9.1 Hypertension

Question 1

HTN

Definition

Answer 1

Normal <80 (no tx)
Prehypertension 120-139 / 80-89 (tx only if end-organ damage)
Stage 1 HTN 140-159 / 90-99 (tx)
Stage 2 HTN ≧160 / ≧100 (2 drug dx)

Question 2

Isolated systolic HTN

Answer 2

≧140 / <90

Progressive ↓ vascular compliance (elasticity)

Question 3

Accelerated HTN

Answer 3

↑ BP with evidence of vascular damage on fundoscopy BUT WITHOUT papilledema

Question 4

Malignant HTN

Answer 4

↑ BP with vascular damage (encephalopathy or nephropathy) AND papilledema in fundoscopy

Question 5

HTN urgency

Answer 5

sBP >210 or dBP >120 with minimal or not target-organ damage

Question 6

HTN emergency

Answer 6

↑ BP and acute target-organ damage

Acute symtomps

Question 7

Resistant HTN

Answer 7

Failure to reach BP control with full doses of 3-drug tx (diuretic included)

Question 8

Mechanisms of HTN

Answer 8

Intravascular volume
Autonome nervous system
Renin-Angiotensin-Aldosterone
Vascular

Question 9

Intravascular volume physiology

Answer 9

Na+ is predominantly extracellular and primary determinant of extracellular volume
↑NaCl intake → ↑extracel. volume → ↑cardiac output

Question 10

Autonome nervous system

Answer 10

Via pressure, volume and chemoreceptor signals
Adrenergic reflexes {short term} + (hormonal + volume-related factors) = long term
Norepinephrine, Epinephrine & Dopamine

Question 11

Adrenergic receptor physiology

Answer 11

alfa 1 postsynaptic smooth muscle cells (vasoconstriction)
alfa 2 presynaptic membranes in postganglionic nerve terminal that synthesizes epinephrine (negative feedback inhibiting norepinephrine release)
beta 1 ↑cardiac output by ↑HR + ↑contraction. ↑renin release from kidney.
beta 2 relaxation of smooth muscle (vasodilatation)

Question 12

Renin physiology

Answer 12

Synthesized in renal afferent arteriole
Secretion stimulated by:
1. ↓NaCl (distal ascending loop of Henle)
2. ↓pressure in renal afferent arteriole (baroreceptor)
3. β1 stimulation

Question 13

Angiotensin II physiology

Answer 13

• Vasoconstriction

- Smooth muscle myocyte growth (artherosclerosis pathogenesis and cardiac hypertrophy)

Question 14

Aldosterone physiology

Answer 14

Stimulated by AT2 and ↑K⁺

Na⁺ retention (exchange Na⁺ for K⁺)

Question 15

Vascular physiology

Answer 15

Elasticity of the vessel
Hypertrophy = ↓elasticity
Nitric oxide = vasodilator
Endotelin = vasoconstriction

Question 16

Investigation in HTN

labs

Answer 16

-Evaluate end-organ damage and rule-out secondary causes-
Urinalyisis (Proteinuria)
Hto. (Is HTN killing the Kidney?)
Electrolytes (K⁺) (Is HTN killing the Kidney?)
Serum Cr & BUN (Is HTN killing the Kidney?)
EKG (Left-ventricular hypertrophy)
Blood Glucose (DM?)
Lipid profile (risk factors)

Question 17

Causes of Secondary HTN

Answer 17

-ABCDE-
A Apnea, Aldosteronism
B Bruits, Bad kidneys
C Coarctation, Cushing's, Catecholamines, Calcemia, Contraceptives
D Drugs
E Endocrine disease

Question 18

Physical findings

Answer 18

Renovascular: abdominal bruit (renal artery stenosis most common cause)
Cushing: weight gain, moon-like facies, striae and ecchymoses
Pheochromocytoma: episodic HTN with headache, palpitations and sweating
Primary aldosteronism (Conn Syndrome): muscular weakness + polyuria/polydipsia from ↓K⁺

