الفهرس 
Cardiac electrophysiologyOnly 14 pages are availabe for public view
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Abstract
Patients with congenital heart disease represent a heterogeneous population with varied arrhythmic diagnoses and issues. The last decade has witnessed major advances in our understanding of arrhythmia mechanisms and therapeutic options. Sudden cardiac death of presumed arrhythmic etiology is the leading cause of mortality, particularly in patients with leftsided obstructive lesions, D-TGA and intraatrial baffles, tetralogy of Fallot, and severe systemic ventricular dysfunction. Sinus node dysfunction is common in left atrial isomerism and with Mustard, Senning, Glenn, or Fontan surgery.
Abnormalities in cardiac rhythm are common following surgery for congenital heart disease and are an important cause of impaired cardiac output in this setting. Timely and accurate identification of the rhythm disturbance is mandatory, and allows for the institution of effective, rhythm specific management strategies in these patients.
Postoperative arrhythmias remain a major cause of morbidity and mortality after pediatric congenital heart surgery. In this hemodynamically vulnerable period, alterations in rhythm and rate may be problematic for patients. Therapeutic options include medication, pacing, and other nonpharmacologic maneuvers. Typically, these arrhythmias are self limited to the postoperative period and do not require long term therapy. The natural history of these arrhythmias combined with the hemodynamic instability of the patients makes it difficult to prospectively study potential antiarrhythmic therapies.
Several studies have defined preprocedural and procedural factors that may contribute to the development of postoperative arrhythmias. Preprocedural factors include young age and small patient size. Procedural factors such as long cardiopulmonary bypass time, longer aortic cross clamp time, higher surgical complexity, and higher maximum postoperative troponin serum levels all are correlated with the development of postoperative arrhythmias. Postoperative arrhythmias can be categorized into bradyarrhythmias and tachyarrhythmias. Brady-arrhythmias include sinus node dysfunction (SND) and atrioventricular (AV; heart) block. The tachyarrhythmias include atrial tachycardias (ATs), junctional ectopic tachycardias (JETs), and ventricular tachycardias (VTs). The most frequently occurring tachycardias are supraventricular tachycardia (SVT, a subgroup of the ATs) and JET. This review article looks at each type of bradyarrhythmia and tachyarrhythmia as well as its natural history and treatment options.
After the diagnosis of dysrhythmia the distinction between benign dysrhythmia and those that carry the risk of sudden death is fundamental. The choice of anesthetic agents is important to minimize episodes of tachydysrhythmias. Prevention is as important as treating dysrhythmias. Recognition of risk factors, adequate selection of drugs for each patient, and monitoring represent the most important steps in prevention. In patients at risk for prolonged QT, recent baseline ECG is important. Electrolytes should be monitored and corrected whenever necessary. Verification of renal and liver function is important in patients using medications that can cause dysrhythmias. Moreover, doses should be adjusted whenever necessary. Prolonged QT interval should be closely monitored by the anesthesiologist, as several drugs can potentially prolong it, and the interaction among them can be catastrophic. Supraventricular tachycardia responds to treatment with adenosine, while AF does not, although in both cases the frequency is controlled by beta-blockers or calcium channel blockers.