Cardiology HTN (Exam 1)

cardiac cycle

a complete heartbeat consisting of contraction and relaxation of both atria and both ventricles

preload

myocardial stretch before contraction, affects force of contraction

afterload

force to push against; wall stress and vascular resistance

contractility

ability of heart muscle to contract independent of preload/afterload

cardiac output

the volume of blood ejected from the left side of the heart in one minute

stroke volume

the amount of blood ejected from the heart in one contraction

total peripheral resistance

the resistance of the entire systemic circulation

venous return

the flow of blood back to the heart

diastole

relaxation phase of the heartbeat

systole

contraction phase of the heartbeat

end diastolic volume

volume of blood in ventricles at end of diastole

end systolic volume

volume of blood remaining in each ventricle after systole

ejection fraction

measurement of the volume percentage of left ventricular contents ejected with each contraction

systolic blood pressure

the pressure created in the arteries when the left ventricle contracts and forces blood out into circulation

diastolic blood pressure

the pressure remaining in the arteries when the left ventricle of the heart is relaxed and refilling

mean arterial pressure

pressure that propels blood to tissues

S1

AV valve closes, first heart sound

S2

aortic and pulmonic valves close, second heart sound

S3

ventricular gallop, overload

S4

stiff ventricle, late diastolic sound

blood pressure

force exerted by blood against the wall of a blood vessel

hypertension

intermittent or sustained elevation of diastolic or systolic blood pressure

<120/<80

normal BP

120-129/<80

elevated BP

130-139/80-89

stage 1 HTN BP

140/90

stage 2 HTN BP

180/120

HTN crisis BP

renin

enzyme secreted and stored by kidney; activates angiotensinogen to angiotensin I

angiotensin II

hormone that causes vasoconstriction and aldosterone release

aldosterone

hormone that increases sodium retention in the kidneys

alpha 1 receptor

adrenergic receptor involved in vasoconstriction, increased peripheral resistance, increased blood pressure

alpha 2 receptor

adrenergic receptor involved in inhibition of norepinephrine release

beta 1 receptor

adrenergic receptor involved in increased heart rate, increased myocardial contractility, increased renin

beta 2 receptor

adrenergic receptor involved in vasodilation and decreased peripheral resistance

essential hypertension

elevated blood pressure of unknown cause that develops for no apparent reason; most common type of HTN

secondary hypertension

elevated blood pressure related to systemic disease that raises peripheral vascular resistance or cardiac output

white coat hypertension

patient's BP is elevated in office but normal at home

masked hypertension

patient's BP is normal in office but elevated at home; proven association with CV risk

labile hypertension

variability of systolic blood pressure with fluctuations in HTN range; may be associated with panic, anxiety, increased catecholamines

<130/80

treatment goal for HTN

ACE inhibitor, angiotensin receptor blocker, aliskiren

RAAS inhibitors

ACE inhibitors

inhibits formation of angiotensin II, stimulates synthesis of vasodilating prostaglandins, can reduce sympathetic nervous system activity

angiotensin receptor blockers

blocks binding of angiotensin II to receptor, prevents effects of angiotensin II and aldosterone (vasoconstriction, Na, and H2O retention)

aliskiren

-produces vasodilation by inhibiting action of renin

-not often used

-do not combine with ACE/ARB

ACE inhibitors

preferred HTN agent in diabetic population due to renal protection

ACE inhibitors

benazepril (Lotensin)

enalapril (Vasotec)

lisinopril (Prinivil, Zestril)

ramipril (Altace)

angiotensin receptor blockers

candesartan (Atacand)

irbesartan (Avapro)

losartan (Cozaar)

telmisartan (Micardis)

valsartan (Diovan)

calcium channel blockers

cause peripheral vasodilation by inhibiting calcium ion influx into vascular smooth muscle and myocardium

dihydropyridine

category of calcium channel blockers predominantly active in peripheral vascular system; preferred category for HTN

non-dihydropyridine

category of calcium channel blockers that has SA and AV node depressant effects

CCB dihydropyridines

amlodipine (Norvasc)

nicardipine (Cardene)

nifedipine (Procardia, Adalat)

