Question
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Answer
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What is the approximate distribution of the 5L of blood in the body?
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9% pulmonary; 7% heart; 84% systemic (64% veins)
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What are some characteristics of blood flow?
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resistance declines in order for blood to flow; increase in pressure
maintains flow; pressure falls as blood moves; blood returns to the heart by
help of venous pump
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What are some characteristics of cardiac output?
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5L/min; CO= stroke volume + heart rate
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How is stroke volume determined?
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contractility; preload; afterload
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What is preload?
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force of venous return, increase in preload increases stroke volume
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What is afterload?
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arterial pressure; increase in afterload decreases stroke volume
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What is starling's relationship?
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the ventricular contraction is proportional to the muscle fiber
length; as fiber length increases, contractile force increases; more blood
brought into healthy heart, more blood pumped out; venous return increases,
cardiac output increases; venous return
|
What are some characteristics of arterial pressure?
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AP= peripheral resistance x cardiac output; regulated by the autonomic
nervous system (rapid steady-state control), renin-angiotensin aldosterone
system (hours/days), and the kidneys (long term)
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How is peripheral resistance regulated?
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constriction/dilation of arterioles
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What are some characteristics of angiotensin?
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angiotensin I = little activity; angiotensin II = high activity
(increase BP & release aldosterone); angiotensin III = moderate activity
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What are some characteristics of angiotensin II?
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renin catalyzes angiotensin to angiotensin I (BP, blood volume, renal
perfusion); ACE catalyzes angiotensin I to antiotensin II (ACE:
angiotensin-converting enzyme; abundant especially in lungs)
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What turns on the RAAS (renin-angiotensin aldosterone system)?
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factors that lower BP; turning on raises blood pressure by
vasoconstriction & retention of sodium & water
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What are some uses for ACE inhibitors?
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hypertension, heart failure, myocardial infarction, diabetic
nephropathy, prevention of MI/stroke/death in patients at high cardiac risk
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What are some examples of ACE inhibitors used for myocardial
infarction?
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captopril (capoten), lisinopril (prinivil), trandolapril (mavik)
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What is an example of an ACE inhibitor used for diabetic neuropathy?
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captopril (capoten)
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What are some characteristics of ACE inhibitors?
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do not interfere with cardiac reflexes; no lethargy, weakness, or
sexual dysfunction; reduce risk of cardio mortality caused by hypertension;
reduce levels of angiotensin II; increase levels of bradykinin
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What are some adverse effects of ACE inhibitors?
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first-dose hypotension (diuretics enhance); cough; hyperkalemia; renal
failure (contraindicated); fetal injury
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What are some characteristics of angiotensin II receptor blockers
(ARBs)?
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used for hypertension, heart failure (valsartan/diovan), diabetic
neuropathy (irbesartan/avapro & losartan/cozaar), blocking action of
angiotensin II (dilation of arterioles & veins; decrease aldosterone);
suffix -sartan
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What are some adverse effects of angiotensin II receptor blockers
(ARBs)?
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fetal harm, renal failure
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What is an example drug for selective aldosterone receptor blockers?
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eplerenone (inspra): only for hypertension, excretion of sodium and
water, adverse effect: hyperkalemia
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Where is calcium critical in the body?
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vascular smooth muscle and heart
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What are some characteristics of the VSM?
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regulate contraction (calcium blocked= dilation)
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What impact does calcium blockage have on the heart?
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decreases contraction
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What is the role of the SA node in the heart?
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pacemaker activity; decrease calcium = decrease heart rate
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What is the role of the AV node in the heart?
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excitability of cells; decrease calcium = decrease velocity of
conduction
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What receptors are coupled to calcium channels?
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beta one receptors; beta blockers have the same effects as calcium
channel blockers (decrease contractility, decrease heart rate, suppress
conduction)
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What is the location of action for the calcium channel blocker family:
dihydropyridines (nifedipine/adalat)?
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arterioles
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What is the location of action for the calcium channel blocker family:
verapamil (calan)/diltiazem (cardizem)?
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arterioles & heart
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What are some uses for verapamil & diltiazem?
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angina pectoris, hypertension, cardiac dysrhythmias, migraines
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What are the hemodynamic effects of verapamil & diltiazem?
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direct: reduce AV conduction, reduce heart rate; overall dilation;
indirect: NE release & increase heart rate
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What are some adverse effects of verapamil & diltiazem?
