Clinical case 1: Wide to narrow QRS complex tachycardia: what is the mechanism?
Mastering Supraventricular Tachycardia Diagnostics in the Electrophysiology Lab, Elsevier, ss.167-169, 2026
- Yayın Türü: Kitapta Bölüm / Araştırma Kitabı
- Basım Tarihi: 2026
- Doi Numarası: 10.1016/b978-0-443-36430-3.00001-1
- Yayınevi: Elsevier
- Sayfa Sayıları: ss.167-169
- Anahtar Kelimeler: aberrancy, atrioventricular nodal reentrant tachycardia, functional bundle branch block, supraventricular tachycardia, tachycardia diagnostics, Wide complex tachycardia
- Dokuz Eylül Üniversitesi Adresli: Evet
Özet
A patient with documented tachycardia underwent diagnostic evaluation during an electrophysiology study (EPS). Critical observations after delivering a His-refractory premature ventricular contraction (PVC) during LBBB tachycardia guided the diagnostic pathway, effectively eliminating the possibilities of ventricular tachycardia, orthodromic reciprocating tachycardia with accessory pathway (AP), and atrial tachycardia (AT) while highlighting atrioventricular nodal reentrant tachycardia (AVNRT) as the most likely mechanism. Conversion of wide QRS tachycardia (LBBB) to narrow QRS tachycardia without altering tachycardia cycle length or atrial activation sequence strongly favored functional aberration unrelated to the circuit. Furthermore, the absence of cycle length (CL) variation during aberration excluded AP involvement. The evidence converged toward typical slow-fast AVNRT, supported by entrainment and premature ventricular contraction maneuvers pinpointing its mechanism. This chapter underscores the diagnostic value of specific maneuvers like His-refractory PVC in electrophysiologic studies to delineate complex tachycardia mechanisms, emphasizing precision and systematic exclusion in arrhythmic evaluation.