Arrhythmias Flashcard 8

C. Rationale: Bradyarrhythmia’s unlikely to respond to atropine are second-degree AV block, Mobitz type 2 and third-degree AV block with wide QRS complex that represent the block to be non-nodal.

C. Rationale: The initial dose of adenosine to be given in this case is 6 mg rapid IV push followed by a normal saline flush. A rapid IV push is necessary because of the short half-life of adenosine. A subsequent dose can be given at 12 mg.

C. Rationale: Tachycardia is a heart rate > 100 bpm.

D. Rationale: Bradycardia is defined as a heart rate < 60 bpm. Patients with bradyarrhythmia will typically have symptoms when the heart rate is < 50 bpm.

C. Rationale: Atropine is given via intravenous bolus administration at a dose of 1 mg. It may be repeated every 3–5 minutes if the desired effect is not reached. Do not exceed a total dose of 3 mg.

D. Rationale: Atropine is an anticholinergic drug. It blocks acetylcholine, thereby inhibiting the parasympathetic nerve impulses and allowing the heart rate to increase. To be specific, atropine is also an antimuscarinic drug because it antagonizes the muscarine-like actions of acetylcholine.

D. Rationale: Atropine improves the heart rate and the signs and symptoms associated with bradycardia.

B. Rationale: If a shock is delivered in a tachyarrhythmia during the refractory period of the cardiac cycle, ventricular fibrillation can be produced. Synchronized cardioversion avoids this effect by delivering the shock during the peak of the QRS complex.

B. Rationale: If the patient does not have a pulse, you should immediately proceed to the ACLS Cardiac Arrest algorithm.

C. Rationale: Atropine is given at a dose of 1.0 mg IV every 3 to 5 minutes until a total dose of 3 mg has been administered. (ACLS Case: Symptomatic Bradycardia)