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constipation, swelling of ankles & feet, exacerbation of cardiac
failure, increase digoxin toxicity, beta blockers have additive effects
(possibility of cardiosuppression)
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What are some uses for Nifedipine?
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angina pectoris, hypertension
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What are the hemodynamic effects of Nifedipine?
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direct: blocks channels in VSM = dilation; indirect: NE released &
increases heart rate; overall lowers BP, increases heart rate, increases
contractile force
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What are some adverse effects of Nifedipine?
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swelling of ankles/feet, reflex tachycardia (does not exacerbate heart
failure)
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What are some characteristics of vasodilators?
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arterioles-decrease afterload; veins-decrease preload; arterioles
& veins; used for hypertension + angina pectoris + heart failure +
Myocardial infarction
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What are some adverse effects of vasodilators?
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postural hypotension, reflex tachycardia, expansion of blood volume
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What are some characteristics/uses for the vasodilator: hydralazine
(apresoline)?
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dilate arterioles, used for hypertension, hypertensive crisis, heart
failure
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What are some adverse effects of the vasodilator hydralazine
(apresoline)?
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reflex tachycardia, increase blood volume, systemic lupus-like
syndrome, minimal hypotension
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What are some characteristics of the vasodilator minoxidil (loniten)?
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dilates arterioles, used for severe hypotension & hair growth
(rogaine); adverse effects are reflex tachycardia, sodium & water
retention, hypertrichosis
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What are some characteristics of the vasodilator sodium nitroprusside
(nitropres)?
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dilate arterioles/veins; used for hypertensive emergencies; adverse
effects include excessive hypotension, cyanide poisoning, thiocyanate
toxicity
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What are the consequences of chronic hypertension?
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morbidity, heart disease, kidney disease, stroke
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What are some lifestyle modifications that can be made to alter
hypertension?
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weight loss, sodium restriction, alcohol restriction, exercise
(aerobic x10), smoking cessation, potassium and calcium maintenance
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What are the primary determinants of arterial blood pressure?
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cardiac output x peripheral resistance
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What is cardiac output determined by?
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heart rate, contractility, blood volume, venous return
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What determines peripheral resistance?
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arteriolar constriction
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What are some sites of action for hyptertensive medications?
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1. brainstem: clonidine, methyldopa 2. sympathetic ganglia:
mecamylamine 3. adrenergic terminals: guanethidine, reserpine 4. Cardiac beta
one receptors: propranolol, metoprolol, other beta blockers 5. vascular alpha
one receptors: prazosin, terazosin
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What are the effects of clonidine, which works at the brainstem?
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suppression of sympathetic outflow decreases sympathetic stimulation
at the heart and blood vessels
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What are the efects of trimethaphan, which works at the sympathetic
ganglia?
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ganglionic blockade reduces sympathetic stimulation of the heart and
blood vessels
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What are the effects of guanethidine, which works at the adrenergic
nerve terminals?
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reduced norepinephrine release decreases sympathetic stimulation of
the heart and blood vessels
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What are the effects of propranolol, which works at the cardiac beta
one receptors?
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beta one blockade decreases heart rate and myocardial contractility
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What are the effects of prazosin, which works at the vascular alpha
one receptors?
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alpha one blockade causes vasodilation
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What are the effects of hydralazine, which works at the vascular
smooth muscle?
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relaxation of vascular smooth muscle causes vasodilation
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What are the effects of chlorothiazide, which works at the renal
tubules?
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promotion of diuresis results in decreased blood volume
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What are the effects of propanolol, which works at beta one receptors
on juxtaglomerular cells?
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beta one blockade suppresses renin release, resulting in vasodilation
secondary to reduced production of angiotensin II and prevention of
aldosterone-mediated volume expansion
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What are the effects of captopril, which works on
angiotensin-converting enzyme (ACE)?
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inhibition of ACE decreases formation of angiotensin II and thereby
prevents vasoconstriction & aldosterone-mediated volume expansion
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What are the effects of losartan, which works on angiotensin II
receptors?
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blockade of angiotensin II receptors prevents angiotensin-mediated
vasoconstriction and aldosterone-mediated volume expansion
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What are the effects of eplerenone, which works on aldosterone
receptors?
