147 Questions
What is the main issue in heart failure (HF)?
Inability to pump sufficient blood
Which systems are chronically activated in the progression of HF?
Sympathetic nervous system and renin–angiotensin–aldosterone system
What is associated with the chronic activation of sympathetic nervous system and renin–angiotensin–aldosterone system?
Remodeling of cardiac tissue
What is the consequence of chronic activation if left untreated?
Leads to death
What is the primary effect of increased sympathetic activity in heart failure?
Increased heart rate and force of heart muscle contraction
How does the activation of the renin–angiotensin–aldosterone system contribute to heart failure?
Increased formation of angiotensin II and release of aldosterone
What is the consequence of myocardial hypertrophy in heart failure?
Weaker contractions due to excessive elongation of the fibers
How does vasoconstriction contribute to the progression of heart failure?
Decreases venous return and preload
Activation of the sympathetic nervous system results in decreased heart rate and weaker muscle contractions.
False
Activation of the renin–angiotensin–aldosterone system leads to increased peripheral resistance and retention of water.
True
Myocardial hypertrophy may result in weaker contractions and diminished ability to eject blood.
True
Vasoconstriction enhances venous return and decreases cardiac preload.
False
What is the primary benefit of vaso- and veno-dilators in the pharmacologic intervention for heart failure?
Reduced myocardial work load
What effect does the use of diuretics have on heart failure?
Decreased extracellular fluid volume
Which pharmacologic intervention is associated with improved cardiac contractility in heart failure?
Positive ionotropic agents
What is the role of beta blockers in the treatment of heart failure?
Reduced rate of cardiac remodeling
What is the primary benefit of ACE inhibitors in the treatment of heart failure?
Decrease vascular resistance and venous tone
Which patients benefit the most from the use of ACE inhibitors in heart failure?
Patients with the lowest ejection fraction
What is the consequence of chronic activation of the renin–angiotensin–aldosterone system if left untreated?
Increased peripheral resistance and water retention
What is the role of beta blockers in the treatment of heart failure?
Improves cardiac contractility
What is the main reason for using angiotensin receptor blockers (ARBs) in heart failure (HF)?
To reduce cough and angioedema caused by elevated bradykinin levels
Which statement best describes the dosing frequency of ARBs used in heart failure treatment?
Most ARBs are dosed once-daily except for valsartan which is twice daily
What is the primary similarity in the actions on preload and afterload between ACE inhibitors and ARBs in heart failure?
Enhanced venous return
Which characteristic sets losartan apart as the prototype of the angiotensin receptor blocker (ARB) class?
The only ARB used for severe cough and angioedema
What is the primary indication for aldosterone antagonists in heart failure?
Patients with advanced heart disease and recent myocardial infarction
What is the primary effect of chronic activation of the renin–angiotensin–aldosterone system in heart failure?
Elevated levels of aldosterone due to angiotensin II stimulation
What characteristic sets losartan apart as the prototype of the angiotensin receptor blocker (ARB) class?
Unique mechanism of action on preload and afterload
Which peptide is secreted from the cardiac atria?
Atrial natriuretic peptide (ANP)
What is the primary function of natriuretic peptides?
Vasodilation and inhibition of cardiac remodeling
Which hormone/paracrine factor signals to decrease blood pressure and cardiac hypertrophy?
ANP
What is the example given in the text of a sacubitril drug class?
Natriuretic peptides
What is the primary purpose of using Sacubitril/Valsartan in the treatment of chronic heart failure?
To inhibit the neprilysin enzyme and reduce the risk of cardiovascular death and hospitalization for heart failure
What is the role of natriuretic peptides in the context of chronic heart failure?
To inhibit cardiac remodeling and promote vasodilation
What is the consequence of chronic activation of the sympathetic nervous system in heart failure if left untreated?
Decreased heart rate and weaker muscle contractions
What is the primary effect of chronic activation of the renin-angiotensin-aldosterone system in heart failure?
Increased peripheral resistance and retention of water
What is the primary benefit of β-blockers in heart failure?
Promoting cardiac remodeling
Which drugs have shown benefit in heart failure as mentioned in the text?
Losartan, carvedilol, and bisoprolol
What is the role of β-blockers in preventing changes in heart failure patients?
