Tachycardia (Tachyarrhythmia) is defined as a rhythm with a heart rate greater than 100 bpm.
The systematic approach algorithm is used to direct the care of the critically-ill or injured child. However, once it is recognized that an infant or child is experiencing symptomatic tachycardia, the tachycardia algorithm is used to simplify and streamline the evaluations and interventions to be carried out.
PALS Tachycardia Algorithm with a Pulse:
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Tachycardia with a Pulse Diagram
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Tachycardia vs. Tachyarrhythmia:
Tachycardia is a term used to describe any heart rate that is rapid compared with the normal heart rate that should be present. A “normal” rate is determined by the child’s/infant’s age. “Normal” for the patient may also vary depending on the child’s baseline.
Sinus Tachycardia is the basic rhythm that can be classified as tachycardia and is not associated with an arrhythmia.
A tachyarrhythmia is an abnormally rapid heartbeat accompanied by an irregular rhythm. The electrical impulse of the rhythm may have its origin in the atria or the ventricles.
Signs & Symptoms:
Sinus tachycardia (ST) is typically a normal response to fever and other forms of stress that increase the metabolic demands of the infant or child. ST will not display a fixed rate but will rise and fall as the demands of the body change. ST in infants and children is common and results from exercise, illness, metabolic stress, etc.
Tachyarrhythmias in infants and children can be difficult to detect until cardiac output becomes significantly compromised.
Symptoms in children that may be present include palpitations, chest pain, dizziness, light-headedness, and syncope. Signs in infants that may be seen include fatigue, shortness of breath, and poor feeding.
Signs that may be present are typically associated with compromised cardiac output and hemodynamic instability. These include hypotension, altered mental status, and other signs of shock.
There are three problems caused by prolonged periods of tachycardia.
- Poor cardiac output: Decreased ventricular filling time during diastole leads to a reduced stroke volume and subsequent reduced cardiac output.
- Decreased blood flow to the heart muscle: Blood flow to the heart muscle takes place primarily during diastole, and diastole is compromised because of the extreme heart rate.
- Increased myocardial oxygen demand: The rapid heart rate leads to further myocardial dysfunction due to the increased myocardial oxygen demand.
**(When tachyarrhythmias go untreated they can result in cardiogenic shock.)**
When the symptoms discussed above are recognized and you have identified that the patient has tachycardia, it is important to determine the nature of the tachycardia or tachyarrhythmia. Correct identification of the tachycardia or tachyarrhythmia determines the interventions that will be carried out within the tachycardia algorithms. The common tachyarrhythmias that occur in infants and children and that are discussed here include:
- Sinus tachycardia
- Supraventricular tachycardia
- Atrial flutter
- Ventricular tachycardia
- Wide-complex QRS tachycardia
Once a tachyarrhythmia is recognized, identify whether any life-threatening conditions exist. Indicators include signs of shock, hypotension, changes in the level of consciousness, etc.
The interventions for the initial management of both stable and unstable tachyarrhythmias are identical to the treatment for any critically-ill child. Begin with the support of the airway, breathing, and circulation and treating the underlying cause of the tachyarrhythmia.
Specific interventions include:
- Maintain an open airway, provide oxygenation and ventilation support
- Monitor oxygen saturation
- Monitor rhythm (attach ECG monitor/defibrillator)
- Obtain 12-Lead ECG (if possible)
- Establish IV/IO access
- Obtain pertinent laboratory studies (studies that may be pertinent include potassium, ionized calcium, magnesium, and glucose. An ABG may also be necessary to assess the status of the pH)
- Begin consideration of medications for use within the appropriate tachycardia algorithm
- Identify and treat any underlying reversible cause of the tachyarrhythmia
Critical interventions for patients experiencing tachyarrhythmias are determined by the degree to which the tachyarrhythmia is compromising perfusion. Use the appropriate pathway within the tachycardia algorithm to determine the interventions necessary. (see diagram below)
Specific critical interventions commonly used in the treatment of tachyarrhythmias include:
- Vagal maneuvers for specific types of SVT
- Synchronized cardioversion
- Medication administration (Antiarrhythmics)
Click to review the algorithm, and click again to close the diagram.
Tachycardia with a Pulse Diagram
or Members Download the Hi-Resolution PDF Here.