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blockade of aldosterone receptors in the kidney promotes excretion of
sodium and water, and thereby reduces blood volume
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What are some thiazides and related diuretics used for chronic hypertension?
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bendrofluinethiazide, benzthiazide, chlorothiazide, chlorthalidone,
cyclothiazide, hydrochlorothiazide, hydrofumethiazide, indapamide,
metolazone, polythiazide, quinethazone, trichlormethiazide
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What are some loop diuretics used to treat chronic hypertension?
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furosemide, ethacrynic acid, bumetanide, torsemide
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What are some potassium-sparing diuretics used to treat chronic
hypertension?
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spironolactone, triamterene, amiloride
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What are some beta blockers used to treat chronic hypertension?
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acebutolol (has ISA), atenolol, betaxolol, bisoprolol, carteolol (has
ISA), metoprolol, nadolol, penbutolol (has ISA), pindolol (has ISA),
propranolol, timolol (ISA= intrinsic sympathomimetic activity)
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What are some alpha one blockers used to treat chronic hypertension?
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doxazosin, prazosin, terazosin
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What are some alpha/beta blockers used to treat chronic hypertension?
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carvedilol, labetalol
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What are some centrally acting alpha2 agonists used to treat chronic
hypertension?
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clonidine, methyldopa, guanabenz, guanfacine
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What are some adrenergic neuron blockers used to treat chronic chronic
hypertension?
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guanethidine, guanadrel, reserpine
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What are some ACE inhibitors used to treat chronic hypertension?
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benazepril, captopril, enalapril, fosinopril, lisinopril, moexipril,
quinapril, ramipril, trandolapril
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What are some aldosterone receptor blockers used to treat chronic
hypertension?
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eplerenone, spironolactone
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What are some angiotensin II receptor blockers used to treat chronic
hypertension?
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candesartan, eprosartan, irbesartan, losartan, olmesartan, valsartan
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What are some calcium channel blockers?
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amlodipine, diltiazem (non-DHP), felodipine, isradipine, nifedipine,
nicardipine, nimodipine, nisoldipine, verapamil (non-DHP)
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What are some direct-acting vasodilators?
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hydralazine, minoxidil
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What are the characteristics of heart failure?
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characterized by reduced cardiac output, fluid retention, and
ventricular dysfunction (dilation, wall thickness, sphere shape)
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What are the compensatory responses?
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compensating for reduced cardiac output, more damage, 1. cardiac
dilation 2. activation of the sympathetic nervous system 3. activation of the
renin-angiotensin-aldosterone system 4. retention of water and increased
blood volume
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What are the classifications for heart failure?
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class I: no limitation class II: slight limitation class III: marked
limitation class IV: symptoms occur at rest (exercise training improves
clinical status)
|
What are the types of drugs used for heart failure?
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ACE inhibitors (dilate arterioles/veins, reduce aldosterone),
diuretics (decrease overload volume)
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What are some characteristics of digoxin (lanoxin)?
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cardiac glycoside, positive inotropic action (increases force of
contraction/CO, inhibits Na+/K+ ATPase, calcium accumulation, facilitates
interaction of myosin/actin), K+ interference
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What are the therapeutic effects of digoxin (lanoxin)?
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increase contractility, increase urine production, reduces heart rate,
afterload, and venous pressure, decrease heart size (does NOT prolong life)
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What are some adverse effects of digoxin (lanoxin)?
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dysrhythmias, nausea/vomiting, fatigue, visual disturbances
(blurred/yellow vision), drug interactions (diuretics-K+ loss, ACE
inhibitors-K+ increase, quinidine, verapamil)
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What are some characteristics of spiranolactone (aldactone)?
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potassium-sparing diuretic, aldosterone-receptor blocker (aldosterone
promotes remodeling: fibrosis, rise in heart failure), ACE inhibitors
decreases formation (spironolactone blocks action), Adverse effects=
gynecomastia, hyperkalemia
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What are some characteristics of dysrhythmias?
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abnormality in rhythm of heartbeat, tachydysrhythmia (increase),
bradydysrhythmia (decrease), drugs can also cause dysrhythmias
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What are some characteristics of impulse conduction in the heart?
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atria/ventricles coordinated, SA node is pacemaker, AV node delays for
blood filling, His-Purkinje system-rapid activity spread
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What are some characteristics of cardiac action potentials?
