Positive Inotropic Drugs in Heart Failure - Ch. 51 Flashcards
What is Heart failure?
The heart is unable to pump enough blood to meet the bodyβs metabolic needs
What do heart failure symptoms depend on?
Cardiac area affected
- left ventricular failure
-Right ventricular failure
What are Inotropic drugs?
Drugs that increase the force of myocardiac contraction
What are inotropic drugs used for?
Treatment of heart failure
What are the kinds of Inotropic drugs?
Cardiac glycosides
Sympathomimetic drugs
Phosphodiesterase inhibitors
Example of cardiac glycoside?
Digoxin
Examples of Sympathomimetic drugs?
Dobutamine
Dopamine
What are some other drugs used in heart failure?
Diuretics (K losing)
Beta-adrenoceptor antagonists
RAAS drugs (ACEIS, ARBs, Aldosterone antagonists)
Vasodilators (hrydralazine)
Organic nitrates (isosorbide dinitrate, nitroglycerin)
What causes heart failure to occur?
Cardiac muscle defect
Supraventricular dysrhythmias
Other defects beyond cardiac muscle
What cardiac muscle defects cause HF?
MI
Congenital
What Supraventricular dysrhythmias cause HF?
Atrial fibrillation
Atrial flutter
What other defects beyond cardiac muscle cause HF?
Coronary artery disease -ischemia
Hypertension/pulmonary hypertension
valve deficiency
Diabetes mellitus
What are the outcomes of HF?
Structural changes in cardiac muscle/connective tissue in ventricular wall
Functional changes in the ability of the ventricle to pump blood
What are symptoms of heart failure?
Reflex tachycardia
Edema
Elevated venous pressure
Dyspnea
Weakness
Cardiomegaly
What are inotropic drug effects on cardiac muscle?
Positive or negative force of muscualr contractions
What are chronotropic drug effects on cardiac muscle?
Positive or negative rate of the heartbeat
What are the dromotropic drug effects on cardiac muscle?
Positive or negative conduction speed of electrical impulses
Where were cardiac glycosides (digoxin) originally obtained from?
Digitalis plant (foxglove)
What are 3 Sβs of Digoxin action?
Strengthens
Slows
Slows
What is βstrengthensβ in digoxin action?
Positive inotropic effect
-increase in force of myocardiac contraction
What is the 1st βSlowsβ in digoxin action?
Negative chronotropic effect
-reduced heart rate at SA node