Preventing changes due to chronic activation of the sympathetic nervous system
Why is it recommended to use β-blockers for all patients with chronic, stable HF?
To prevent changes due to chronic activation of the sympathetic nervous system
β-Blockers are recommended for all patients with chronic, stable HF.
True
β-Blockers have positive inotropic activity in HF.
False
Three β-blockers that have shown benefit in HF are bisoprolol, carvedilol, and long-acting metoprolol.
True
The benefit of β-blockers in HF is attributed to their ability to promote chronic activation of the sympathetic nervous system.
False
What is the primary purpose of using loop diuretics in the treatment of heart failure?
To relieve pulmonary congestion and peripheral edema
What is the consequence of chronic activation of the sympathetic nervous system in heart failure if left untreated?
Increased heart rate and stronger muscle contractions
Which drugs have shown benefit in heart failure as mentioned in the text?
β-blockers and sacubitril/valsartan
What is the role of β-blockers in preventing changes in heart failure patients?
Improving cardiac contractility
Loop diuretics are the most commonly used diuretics in HF.
True
Diuretics have been shown to improve survival in HF.
False
The primary purpose of using loop diuretics in the treatment of heart failure is to decrease plasma volume and subsequently decrease venous return to the heart.
True
The benefit of β-blockers in HF is attributed to their ability to promote chronic activation of the sympathetic nervous system.
False
Which drug combination may be used if the patient is intolerant of ACE inhibitors or β-blockers and requires additional vasodilator response?
Hydralazine and isosorbide dinitrate
What is the primary purpose of using vaso- and veno-dilators in the pharmacologic intervention for heart failure?
To increase venous capacitance
Which peptide is secreted from the cardiac atria?
Natriuretic peptide
What effect does the use of diuretics have on heart failure?
Decrease in venous return to the heart
What is the primary concern associated with the use of positive inotropic agents in heart failure?
Reduced survival
Which drug class, except for digoxin, is mainly used for a short period in the inpatient setting for heart failure treatment?
Positive inotropic agents
What is the consequence of chronic activation of the sympathetic nervous system and renin–angiotensin–aldosterone system if left untreated in heart failure?
Worsening of heart failure symptoms
What is the primary indication for using aldosterone antagonists in heart failure?
Decreased plasma volume
What is the primary concern associated with the use of positive inotropic agents in heart failure?
Reduced survival
What is the primary function of natriuretic peptides in the context of chronic heart failure?
Induce diuresis and natriuresis
What is the primary indication for using aldosterone antagonists in heart failure?
Prevent sodium and water retention
What is the primary similarity in the actions on preload and afterload between ACE inhibitors and ARBs in heart failure?
Decrease both preload and afterload
What is the primary benefit of using digitalis glycosides in heart failure?
Increasing the contractility of the heart muscle
Which drug class, except for digoxin, is mainly used for a short period in the inpatient setting for heart failure treatment?
Loop diuretics
What is the primary indication for using aldosterone antagonists in heart failure?
Reducing water retention
What is the main reason for using angiotensin receptor blockers (ARBs) in heart failure (HF)?
Blocking the effects of angiotensin II
Digoxin is the most widely used agent in heart failure.
True
Digitalis glycosides have a high therapeutic index.
False
Loop diuretics are not commonly used in heart failure.
False
Activation of the sympathetic nervous system results in decreased heart rate and weaker muscle contractions.
False
What is the mechanism of action of inotropic drugs in increasing muscle contractility?
Inhibition of the Na+/Ca2+-exchanger to move calcium out of the cell
What is the primary effect of digoxin on cardiac contraction?
Enhances vagal tone
What is the primary purpose of using digoxin therapy in patients with severe HF?
To enhance vagal tone and decrease heart rate
What is the role of digoxin in slowing conduction velocity through the AV node?
To enhance vagal tone
What is the reason for targeting a lower serum drug concentration of digoxin in HFrEF?
To inhibit sympathetic activation
What is the effect of digoxin therapy on myocardial oxygen demand?
Decreases myocardial oxygen demand
Inotropic drugs work by inhibiting the Na+/K+-adenosine triphosphatase (ATPase) enzyme, which increases the intracellular Na+ concentration and decreases the ability of the Na+/Ca2+-exchanger to move calcium out of the cell.
