Although AET may resolve spontaneously, the majority of patients require therapy, especially if a cardiomyopathy has resulted. Diagnosis of this arrhythmia is important because chronic AET at rates greater than 125 beats/min may lead to ventricular dysfunction (tachycardia-induced cardiomyopathy). In those cases the rhythm is typically named a focal atrial tachycardia. 35,36 A presumed microreentrant mechanism can be the cause in a smaller proportion of these tachycardias. The majority of cases are due to abnormal automaticity. As in sinus tachycardia, the P wave is usually temporally nearer to the succeeding (not the preceding) QRS, making this a long R-P tachycardia. Idriss MD, PhD, in Critical Heart Disease in Infants and Children (Third Edition), 2019 Atrial Ectopic Tachycardia.ĪET is a regular narrow QRS complex tachycardia with an abnormal P-wave morphology. In very rare cases, mechanical support using extracorporeal membrane oxygenation (ECMO) is required to support the circulation until the tachycardia can be controlled. Cardiac catheterization and radiofrequency ablation (RFA) are very high-risk procedures in neonates and are typically not performed except in extreme cases of medically refractory atrial tachycardia with depressed function. The majority of neonatal AETs resolve spontaneously in the first 6 months of life, and long-term therapy is rarely necessary. Treatment of atrial ectopic tachycardia may be attempted with medications such as beta blockers (propranolol), sodium channel blockers (flecainide), or class III antiarrhythmic medications (sotalol, amiodarone). Electrolyte disturbances are a very rare cause of AET in neonates but should be corrected if present. Therefore, an echocardiogram is usually part of the initial evaluation in the newborn period to evaluate function and rule out congenital heart disease with a dilated atrium as the cause of the atrial tachycardia. Rapid, incessant AET can negatively affect ventricular function because of the heart's inability to “rest” or slow down. A chest radiograph to visualize line position should be performed to ensure that the cause of the tachycardia is not line related before initiation of treatment.Įvaluation of an atrial tachycardia involves an ECG and Holter monitoring. One differential clue to the mechanism of this unique form of SVT is a very fast and irregular atrial tachycardia. This catheter then creates an atrial tachycardia by directly stimulating the atria. This is frequently seen in neonates who have an intravenous catheter with the tip located in the atrium. Occasionally, the focus may occur near the sinus node (i.e., right upper pulmonary vein or right atrial appendage), producing P-wave morphology similar to the one in sinus rhythm, so careful inspection of the P-wave morphology using a 12- or 15-lead ECG is warranted to look for subtle changes in P-wave morphology.Īlthough an abnormal focus of atrial tissue is the usual cause of atrial tachycardia, mechanical stimulation of the atria can also cause an atrial tachycardia. In AET, the activation of atria is different from that of normal sinus rhythm, resulting in a different P-wave morphology on the ECG. The abnormal focus can be located almost anywhere in the atrium, with common foci being along the crista terminalis in the right atrium or the pulmonary veins. The majority of neonates with AET also have frequent isolated PACs. Most AETs are paroxysmal in nature, resulting in little if any harm to the patient, but they may be incessant. This frequently involves rapid increases or decreases in heart rate over several beats rather than initiation or termination in a single beat. With an automatic focus, there are typically “warming up” and “cooling down” periods for the tachycardia. With this mechanism, there is abnormal firing of atrial tissue originating outside the sinus node. Atrial ectopic tachycardia is typically the result of an increased automaticity of atrial myocardium. When three or more consecutive PACs occur in an infant or neonate at a rate faster than 120 beats per minute, the term atrial ectopic tachycardia (AET) is used. Martin MBBS, FRACP, in Fanaroff and Martin's Neonatal-Perinatal Medicine, 2020 Atrial Ectopic Tachycardia
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |