Free PALS Tachycardia Questions and Answers — Questions and Answers
Question 1: Which tachyarrhythmia is most likely to impair a baby's cardiovascular health during infancy?
- Sinus tachycardia
- Paroxysmal supraventricular tachycardia
- Supraventricular tachycardia (Correct answer)
- Ventricular tachycardia
Correct answer: Supraventricular tachycardia
Supraventricular tachycardia (SVT) is the most common symptomatic tachyarrhythmia in infants and children. While sinus tachycardia is often a physiological response, sustained SVT can significantly impair a baby's cardiovascular health. This is because the rapid heart rate reduces ventricular filling time and cardiac output, potentially leading to heart failure if untreated for an extended period.
Question 2: Which of these imbalances in electrolytes wouldn't cause ventricular tachycardia?
- Hypomagnesemia
- Hypocalcemia
- Hyperkalemia
- Hyponatremia (Correct answer)
Correct answer: Hyponatremia
Ventricular tachycardia can be caused by several electrolyte imbalances that affect myocardial excitability and repolarization, such as hypomagnesemia, hypocalcemia, and hyperkalemia. Hyponatremia, which is a low sodium level, primarily affects neurological function and fluid balance. It is not typically a direct cause of ventricular tachycardia.
Question 3: What is the typical duration of the QRS in pediatric patients?
- Less than or equal to 0.09 seconds (Correct answer)
- Less than or equal to 0.15 seconds
- Less than or equal to 0.9 seconds
- Less than or equal to 0.03 seconds
Correct answer: Less than or equal to 0.09 seconds
In pediatric patients, the normal duration of the QRS complex is typically less than or equal to 0.09 seconds. A wider QRS complex (greater than 0.09 seconds) suggests a ventricular conduction delay or a ventricular origin of the rhythm. This measurement is a crucial diagnostic indicator in PALS for identifying different types of arrhythmias.
Question 4: If untreated tachyarrhythmias go untreated for an extended length of time, they may eventually result in congestive heart failure (CHF). Of the following, which one would not be a marker of CHF in infancy?
- Poor feeding
- Sunken fontanel (Correct answer)
- Rapid breathing
- Irritability
Correct answer: Sunken fontanel
Poor feeding, rapid breathing (tachypnea), and irritability are common signs of congestive heart failure (CHF) in infants, reflecting increased metabolic demand and respiratory distress. A sunken fontanel, however, is a sign of dehydration, indicating a decrease in intracranial pressure and fluid volume, rather than a direct symptom of CHF.
Question 5: Tachyarrhythmias can result in a substantial reduction in cardiac perfusion. What cardiovascular component's shorter duration is the cause of these perfusion changes?
- Systole
- Atrioventricular valve conduction
- Atrioventricular valve closure
- Diastole (Correct answer)
Correct answer: Diastole
Tachyarrhythmias significantly shorten the duration of diastole, which is the phase when the ventricles relax and fill with blood. This reduced filling time leads to decreased ventricular preload and subsequently a substantial reduction in cardiac output. Consequently, coronary perfusion is impaired, compromising the heart's ability to supply blood to the body and itself.
Question 6: Which arrhythmias below have a QRS complex lasting longer than 0.09 seconds?
- Supraventricular tachycardia with aberrant intraventricular conduction (Correct answer)
- Atrial flutter
- Supraventricular tachycardia
- Sinus tachycardia
Correct answer: Supraventricular tachycardia with aberrant intraventricular conduction
A QRS complex lasting longer than 0.09 seconds indicates a delay in ventricular depolarization. While typical supraventricular tachycardia (SVT) has a narrow QRS, SVT with aberrant intraventricular conduction means the supraventricular impulse is conducted abnormally through the ventricles. This mimics a wide QRS complex, making it challenging to distinguish from ventricular tachycardia.
Question 7: Which of the following arrhythmias would be indicated by typical sawtooth P-wave activity on the ECG monitor, using the ILCOR PALS Provider Manual?
- Atrial fibrillation
- Sinus tachycardia
- Supraventricular tachycardia
- Atrial flutter (Correct answer)
Correct answer: Atrial flutter
The characteristic 'sawtooth' pattern of P-waves on an ECG, particularly in leads II, III, and aVF, is a hallmark finding of atrial flutter. This pattern represents rapid and regular atrial depolarization, typically at a rate of 250-350 bpm. This distinct ECG finding helps differentiate atrial flutter from other arrhythmias like atrial fibrillation or sinus tachycardia.
Question 8: When a narrow QRS complex is present in both stable and unstable sinus tachycardia situations, what is the most crucial intervention?
- Obtain a 12-lead ECG
- Identify and treat the underlying cause (Correct answer)
- Monitor blood pressure and pulse oximetry
- Provide oxygen therapy
Correct answer: Identify and treat the underlying cause
Sinus tachycardia is a physiological response to an underlying stressor, such as fever, hypovolemia, pain, or anxiety. The most crucial intervention is to identify and treat this underlying cause, as addressing it will resolve the tachycardia. Attempting to slow the heart rate directly without addressing the root cause could be detrimental if the tachycardia is compensatory.
Question 9: When a youngster has ventricular tachycardia, poor perfusion, and indications of shock, what is the most crucial course of action?
- Perform vagal maneuvers
- Administer amiodarone
- Perform synchronized cardioversion (Correct answer)
- Administer adenosine
Correct answer: Perform synchronized cardioversion
When a child presents with ventricular tachycardia, poor perfusion, and signs of shock, it indicates an unstable rhythm requiring immediate intervention to restore adequate cardiac output. Synchronized cardioversion is the definitive treatment in this scenario. It delivers an electrical shock timed with the QRS complex to reset the heart's rhythm, which is more effective than medications or vagal maneuvers for unstable VT.
Question 10: Which drug is suggested as a first line of treatment for supraventricular tachycardia?
- Adenosine (Correct answer)
- Epinephrine
- Atropine
- Procainamide
Correct answer: Adenosine
Adenosine is the recommended first-line drug for supraventricular tachycardia (SVT) in pediatric patients, especially if vagal maneuvers are unsuccessful. It works by transiently blocking AV nodal conduction, which can interrupt the re-entry circuit responsible for most SVTs. This allows the heart to reset to a normal sinus rhythm.
Question 11: In order to simulate a right tension pneumothorax, where should the needle go?
- 4th intercostal space right of the mediastinum
- 1st intercostal space right of the mediastinum
- 2nd intercostal space right of the mediastinum (Correct answer)
- 4th intercostal space left of the mediastinum
Correct answer: 2nd intercostal space right of the mediastinum
For needle decompression of a tension pneumothorax, the standard anatomical landmark is the second intercostal space in the midclavicular line. Therefore, to simulate a right tension pneumothorax, the needle should be placed in the 2nd intercostal space right of the mediastinum (or midclavicular line) to access the pleural space effectively.
Free PALS Tachycardia Questions and Answers
Which tachyarrhythmia is most likely to impair a baby's cardiovascular health during infancy?