Essential Hypertension Review| USMLE Step 2

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Essential Hypertension Review| USMLE Step 2

  1. 1. Cardiology HYPERTENSION USMLE Step 2 Review Marc Imhotep Cray, M.D. BMS and CK Teacher http://www.imhotepvirtualmedsch.com/
  2. 2. Cardiology| Hypertensive Vascular Disease Marc Imhotep Cray, M.D. Topics Covered 2  Definition  Classification  BMS Concepts  RAAS  Causal Conditions  Target Organ Damage  Approach  Management  HTN in Elderly
  3. 3. Cardiology| Hypertensive Vascular Disease Marc Imhotep Cray, M.D. DEFINITION of HTN • A BP of >140/90 mm Hg on two separate occasions • If there is end-organ damage, diagnosis is made on the first visit 3 HY Points: HTN is not diagnosed until two separate measurements on two separate occasions are above 140/90 mm Hg (except in pregnancy, when preeclampsia may be cause of hypertension) Also, if hypertension is severe (>210 mm Hg systolic, >120 mm Hg diastolic, or end-organ effects), immediate treatment with medication is warranted
  4. 4. Cardiology| Hypertensive Vascular Disease Marc Imhotep Cray, M.D. JNC Classification of HTN 4 National High Blood Pressure Education Program. The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. Bethesda (MD): National Heart, Lung, and Blood Institute (US); 2004 Aug. Classification of Blood Pressure. Available at http://www.ncbi.nlm.nih.gov/books/NBK9633/
  5. 5. Cardiology| Hypertensive Vascular Disease Marc Imhotep Cray, M.D. BMS CONCEPTS OF HTN Effect of CO and SVR on BP: CO = HR × SV MAP = TPR × CO BP ∼ CO × TPR CO = MAP / TPR MAP = dBP + 1 / 3 pulse pressure AUTOREGULATION ↑ CO → ↑ MAP, detected by aortic and carotid baroreceptors → vasodilation → ↓ TPR and hence ↓ CO (to balance the initial ↑ CO) PRESSURE NATRIURESIS ↑ MAP = ↑ renal perfusion, ↑ GFR, and ↓ aldosterone → ↑ Na + H2O excretion (natriuresis) 5
  6. 6. Cardiology| Hypertensive Vascular Disease Marc Imhotep Cray, M.D. 6  RAAS plays an important role in regulating blood volume and systemic vascular resistance, which together influence cardiac output and arterial pressure  Three important components to this system: 1) renin, 2) angiotensin, and 3) aldosterone • Renin, which is primarily released by kidneys, stimulates formation of angiotensin in blood and tissues, which in turn stimulates the release of aldosterone from the adrenal cortex Renin-angiotensin-aldosterone system (RAAS)
  7. 7. Cardiology| Hypertensive Vascular Disease Marc Imhotep Cray, M.D. RAAS cont. 7  Renin is a proteolytic enzyme that is released into the circulation primarily by the kidneys. Its release is stimulated by: i. sympathetic nerve activation (acting through β1- adrenoceptors) ii. renal artery hypotension (caused by systemic hypotension or renal artery stenosis) iii. decreased sodium delivery to distal tubules of kidney
  8. 8. Cardiology| Hypertensive Vascular Disease Marc Imhotep Cray, M.D. RAAS schematic 8 http://en.wikipedia.org/wiki/File:Renin-angiotensin-aldosterone_system.png
  9. 9. Cardiology| Hypertensive Vascular Disease Marc Imhotep Cray, M.D. CAUSAL CONDITIONS of HTN 1. 1◦ (essential HTN—95% of cases) 2. 2◦ HTN • Renal/vascular (↑ CO) • RF, polycystic kidney disease, CoA, RAS • Endocrine (↑ SVR) • Hyperthyroidism, adrenal adenoma (↑ aldosterone, ↑ cortisone), pheochromocytoma, Hyperparathyroidism Reversible RF: obesity, poor dietary habits, high Na+ intake, sedentary lifestyle, high EtOH and/or coffee consumption, high stress, high normal BP, illicit drug use (e.g., cocaine), herbal med (e.g., ma huang, ginseng, licorice, ginger) 9
  10. 10. Cardiology| Hypertensive Vascular Disease Marc Imhotep Cray, M.D. Target Organ Damage in HTN 10 Cerebrovascular disease • TIA • Ischemic or hemorrhagic stroke • Vascular dementia Hypertensive retinopathy LV dysfunction CAD • MI • Angina • CHF CKD • Hypertensive nephropathy • Albuminuria Peripheral artery disease • Intermittent claudication
  11. 11. Cardiology| Hypertensive Vascular Disease Marc Imhotep Cray, M.D. APPROACH Hx • Age of onset, duration, prior Rx and response, Hx of refractory HTN? associated Sx (chest pain, palpitations, SOB, renal problems, headaches, diaphoresis, polyuria, hematuria, edema), Hx, or symptom of sleep apnea • Family Hx, meds, diet, coffee intake, and EtOH • End-organ damage (stroke/TIA, MI, CHF, renal disease, retinal disease), CV risk stratification • Elicit hypertensive emergency (hypertensive encephalopathy, strokes, dissecting thoracic aortic aneurysm, malignant HTN, acute LV failure, acute glomerulonephritis) 11
