Arrhythmias Flashcard 1

A. Rationale: The PALS guidelines recommend giving epinephrine IV at a dose of 0.01 mg/kg every 3 to 5 minutes, or as needed until the patient’s condition improves, for pediatric patients with AV block with persistent and symptomatic bradycardia despite adequate oxygenation, ventilation, and cardiopulmonary resuscitation.

C. Rationale: According to the PALS guidelines for tachycardia with a pulse, “the initial interventions in a child presenting with tachycardia are as follows: maintain a patent airway and assist breathing as needed. Administer oxygen if hypoxemic. Attach to a cardiac monitor and identify the rhythm. Monitor blood pressure and oximetry. Establish intravenous access. Do not delay therapy.” Maintaining a patent airway with adequate oxygenation and ventilation helps ensure that vital organs are perfused, especially in cases where perfusion is compromised.

C. Rationale: Since hypoxia is the most common cause of bradycardia in a child, the team should first establish a patent airway and assist breathing as needed with 100% oxygen. The team should quickly obtain intravenous or intraosseous access and perform 12-lead electrocardiography (ECG). Maintaining a patent airway with adequate oxygenation and ventilation helps ensure that vital organs are perfused, especially in cases where perfusion is compromised. If these interventions do not quicky improve the child, CPR with high quality chest compressions is initiated.

C. Rationale: This is a second-degree AV block, or Mobitz type II. Impulses from below the AV node within the Purkinje system are blocked. On 12-lead ECG, the tracing shows a fixed PR interval (no progression or lengthening) with intermittent dropped beats. This type of AV block causes symptoms.

C. Rationale: Synchronized cardioversion is indicated in patients with supraventricular tachycardia with a pulse who remain unresponsive to medication and are deteriorating hemodynamically. Synchronized cardioversion delivers energy or shock in coordination with the R wave. It is important to note that the delivery of the shock is timed with the R-wave. Otherwise, the shock may be delivered during the vulnerable T waves, converting SVT to VF. Synchronized cardioversion is a painful procedure, and thus sedating the patient is recommended.

B. Rationale: Supraventricular tachycardia (SVT) is caused by aberrant impulses coming from random areas in the ventricles. These impulses reenter within the atrioventricular node or through an accessory pathway, generating additional aberrant impulses. On the 12-lead ECG, SVT is seen as a regularly occurring narrow QRS complex with no discernible P waves. The P waves are either buried within the QRS complex or seen before or right after it, distorting the morphology. SVT is sudden in its onset and termination.

D. Rationale: Pediatric patients with a cardiac condition that produces an arrhythmia are at risk for developing cardiac arrest rhythms such as ventricular fibrillation or pulseless electrical activity while performing strenuous activities. Therefore, athletic departments require coaches and other personnel present in athletic events to be trained in BLS and provide emergency equipment to be used when needed in sports events.

A. Rationale: Bradycardia in children is a heart rate that is less than 60 beats per minute. Bradycardia is an indication that a child is critically ill. Older children may have a HR < 60 bpm during sleep, especially if they are athletes.

A. Rationale: Torsade’s de pointes is a form of polymorphic ventricular tachycardia occurring in the context of a prolonged QT interval. It is characterized in the 12-lead ECG as a rapid, irregular QRS complex that twists around the isoelectric line at a rate of about 200–250 bpm. This tachyarrhythmia occurs in bursts and then resolves spontaneously, or it may develop into VF, causing significant hemodynamic compromise and even death. To diagnose torsade’s de pointes, the patient must have evidence of both paroxysmal ventricular tachycardia and a prolonged QT interval.

D. Rationale: This 12-lead electrocardiogram depicts atrial flutter. There is a reentrant circuit in an atrial flutter that causes a repeated loop that depolarizes the atrium. Because of these reentries, not all the P waves conduct a circuit through the AV node, resulting in a much faster atrial rate than the ventricular rate. The atrium beats at a rate of 250–350 beats per minute, while the ventricular rate is about 150 beats per minute. The P waves that reenter and don’t conduct through the AV node cause the sawtooth appearance on ECG characteristically seen in atrial flutter.