Left ventricular endocardial pacing in cardiac resynchronisation therapy: Moving from bench to bedside

Abstract

In cardiac resynchronisation therapy, failure to implant a left ventricular lead in a coronary sinus branch has been reported in up to 10% of cases. Although surgical insertion of epicardial leads is considered the standard alternative, this is not without morbidity and technical limitations. Endocardial left ventricular pacing can be an alternative as it has been associated with a favourable acute haemodynamic response compared with epicardial pacing in both animal and human studies. In this paper, we discuss left ventricular endocardial pacing and compare it with epicardial surgical implantation. Ease of application and procedural complications and morbidity compare favourably with epicardial surgical techniques. However, with limited experience, the most important concern is the still unknown long-term risk of thromboembolic complications. Therefore, for now endovascular implants should remain reserved for severely symptomatic heart failure patients and patients at high surgical risk of failed coronary sinus implantation.

Fig. 1

Atrial septal puncture by a superior approach with radiofrequency and introduction of the lead superiorly. a The assemblage of the deflectable sheath, the Attain Select II sheath and dilator positioned against the fossa ovalis with the guidewire just protruding from the dilator. b On intracardiac echocardiography, the tenting (solid arrow) of the inter-atrial septum by the sheaths (dashed arrow) is shown. c The Attain Select II with the dilator (dashed arrow) is advanced over the guidewire towards the left ventricle. The deflectable sheath (solid arrow) remains at the right atrial surface of the septum. d Final position of the Select Secure lead with the Attain Select catheter withdrawn in the steerable guiding catheter at the right side of the septum. See text for full discussion

Fig. 2

Transfemoral introduction of the lead with transvenous tunnelling towards the generator pocket. a The Mullins sheath (solid arrow) has passed the septum and the Attain Select guiding system (long dashed arrow) has been directed over a guidewire into the left ventricle. The tip of the Attain Select is rotated towards the basal posterolateral wall of the left ventricle. The Select Secure lead (short dashed arrow) is positioned against the myocardium. b The stiff guidewire (solid arrow), introduced via the Mullins sheath towards the superior vena cava, is captured by a snare (dashed arrow), which was introduced via the subclavian vein. c The lead secured into the angiocatheter is introduced into the 12 F sheath that emerges retrogradely from the femoral vein through the same puncture site as the previously introduced lead. d The 12F sheath (solid arrow) and the angiocatheter (long dashed arrow) with the Select Secure lead (short dashed arrow) are pulled back through the venous system. The tip of the sheath is still in the vena cava inferior, but the lead has already been pulled into the vein

Fig. 3

Transapical surgical insertion of a left ventricular endocardial lead. a The Select Secure guiding system is introduced through the LV apex and bleeding controlled by tightening the purse string around it. b The Select Secure lead is introduced into the guiding system, which can be deflected by turning the knob. c The Select Secure lead is implanted, the sheath withdrawn before splitting, and the pursue string fortified with additional pledge material tightened around the puncture site. d X-ray of final position of the lead. The solid arrow indicates the exit site of the lead from the left ventricle, the dashed arrow the anchoring site of the lead at the ribcage