cardio: HTN Flashcards
pathophysiology of HTN
- defects in renal sodium hemostasis
- functional vasoconstriction
- defects in vascular smooth muscle and structure
secondary causes of HTN
CKD, cushing’s syndrome, thyroid disease, NSAIDs, aspirin, decongestants, excessive consumption of licorice, st. john’s wort, bb or centrally acting a-agonists when abruptly discontinued
recommending BP monitor cuff sizes: adult
width 37-50% of limb’s length (length: width ratio, 2:1), inflatable bladder must cover 75-100% of the arm’s circumference
recommending BP monitor cuff sizes: obese
consider using wrist meters place at level of heart
- below heart - overreads
- above heart - underreads
recommending BP monitor cuff sizes: paediatrics
right arm BP, unless coarctation of aorta (aka imbalance of BP on L and R side)
grade 1 HTN
140-159/90-99
grade 2 HTN
160-179/100-109
grade 3 HTN
> = 180/ >= 110
unless c/i, advise patients to reduce weight to a BMI below
23kg/m2, and to a waist circumference below 90cm in men and below 80cm in women (for Asians)
advise pt to restrict salt intake to ___g per day
5-6
moderate alcohol consumption to no more than
2 standard drinks per day for men, and to no more than 1 standard drink per day for women
drug treatment should not be delayed without reason beyond ____________ if indicated
3-6months
advise pt to do at least ____ minutes of moderate dynamic exercise ____ days/week
30 mins, 5-7 days
any physical exercise above the basal level up to ____mins/week, confers incremental cv and metabolic benefits including BP reduction
150
bp lowering effects are likely similar btw classes, but
disease outcomes mismatch degree of bp reduction
which antihypertensive drug class have evidence of reducing risk of ESRD?
ACEi/ARB - most effective agents to reduce albuminuria, delay progression of diabetic and non-diabetic CKD
should we combine ACEi and ARB?
nope, no added benefit and excess of renal adr
when are ACEi/ARBs compellingly indicated?
post MI, HFrEF, albuminuria and CKD, HTN in DM
Antihypertensive class choice in pregnancy?
Labetalol, methyldopa, nifedipine, or vasodilators
- do not use ACEi (teratogenic in 2nd and 3rd trimester), ARB or direct renin inhibitors
BP target for most pt
120-130/70-80
initiation of antihypertensive drug therapy with 2 first-line agent of different classes, either as separate agents or in a fixed-dose combi, is recommended in adults with
stage 2 hypertension (BP>160/100mmHg) and an average BP >20/10mmHg above their BP target
what might help w DHP CCB a/w LL edema?
tolerance w time and combine w RASi (decr vasoconstriction) with CCBs (decr vascular SM tone)
avoid non-DHP in
HFrEF
caution use of non-DHP in
high-grade SA and AV block, bradycardia <60bpm, concomitant use of BB
loop diuretics site of action
thick ascending limb
thiazides site of action
distal convoluted tubule
K-sparing diuretics
aldosterone antagonist, mineralocorticoid antagonist
thiazide-like diuretics eg
indapamide
thiazide-like diuretics vs thiazides
thiazide-like diuretics have:
- better BP lowering effect, longer duration of action
- more RCT evidence in reducing CV events and mortality
thiazides/thiazides-like diuretics: reduced effectiveness when eGFR<____ml/min
45
- thiazides probably ineffective when eGFR<30, may req loop diuretics for intended diuresis
ADR of thiazide/thiazide-like diuretics
electrolyte dysregulation: hypoK/Na, enhanced Ca reabsorption
dysmetabolic effects: insulin resistance, new-onset DM (do not use with BB, may be attenuated by K-sparing diuretic), hyperTG/LFL, hyperuricemia
Which BB can be used with diuretics?