True
Digoxin enhances vagal tone, leading to an increase in both heart rate and myocardial oxygen demand.
False
Low-dose digoxin inhibits sympathetic activation with minimal effects on contractility.
True
Digoxin therapy is recommended before the initiation of ACE inhibitor, β-blocker, and diuretic therapy for patients with severe heart failure.
False
Digoxin slows conduction velocity through the AV node, making it useful for atrial fibrillation and flutter.
True
The primary effect of chronic activation of the renin-angiotensin-aldosterone system is to decrease peripheral resistance and promote diuresis.
False
Why is a loading dose used for digoxin in acute situations?
To quickly achieve therapeutic levels despite its long half-life
What is the primary reason for digoxin toxicity being a common adverse drug reaction leading to hospitalization?
It has a very narrow therapeutic index
What are the initial indicators of digoxin toxicity?
Anorexia and nausea
What is the reason for the large volume of distribution of digoxin?
Accumulation in muscle tissue
How can toxicity of digoxin often be managed?
Discontinuing digoxin
What may be required for severe digoxin toxicity resulting in ventricular tachycardia?
Antiarrhythmic drugs
What should be done if indicated for patients receiving thiazide or loop diuretics?
Replenishing potassium
What is a potential risk factor for hypokalemia in patients receiving digoxin?
Use of thiazide or loop diuretics
What is the primary mechanism of action of β-adrenergic agonists like dobutamine and dopamine in the treatment of acute heart failure?
Causing positive inotropic effects and vasodilation
What is the primary similarity in the actions on preload and afterload between ACE inhibitors and ARBs in heart failure?
ACE inhibitors decrease preload while ARBs decrease afterload
What is the consequence of chronic activation of the renin–angiotensin–aldosterone system if left untreated in heart failure?
Increased peripheral resistance and water retention
What is the primary concern associated with the use of positive inotropic agents in heart failure?
Risk of worsening myocardial hypertrophy
What is the primary concern associated with long-term milrinone therapy?
Substantial increased risk of mortality
What is the consequence of chronic activation of the renin–angiotensin–aldosterone system if left untreated in heart failure?
Increased peripheral resistance and retention of water
What is the primary function of natriuretic peptides in heart failure?
Induction of natriuresis and diuresis
What is the primary benefit of using digitalis glycosides in heart failure?
Reduction in myocardial oxygen demand
What is the primary purpose of using anti-arrhythmic drugs?
To normalize the electrical activity of the heart
Which type of myocardial tissues has the ability to initiate action potential?
Conducting tissues
What is the primary role of natriuretic peptides in heart failure?
To decrease plasma volume
How do vasoconstrictors contribute to the progression of heart failure?
By increasing venous return to the heart
What is the primary characteristic that sets pacemaker cells apart from other myocardial cells?
They show a slow, spontaneous depolarization during diastole caused by an inward positive current carried by Na+ and Ca+2
What may arise if cardiac sites other than the sinoatrial (SA) node show enhanced automaticity?
Arrhythmias
Which types of dysfunction can cause an abnormality in cardiac rhythm?
Impulse generation or impulse conduction
What causes the fastest depolarization in the sinoatrial (SA) node?
Inward positive current carried by Na+ and Ca+2
How do antiarrhythmic agents prevent reentry?
By enhancing the refractory period of the ventricular muscle
What is the phenomenon that occurs if a unidirectional block caused by myocardial injury results in an abnormal conduction pathway resulting in reexcitation of the ventricular muscle?
Ventricular arrhythmia
What is the most common cause of arrhythmias?
Reentry
What is the primary purpose of using inotropic drugs in heart failure?
To strengthen cardiac contractions
Why has the use of sodium channel blockers declined?
As a result of their proarrhythmic effects
What property of sodium channel blockers causes a greater degree of blockade in frequently depolarizing tissues?
Use dependence
What is the primary consequence of chronic activation of the renin–angiotensin–aldosterone system if left untreated in heart failure?
Worsening of heart failure symptoms
What is the mechanism of action of inotropic drugs in increasing muscle contractility?
Inhibition of Na+/K+-adenosine triphosphatase (ATPase) enzyme
Which action of Class IA antiarrhythmic drugs leads to a decrease in conduction velocity?
