Arrhythmias Flashcard 1
Rationale
C. Rationale: Bradyarrhythmias are heart rates < 60 beats per minute. But when symptoms arise, the rate has usually fallen to < 50 beats per minute, and thus this is the working definition of bradycardia (ACLS Case: Symptomatic Bradycardia)
Question
The working definition of bradycardia in the symptomatic patient with a heart rate is:
a. < 40 beats per minute
b. < 45 beats per minute
c. < 50 beats per minute
d. < 60 beats per minute
Answer
c. < 50 beats per minute
Rationale
B. Rationale: In this scenario, the patient has symptomatic bradycardia. Atropine is the first choice for the medication in this scenario. (Case: Bradycardia)
Question
The patient presents with a palpable pulse of 38 beats per minute and a decreasing level of consciousness. He has some shortness of breath, and his skin is pale and cool. The first choice of medication for this patient is:
a. Epinephrine
b. Atropine
c. Dopamine
d. rtPA
Answer
b. Atropine
Rationale
A. Rationale: It is likely that the patient’s symptoms are precipitated by the recreational drug. Hypoxemia can also induce tachycardia. ECC guidelines suggest to maintain a patent airway initially and assist breathing if necessary. The underlying cause must be addressed as well. If the tachyarrhythmia persists, then pharmacologic intervention is recommended.
Question
A 21-year-old woman was brought to the emergency department in an agitated state, but she listens and follows commands. Her companions report that she recently “popped” ecstasy pills. She presents with the following vital signs: HR = 210 bpm, BP = 150/90 mm Hg, RR = 33/min, oxygen saturation = 95%. She presents with the following ECG tracing:
What intervention is the priority at this time?
a. Oxygen support and gastrointestinal decontamination
b. Synchronized cardioversion
c. Adenosine 6 mg rapid IV push
d. Amiodarone 150 mg over 10 minutes
Answer
a. Oxygen support and gastrointestinal decontamination
Rationale
D. Rationale: This ECG strip shows that the atria beat at their own rate, while a junctional pacemaker determines the ventricular rate. Early recognition of complete heart block is necessary because these patients are at risk for sudden cardiac death. They must be admitted for definitive treatment, such as temporary pacing or insertion of a pacemaker.
Question
A 22-year-old patient comes to the emergency department with a report of chest pain and dizziness. An ECG was requested, and you are presented with the following tracing:
What is your diagnosis?
a. First-degree heart block
b. Second-degree atrioventricular block, Mobitz type I
c. Second-degree atrioventricular block, Mobitz type II
d. Complete heart block
Answer
d. Complete heart block
Rationale
D. Rationale: Significant tachyarrhythmias are likely produced at heart rates of 150 bpm or more. The patient may be clinically hyperthyroid, and the most appropriate treatment is adjusting her anti-thyroid hormone medications or, if ineffective, scheduling her for low-dose radioactive iodine-131 ablation therapy.
Question
A 45-year-old woman with a history of Graves disease presents to the outpatient clinic with a report of palpitations. You measure the following vital signs: HR = 105 bpm, BP = 130/80 mm Hg, RR = 12/min, T = 36.8°C, oxygen saturation = 99%. What can be done for the patient at this time?
a. Amiodarone 150 mg IV push for 10 minutes
b. Synchronized cardioversion
c. Oxygen supplementation via nasal cannula at 2–3 L/min
d. No direct interventions are necessary
Answer
d. No direct interventions are necessary
Rationale
C. Rationale: The key to the answer lies in the patient’s history of SLE along with the heart rhythm. The ECG shows no prolongation of the PR interval and wide QRS complexes. The P waves march through at a constant rate, while dropped beats (absent QRS complexes) occur in a number equivalent to that of the preceding R-R interval. This is a second-degree AV block, Mobitz-type 2. This is a symptomatic bradyarrhythmia that, according to guidelines, is not responsive to the effects of atropine. This condition is preferably treated with temporizing measures, such as TCP or β-adrenergic support, while the patient is prepared for transvenous pacing.
Question
A 45-year-old woman with a history of systemic lupus erythematosus comes to the ED because her friends told her she had just fainted. You record the following vital signs: HR = 42 bpm, BP = 80/60 mm Hg, RR = 22/min, temperature = 37.0°C, oxygen saturation = 98%. You request an ECG and see the following results:
What is the treatment of choice for her cardiac condition?
a. Adenosine 6 mg IV bolus
b. Atropine 1 mg IV bolus
c. Transcutaneous pacing
d. Oxygen via nasal cannula at 2 to 3 L
Answer
c. Transcutaneous pacing
Rationale
B. Rationale: The ECG tracing represents a wide complex tachycardia consistent with ventricular tachycardia.
Question
A 49-year-old man comes to the emergency department for chest pains and a “racing heartbeat.” You request a 12-lead ECG and are presented with the following tracing:
What is your interpretation of this ECG finding?
a. ST segment elevation
b. Ventricular tachycardia
c. Torsade’s de pointes
d. Left bundle branch block
Answer
b. Ventricular tachycardia
Rationale
B. Rationale: Hypoxemia is a common cause of bradycardia. Therefore, in a patient with bradycardia, the provider must initially evaluate for signs of labored breathing and assess the oxygenation status. Guidelines suggest that supplemental oxygen must be provided immediately.
Question
A 52-year old woman with a history of chronic obstructive pulmonary disease is rushed to the ED with dyspnea. You observe intercostal retractions and abdominal breathing. You then record the following vital signs: HR = 39 bpm, BP = 110/60 mm Hg, RR 33 breaths/min, temperature = 36.8°C, oxygen saturation = 94%. What is your first course of action?
a. Atropine 1 mg IV bolus
b. Oxygen via nasal cannula at 2–3 L
c. Transcutaneous pacing
d. Dopamine IV infusion 20 mcg/kg/minute
Answer
b. Oxygen via nasal cannula at 2–3 L
Rationale
D. Rationale: The patient is in stable wide QRS complex tachycardia. The treatment of choice is an antiarrhythmic infusion with the following antiarrhythmic agents: procainamide, amiodarone, and sotalol.
Question
A 54-year-old man comes to the emergency department with reports of dizziness, shortness of breath, and palpitations. His heart rate is 200 bpm, and his blood pressure is 110/80 mm Hg. The patient’s ECG tracing shows the following:
Which one of the following medications is the treatment of choice in this case?
a. Procainamide
b. Amiodarone
c. Sotalol
d. All of the above
Answer
d. All of the above
Rationale
A. Rationale: The healthcare provider must know the signs of poor perfusion secondary to bradycardia. In this patient ,these signs are altered mental status, hypotension, and low oxygen saturation. The treatment of choice is atropine.
Question
A 62-year-old man is brought to the ED confused and incoherent, and he doe not respond to questions. You check his vital signs and record the following result: HR = 45 bpm, BP = 90/60 mm Hg, RR = 15/min, temperature = 36.5°C, oxygen saturation = 95%. What is your next course of action?
a. Administer atropine 1 mg IV bolus
b. Dopamine IV infusion 20 mcg/kg/minute
c. Transcutaneous pacing
d. Administer adenosine 6 mg IV bolus
Answer
a. Administer atropine 1 mg IV bolus