  12. 12. Cardiology| Hypertensive Vascular Disease Marc Imhotep Cray, M.D. APPROACH PE • BP measurement with calibrated instrument and appropriate cuff size • Fundi (copper wire, cotton wool spots, AV nicking, papilledema) • Complete CV exam (clubbing, cyanosis, peripheral pulses, bruits, JVP, apex beat, parasternal heave, heart sounds and murmurs, compare U/E and L/E BP), • Lungs auscultation, • Abdo exam for renal mass and bruits, edema, weight 12
  13. 13. Cardiology| Hypertensive Vascular Disease Marc Imhotep Cray, M.D. APPROACH Standard Workup Electrolytes, BUN, CR, fasting gluc., U/A, lipid profile (fasting total cholesterol, HDL, LDL, triglycerides), EKG (to evaluate LVH s) 13
  14. 14. Cardiology| Hypertensive Vascular Disease Marc Imhotep Cray, M.D. APPROACH 2◦ Causes Workup 1. Renal and vascular • Renovascular (older pt, Hx of atherosclerosis, renal artery bruit) • Captopril renal scan/duplex U/S, MRI, angiography • Unilateral RAS: normal Cr • Bilateral RAS: hypervolemia, ↑ Cr • Renal parenchymal • BUN, Cr, Cr clearance • CoA • ↓ LE pulses, radiofemoral delay, systolic murmur, LVH, rib notching on CXR • ECHO, aortogram 2. Endocrine • TSH, cortical, urinary VMA, PTH, aldosterone, renin, renin / aldosterone ratio 14
  15. 15. Cardiology| Hypertensive Vascular Disease Marc Imhotep Cray, M.D. MANAGEMENT 15 Annual F/U with high normal BP is recommended as 40% of pts with sBP 130 to 39 mm Hg or dBP 85 to 89 mm Hg develop HTN in 2 years Home BP monitoring Goal ↓ BP to <140/90 mm Hg; and if pt has diabetes or renal disease, BP <130/80 mm Hg Pharmacologic Rx • Select med with minimal or Ø adverse effects on diabetes, asthma, and that benefits CHF or myocardial ischemia • Initiate pharmacologic Rx for hypertensive pt refractory to lifestyle s or pre-HTN + diabetes/renal disease
  16. 16. Cardiology| Hypertensive Vascular Disease Marc Imhotep Cray, M.D. MANAGEMENT 16 HTN Alone Thiazide diuretics, β-blockers, ACEIs, ARBs, long-acting CCBs as first-line Rx • If still Ø response to Rx despite max tolerated dose or Rx- related adverse effect, add CCB/ARB/α-receptor blocker/centrally acting agents (methyldopa) HY Point: For HTN that is nonresponsive to Rx, consider noncompliance, 2◦ HTN, drug interactions ACEIs and ARBs are contraindicated in pregnancy β-Blockers are not recommended for pts older than 60 years without indication Avoid diuretic-induced hypokalemia by using K+ sparing agent
  17. 17. Cardiology| Hypertensive Vascular Disease Marc Imhotep Cray, M.D. Antihypertensives in Pt with Other Comorbidities 17 Whalen KL, Stewart RD. Pharmacologic management of hypertension in patients with diabetes. Am Fam Physician. 2008 Dec 1;78(11):1277-82. Available at http://www.aafp.org/afp/2008/1201/p1277.html#abstract Which agent you choose is often based on comorbidities
  18. 18. Cardiology| Hypertensive Vascular Disease Marc Imhotep Cray, M.D. Exogenous Aggravators of HTN 18 Prescription Drugs • NSAIDs, including coxibs • OCP and sex hormones • Corticosteroids and anabolic steroids • Vasoconstricting / sympathomimetics • Calcineurin inhibitors (cyclosporin, tacrolimus) • EPO and analogs • MAOIs • Midodrine Other • Salt • Excessive EtOH use • Sleep apnea • Licorice root • Stimulants including cocaine HY Point: Urinary Albumin Secretion Identify urinary albumin secretion for DM and CKD: Rx differs without proteinuria albumin/ creatinine ratio (ACR) >30 mg/mmol is AbN
  19. 19. Cardiology| Hypertensive Vascular Disease Marc Imhotep Cray, M.D. Lifestyle Therapies in HTN 19 Refer to United States food guide
  20. 20. Cardiology| Hypertensive Vascular Disease Marc Imhotep Cray, M.D. HYPERTENSION IN ELDERLY 20 DEFINITION • A BP of >140/90 mm Hg • Isolated systolic HTN (sBP >140; dBP <90) is more common in elderly population • Prevalence may reach 60% to 80% in pts aged 60 years and older BMS: Factors that contribute to ↑ prevalence of HTN in elderly: ↓ Compliance of arterial wall ↓ NO dependent arterial vasodilation ↓ Numbers of functioning nephrons ↑ Collagen, ↑ vascular thickening, ↓ elasticity ↓ CV physiological reservoir Nikolaos Lionakis et. al. Hypertension in the elderly World J Cardiol. May 26, 2012; 4(5): 135–147. Published online May 26, 2012. Available at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3364500/