Binding to open and inactivated sodium channels
What is the primary reason for using Class IA antiarrhythmic drugs?
To suppress arrhythmias by slowing conduction velocity and increasing refractoriness
Which factor contributes to the prolongation of the action potential duration by Class IA antiarrhythmic drugs?
Inhibiting potassium channels
What effect do Class IA antiarrhythmic drugs have on refractoriness?
They increase refractoriness
Which antiarrhythmic drug has the most anticholinergic adverse effects?
Disopyramide
What is the primary adverse effect of large doses of quinidine?
Blurred vision
Which antiarrhythmic drug is less cardiotoxic than quinidine?
Procainamide
Which antiarrhythmic drug is used as an alternative to procainamide or quinidine in the treatment of ventricular arrhythmias?
Disopyramide
What is the primary therapeutic use of lidocaine in the treatment of ventricular arrhythmias?
Little effect on atrial or AV junction arrhythmias
What is the primary concern associated with the use of Mexiletine?
Narrow therapeutic index
What is the mechanism of action of lidocaine and mexiletine in the treatment of ventricular arrhythmias?
Weak sodium channel blockade
Which drug is considered the first-line treatment for ventricular arrhythmias due to acute myocardial infarction?
Lidocaine
What is the primary therapeutic use of Flecainide?
Maintenance of sinus rhythm in atrial flutter or fibrillation in patients without structural heart disease
Why is the use of propafenone restricted mostly to atrial arrhythmias?
It has beta-blocking properties
What is the main concern associated with using propafenone in patients with asthma?
Bronchospasm due to beta-blocking effects
What is the reason for the restricted use of propafenone in treating ventricular arrhythmias?
Beta-blocking properties
Class II antiarrhythmic drugs are β-adrenergic agonists.
False
Metoprolol is the most widely used β-blocker in the treatment of cardiac arrhythmias.
True
Esmolol is a long-acting β-blocker used for intravenous administration in acute arrhythmias.
False
Class II antiarrhythmic drugs are useful in treating bradycardia caused by increased sympathetic activity due to exercise or emotion.
False
What is the primary mechanism of action of Class III antiarrhythmic drugs like amiodarone and sotalol?
Blockade of potassium channels, resulting in the prolongation of the action potential duration
What is the main risk associated with the use of Class III antiarrhythmic drugs like amiodarone and sotalol?
Increase in the QT interval, raising the risk of life-threatening ventricular tachyarrhythmias
What is the primary use of Class III antiarrhythmic drugs like amiodarone and sotalol?
Prevention of ventricular fibrillation
How do Class III antiarrhythmic drugs like amiodarone and sotalol affect the refractoriness of cardiac cells?
Prolong both the duration of the action potential and effective refractory period
What is the main action of Amiodarone as a Class III antiarrhythmic drug?
Prolongation of the action potential duration and refractory period by blocking K+ channels
What is the extra action of Amiodarone as a Class III antiarrhythmic drug, as mentioned in the text?
Showing class I, II, III, IV actions, as well as α-blocking activity
What is the significant side effect of Amiodarone related to its structural similarity to thyroxine?
Hypo- or hyperthyroidism (thyroid dysfunction)
What is the primary benefit of using Amiodarone as a Class III antiarrhythmic drug?
Prolonging refractoriness and action potential duration in atrial fibrillation
What is the primary effect of calcium channel blockers in the treatment of arrhythmias?
Prolong ERP of AV node and decrease conduction of impulses from the atria to the ventricles
In which type of arrhythmias are calcium channel blockers more effective?
Atrial arrhythmias
Which class of drugs decrease inward Ca2+ currents resulting in a decrease of phase 4 spontaneous depolarization?
Class IV antiarrhythmic drugs
What is the primary characteristic that sets calcium channel blockers apart from other antiarrhythmic drugs?
Decrease in inward Ca2+ currents
This quiz explores the role of physiologic compensatory mechanisms in the progression of heart failure, focusing on the chronic activation of the sympathetic nervous system and the renin–angiotensin–aldosterone system, and their association with cardiac tissue remodeling. The quiz also covers the importance of drug therapy in stopping the progression of heart failure.
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