Conduction System Pacing in a Patient with Persistent Left Superior Vena Cava: A Case Report

Background: Anomalies of the thoracic venous system are usually discovered incidentally, but they become clinically relevant in patients requiring cardiac device implantation. This is especially important when cardiac physiologic pacing (CPP) (conduction-system-pacing or cardiac resynchronization therapy) is required.
  

Case summary: We report a case of a persistent left superior vena cava, in a patient with paroxysmal atrial fibrillation and reduced ejection fraction in combination with a trifascicular block (left anterior hemiblock, right bundle branch block, AV Block I°, 208 ms) And symptomatic bradycardia.

Discussion: Cardiac asynchrony represents a crucial pathophysiological point in the development and progression of heart failure, especially when bradycardia is also present. Therefore, physiologic pacing and resynchronization is important when pacing these patients. However, not all patients qualify for standard CRT. CSP as an alternative CPP option emerges as a therapeutic and effective option for these patients. HRS and ESC/EHRA guidelines and consensus documents are emphasizing this technique.

The persistence of a left superior vena cava predisposes to arrhythmias such as atrioventricular blocks as well as the development of atrial fibrillation. This anomaly presents an added challenge for a patient with indications for the implantation of a CSP or CRT system.

We present the case of a patient with persistent  left superior vena cava and the indication for a physiological pacing system.

The existing tools and sheath are designed to implant leads from left-pectoral access and a vena cava superior. In this case we used a standard CSP 3D sheath and standard pacing-lead to access the  right ventricle and perform left-bundle branch pacing. This demonstrates the opportunity to treat patient with a persistent superior vena cava guideline directed with a cardiac physiologic pacing system.

 
Image 1:

Advancement of a 3D lead delivery system (Biotronik Selectra 3D, 55) sheath into the right ventricle over a guide wire in AP view

RV angiography in LAO 30° views showing the approach to the high septal area, followed by the placement of the RV lead through the sheath after appropriate preparation




Final image showing the RA and LV electrodes in RAO 20° view