Question | Answer |
What is automaticity? | Property of specialized excitable tissue that allows self-activiation through the spontaneous dev of an action potential, as in the pacemaker cells of the heart. |
What is positive chronotropic?
Negative chronotropic? | increase of heart rate
decr of heart rate |
What is + dromotropic?
what is - dromotropic? | + = accelerate conduction
- = deccelerate conduction |
What is + inotropic?
what is - inotropic? | + = incr. force of contraction
- = decr. force of contraction |
What is left ventricular end-diastolic volume?
Also known as? | Total amt of blood in vent. immediately before it contracts
Preload |
what is ejection fraction?
what is normal %? | proportion of blood that is ejected during ea vent contraction
65% |
Systolic dysfunction is inadequate ventricular contraction or refilling? | contraction
diastolic dysfunction is inadequate vent filling |
Name two typical cardiac defects that lead to heart failure | Myocardial Infarction and Valve deficiency |
Name three defects outside the heart that leads to heart failure | diabetes
coronoary artery disease
pulmonary hypertension |
What are supraventricular dysrhythmias? | problems in the atria: atrial fibrillation, flutter |
heart failure drugs that are most common positive inotropic drugs? | phosphodiesterase inhibitors
cardiac glycosides
B-type natriuretic peptids
ACE inhibitors
ARB's (angiotensin II receptor blockers)
beta blockers |
ACE inhibitors do what? | convert angiotensin I to II, a vasoconstrictor and induces aldosterone secretion. Prevents Na and H2O resportion by inhibiting aldosterone secretion. |
What does aldosterone do? | stimulates Na and H2O resportion, can raise BP |
What is renin? | vasoconstrictor released by kidneys |
what is the renin-angiotensin-aldosterone system? | process to raise BP by reorption of Na and h20 |
What is the most common ACE inhibitor? | lisinopril (Prinvil, Zestril) |
What are three ARB's available? | valsartan, candesartan, losartan |
What is an adverse effect of lisinopril? | dry cough, hyperkalemia |
What is the advantage of ARB's over ACE ihnibitors? | no cough |
What do ARB's ultimately do? | vasodilators which decr systemic vascular resistance or afterload |
What are B-type natiurectic peptides and name one | used in severe life threatening heart failure. vasodilators, incr CO, suppress renin-angiotensin system, diuresis
nesiritide (Natrecor) |
What do beta blockers block? | SNS stimulation to the heart adn heart's conduction system. Prevent catecholamine actions on heart. |
What is the most common beta blocker? | Metoprolol |
catecholamines are what? | SNS neurotransmitters: epi, norepi, dopamine |
Name 4 adverse effects for B-type natiurectic peptides | hypotension, dysrhythmia, headache, abd pain |
phosphodiesterase inhibitors (PDI's)inhibit what?
What is inodilators?
Name two drugs | phosphodiesterase
inodilators +inotropic,vasodilation
inamirone, milirone |
phosphodiesterase inhibitors are given when pxt does not respond to what? | digoxin, diurectics, &/or vasodilators
short term mgmt for heart failure |
What are adverse effects of inamrinone?
milrinone? | thrombocytopenia (dec platelets)
dysrhythmia, hypokalemia, hypotension |
Cardiac glycosides are oldest cardiac drugs. Obtained from what plant? | foxglove |
what is prototypical cardiac glycoside?
What treatment is it used for? | Digoxin
systolic heart failure, atrial fibrillation |
Digoxin has a + intotropic or - without an increase in what?
+ or - dromotropic?
What does it prolong? | + inotropic, w/o incr in O2 consum.
- dromotropic
refractory period (area b/n SA & AV nodes) |
What is result of digoxin? | reduced cardiac heart rate and improved cardiac effeciency, reduced heart size, less edema, incr coronary circulation (more blood to heart), help pxt exert and breathe better |
A normal ventricle squeezes how much blood out with how much blood left behind?
Weak left vent? | 60%, 40%
33%, 67% |
Heart Failure symptoms | SOB, feet swell, no energy, insomnia, abd swell, cough, diuresis, confusion |
Dig adverse effects | very narrow therapeutic window, can get toxic quickly, drug levels must be .5-2ng/mL
Low K incr toxicity
electrolyte levels monitored
dysrhythmias, headaches, colored vision, anorexia |
What is the antidote for dig overdose? | Digoxin immune Fab (digibind) |
In measure the apical pulse for Dig, what should you look for? | Measure apical for 1 min.
If <60 or lower, or >100, then withhold dose and notify doctor |
What food should not be adm. with Dig? | high fiber foods b/c fiber binds and alters absorption adn bioavailability |
Therapeutic effects of pos. inotropic drugs | incr urinary output
decr edema
decr dyspnea/crackles
decr fatigue
resolve paroxysmal noct. dyspnea
Impr. peripheral pulses,skin color, temp |
What are the parameters for weight gain with heart failure drugs | 2+ lbs in day or 5+ in week, report |
When adm. inamrinone or milrinone, how should you adm. it? | use infusion pump |
An IV inamrinone should never be mixed with what?
What color is the solution? | dextrose
yellow |