Arrhythmias Flashcard 4
Rationale
D. Rationale: Isoproterenol, dopamine, and epinephrine are alternative drugs to treat symptomatic bradycardia. Isoproterenol is a beta-adrenergic drug that stimulates beta-1 and beta-2 receptors to increase the heart rate and cause vasodilatation. Amiodarone is a class III antiarrhythmic drug, while lidocaine is a class-1B antiarrhythmic drug. Both will worsen the patient’s bradyarrhythmia.
Question
After treating a patient with atropine for symptomatic bradyarrhythmia, it continues to be ineffective. While waiting for the arrival of a transcutaneous pacing apparatus, which of the following drugs can be used instead to treat this patient?
a. Amiodarone
b. Magnesium sulfate
c. Lidocaine
d. Isoproterenol
Answer
d. Isoproterenol
Rationale
A. Rationale: When a biphasic defibrillator is used, follow the manufacturer’s recommendations for the initial dose. The second and subsequent shocks should deliver the same or a higher dose. If the manufacturer guidelines for a biphasic defibrillator are unknown, use the maximum dose that can be delivered.
Question
An adult patient is unresponsive, apneic, and pulseless. Two rescuers are providing high-quality chest compressions and ventilations with a bag-mask. Another rescuer arrives with the crash cart, which contains a biphasic defibrillator. The patient is confirmed to be in VF. The initial dose recommended for the defibrillator is 200 joules, which is provided, followed by immediate resumption of CPR. The patient remains in VF. The second energy dose should be:
A. The same or higher than the first dose
B. Lower than the initial dose
C. Never higher than the initial dose
D. At least 360 J
Answer
A. The same or higher than the first dose
Rationale
A. Rationale: The most important decision point is to determine if the patient has poor perfusion and if it is likely their symptoms are caused by poor perfusion.
Question
An important decision point in the treatment of bradycardia is:
a. Determining if the patient has poor perfusion
b. Determining if the patient has heart block
c. Whether or not to use atropine
d. Whether or not to use dopamine
Answer
a. Determining if the patient has poor perfusion
Rationale
D. Rationale: Patients with symptomatic tachyarrhythmias usually have a heart rate of 150 bpm or more.
Question
At what rate does tachyarrhythmia cause symptoms in susceptible patients?
a. 40 bpm
b. 50 bpm
c. 120 bpm
d. 150 bpm
Answer
d. 150 bpm
Rationale
B. Rationale: Atropine has been shown to cause further bradycardia if a dose < 0.5 mg is administered.
Question
Atropine has been shown to cause further bradycardia if a dose of less than how many mg is administered?
a. 0.1 mg
b. 0.5 mg
c. 1.0 mg
d. 1.2 mg
Answer
b. 0.5 mg
Rationale
C. Rationale: Clinicians should not rely upon atropine in the presence of Mobitz type II second- or third-degree AV block. The maximum total dose of atropine is 3 mg.
Question
Atropine:
a. Is useful in patients with Mobitz type II second-degree block
b. Is useful in patients with third-degree AV block
c. Should be used cautiously in the presence of acute MI
d. Can be given up to a total maximum dose of 0.08 mg/kg
Answer
c. Should be used cautiously in the presence of acute MI
Rationale
C. Rationale: Although they are not the first-line choice for the treatment of symptomatic bradycardia, dopamine and epinephrine are alternatives to TCP and can be used in special circumstances such as an overdose with a beta-blocker or calcium channel blocker.
Question
Beta-adrenergic agents:
a. Are not indicated for bradycardia
b. Are indicated only for overdose with a beta-blocker
c. Include dopamine and epinephrine
d. All of the above
Answer
c. Include dopamine and epinephrine
Rationale
D. Rationale: The American Heart Association/American College of Cardiology (AHA/ACC) statement on syncope notes that CSM should not be performed in patients with a recent transient ischemic attack or stroke, ipsilateral significant carotid artery stenosis, or carotid artery bruit.
Question
Carotid sinus massage should be avoided in patients with:
A. Wide complex tachycardia
B. Narrow complex tachycardia
C. Dysphagia
D. Recent transient ischemic attack or stroke
Answer
D. Recent transient ischemic attack or stroke
Rationale
C. Rationale: An initial attempt to defibrillate the patient may be warranted if care providers are unsure whether the rhythm is fine VF or asystole, as fine VF may be the result of a prolonged arrest and resuscitation.
Question
Defibrillation may be warranted for the patient in asystole when:
A. Other interventions are having no effect, and there is team consensus
B. A defibrillator is readily available
C. It is unclear whether the rhythm is fine ventricular fibrillation (VF) or asystole
D. The patient is to be declared dead (i.e., as a last-ditch effort)
Answer
C. It is unclear whether the rhythm is fine ventricular fibrillation (VF) or asystole
Rationale
A. Rationale: Adenosine should be considered only if the wide QRS is regular and monomorphic. AV nodal blocking agents such as adenosine may cause a paradoxical increase in the ventricular response in patients with pre-excitation atrial fibrillation.
Question
Drugs to avoid in the treatment of irregular wide-complex tachycardia include:
a. Adenosine
b. Procainamide
c. Amiodarone
d. Sotalol
Answer
a. Adenosine