Wagner_Marriot's Practical Electrocardiography, 12e

ABLATION OF ACCESSORY PATHWAYS

I

II

III

aVR aVL aVF V1

V2

V3

V4

V5

V6

A

I

II

III

aVR aVL aVF V1

V2 V3 V4

V5 V6

B

F I G U R E 7 . 1 1 .

Radiofrequency ablation of bundle of Kent. A. Before the procedure ( arrows,

delta waves). B. After the procedure ( arrows , normal QRS complex).

aVL

V3

I

II

III

aVR

aVF V1

V2

V4 V5

V6

A

I

II

III

aVR aVL aVF V1 V2

V3

V4 V5

V6

B

F I G U R E 7 . 1 2 .

Radiofrequency ablation of bundle of Kent. A. Before the procedure ( arrows,

delta waves). B. After the procedure ( arrows , normal QRS complex).

Ablation may be performed by surgical dissection or by percutaneous catheter tech- niques, in conjunction with a diagnostic electrophysiology test in localizing the accessory pathway. Figures 7.11A and 7.12A illustrate the typical ECG appearances of preexcitation of the right ventricular free wall and the interventricular septum, respectively. Successful ablation of the accessory pathways (see Figs. 7.11B and 7.12B) revealed the underlying presence of normal QRS complexes.

162

SECTION II: Abnormal Wave Morphology