrosclerosis
• Eyes: retinal damage

Primary Hypertension: Clinical Manifestations

• Sustained elevation of systemic arterial blood pressure (BP)
• One of most important modifiable risk factors of cardiovascular disease and mortality in Canada
• Increased BP □ increased risk for myocardial infarction (MI), heart failure (HF), stroke, renal disease, and death
• WHO Identifies HTN as “silent killer"

Hypertensive Crisis

• A hypertensive crisis is a severe, abrupt elevation in blood pressure
• It is defined as diastolic BP greater than 120-130 mm Hg
• The rate of rise is more important than the absolute value in determining the need for emergency treatment
• Prompt recognition and management are essential
• It's most common in patients with a history of hypertension who have failed to adhere to medication regimens or who are unmedicated
• Life-threatening damage may occur to target organs
• The condition is classified by the degree of organ damage and the rapidity with which BP must be lowered

Hypertensive Crisis: Clinical Manifestations

• A sudden rise in BP can cause Headache, nausea, vomiting, seizures, confusion, stupor, coma, blurred vision, and/or transient blindness
• May lead to minor to complete renal shutdown
• May cause rapid heart decompensation such as unstable angina and pulmonary edema
• Causes extreme chest and back pain as well as diaphoresis often
• The stroke symptoms are similar without the lateralizing signs

Hypertensive Crisis: Nursing And Interprofessional Management

• Association between elevated BP and end-organ damage severity
• Hospitalization might be nessecary, including parental administration of various medications
• Initial goal: decrease mean arterial pressure (MAP) 10-20% in first 1-2 hours and then gradual reductions within next day
• Lowering too far, too fast may decrease cerebral perfusion and precipitate stroke
• Patiernts should be sitting in quiet environment
• Provide encouragement and answer questions and eliminate extra noise

Atherosclerosis

• The presence of lipids is a major cause of coronary artery disease as the person ages
• Can involve Fatty streaks, Fibrous plaque, and Complicated lesions
• Atherosclerosis can be caused by modifiable elements, such as diet or exercise
• Atherosclerosis can be caused by Nonmodifiable elements, such as age or race

Coronary Artery Disease: Etiology

• Shear stress, response-to-injury can all lead to Atherosclerosis
• Can result in Endothelial dysfunction, where synthesis decreases
• Smooth muscle proliferation may affect arteries

Coronary Artery Disease: Risk Factors

• Risk factors include high serum lipid levels, tobacco use, and high BP
• Risk factors also include diabetes, early menopause, and low physical activity
• Ethnicity, Age, and family history are also risk factors

Dyslipidemia

• Dyslipidemia can be tested through different phases of measurement to check the cardiovascular risk of the patient.
• Men over 40, women over 50 (are advised during checkups
• Early screening can be done for high risk ethnic groups

Coronary Artery Disease: Patient and Family Teaching

• Should involve taking medications as prescribed, and monitoring levels/reporting to health specialists
• There will be the adjustment of caloric intake and diet
• Moderate exercise/stress reduction and adequate rest/sleep is recommended

Chronic Stable Angina

• It becomes reversible myocardial ischemia
• There is chest pain but the individual still has a chance of survival, however can lead to death and myocardial infarction
• Many people report indigestion along with the symptoms of angina

Interprofessional Management

• It's designed to stabilize and treat the patient in an ethical and professional way
• There are a number of nursing interventions, such as administering nitrates

Prinzmetal's Angina

• Can occur at any time however is usually in response to spasm of a major coronary artery
• Strong contraction of smooth muscle caused by increase in intracellular calcium

More serious ACS effects

• The disease is either Unstable or Myocardial Infarctions

Acute Stable Angina

• May develop after chronic conditions, or be a first CAD sign
• Might cause significant changes or pattern in fatigue/SOB

Acute Myocardial Infarctions

• Occurs in part due to development in Thrombus
  • Can only withstand Ischemic conditions for a few minutes

Acute Cardio Signs

• Pain or SNS stimulation may occur
• Fever may occur

Knowledge check about heart disease

• Can involve Plaque formation in the coronaries and abnormal lipid levels