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relate to ion movement (depolarized or polarized), fast or slow action
potentials
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What are some characteristics of fast action potentials in the cardiac
system?
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His-purkinje & atrial/ventricular muscle, Phase O: influx of
sodium; phase 1: repolarization phase 2: calcium enters; phase 3: exit of
potassium; phase 4: automaticity
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What are some characteristics of slow action potentials?
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SA & AV node, phase 0: slow influx of calcium; phase 1, 2, 3: not
significant; phase 4: not well understood
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What occurs during the P wave of an EKG?
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depolarization in the atria (contraction)
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What occurs during the QRS wave of an EKG?
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depolarization in the ventricles (contraction, widens if slow)
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What occurs during the T wave of an EKG?
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repolarization of the ventricles
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What occurs during the PR interval of an EKG?
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time between P wave & QRS (lengthen= delay in AV node conduction,
common med side effect)
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What occurs during the QT interval of an EKG?
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time between QRS and T wave
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What occurs during the ST segment of an EKG?
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end of QRS and beginning of T wave
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How are dysrhythmias generated?
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disturbances of automaticity, or conduction
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What are the locations for dysrhythmias generated due to disturbances
of automaticity?
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cells in SA node, AV node, or His-Purkinje
|
What are some dysrhythmias generated due to disturbances of
conduction?
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AV block (first degree-delayed impulse conduction, second degree-some
impulses pass, third degree-none pass), reentry (cycle of repetitive cardiac
stimulation)
|
What are class I antidysrhythmic drugs?
|
sodium channel blockers (examples IA: quinidine, procainamide/pronestyl,
disopyramide/norpace)(examples IB: lidocaine/xylocaine, phenytoin/dilantin,
mexiletine/mexitil, tocainide/tonocard) (examples IC: flecainide/tambocor,
propafenone/rythmol; other: mor
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What are class II antidysrhythmic drugs?
|
beta-blockers (examples: propranolol/inerdal, acebutolol/sectral,
esmolol/brevibloc)
|
What are class III antidysrhythmic drugs?
|
potassium channel blockers-delay repolarization (examples:
amiodarone/cordarone/pacerone, dofetilide/tikosyn, bretylium,
sotalol/betapace)
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What are class IV antidysrhythmic drugs?
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calcium channel blockers
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What are some proarrythmic drug effects?
|
drugs worsen dysrhythmia & generate new cases; doubled rate of
mortality (esp class I); severe situations; benefits must be clear; prolong
QT interval
|
supraventricular dysrhythmias
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areas of heart above ventricle (atria, SA node, AV node); not
especially harmful; class II & IV; sustained supraventricular
tachycardia; atrial flutter; atrial fib
|
ventricular dysrhythmias
|
significant disruption; class I & III; sustained ventricular
tachycardia, ventricular fib, ventricular premature beats, Digoxin-induced
ventricular dysrhythmias, Torsades de Pointes
|
treatment of dysrhythmias
|
termination of dysrhythmias, long-term suppression with drugs,
implantable defibrillator
|
sodium channel blockers
|
class I, decrease conduction in atria, ventricles & His-purkinje
system
|
quinidine
|
class IA sodium channel blocker (similar to anesthetics); heart:
delays repolarization, EKG: widens QRS/prolongs QT, Use: ventricular dysrhythmias,
Side effects: GI, arterial embolism, prodysrhythmia, hypotension; Drug
interaction: digoxin
|
lidocaine
|