Nebivolol
ADRs of BBs
- associated with new onset DM (do not use with diuretics, except nebivolol)
- sexual dysfunction (less with nebivolol)
- severe claudication: muscle pain triggered by activity
Compelling indications for use of BB
Angina, heart rate control, a
thirdline agents used for
resistant hyperTN: full dose of 3 drugs and BP still not controlled
compelling indications: HF
BB + ACEi/ARB or ARNI
-> aldosterone antagonist
-> diuretics
DO NOT use non-dhp ccb, but can use amlodipine or felodipine
compelling indications: angina pectoris
BB
-> ACEi/ARB or DHP CCB (reduce LVH)
compelling indications: post MI
BB
-> ACEi or ARB
compelling indications: AF prevention
BB, ACEi or ARB (may prevent recurrence)
compelling indications: AF ventricular rate control
BB
compelling indications: DM
ACEi or ARB
-> DHP CCB: slows progression of carotid atherosclerosis
-> diuretic or BB
compelling indications: DM with albuminuria (moderately or severely increased albuminuria)
ACEi or ARB
DO NOT use any combi of ACEi with ARB
compelling indications: recurrent stroke prevention
thiazide-like diuretic + ACEi
compelling indications: gout
DO NOT use diuretics
compelling indications: bilateral renal stenosis
DO NOT use ACEi/ARB
compelling indications: ESRD
DO NOT use ACE/iARB/aldosterone antagonist (worsens renal function and hyperK)
compelling indications: heart block
DO NOT use BB, non-DHP CCB
compelling indications: peripheral artery disease
ACEi or DHP CCB
compelling indications: aortic aneursym
BB
compelling indications: isolated SBP
diuretic, or DHP CCB
BP goal for 65-80yo
stepwise <150mmHg, then <140mmHg if tolerated and achievable, ideally <130mmHg
perindopril +/- indapamide
reduces intracranial bleeding by 46%, in pt w or without AF on antithrombotic
isolated systolic hyperTN
wide pulse pressure (SBP-DBP>80mmHg) + SBP>140mmHg and DBP<90mmHg
- function of aging and arteriolar stiffness
- when treating ISH, may lead to orthostatic hypoTN - start low, go slow, watch to avoid OH
preferred antihypertensives in older adult
CCB, diuretics
oral contraceptives can cause
incr BP, proportionate with duration fo use
orthostatic hypoTN
supine-to-standing BP decr by >20mmHg SBP or >10mmHg DBP, within 3 mins of standing
- possible etiologies: age-related, severe volume depletion, baroreflex dysfunction, autonomic insufficency eg diabetes, certain antihypertensives
- postural unsteadiness, dizziness, fainting, may be a/w falls and fractures
- educate pt to rise slowly
hypertensive emergency
severe HTN (grade 3>180/110mmHg) a/w acute HMOD
- often life threatening and requires immediate but careful intervention to lower BP (usually iv)
- complaints: HA, visual disturbances, chest pain, dyspnea, dizzines sand other neurological deficits
- rarely: somnolence, lethargy, tonic clonic seizures, and corticol blindess may precede a loss of consciousness
hypertensive urgency
severe HTN but no evidence of acute HMOD, does not require admission to hospital
adrenaline moa
a1 (vasodilatation of arteries and increased vascular permeability leading to loss of intravascular fluid and subsequent hypotension/vasopressor), b1 (increased myocardial force of contraction (positive inotrope) and heart rate (positive chronotrope)), b2 (bronchial smooth muscle relaxation that helps to relieve bronchospasm) stimulation
ACEi is particularly useful in treating
- chronic renal failure: diminish proteinuria and stabilise kidney function (even in the absence of decreased BL), particularly useful in slowing progress of diabetic nephropathy
- HF and post MI: slowing remodeling effects
CCBs bind more effectively to _____ and ____ channels
open and inactivated
- binding of the drug reduces freq of opening in response to depolarisation and decreases transmembrane calcium current
vs neuronal cells possess L-type calcium channels but less sensi to these drugs as the channels spend less time in open and unactivated state
DHPs vs non-DHPs
DHPs are more selective as vasodilators (relax vascular SM, leading to vasodilation) and have less cardiac effects
why are skeletal muscles not depressed by CCBs?
they use intracellular pools of calcium
CCBs: lowering BP
DHP = diltiazem = verapamil
CCBs: vasodilator
DHP>diltiazem>verapamil
CCBs: cardiac depressant
verapamil>diltiazem>DHP
a1 adrenoceptor antagonist MOA
block vasoconstriction, esp. visceral blood flow (dilate both resistance and capacitance vessels)
- retention of salt and water increased when administered without diuretics, hence more effective when used with diuretic or bb
toxicities of a1 blockers
dizziness, palpitations, headache, lassitude