Implantation Techniques of Leads for Left Ventricular Pacing in Cardiac Resynchronization Therapy and Electrocardiographic Consequences of the Stimulation Site

The first descriptions of beneficial effects of left ventricular (LV) or simultaneous LV and right ventricular (RV) pacing were published more than 35 years ago (Vagnini et al.,1967; Tyers et al.,1970; Gibson et al.,1971). In 1994 Cazeau published the first successful cases of biventricular pacing in patients with severe congestive heart failure (CHF) and no conventional indication for cardiac pacing (Cazeau et al.,1994). At the same time Bakker and colleagues reported their experiences (Bakker et al.,2000), with epicardial LV pacing by thoracotomy. The transvenous approach via the coronary sinus (CS) tributaries was first published by Daubert in 1998 and was an important contribution in the application of cardiac resynchronization therapy (Daubert et al.,1998) (Fig 1). The transvenous approach has been more and more developed and has become the implantation technique of choice. CRT is recently categorized as class I level of evidence A in the European Society of Cardiology guidelines in patients with a dyssynchronous failing heart (Swedberg et al.,2005). In case of unsuccessful transvenous implantation, surgical LV lead placement can be achieved under direct visualization. Another approach for LV lead placement, when neither CS placement nor surgical options are available, is a trans-atrial septal puncture to pass the LV lead via the left atrium through the mitral valve and screw into the LV lateral wall (Leclercq et al.,1999; Jaïs et al.,1998; van Gelder et al.,2007), or by apical insertion of the LV lead (Kassaï et al.,2009).