Rare supraventricular tachycardias

Rare supraventricular tachycardias 

Rare supraventricular tachycardias: Pulmonary vein tachycardia has positive P waves in V2 to V6 as the atrial activation starts posteriorly and moves towards the recording electrodes. Tachycardia originating from the right atrial appendage may have negative P waves in chest leads. Tachycardiomyopathy in a four year old child induced by right atrial appendage tachycardia has been reported in Indian Pacing and Electrophysiology Journal by Deep Chandh Raja, Sabari Saravanan, Anitha G Sathishkumar and Ulhas M Pandurangi [1]. Successful radiofrequency ablation was done using 3-D electroanatomical mapping and fluoroscopy was used sparingly. Left ventricular function returned to normal. Refractory cases may need surgical removal of right atrial appendage.

Atrial fibrillation is extremely rare in a new born because it needs a larger atrium for maintenance. If atrial fibrillation is seen in a newborn, it indicates atrial enlargement as in ventricular dysfunction and could be due to conditions like anomalous left coronary artery from the pulmonary artery (ALCAPA).

On the contrary, atrioventricular reentrant tachycardia (AVRT) is quite likely in newborns as accessory pathways are congenitally present. In fact many of them disappear later on due to apoptosis. Accessory pathways are just modified strands of atrial musculature connecting the atria and ventricles electrically across the mitral or tricuspid annulus, which acts as an electrical barrier for direct transmission of impulses from the atria to the ventricles.

Reference

  1. Deep Chandh Raja, Sabari Saravanan, Anitha G Sathishkumar, Ulhas M Pandurangi. Right atrial appendage tachycardia: A rare cause of tachycardia induced cardiomyopathy in a 4-year-old child. Indian Pacing Electrophysiol J. Sep-Oct 2018;18(5):176-179.