An 85 year old man with non-ischaemic dilated cardiomyopathy, severe left ventricular systolic dysfunction and severe symptoms of heart failure was referred for Cardiac Resynchronisation Therapy (CRT). His resting 12 lead ECG revealed atrial fibrillation with a bradycardic ventricular response despite no rate limiting agents, and a left bundle branch block with the QRS duration of 156 ms.

Positioning of the right ventricular lead (St. Jude Optisense 1999 52cm) was straightforward via a left infraclavicular approach. Accessing the Coronary Sinus (CS) to implant the left ventricular lead was difficult due to repeated cannulation of a small parallel tributary (Figure 1 image A). Retrograde contrast venography using this vein revealed a large CS with a tight proximal stenosis, and a small persistent left sided superior vena cava (PLSVC) (Figure 1 images B and C). Access to the PLSVC was gained using a hyperacute sub-selection catheter (Medtronic Attain Select II), and a hydrophilic coated guidewire (Terumo Glidewire) was passed into the coronary sinus. The PLSV was engaged with a steerable sheath (Medtronic Attain Command system) to provide support for the sub-selection catheter which was advanced into the coronary sinus (Figure 1 image D). Antegrade venography revealed a high lateral vein, with a retrograde junction to the main CS (Figure 1 image E). The Left Ventricular (LV) lead (St Jude Quick Flex micro 1258 88cm) was successfully passed into a satisfactory position (Figure 1 image F). Lead thresholds and positions were stable at 24 hour post procedural device interrogation (Figure 2).

Figure 1: Venography
Image A: Venography of a small lateral tributary to the main coronary sinus
Image B: Retrograde venography via the small lateral tributary suggesting the coronary sinus stenosis
Image C: Retrograde venography revealing Persistent Left Sided Superior Vena Cava (PLSVC)
Image D: Antegrade catheterisation of the PLSVC with the steerable guide sheath and a sub-selection sheath
Image E: Antegrade venography revealing a suitable high lateral vein
Image F: Final stable lead position (before removal of the sub-selection sheath).

Figure 2: Post procedure chest radiograph showing the two pacing leads in adequate positions.

This case describes how standard sheath and catheter shapes used imaginatively can overcome difficult anatomy. A PLSVC is estimated to occur in 0.3% of individuals without congenital abnormalities. It is the most common venous cardiac abnormality, and is most often identified incidentally during pacemaker implantation [1]. Due to increased flow, the CS in patients with a PLSCV is often large, usually making cannulation for LV lead placement during cardiac resynchronisation therapy easy, but achieving a stable lead position more difficult. Our case demonstrates the benefit of doing a complete venogram during CRT implantation and that even a vestigial PLSCV can be used to access the CS for LV lead placement [2,3].