  21. 21. Cardiology| Hypertensive Vascular Disease Marc Imhotep Cray, M.D. BMS of HTN in Elderly 21 • Age-related s in aortic vascular property • ↑ Age → progressive thickening of arterial walls—predominantly in the intimal layer→↑intimal to medial thickness ratio • ↑ Fragmentation and depletion of arterial elastin coupled with medial deposition of matrix metalloproteins and collagen • Collectively, this leads to thicker and stiffer arteries, predominantly central elastic arteries • In elderly, ↑ sBP is characterized by widened arterial pulse pressure or s in vascular morphology associated with ↑ age → small artery constriction that ↑ reflected component of the pulse wave • Large artery stiffening that ↑ velocity of reflected wave, where it moves from diastole to systole hence ↑ sBP
  22. 22. Cardiology| Hypertensive Vascular Disease Marc Imhotep Cray, M.D. HTN in Elderly cont. 22 CAUSAL CONDITIONS • 1◦ HTN • 2◦ HTN • Med related (Na+ retaining agents e.g.,mineralocorticoids, anabolic steroids, NSAIDs, antidepressants, sympathomimetics e.g., pseudoephedrine, herbal agents) • Endocrine: thyrotoxicosis, pheochromocytoma, Cushing disease, 1◦ aldosteronism, hyperparathyroidism, hyper/hypothyroidism • Renal: renovascular disease (RAS), renal parenchymal disease • Vascular: aortic coarctation • Sleep apnea Other causes • White coat HTN • Pseudohypertension also prevalent in the elderly population due to thickening and calcification of the arteries
  23. 23. Cardiology| Hypertensive Vascular Disease Marc Imhotep Cray, M.D. HTN in Elderly cont. 23 APPROACH Hx In addition to usual Hx taking for HTN: • Meds: Prescribed, OTC and herbal drugs • Past medical history: DM, CRF, pre-HTN, hyperlipidemia, CAD • Social Hx: smoking, EtOH intake, dietary habits (↑ salt &↑ fat diet) PE • Vitals: BP (compare for both arms), weight, height, BMI, waist circumference (assess for MS) • Head and Neck: funduscopy for retinal s, thyroid exam, JVP, carotid bruit • Chest: signs of CHF, palpable murmur • CV exam: murmurs, Abdo aorta bruit, renal artery bruit, Abdo. aorta aneurysm
  24. 24. Cardiology| Hypertensive Vascular Disease Marc Imhotep Cray, M.D. HTN in Elderly cont. 24 MANAGEMENT sBP and pulse pressure should be regarded as major predictor of outcome • Rx should be initiated when sBP >160 mm Hg or >140 mm Hg when pt has other RF like diabetes and smoking • Nonpharmacologic Rx: lifestyle modification, achieve target BMI through diet and exercise, Na restriction, cessation of smoking, judicious consumption of EtOH • Pharmacologic Rx: initiated if the above is inadequate • Benefit in treating systolic HTN in the elderly is two to four times greater than in younger pt with 1◦ HTN
  25. 25. Cardiology| Hypertensive Vascular Disease Marc Imhotep Cray, M.D. HTN in Elderly Mx cont. 25 • Thiazide diuretic-First-line choice for elderly pt • Use lower doses (half of what is usually used in younger population) to minimize side effects like postural hypotension due to sluggish autoregulation in elderly population • Periodically monitor lytes; hypokalemia may negate CV benefit • Dihydropyridines (nifedipine ) may also be used as an alternative William JE, Black HR Treatment of Hypertension in the Elderly Am J Geriatr Cardiol. 2002;11(1) Available at http://www.medscape.com/viewarticle/423503_1
  26. 26. Cardiology| Hypertensive Vascular Disease Marc Imhotep Cray, M.D. Further Study 26  Chobanian AV, Bakris GL, Black HR, et al. The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure: The JNC 7 Report. JAMA. 2003;289(19):2560-2571. Available at http://jama.jamanetwork.com/article.aspx?articleid=196589  Kotchen TA Hypertensive Vascular Disease Ch. 247 In Kasper DL, Braunwald E, Fauci AS, et al. Harrison's Principles of Internal Medicine (18th ed.). New York, NY: McGraw-Hill 2013. pp. 2040–58. For more like this visit IVMS’s latest Website/ Blog http://drimhotepmd.wordpress.com/  Medscape Meena SM Hypertension Available at http://emedicine.medscape.com/article/241381-overview  Nikolaos Lionakis et. al. Hypertension in the elderly World J Cardiol. May 26, 2012; 4(5): 135–147. Published online May 26, 2012. Available at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3364500/

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