Classification
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Arrhythmias may occur in children with otherwise normal hearts, in the perioperative cardiac surgical period or as a late complication of cardiac surgery. The true incidence of arrhythmias is uncertain but estimates have been between 1-4/1000 children. About 30% present in the first year of life. Arrhythmias are generally divided into those that are rapid (tachycardia) or slow (bradycardia) and regular or irregular. |
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The commonest is sinus arrhythmia - a normal physiological responses to the phase of respiration. Ectopic beats are also a very common phenomenon. |
TachycardiaSupraventricular Tachycardia (SVT)These arrhythmias are usually due to an accessory pathway (AP) either across the AV junction (AV re-entry tachycardia, permanent junctional re-entry tachycardia) or within the AV node (AV nodal re-entry tachycardia). More rarely they may be due to an automatic ectopic focus within the atrial myocardium or a micro or macro re-entry circuit within the atrial myocardium (atrial flutter and atrial fibrillation). Ventricular Tachycardia (VT)Ventricular tachycardia is a rare disease in childhood except in the perioperative period. It may be due to an ectopic focus or to the electrical instability caused by drug ingestion or the long QT syndrome. |
BradycardiaThese may be due to disease of the sinus node, atrioventricular node or the bundle of His. Disease of the sinus node is uncommon in young children but may occur as part of the neurocardiogenic syndrome. In the older children sino atrial disease may present with bradycardia and even sinus arrest in late post operative cases. AV block either first degree, 2nd degree of 3rd degree are more common. Heart block due to damage to the bundle of His may occur at the time of heart surgery. Regular or IrregularThe above arrhythmias usually give a regular pulse during the arrhythmia. The exception is atrial fibrillation. Ectopic beats (either atrial or ventricular) in contrast give an irregular rhythm. |
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This page was last edited 14/2/2004 |