CCB non-dihydropyridines

diltiazem (Cardizem, Dilt, Cartia)

verapamil (Calan, Verelan)

thiazide diuretics

decrease plasma volume and peripheral vascular resistance by inhibition of sodium and chloride resorption in the distal convoluted tubule

thiazide diuretics

hydrochlorothiazide (HCTZ)

chlorthalidone

metolazone

indapamide

loop diuretics

decrease plasma volume and peripheral vascular resistance by inhibition of Na, K, and Cl reabsorption in thick ascending loop of Henle; often more for fluid management than purely BP control

loop diuretics

bumetanide (Bumex)

furosemide (Lasix)

torsemide (Demadex)

beta blockers

decrease HR and CO by binding to beta adrenoreceptors and blocking the binding of norepinephrine and epinephrine, also decrease renin release; beneficial in patients with CHF and previous MI

cardioselective beta blockers

specific to beta-1 receptors, preferred in patients with chronic lung disease

bisoprolol, esmolol, atenolol, metoprolol

nonselective beta blockers

block beta-1 and beta-2 receptors (bronchi & vasculature)

carvedilol, labetalol, propranolol

aldosterone receptor antagonists/mineralocorticoid receptor antagonists

includes excretion of Na by kidneys, especially in Na retaining states like CHF and cirrhosis; also referred to as "potassium-sparing diuretics", can protect against ventricular and vascular hypertrophy secondary to HTN

aldosterone receptor antagonists

spironolactone

eplerenone

alpha blockers

blocks postsynaptic alpha-receptors, relaxes smooth muscle, reduces BP by reducing SVR; helpful in HTN emergency in setting of pheochromocytoma along with beta blockers

alpha blockers

prazosin (Minipress)

terazosin (Hytrin)

doxazosin (Cardura)

phentolamine

phenoxybenzamine

hydralazine

arteriolar dilator, not first or second line, requires frequent dosing (4x/day), poorly tolerated, used in HTN crisis/emergency, can cause reflex tachycardia

methyldopa

CNS action, reduces efferent peripheral sympathetic outflow, reasonable option for pregnant patients, avoid in liver disease

clonidine

similar MOA to methyldopa, available in patch which may benefit non-compliant patients, rebound HTN can occur with discontinuation, needs to be weaned or combined with beta-blockers

ACEi/ARB, thiazide, CCB

first line agents for essential HTN

CCB or thiazide

first line agents for black patients

RAAS inhibitors

class that is contraindicated in pregnancy

resistant HTN

failure to reach goal despite maximally tolerated dose 3-drug regimen with compliance

ACEi/ARB, BB, diuretics, MRA

preferred agents for patients with CHF w/reduced EF

ACEi/ARB, BB, MRA

preferred agents for patients with previous MI

ACEi/ARB

preferred agents for patients with CKD

ACEi/ARB

preferred agents for patients with diabetes

BB, CCB

preferred agents for patients with angina

BB, non-DHP CCB

preferred agents for patients with atrial fibrillation

labetalol, methyldopa

preferred agents for pregnancy patients

ACEi

do not use with angioedema

non-selective BB

do not use with bronchospastic disease

methyldopa

do not use with liver disease

BB, non-DHP CCB

do not use with 2nd or 3rd degree heart block unless functioning pacemaker is in place

HTN urgency

asymptomatic, BP>180/120

HTN emergency

BP>180/120 with evidence of end organ damage

clonidine, captopril, nifedipine

PO or IV meds used to treat HTN urgency

nicardipine, labetalol, loop diuretic

IV meds used to treat HTN emergency

orthostatic hypotension

reduction in systolic BP >20mmHg or reduction of diastolic BP >10mmHg within 3 minutes of standing or head-up on tilt table

postprandial hypotension

reduction in BP within 15-20 minutes of eating

midodrine, fludrocortisone

preferred agents to treat orthostatic hypotension

hypertensive retinopathy

disease of the retina secondary to high blood pressure; AV nicking, cotton-wool spots, exudates, optic disc swelling, retinal hemorrhages

obstructive sleep apnea, cushing's disease, renal artery stenosis/fibromuscular dysplasia, aortic coarctation, pheochromocytoma, hyperthyroid, hyperaldosteronism, hyperparathyroidism

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