Case Report: Wide-to-Narrow QRS Tachycardia in a 3-Month-Old Infant

Introduction: It is rare to find that wide QRS tachycardia automatically changes to narrow QRS tachycardia, and it is more difficult to clarify the mechanism.Case Report: A 3-month-old infant with recurrent paroxysmal supraventricular tachycardia underwent transesophageal cardiac electrophysiological examination. The wide QRS tachycardia was induced by atrial RS2 stimulation, and it soon changed to narrow QRS tachycardia automatically. By the accurate measurement of esophageal lead, it was found that the electrocardiogram changes completely conform to Coumel law. The mechanism of wide and narrow QRS tachycardia was orthodromic atrioventricular reentrant tachycardia with or without ipsilateral functional bundle branch block, and the accessory pathway was defined as the left free wall-concealed accessory pathway.Conclusion: Transesophageal cardiac electrophysiological examination can reveal some special electrophysiological phenomena, and its non-invasive nature is especially suitable for infants.

Left atrial ıntramural hematoma after radiofrequency catheter ablation of left lateral accessory pathway

We report a case of left atrial hematoma after ablation of left lateral concealed accessory pathway. A 46-year-old male patient experienced chest pain after radiofrequency ablation. Transthoracic echocardiography and computed tomography revealed the intramural mass consistent with hematoma in the left atrium. He was hemodynamically stable, and conservative approach was decided. Atrioventricular groove is a vulnerable part of left atrium, and ablation of left free wall accessory pathway may require targeting both atrial and ventricular surfaces of the mitral annulus. Avoidance of forceful catheter manipulation during the electrophysiological procedure is important for prevention of this complication. Optimal periprocedural anticoagulation might reduce the risk of procedure-related thromboembolic complications, but electrophysiologists should always pay attention to an intramural hematoma that may occur after radiofrequency catheter ablation.