Heart Failure Drugs Flashcards
heart failure
the heart is unable to pump blood in sufficient amounts from the ventricles to meet the body’s metabolic needs
what do the symptoms of heart failure depend on?
the cardiac area affected
what are the two dysfunctions contributing to heart failure and which is less common
systolic dysfunction and diastolic dysfunction
diastolic dysfunction is less common
cardiac defects that cause heart failure
myocardial infarction
valve deficiency
defects outside the heart that cause heart failure
coronary heart disease
pulmonary hypertension
diabetes
supraventricular dysrhythmias that cause heart failure
atrial fibrillation
atrial flutter
positive inotropic drugs for heart failure
increase the force of myocardial contraction
positive chronotropic drugs
increase heart rate
positive dromotropic drugs
accelerate cardiac conduction
used to treat heart muscle failure
drug therapy for heart failure
ACE inhibitors Angiotensin 2 Receptor Blockers B-type natriuretic peptides Phosphodiesterase inhibitors Cardiac glycosides
ACE inhibitors
prevent sodium and water resorption by inhibiting aldosterone secretion
diuresis results, which decreases preload, or the left ventricular end-volume, and the work of the heart
-lisinopril
-enalapril
-captopril
Angiotensin 2 Receptor Blockers
Potent vasodilators, decrease systemic vascular resistance(afterload)
- valsartan
- candesartan
- losartan
B-type natriuretic peptides
nesertide(Natrecor)
-used in severe, life-threatening heart failure
hormone produced by the ventricles
BNP is released from the ventricles in response to increased blood volume in the heart
Atrial Natriuretic Peptide
hormone produced by the atria
ANP is produced in the atria in response to increased blood volume in the heart
B-type Natriuretic peptide mechanism of action
vasodilating effects on arteries and veins
indirectly increases cardiac output
supresses the renin angiotensin system
diuresis
B-type natriuretic peptides adverse effects
hypotension
dysrhythmia
headache
abdominal pain
state of cardiac muscle in HF
in HF the cardiac muscle is overstretched and failing
where are catecholamines released from
from the SNS in an effort to compensate for the failing heart
what do the catecholamines do
bind with beta 1 adrenergic receptors and activate adenylyl cyclase to form cAMP
cAMP coupled with other intracellular messengers does what?
increases contractility(inotropy) heart rate (chronotropy) conduction velocity(dromotrophy)
what enzyme breaks down cAMP
phosphodiesterase
what would inhibiting phosphodiesterase do
prevent breakdown of cAMP
increased inotropy
increased dromotrophy
increased chronotropy
adverse effects of inamrinone
thrombocytopenia dysrhythmia nausea hypotension elevated liver enzymes with long-term use
adverse effects of milrinone
milrinone dysrhythmia: mainly ventricular hypotension angina hypokalemia tremor thrombocytopenia
cardiac glycosides
no longer used as a first line treatment
originally obtained from the digitalis plant, foxglove
digoxin is the prototype
used in heart failure and to control ventricular response to atrial fibrillation or flutter
mechanism of action of cardiac glycosides
increase myocardial contractility
change electrical conduction properties of the heart
-decrease the rate of electrical contraction
-prolong the refractory period
-area between the SA node and AV node
drug effects of cardiac glycosides
positive inotropic effect
increased force and velocity of myocardial contraction(without an increase on oxygen consumption)
negative chronotropic effect
reduced heart rate
negative dromotropic effect
-decreased automaticity at SA node, decreased AV nodal conduction and other effects
cardiac glycosides more drug effects
increased stroke volume
reduction in heart size during diastole
decrease in venous BP and vein engorgement
increase in coronary circulation
promotion of diuresis because of improved blood circulation
palliation of extertional and paroxysmal nocturnal dyspnea, cough, and cyanosis
indications that you need cardiac glycosides
heart failure
supraventricular dysrhythmias
-atrial fibrilationand atrial flutter
adverse effects of cardiac glycosides
digoxin(Lanoxin) -narrow therapeutic window drug levels must be monitored low potassium levels increase its toxicity electrolyte levels must be monitored
adverse effects of digoxin in the cardiovascular system
dysrhythmias, including either bradycardia or tachycardia
adverse effects of digoxin on the CNS
headaches, fatigue, malaise, confusion, convulcsions
adverse effects of digoxin on the eye
colored vision, halo vision, flickering lights,
adverse effects of cardiac glycosides on the GI tract
anorexia, nausea, vomiting, diarrhea
digoxin toxicity
hyperkalemia
life-threatening cardiac dysrhythmias
life-threatening digoxin overdose
conditions that predispose to digoxin toxicity
jypokalemia use of cardiac pacemaker hepatic dysfunction hypercalcemia dysrhythmias hypothyroid, respiratory, or renal disease advanced age