Question 19

Lifestyle modifications

may be sufficient in stage 1 HTN

Answer 19

• Diet: DASH (↓colesterol & ↓saturated fats) & limit sodium intake to 65-100 mmol (1.5-2.3 g)
• Exercise: 30-60 min, 4-7 x/wk
• Smoking cessation
• ↓OH
• Weight loss (most important= 1kg:1mmHg)

Question 20

Tx Target BP in HTN

Answer 20

<140/90 in the rest

Pregnant with crisis: dBP 90-100 (to avoid hypoperfusion of placenta)

Question 21

Who to treat?

Answer 21

dBP >90 despite 3- to 6-month with lifestyle modifications

Question 22

First line Tx

Answer 22

Diuretic, ACEI, β-Blockers, CCB
In absence of specific indication or contraindication, diuretics should be first tx (morality benefit)
Stage 2 HTN, a two-drug tx should be used (diuretic + “X”)

Question 23

How to combine anti-HTN drugs

Answer 23

ACEI β-Blockers Younger px / Heart failure
| x | —————–
CCB Diuretic >50 yr / low-renin HTN

Question 24

Tx for Specific HTN groups

Answer 24

• DM: ACEI or ARB
• Post-MI: β-Blockers
• ↓left-ventricular systolic function: ACEI ± β-Blockers
• Blacks: least effective with ACEI
• Pregnant: methyldopa / hydralazine (eclampsia) (NEVER ACEI nor ARB)

Question 25

HTN emergency Tx

Answer 25

- EKG more important as an initial test to exclude MI - IV tx: Nitroprusside (nitroglycerine if MI) - Goal: ↓MAP by no more than 25% in first 1-2 hrs

Question 26

Renal Artery Stenosis | Causes, Dx and Tx

Answer 26

- Causes: Artherosclerotic disease OR fibromuscular dysplasia in young women. - Dx: Upper abdominal bruit → best initial test: Abdo USG → Confirmation test: Arteriogram. - Tx: Percutaneous transluminal angioplasty (if Qx fails=ACEI)

Question 27

``` Primary Hyperaldosteronism (Causes, Dx and Tx) ```

Answer 27

- Cause: Adenome (most common) or Bilateral Hyperplasia - Dx: HTN + ↓K⁺ (muscular weakness + polyuria/polydipsia) → ↑aldosterone in urine and blood (with normal renin) - Tx: Adenome = Qx / Hyperplasia = Spironolactone

Question 28

Pheochromocytome | Causes, Dx and Tx

Answer 28

- Cause: Adrenal gland benign tumor - Dx: EPIsodic HTN + headaches, sweating, palpitations and ↑HR → urinary vanillylmandelic acid (VMA), metanephrine and free urinary catecholamines. (metabolites: EPInephrine→metanephrine→VMA) - Tx: alfa-blockers (Fenoxibenzamina or Phentolamine) followed by Qx

Question 29

Cushing Disease | Causes, Dx and Tx

Answer 29

- Cause: Pituitary adenoma (most common) Glucocorticoids inhibit protein production (amino-acids are turned into glucose) - Dx: HTN + Truncal obesity, buffalo hump, menstrual abnormalities, striae, hyperpigmentation and impaired healing → best initial test: Dexamethasone suppression test + 24-hour urine cortisol (DO NOT START WITH CT) - Tx: Qx **note** If dexa test is positive = look for ACTH? ↑ACTH = pituitary ↓ACTH = adrenal or ectopic

Question 30

Coarctation of the Aorta | Causes, Dx and Tx

Answer 30

- Causes: Aorta narrows where ductus arteriosus - Dx: HTN greater in upper extremities than in lower + murmur posterior left interscapular area → transesophageal echocardiography - Tx: Qx

Question 31

When to investigate secondary HTN?

Answer 31

- Very young or very old - Those with key features - HTN refractory to therapy