cardiovascular Flashcards
how would you explain what is SBP and DBP
SBP measures the pressure in the arteries when the heart beats
DBP measures the pressure in the arteries in between heart beats
what are the factors to consider for ASCVD risk estimator
demographics
- age
- sex
- race
labs
- SBP
- DBP
- HDL-C
- total cholesterol
PMHx
- DM
- smoler
- HTN treatment
what are the risk factors of CVD
- SBP and DBP
- age (≥65yo for women; ≥55yo for male)
- FHx of premature CVD
- dyslipidemia
- DM
- obesity (BMI≥30)
what are the prognostic factors of CVD
cerebrovascular diseases
- stroke
- TIA
renal diseases
- albuminuria/ proteinuria
- CKD ≥stage 3
heart diseases
- CHF
- angina pectoris
- MI
- coronary revascularisation
- left ventricle hypertrophy
vascular diseases
- aortic aneurysm
- peripheral artery disease
- hypertensive retinopathy
atherosclerosis
what are the identifiable secondary causes of HTN
- drug-induced
- CKD
- renal artery stenosis
- thyroid or PTH diseases
- nephropathy from T1DM
- obstructive sleep apnea
- primary hyperaldosteronism
- hypercortisolism
- rare monogenic ion transport disorders
- pheochromocytoma
- coarctation of the aorta
what are the drugs that can induce HTN
- illicit substances (cocaine, amphetamine, crystal meth, ecstasy)
- corticosteroids, NSAIDs, coxibs
- OCs with estrogen
- diet pills
- decongestants (pseudoephedrine, naphazoline)
- immunosuppressants
- herbal (ma huang)
what are the non-pharmacological management for HTN
- limit alcohol intake to max 2u/day for men and 1u/day for women
- smoking cessation
- physical activity (≥150mins/w of moderate intensity where HR is elevated from baseline on ≥3d/w)
- weight management to obtain BMI ≤23
- diet modifications to include more fruits and vegetables and low-fat dairy products while reducing intake of total and saturated fats
- limit salt intake to 5-6g/d (approx 1 teaspoon) –> choose homecooked meals, eat less gravy, sauces and soup when eating out, use herbs and spices to flavor food instead of salt and sauces
- stress management through adopting meditation, deep breathing or massage techniques and ensuring adequate good quality sleep
how is BP classified
normal BP: SBP <130 and DBP <85
high-normal BP: SBP 130-139 or DBP 85-89
grade I HTN: SBP 140-159 or DBP 90-99
grade II HTN: SBP 160-179 or DBP 100-109
grade III HTN: SBP ≥180 or DBP ≥110
isolated systolic hypertension: SBP ≥140 and DBP <90
what are the target BP goals
120-130/70-80
as tolerated for >65yo
what are the general monitoring parameters and follow ups
- BP q6-12m if low risk, q3-6m if moderate to very high risk
- BMI, FBG, lipid, electrolytes q12m
- others as indicated per individual profile
what are the key things to note regarding choice of antihypertensives
- caution diuretic in DM –> increases risk of hyperglycemia
- caution BB in DM –> masking of hypoglycemic symptoms
- avoid ACEi/ARB in CKD –> can increase risk of hyperkalemia and renal failure and angioedema
- avoid Spironolactone in CKD esp with ACEi/ARB –> can increase risk of hyperkalemia and renal failure
what are the drug-specific monitoring parameters and follow up upon initiation
ACEi/ARB
- renal panel in 1-2w
- presence of cough
- ADR cross reactivity (with other classes that target RAAS)
BB
- in 2-4w
- check PR control
CCB
- in 2-4w
- check PR control for NDHP-CCB
diuretic
- renal panel in 1-2w
what are the major factors influencing BP
Arterial BP = CO x Peripheral Resistance
components of CO
- HR
- contractility
- filling pressure (as determined by venous tone and blood volume)
components of peripheral resistance
- arteriolar tone
which of the components are part of preload vs which are part of afterload and define both these terms
preload is the stretching of cardiac muscles before contraction, associated with ventricular filling
- filling pressure as determined by blood volume and venous tone
