Cardiac Implantable Electronic Devices in Different Anatomical Types of Persistent Left Superior Vena Cava: A Case of Innovative Solution of Pacing

Abstract A male patient(pt)76y old hypertensive,smoker underwent a right vocal cord biopsy.At the end of that procedure he presented lightheadedness and fatigue,with junctional escapement rhythm at the mean ventricular rate of 45 bpm and marked sinus bradycardia unresponsive to therapy.He was transferred to the cardiology intensive care unit(ICU).ECG:no atrial activity with ventricular escapement rhythm at 40 bpm.Color Doppler CDE (CDE):mild uniform left ventricular hypertrophy,normal ventricular functionality with 60% LVEF,coronary sinus(CS) dilatation as persistence of left superior vena cava (PLSVC).Isoprenaline infusion was started.Evidence ECG monitoring of sporadic and symptomatic sinus pauses lasting up to 4600 msec.A pacemaker(PM)implant was indicated under ESC 2021 guidelines(GL).Phlebography was done in the cathlab which confirmed PLSVC draining into the CS and no anonymous vein connecting the right and left superior vena cava (LSVC) and right subclavian draining into the PLSVC was documented through right phlebography.In accordance with ESC GL,we implanted a leadless VVI PM.PLSVC is a congenital anomaly due to an abnormal CS development during early fetal life with an incidence ranging from 0.3% in the general population to 4.3%.In 8% of cases,it drains into the left atrium causing hemodynamic changes as a left–right shunt.In the vast majority of cases it drains into the CS and remains asymptomatic.The unexpected presence of a PLSVC can complicate PM implantation,increasing the procedure time or forcing the operator to reinitiate the procedure on the right if a right SVC is present.In our case,both venous accesses were abnormal.The pt was a candidate for PM implantation via PLSVC as already demonstrated in the literature but this approach would have used the only upper venous access available,impacting the feasibility of future upgrading procedures.An epicardial PM implantation could have been an alternative but this approach was considered anachronistic.We opted for the implantation of a leadless VVI PM.This is recommended by ESC GL in class IIB.Essential information that contributed to our decision was knowing that the pt was a caregiver of a bedridden relative and needed to carry heavy weights as soon as possible after discharge.This choice ensured our pt a minimally invasive implant with the same length of stay as a transvenous PM,low infection risk,and preserved only venous access,albeit abnormal,for potential future procedures.