PALS Tachycardia Algorithm

Initial Assessment and Support

Healthcare providers must establish basic life support measures immediately upon identifying pediatric tachycardia. Maintain a patent airway while assisting breathing as necessary, then administer supplemental oxygen to optimize tissue oxygenation. Attach cardiac monitoring equipment to identify the specific rhythm while continuously monitoring pulse quality, blood pressure, and oxygen saturation levels. Establish intravenous or intraosseous access for medication administration, and obtain a 12-lead ECG when available to enhance diagnostic accuracy and guide treatment decisions.

Evaluate Rhythm

The critical decision step includes differentiating between compensatory sinus tachycardia and pathological tachyarrhythmias. Use the 12-lead ECG or continuous monitor to analyze rhythm characteristics, focusing on P wave morphology, RR interval consistency, and heart rate ranges. At the same time, assess for signs of cardiopulmonary compromise, including acutely altered mental status, clinical signs of shock, and hypotension.

For Probable Sinus Tachycardia

Sinus tachycardia represents the heart’s normal physiological response to stress, fever, or volume loss rather than a primary cardiac arrhythmia. Key features of this tachycardia include present and normal P waves, variable RR intervals that change with patient activity or stimulation, and age-appropriate heart rate thresholds, with infant rates typically remaining under 220 beats per minute and child rates usually under 180 beats per minute.

Search for and Treat the Cause

Focus treatment efforts on identifying and correcting the underlying condition causing sinus tachycardia rather than attempting to slow the heart rate directly. Common causes include fever requiring antipyretics, dehydration needing fluid resuscitation, pain management, or infection control measures. The heart rate should normalize once the condition resolves, making symptomatic rate control unnecessary and potentially harmful in most cases.

Patients with Cardiopulmonary Compromise

Evaluate QRS Duration

Measuring QRS width becomes the crucial determinant for selecting appropriate treatment pathways in unstable patients. Use calipers or electronic measurements to assess QRS duration accurately, establishing whether the tachyarrhythmia originates above or below the AV node. This distinction directly influences medication choices and cardioversion energy requirements, with narrow complexes typically responding to AV nodal blocking agents while wide complexes require different therapeutic approaches.

For Narrow QRS Duration

Narrow-complex tachycardia in unstable patients typically represents supraventricular tachycardia requiring rapid intervention to restore normal rhythm. Characteristic features include absent or abnormal P waves, consistent RR intervals without variability, infant heart rates usually exceeding 220 beats per minute, child rates typically above 180 beats per minute, and patient history revealing abrupt rate changes. Treatment focuses on adenosine administration if IV access exists or immediate synchronized cardioversion when vascular access is unavailable or adenosine proves ineffective.

For Wide QRS Duration

Wide-complex tachycardia in unstable pediatric patients indicates possible ventricular tachycardia and requires immediate electrical cardioversion to prevent deterioration to cardiac arrest. Prepare synchronized cardioversion equipment while ensuring appropriate energy settings and sedation when there is time. Expert cardiology consultation is strongly advised before attempting additional drug therapies, as pharmacological interventions may delay definitive treatment or worsen hemodynamic status in critically unstable patients.

Patients without Cardiopulmonary Compromise

Evaluate QRS Duration

Stable patients with tachyarrhythmias need more time for careful rhythm analysis and consideration of less aggressive interventions before proceeding to cardioversion. Measure QRS duration precisely while assessing rhythm regularity, P wave characteristics, and rate variability patterns. The absence of immediate hemodynamic compromise permits a trial of vagal maneuvers or pharmacological interventions that might avoid the need for electrical cardioversion and associated sedation risks.

For Narrow QRS Duration

Stable supraventricular tachycardia patients benefit from a stepwise approach beginning with vagal maneuvers before pharmacological intervention. Look for absent or abnormal P waves, non-variable RR intervals, infant rates typically exceeding 220 beats per minute, child rates usually above 180 beats per minute, and a history of sudden rate changes. Consider age-appropriate vagal stimulation techniques such as Valsalva maneuvers, followed by adenosine administration if IV access is established.

For Wide QRS Duration

Stable wide-complex tachycardia requires careful evaluation to distinguish ventricular tachycardia from other causes of wide QRS morphology. Consider adenosine administration only when the rhythm appears regular and shows monomorphic QRS complexes. Expert consultation is strongly recommended before additional interventions, as misdiagnosis could lead to inappropriate treatment choices that compromise patient safety or delay effective therapy.