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Terminology Cardiac output – the amount to blood pumped from the left ventricle each minute Stroke Volume – the amount of blood ejected from the left ventricle during each contraction Blood pressure – the force of blood exerted against the vessel walls Determined by the quantity of blood flow or cardiac output & resistance in the arterioles Systolic & diastolic bp o Systolic Amount of pressure or force generated by the left ventricle to distribute blood into the aorta with each contraction Measures the effectiveness of the heart pump and vascular tone o Diastolic Amount of pressure or force against the arterial walls during cardiac relaxation Factors affecting bp Anything that increases cardiac output or peripheral vascular resistance o Excessive sodium intake o Fewer nephrons o Stress o Genetics o Obesity o Endothelial factors Bp regulation ANS by way of the sympathetic nervous system Kidneys – renin-angiotensin-aldosterone mechanism Endocrine system – hormone release to stimulate Sympathetic nervous system o Baroreceptors Found in the arch of the aorta & internal carotids Respond to stretching of the vessel that occurs with an increase in bp Receptors inhibit vasomotor centers in the pons & medulla causing a drop in bp o Chemoreceptors Found in carotid arteries & aortic arch Sensitive to hypoxemia Send impulses along vagus nerves to activate vasoconstrictor receptors & raise bp when stimulated Found in respiratory center of brain Sensitive to hypercapnia & acidosis o Kidney regulation Decrease renal flow causes resorption of H2O & Na – increase fluid causes increase bp
Activation of renin-angiotensin-aldosterone system
o Masked Health considerations o Prevalence Worldwide problem United States – 1 in 3 adults Can shorten life expectancy o Health Promotion Vegetables, fruits & whole grains Low-fat dairy, poultry, fish, legumes, nuts, non-tropical oil Limit sweets, sugar beverages & red meats <2400mg sodium daily Exercise 3xweek, 40 min Healthy people 2020 o From 2010
of people with HTN are taking action
of people who are checked
Modified from 2010 < pop with HTN
pre-HTN group with BMI, fat consumption, Na intake, Activity, alcohol consumption o New 2020 med compliance
ASSESSMENT
Clinical manifestations Headache Dizziness Facial flushing Syncope Asymptomatic for YEARS What does prolonged Hypertension result in? Assessment Always assess blood pressure Eval for anxiety Use appropriate cuff size Forearm as accurate as upper arm Blood pressure in both arms Detect orthostatic changes (2 min rule) Funduscopic exam of eyes Stressors Coping strategies Diagnostics o Kidney disease Protein or blood in the urine, elevated BUN & serum creatinine, GFR o Chest Xray cardiomegaly o ECG Degree of cardiac involvement, hypertrophy Lifestyle changes Restrict sodium intake Reduce weight Use alcohol sparingly (1 drink per day for women, 2 for men) Exercise Relaxation tech Avoid tobacco & caffeine Alternative therapy o Garlic does lower cholesterol & decrease bp Can damage liver
Spironolactone, triamterene, amiloride Inhibit reabsorption of sodium in exchange for potassium Retain potassium in the body Used in combo with other diuretics or antihypertensives Calcium channel blockers Verapamil, amlodipine, nifedipine, diltiazem Interfere with the movement of calcium, causing vasodilation then decreased blood pressure Block Sa & av node conduction resulting in decreased heart rate Can react to grapefruit Angiotensin-converting enzyme inhibitors -pril drugs captopril, lisinopril, enalapril Single or combo treatment Block the action of angiotensin-converting enzyme inhibiting the vasoconstricting effect Decreases sodium & water retention Most common side effect – nagging, dry cough Instruct patients to rise slowly to avoid hypotension that can occur initially Notify md of changes in systolic bp greater than 20mmhg Angiotensin II receptor blockers -tan drugs valsartan, losartan, azilsartan Single or combo No dose adjustment for age or renal impairment Not effective in African American population unless used with diuretic Aldosterone receptor antagonist Eplerenone Block the hypertensive effect of aldosterone Avoid grapefruit When used in conjunction with arbs or ace inhibitors increases risk of hyperkalemia Beta-adrenergic blockers -lol drugs atenolol, bisoprolol, metoprolol Cardio selective (beta1) & non- cardio selective (beta1 & 2) Decrease the 3 C’s Contraction Conduction Constriction Side effects include fatigue, weakness, depression & sexual dysfunction Can mask the effect of hypoglycemia Drug of choice for hypertension with ischemic heart disease Dietary Changes o DASH diet ( Dietary Approaches to Stop Hypertension) pg 403 Table 403 Na < 2300mg/day or 1500mg/day if > 51 yrs
Non-compliance Medication management is typically needed for the rest of the patient’s life Some patients are not compliant because of side effects Teaching is required to educate the patient Nonadherence can result in organ damage and hypertensive crisis
