#1
Which of the following is a positive inotropic agent?
Digitalis glycosides
ExplanationPositive inotropic agents strengthen heart contractions.
#2
Which condition might require the administration of positive inotropic agents?
Heart failure with reduced ejection fraction
ExplanationPositive inotropic agents can be used to improve cardiac function in heart failure with reduced ejection fraction.
#3
Which of the following drugs is classified as a cardiac glycoside?
Digoxin
ExplanationDigoxin belongs to the class of cardiac glycosides, exerting positive inotropic effects.
#4
Which receptor type does dobutamine primarily target?
Beta-1 adrenergic receptors
ExplanationDobutamine primarily acts on beta-1 adrenergic receptors to increase heart contractility.
#5
Which of the following drugs is NOT a phosphodiesterase inhibitor?
Digoxin
ExplanationDigoxin exerts positive inotropic effects through a different mechanism than phosphodiesterase inhibitors.
#6
Which of the following is a potential adverse effect of positive inotropic agents?
Hypotension
ExplanationPositive inotropic agents can cause hypotension due to increased cardiac output.
#7
Which electrolyte imbalance is important to monitor when administering positive inotropic agents?
Hypomagnesemia
ExplanationHypomagnesemia can exacerbate arrhythmias associated with positive inotropic agents.
#8
Which positive inotropic agent is commonly used in the management of acute decompensated heart failure?
Dobutamine
ExplanationDobutamine is frequently used in acute decompensated heart failure to improve cardiac function.
#9
Which mechanism of action is NOT associated with positive inotropes?
Enhanced release of norepinephrine
ExplanationPositive inotropes do not typically involve enhanced release of norepinephrine.
#10
Which class of positive inotropic agents directly increases intracellular calcium concentration?
Digitalis glycosides
ExplanationDigitalis glycosides directly increase intracellular calcium, leading to stronger heart contractions.
#11
Which of the following is a contraindication for the use of positive inotropic agents?
Acute myocardial infarction with systolic dysfunction
ExplanationPositive inotropic agents may worsen ischemia and exacerbate myocardial damage in acute myocardial infarction.
#12
Which of the following is a potential mechanism of action for positive inotropic agents?
Increasing cAMP levels
ExplanationPositive inotropic agents may increase cAMP levels, leading to enhanced cardiac contractility.
#13
Which class of positive inotropic agents primarily acts by inhibiting phosphodiesterase III enzymes?
Milrinone
ExplanationMilrinone is a phosphodiesterase III inhibitor, leading to increased cAMP levels and enhanced cardiac contractility.