Cardiac Arrhythmias

Abstract

An initial and crucial step in managing any child with a cardiac arrhythmia is to determine the hemodynamic stability of the child. A healthy pink color of skin/mucosa, brisk capillary refill, good peripheral pulses, normal blood pressure, and absence of respiratory distress are all reassuring signs that the hemodynamic status of the child is normal or near normal. Stable hemodynamics suggests that the cardiac output generated by the heart, despite the arrhythmia, is adequate. Management of children with stable hemodynamics allow the treating physician to use less invasive measures, such as inserting an intravenous line and using pharmacological agents. Failure to respond to medications will then require more invasive management such as pacemaker insertion in patients with bradycardia or the use of cardioversion in patients with tachyarrhythmias. Children with significant bradycardias resulting in hemodynamic instability may require atropine and/or epinephrine to increase the rate of the escape rhythm, particularly in patients who present with complete heart block and slow junctional rhythms. Transcutaneous pacing can be performed with most bedside external defibrillators, although this maneuver is quite painful. Thereafter insertion of pacemaker may be needed. Tachyarrhythmias with stable hemodynamics can be treated with pharma­cological agents such as rapid intravenous bolus of adenosine in patients with SVT. A wide range of pharmacological agents are available for treating and preventing cardiac tachyarrhythmias. The more commonly used medications include beta-blockers, amiodarone, digoxin, and other agents. The specific type of antiarrhythmic agent, route of administration, and dose depends upon the type of arrhythmia and patient stability. These agents should be prescribed and administered under the supervision of a pediatric cardiologist. Many of these agents are listed in the Appendix section of this book. Truly unstable or pulseless tachyarrhythmias should be treated with prompt cardioversion.