Arrhythmias Flashcard 9
Rationale
C. Rationale: A patient with neurologic dysfunction and bradycardia must be assessed for increased intracranial pressure, particularly after head trauma.
Question
Which of the following can be a cause of bradycardia?
a. Atropine intravenous injection
b. Clinical hyperthyroidism
c. Increased intracranial pressure
d. Vigorous exercise
Answer
c. Increased intracranial pressure
Rationale
A. Rationale: Severe hypothermia is a contraindication for TCP. Transcutaneous pacing is not recommended for asystole. The other conditions mentioned are indications for TCP.
Question
Which of the following is a contraindication to transcutaneous pacing?
A. Severe hypothermia
B. Hemodynamically unstable bradycardia
C. Bradycardia with symptomatic ventricular escape rhythm
D. Unstable clinical condition likely due to the bradycardia
Answer
A. Severe hypothermia
Rationale
C. Rationale: Pheochromocytoma is a tumor that secretes catecholamine, a hormone for fight and flight responses. This condition causes tachycardia.
Question
Which of the following is not a pathophysiologic setting for bradycardia?
a. Pheochromocytoma
b. Exaggerated vagal activity
c. Endurance athlete
d. Obstructive sleep apnea
Answer
c. Endurance athlete
Rationale
A. Rationale: It is important to determine signs and symptoms of poor perfusion to decide what appropriate treatments are needed for the patient with bradycardia.
Question
Which of the following is not a sign or symptom of poor perfusion related to bradycardia?
a. Palpitations
b. Hypotension
c. Acutely altered mental status
d. Ischemic chest discomfort
Answer
a. Palpitations
Rationale
A. Rationale: Emergency cardiovascular care guidelines designate atropine as the first-line drug treatment for acute symptomatic bradycardia. Transcutaneous pacing and dopamine may be used if atropine is not effective.
Question
Which of the following is not a treatment for bradycardia?
a. Adenosine
b. Atropine
c. Transcutaneous pacing
d. Dopamine
Answer
a. Adenosine
Rationale
C. Rationale: When dealing with bradycardia in the ED setting, it is best to find and treat the underlying cause. Possible intrinsic causes of bradycardia include the following: idiopathic degenerative disorder, ischemic heart disease, chronic ischemia, acute myocardial infarction, hypertensive heart disease, cardiomyopathy, trauma, surgery for congenital heart disease, heart transplant, inflammation, collagen vascular disease, rheumatic fever, pericarditis, infection, viral myocarditis, Lyme disease, neuromuscular disorders, Friedreich ataxia, X-linked muscular dystrophy, and other familial disorders.
Question
Which of the following is not an intrinsic cause of bradycardia?
a. Ischemic heart disease
b. Pericarditis
c. Graves disease
d. Lyme disease
Answer
c. Graves disease
Rationale
D. Rationale: Research has shown that amiodarone improves rates of ROSC and survival to admission in patients with refractory VF/pulseless VT. It is the first-line antiarrhythmic agent for cardiac arrest.
Question
Which of the following is the first-line antiarrhythmic agent for refractory VF?
A. Magnesium
B. Procainamide
C. Lidocaine
D. Amiodarone
Answer
D. Amiodarone
Rationale
B. Rationale: The patient in atrial fibrillation with a heart rate of 155 beats/minute experiencing acute shortness of breath, hypotension, and pulmonary edema will likely require cardioversion. A patient with these symptoms related to a rapid heart rate is unstable and thus requires cardioversion.
Question
Which of the following patients is likely to require cardioversion?
A. An otherwise healthy patient in atrial flutter with a heart rate of 150 beats/min and no symptoms aside from palpitations
B. A patient with new-onset atrial fibrillation at a rate of 155 beats/min with acute shortness of breath, hypotension, and pulmonary edema
C. An adolescent patient with a high fever and a heart rate of 130 beats/min
D. A patient with known paroxysmal supraventricular tachycardia who has responded well in the past to IV adenosine
Answer
B. A patient with new-onset atrial fibrillation at a rate of 155 beats/min with acute shortness of breath, hypotension, and pulmonary edema
Rationale
A. Rationale: Epinephrine has been shown to increase ROSC but not survival from cardiac arrest. Studies have not supported the use of vasopressin over epinephrine in cardiac arrest. Vasopressin causes renal and coronary vasoconstriction. Epinephrine increases cerebral perfusion pressure during CPR.
Question
Which of the following statements is TRUE concerning the use of vasopressors?
A. Studies have shown that epinephrine improves the chance of ROSC but does not improve overall survival.
B. Vasopressin has been shown to be superior to epinephrine in terms of both ROSC and long-term survival from cardiac arrest.
C. Vasopressin causes renal vasodilation.
D. Epinephrine causes a decrease in cerebral perfusion pressure during CPR.
Answer
A. Studies have shown that epinephrine improves the chance of ROSC but does not improve overall survival.
Rationale
D. Rationale: Synchronized cardioversion requires a lower energy level than defibrillation. Doses of energy in synchronized cardioversion generally range between 50 and 200 joules.
Question
Which of the following statements regarding synchronized cardioversion is INCORRECT?
A. In synchronized cardioversion, the shock is delivered at the peak of the R wave, avoiding delivery of the shock during repolarization.
B. Low-energy shocks should always be delivered as synchronized shocks to avoid precipitating VF.
C. Synchronization can take longer than defibrillation because the sensor must detect the R wave peaks.
D. Synchronized cardioversion requires a higher energy level than defibrillation.
Answer
D. Synchronized cardioversion requires a higher energy level than defibrillation.