Fig 1; certain persistent left superior vena cava anatomic
variations: a. Typical venous drainage into the right atrium.b. Persistent left superior vena cava and its tributaries
draining into the coronary sinus. c. Persistent left superior
vena cava draining into the left atrium by means of an
unroofed coronary sinus. d. Persistent left superior vena cava
draining into the coronary sinus and also connected to the right
superior vena cava by an innominate vein. e. Persistent left
superior vena cava with an absent right superior vena cava[11]
PLSVC typically drains into the right atrium (RA) via the coronary sinus
(CS), which can become enlarged due to volume overload [12 ].
This enlarged CS can complicate mapping and ablation procedures of
supraventricular tachyarrhythmias (SVA) arising from the CS ostia, the
triangle of Koch [13 ] and mitral annulus.
Also, excessive motion of a CS mapping catheter has been shown to
preclude accurate electrogram localization
[14 ]. Thus, the
presence of PLSVC can impact the evaluation and treatment of SVAs
[15 ].
In AVRT, a CS electrode catheter cannot be used for guidance during
ablation of the left-sided accessory pathway and may not allow for a
stable electrode position at an endocardial target site
[16,17 ].
Despite these difficulties, successful catheter ablation of AVNRT and
AVRT was performed in previous case reports. Therefore, catheter
ablation can be a reasonable method in the treatment of AVNRT and AVRT
patients with PLSVC.