Arrhythmias Flashcard 3
Rationale
D. Rationale: The patient with symptomatic tachycardia needs immediate attention. Always assume that these patients will soon become unstable if left untreated. It is thus necessary to keep their airway open and assist breathing if necessary. This patient is hypoxemic (O2 sat is only 93%), and oxygen supplementation must be given. A pulse oximeter can be placed to help monitor the patient’s progress. A 12-lead ECG must be obtained to determine the patient’s rhythm. A cardiac monitor can detect any progression or regression of the patient’s status.
Question
A patient presents to the emergency department with a report of palpitations and feeling faint. Vital signs include a heart rate of 155 bpm, blood pressure of 100/80 mm Hg, temperature of 36.8°C, and oxygen saturation of 93%. What is your next course of action?
a. Provide oxygen supplementation
b. Attach a cardiac monitor
c. Attach a pulse oximeter
d. All of the above
Answer
d. All of the above
Rationale
B. Rationale: emergency cardiovascular care guidelines suggest that transcutaneous pacing is probably indicated if patients with bradycardia are unresponsive to appropriate drugs.
Question
A patient suddenly develops hypotension and chest pain with bradycardia. Her condition does not improve after repeated doses of atropine and an epinephrine infusion. What other treatments are likely to improve the patient’s condition?
a. Synchronized cardioversion
b. Transcutaneous pacing
c. Adenosine 6 mg IV bolus
d. Amiodarone 300 mg IV bolus
Answer
b. Transcutaneous pacing
Rationale
A. Rationale: Idioventricular rhythm is produced by impulses arising from within the ventricle. It will be seen as bizarre-looking QRS complexes. Since it is ventricular in origin, there will be no P waves.
Question
A patient tells you that he has been diagnosed with a “slow heart” and has had it for the past year. An ECG shows the following tracing:
What is your interpretation of this ECG finding?
a. Idioventricular rhythm
b. Junctional rhythm
c. Premature atrial complex
d. Premature ventricular contractions
Answer
a. Idioventricular rhythm
Rationale
C. Rationale: When an arrhythmia reoccurs later during a resuscitation attempt, deliver a shock at the energy level that was previously successful.
Question
A patient was successfully defibrillated, terminating pulseless VT. One minute later, the patient again goes into VT and loses his pulse. A shock should be delivered at:
A. The lowest energy level, building from there
B. The highest energy level available
C. The same energy that was successful initially
D. 200 joules
Answer
C. The same energy that was successful initially
Rationale
C. Rationale: Dopamine is a beta-adrenergic agonist that has rate-accelerating effects; an alternative is epinephrine.
Question
A patient who is hypotensive secondary to bradycardia is unresponsive to atropine. Which one of the following drugs, if any, can be given to this patient?
a. No other medication is necessary
b. Amiodarone IV bolus
c. Dopamine IV infusion
d. Dipyridamole IV bolus
Answer
c. Dopamine IV infusion
Rationale
B. Rationale: Emergency cardiovascular care guidelines suggest that transcutaneous pacing is indicated if patients with bradycardia are unresponsive to drugs. (ACLS Case: Symptomatic Bradycardia)
Question
A patient with bradycardia that has suddenly developed hypotension and chest pain has not improved after receiving repeated doses of atropine and epinephrine. What other alternative treatments will potentially improve the patient’s condition?
a. Synchronized cardioversion
b. Transcutaneous pacing
c. Adenosine 6 mg IV bolus
d. Amiodarone 300 mg IV bolus
Answer
b. Transcutaneous pacing
Rationale
D. Rationale: Direct your attention to the long rhythm strip of lead V1 below the 12-lead ECG report. This is a third-degree AV block showing regular P-P intervals and regular R-R intervals. There is no relationship between the P waves and the QRS complexes as they are independent of each other.
Question
A patient with symptomatic bradyarrhythmia has the following 12-lead ECG tracing:
What is your diagnosis?
a. First-degree AV block
b. Second-degree AV block, Mobitz type 1
c. Second-degree AV block, Mobitz type 2
d. Third-degree AV block
Answer
d. Third-degree AV block
Rationale
D. Rationale: Vagal maneuvers (e.g., blowing on an occluded straw, bearing down, carotid massage) will occasionally convert a tachyarrhythmia. They are non-invasive and carry no risk; thus, it is worth attempting a vagal maneuver in a stable patient. If vagal maneuvers are ineffective, adenosine can be given at a dose of 6 mg IV push, followed by a second dose of 12 mg if the first dose fails to convert the rhythm.
Question
A stable patient has a regular narrow complex tachycardia. The indicated treatment is:
A. Defibrillation
B. Antiarrhythmics (e.g., amiodarone)
C. Synchronized cardioversion
D. Vagal maneuvers followed by adenosine if ineffective
Answer
D. Vagal maneuvers followed by adenosine if ineffective
Rationale
B. Rationale: Adenosine increases AV block and will not terminate atrial flutter or atrial fibrillation. But it will slow AV conduction, allowing identification of the rhythm.
Question
Adenosine will terminate atrial flutter.
a. True
b. False
Answer
b. False
Rationale
C. Rationale: After a first dose of adenosine 6 mg IV rapid push to convert paroxysmal supraventricular tachycardia to sinus rhythm is ineffective, a second dose of adenosine 12 mg rapid IV push is recommended.
Question
After a dose of adenosine 6 mg IV rapid push for the treatment of paroxysmal supraventricular tachycardia, the patient’s symptoms have not improved. What is the next therapy of choice?
a. Synchronized cardioversion
b. Amiodarone 300 mg IV bolus injection
c. Adenosine 12 mg IV rapid push
d. Sotalol 100 mg IV injection over 5 minutes
Answer
c. Adenosine 12 mg IV rapid push