Bệnh viện trung ương Quân đội 108 Viện tim mạch Triệt phá đường dẫn truyền phụ vùng vách sóng RF (Ablation of Posteroseptal AP) Bs Phạm Trường Sơn Posteroseptal AP :Inferoseptal AP (inferior to the true septal) The most complex: Pyramid space, confluence of chamber - Superior: Central fibrous - Anterior:Ventricular septum - Posterior: left and Right Atria - TV is mm to MV: + right atrium- left Ventricle space (thin tissue: AP inside) + CS os: at the superior (ablation site) courses: Right to right, Right to left (common) Left to left, CS to left , CS to Diverticulum Ablated at: the MV ring , TV ring, inside CS ECG characteristic 1/ Negative delta waves in leads III, aVF (less common) positive delta waves in I and aVL 2/Retrograde P’ waves : - Negative in the leads II, III, aVF - Positive in AVR ,AVL 3/ Slow and decremental retrograde conduction: incessant tachycardia - Permanent junctional reciprocating tachycardia(PJRT) EP Studying: During AV reentrant tachycardia, the earliest atrial activation usually is recorded from + The ostium of the coronary sinus + The proximal coronary sinus within cm (those beyond 1–2 cm are considered as left free-wall pathways: leftsided endocardial approach) Functional left bundle branch block during tachycardia results in either no change or only a nominal prolongation of the VA interval (10 to 30 msec) - Functional right bundle branch block usually does not affect the VA interval Differentiation with SS-AVNRT (long VA time) - Advanced A during His refractoriness - Terminate tachy by PVC not conduct to A - Parahisian pacing: No change Stim to A - VA (V pacing and Tachy)< 85ms - VOD (PPI – CL)