Hypertension Flashcards
When hypertension decreases renin secretion causes?
Natriuresis
Phenotypes associated with
salt-sensitive hypertension
Low renin Hpt (Primary) Black ethnicity Older age Obesity Metabolic syndrome
What can cause a natriuretic handicap?
Sodium Channelopathies
Genetics (APOL1 gene variants)
Renal injury
Low nephron mass
What can cause renal injury?
Sympathetic system
Uric acid
High salt diet
When is ambulatory BP monitoring indicated?
For the evaluation of “white coat” HTN (in absence of target organ injury)
If there is an absence of a BP drop while sleeping, it could indicate?
Increased CVD risk
Circumstances needed for office BP measurement
No coffee 30min before Pt seated quietly 5min Arm supported at heart level Appropriate sized cuff At least 2 measurements
Uses for self-measurment of BP
Check response to antihypertensive Rx
Improve adherence with Rx
Evaluate ‘white coat’ HTN
3 objectives when evaluating a pt. with HTN
Identify other CV risk factors or concomitant disorders that affects prognosis and guides treatment
Reveal identifiable causes of high BP
Assess the presence or absence of target organ damage and CVD
Name some CVD risk factors
Metabolic syndrome components Smoking Inactivity Microalbuminuria/GFR<60 Age Family history of premature CVD
Name some identifiable causes of HTN
Sleep apnea Drug-induced Chronic kidney disease Chronc steriod Rx (Cushing's) Pheochromocytoma Coarctation of the aorta Thyroid/parathyroid disease
Name some possible effects of target organs damage
LVH, Angina, prior MI, HF, Prior coronary revascularization Stroke, transient ischaemic attack Chronic kidney disease Peripheral artery disease Retinopathy
Important aspects on clinical exam
Fat distribution and muscle strength
Peripheral pulses
Wheezes and crackles
Renal masses and bruits
Lab tests for HTN
ECG (LVH) Urinalysis (albumin:creatinine) Glucose, hematocrit Creatinine, GFR Lipid profile
How does the sympathic nervous system respond to a decrease in BP?
It stimulates the activation of both the B1 adrenoceptors of the heart and the A1 adrenoceptors on smooth muscle
How does the renin-angiotensin-aldosterone system respond to a decrease in BP?
The decrease in renal blood flow causes:
- An increase in renin and therefore angiotensin secretion which increases aldosterone secretion
- decrease in GFR causing increase in retention of sodium and water
5 classes of anti-hypertensive drugs
Diuretics ACE-I ARB Sympatholytics Calcium channel blockers
What is Furosemide’s MOA?
Inhibits Na-K-Cl co-transporter
How do thiazide diuretics decrease BP?
They decrease peripheral resistance and sodium retention
What are the AE of hydrochlorothiazide?
Decrease K and Na
Hyperuricaemia and gout
High doeses - glucose intolerance and adverse lipid profile
Classes of ACE-I
- Captopril
- Prodrugs: enalapril
- Water-soluble: lisinopril
ACE-I can cause coughing as they prevent the metabolism of?
Bradykinin
AE of ACE-I
Coughing
Othostatic HTN
Hyperkalaemia
Angioedema
C/I of ACE-I
Pregnancy
Renal artery stenosis
What important AEs of ACE-I is not found when using ARBs?
Coughing
Angioedema
2 e.g. of ARBs
Losartan
Volsartan
Egs of sympatholytics
B1 and B2: propranolo, nadolol
B1: atenolo, bisoprolol, metoprolol
How do sympatholytics decrease BP?
They decrease renin secretion and activity of B1 on the heart
When are B-blockers used?
Not recommended unless compelling indication
AE and C/I of B-blockers
Asthmatics IDDM Heart block Verapamil Symptomatic CCF
Eg of calcium channel blocker
Nifedipine
Verapamil
CCB C/I
Tachycardia
Hypotension
Unstable angina/acute MI
B-blockers
Stepwise approach to HTN Rx
Lifestyle modification
Low dose HCTZ
ACE-I/ARB
Long acting CCB
When can combination Rx be considered from the start?
If BP>20/10 above goal
Compelling indications for diuretics
HF
Elderly
Isolated systolic HTN
Africans respond well
Compelling indications for ACE-i & ARB
HF
Post MI
Non-diabetic & diabetic nephropathy
Proteinuria
Compelling indications for B-blockers
Angina pectoris
Post MI
HF (unless bradycardia or poorly controlled) - carvedilol, metoprolol & bisoprolol
Tachyarrythmias
Compelling indications for CCB
Isolated systolic hypertension
Peripheral vascular disease
Stable angina
Pregnancy (nifedipine)
Drugs that cause HTN
NSAIDs Sympathomimetics: Nasal decongestants & appetite suppressants Cocaine, amphetamines, caffeine Liquorice Cyclosporine, tacrolimus, EPO •MAO-I, TCA
Who to treat with anti-hypertensive drugs?
If repeated BP >140/90
If DM/chr renal failure BP >130/80
What is usually measured during follow-ups for HTN?
Serum potassium and creatinine
Special situations for HTN Rx
Women, elderly, children and adolescents Black pts Metabolic syndrome LVH PVD Postural hypotension
BP management with LVH
Weight loss
Sodium restriction
All drug classes (not hydralazine, minoxidil)
Aspirin should be used with HTN in the case of?
PVD
Postural hypotension is more frequently seen in older pts wiith?
DM
Diuretics
Venolators
Psychotrpoic drugs
Favorable effects of anti-hypertensive drugs
Thiazide diuretics: slows osteoporosis
BBs: AF, thyrotoxicosis, perioperativee HTN
CCBs: Raynaud’s, arrhythmias
A-blockers: prostatism
Unfavorable effects of anti-hypertensive drugs
Thiazide diuretics: cautious in gout, Hx of hyponatremia
BBs: avoid in pts with asthma, reactive airways disease, 2nd or 3rd degree block
ACEIs/ARBs: C/I pregnancy (incl. future)
ACEIs: not used if Hx of angioedema
Aldosterone antagonists and potassium-sparing diuretics can cause hyperkalemia.
Causes of resistant HTN
Improper BP measurement Excess sodium intake Inadequate medication Drugs that worsen HTN Excess alcohol intake Identifiable causes of HTN