afterload is the force against which the heart has to contract to eject the blood
- peripheral resistance as determined by arteriolar tone
elaborate on the RAAS system for when there is a drop in BP
short term
- drop in BP –> activation of sympathetic nervous system –> (i) activation of beta1 receptors in heart (ii) activation of beta1 receptors in smooth muscle –> (i) increases cardiac output (ii) increases peripheral resistance –> both (i) and (ii) lead to increase in BP
long term
- drop in BP –> decreased renal blood flow –> increases renin –> increased angiotensin II –> increases aldosterone –> increase Na+ and H2O retention –> increases blood volume –> increases BP
- drop in BP –> decreased renal blood flow –> decreases GFR –> increases Na+ and H2O retention –> increases in blood volume –> increase BP
what are the determinants of vascular tone, outline the r/s
- ca2+ channel
- Ca2+ ions forms a complex with calmodulin that activates MLCK to phosphorylate myosin-LC, leading to muscle contraction - adenylyl cyclase
- adenylyl cyclase converts ATP into cAMP that activates protein kinase A to increase reuptake of Ca2+, thus reducing formation of complex, subsequent activation of MLCK and phosphorylation of myosin-LC - guanylyl cyclase
- guanylyl cyclase converts GTP into cGMP which increases de-phosphorylation of myosin-LC, leading to muscle relaxation
what are the key functions of angiotensin II
angiotensin II causes vasoconstriction and stimulates secretion of aldosterone from adrenal cortex
what is the role of aldosterone
aldosterone is a hormone that acts on the kidneys to increase reabsorption of Na+ and H2O from the urine back into the bloodstream, leading to salt and water retention in the kidneys, leading to increased blood volume and BP
what is the moa of ACEi and list the drugs in this class
lisinopril, enalapril, captopril, ramipril
- ACE enzyme is involved in conversion of angiotensin I to angiotensin II, inhibition of this path reduces the ability of angiotensin II to induce vasoconstriction and aldosterone secretion, causing reduced peripheral vascular resistance and salt and water retention, leading to a drop in BP
- ACE enzyme is also involved in inactivation of bradykinin, thus inhibiting this path causes reduced inactivation of bradykinin which is the component largely responsible for dry cough s/e; bradykinin also activates NO and PG to further induce vasodilation and decrease BP
what are the available formulations and max dosing for each ACEi
lisinopril
- avail in 5, 10mg
- max 40mg/day
enalapril
- avail in 5, 10mg
- max 40mg/day
captopril
- avail in 12.5, 25mg
- max 150mg/day
what are the c/i and s/e of ACEi
- c/i in pregnancy
- s/e are severe hypotension, acute renal failure, hyperkalemia, dry cough, angioedema
what is the moa of ARB and list the drugs in this class
losartan, valsartan, telmisartan, candesartan, irbesartan, eprosartan
- works by direct antagonism of angiotensin II receptors and produce BP lowering effects by antagonising AT1-induced vasoconstriction, aldosterone release, catecholamine release, arginine vasopressin release, water intake and hypertrophic response
what are the c/i and s/e of ARBs
- c/i in pregnancy
- s/e include (less) dry cough, acute renal failure, hypotension, hyperkalemia, angioedema
what is the moa of BB and list the drugs in this class
non-selective
- propranolol
- pindolol
- carvedilol
selective
- atenolol
- bisoprolol
- metoprolol
- BB competitively block beta adrenergic receptors to prevent epinephrine and norepinephrine from binding to the beta receptors
- this blockade reduces activation of adenylyl cyclase that would have typically resulted from interaction of epinephrine and norepinephrine with beta receptors –> reduced formation of cAMP from ATP –> reduced activation of MLCK –> reduced phosphorylation of myosin-LC –> reduced muscle contraction