class IB sodium channel blocker; heart: accelerates repolarization;
EKG: none; Use: ventricular dysrhythmias; side effects: drowsiness, confusion,
prodysrhythmias
|
Propranolol
|
class II: beta blocker; effects B1 & B2 receptors, Heart:
decreased velocity of conduction (also blocks calcium channels); EKG:
prolonged PR interval; Use: supraventricular & ventricular premature
beats; Side effects: heart failure, hypotension, bronchosp
|
Bretylium
|
class III potassium channel blockers; short-term therapy; heart: delay
repolarization; EKG: prolongs QT interval; side effects: hypotension; use:
ventricular dysrhythmias
|
Amiodarone
|
class III potassium channel blockers; heart: delay repolarization;
EKG: QRS widening, PR/QT lengthening; side effects: lung damage, visual
impairment, prodysrhythmias; use: ventricular and supraventricular; Drug
interactions: quinidine, procainamide, digo
|
Verapamil & Diltiazem
|
class IV calcium channel blocker; heart: decreases velocity of
conduction; EKG: prolong QT interval; side effects: hypotension, bradycardia,
heart failure; use: supraventricular; drug interactions: digoxin, beta
blockers
|
VLDL
|
triglycerides; probably contribute to atherosclerosis
|
LDL
|
cholesterol (bad); definately contribute to atherosclerosis <100
optimal
|
HDL
|
protect against atherosclerosis, cholesterol (good) ~50
|
HMG-CoA reductase inhibitors (statins)
|
decrease LDL; increase HDL; decrease TG; inhibits enzyme needed for
cholesterol synthesis; side effects: hepatoxicity, myopathy, fetal
malformations; atorvastatin, simvastatin
|
Nicotinic Acid
|
decrease LDL, increase HDL, decrease TG, decreases VLDL (LDL are
byproducts of VLDL), side effects: itching, GI, hepatoxic, gouty arthritis,
Niaspan, niacor
|
Bile-acid sequestrants
|
decreases LDL, increases HDL, NO change TG, cholesterol is required to
produce bile-acid--liver cells increase LDL receptors therby increasing LDL
uptake; side effects: constipation; cholestyramine, colesevelam
|
fibric acid
|
little/no effect on LDL; increases HDL; lowers TG; accelerate
clearance of VLDL therby reducing TG; side effects: gallstones, myopathy,
hepatoxic; gemfibrozil
|
Nitroglycerin
|
organic nitrate, stable angina-decrease oxygen demand; variant
angina-increases oxygen supply; side effects: headache, orthostatic
hypertension, reflex tachycardia; drug interactions: sildenafil; tolerance
|
Beta blockers
|
stable angina-decreases oxygen demand; not used for variant angina;
side effects: bradycardia, bronchoconstriction; Propanolol, metoprolol
|
Calcium channel blockers
|
stable angina-decrease oxygen demand; variant angina-increase oxygen
supply; side effects: hypotension, reflex tachycardia; Verapamil &
Diltiazem
|
reducing risk factors for angina
|
stop smoking, lower cholesterol, lower BP, diabetic management,
decrease obesity, increase physical activity
|
coagulation
|
produces fibrin to reinforce plug, fibrin produced through clotting
factors, vitamin K required for clotting factor synthesis
|
Heparin (unfractionated)
|
helps antithrombin inactivate clotting factors, suppresses formation
of fibrin, use: pregnancy/surgery/MI; side effects: hemorrhage, allergies,
thrombocytopenia; MW: 3000-30000daltons; lab monitoring
|
Low molecular weight heparin
|
used for DVT following hip/knee replacement; side effects:
hemorrhage/thrombocytopenia; MW: 1,000-9,000daltons; no lab monitoring;
Enoxaprin, Dalteparin
|
Warfarin
|
oral anticoagulant, antagonist of vitamin K, use prophylaxis of
thrombosis; side effects: hemorrhage/teratogenesis; Drug interactions:
heparin, asprin, acetaminophen, prothrombin time (PT)
|
Asprin
|
inhibits COX needed to synthesize thromboxane
|
adenosine receptor antagonist
|
inhibit ADP-simulated aggregation, Ticlopidine, Clopidogrel
|
glycoprotein IIb/IIa receptor antagonist
|
block final step of aggregation, Abciximab, tirofibam
|
streptokinase
|
thrombolytic drug, remove thrombi, binds to plasminogen to form
plasmin, which digests fibrin, use: MI & DVT
|
Alteplase
|
tPA, tissue plasminogen activaor, recomb DNA technology, side effects:
intracranial bleeding
|
drug therapy for MI
|
reperfusion, morphine, antiplatelet drugs, anticoagulants,
nitroglycerin, beta-adrenergic blocking agents, ACE inhibitors
|
Complications of MI
|
ventricular dysrhythmias, cardiogenic shock, CHF, Cardiac rupture,
pericarditis
|
secondary prevention for MI
|
reduce risk factors, exercise, drug therapy
|
Hai fellow physiotherapists....this blog basically contains Amal's compilation of exam preparation materials for NPTE, PCE, HAAD, DHA,MOH, PROMETRIC, ACOPRA.
Thursday, July 2, 2015
Pharmacology focused of cardio-vascular drugs
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