Objective: The persistence of a left superior vena cava
(LSVC) has been observed in 0.3% of the general population as
established by autopsy. In the adult population, it is an important
anatomic finding if a left superior approach to the heart is
considered. The aim of the study was to evaluate the prevalence of a
LSVC in patients undergoing pacemaker (PM) and
cardioverter-defibrillator (CD) implantation.
We observed the prevalence of LSVC during a 10-year period; each
patient undergoing PM or transvenous CD implantation received a left
cephalic/left subclavian venous approach to the heart. With this
technique, LSVC persistence is easily diagnosed during lead
Results: A total of 1,139 patients
consecutively underwent PM implantation during 10 years: 4 patients had
persistent LSCV (0.34%). Among 115 patients undergoing CD
implantation, 2 patients with LSVC (1.7%) were observed. Overall LSVC
persistence was found in 6 of 1,254 patients (0.47%). Two patients,
one of whom had no right superior vena cava (RSVC), received a
left-sided PM, whereas two other patients received right-sided devices.
Both CD patients received a left-sided active-can device: the first
patient with a right-sided lead tunneled to the left pectoral pocket,
as a result of poor catheter handling through the LSVC and coronary
sinus, and the second patient with a screw-in lead from LSVC. Long-term
follow-up of these patients (average ± SD, 41 ± 26 months)
revealed absence of lead dislodgment and appropriate device function
regardless of lead implantation site.
Persistence of LSVC in adults undergoing PM/CD implantation is similar
to that of the general population (0.47% in our study). The left-sided
implant can be achieved by stylet shaping and by use of active fixation
leads in most patients, with a reliable outcome at short term in
addition to appropriate device performance at follow-up. Assessment of
the RSVC is advisable when planning a right-sided implantation, since a
minority of patients lacks this vessel.