Troubleshooting the difficult left ventricular lead placement in cardiac resynchronization therapy: current status and future perspectives

Abstract

Introduction: Cardiac resynchronization therapy (CRT) is an important option in modern cardiac implantable electronic device (CIED) treatment. Techniques for left ventricular (LV) lead placement in the coronary sinus and its tributaries are neither well described nor studied systematically, despite attention regarding where to place the LV lead. Areas covered: This review presents specialized tools and techniques to overcome some of the most common problems encountered in LV lead placement in CRT. These tools and techniques are termed Interventional CRT (I-CRT), as they share technology with other interventional procedures. The main principle in I-CRT, compared to the traditional over-the-wire technique, is to add better support for delivery of the LV lead through dedicated inner catheters that also allows more flexibility with the use of more guidewires and better imaging with direct venography in the target vein. Expert opinion: Even though CRT is an established therapeutic option, there are still many challenges in the implementation of the therapy. The cornerstone should be an ease of delivering the CRT and specifically implantation of the LV lead. Therefore, knowledge of the principles in I-CRT is necessary, as I-CRT could make implantation simpler in general and easier to reach the optimal LV pacing site.

Is interventional technique better than the traditional over-the-wire method for left ventricular lead implantation in cardiac resynchronization therapy?

“… 1 CRT is based on the principles of biventricular pacing, which aims to correct electromechanical dyssynchrony of the ventricles by endocardial pacing of the right ventricle and epicardial pacing of the left ventricle (LV). 2 Epicardial pacing of the LV relies on placement of a pacing lead in one of the tributaries of the coronary sinus (CS). 2 , 3 Previous studies have shown that CRT improves heart failure symptoms, cardiac function, and reduces mortality.…”

“… 2 Epicardial pacing of the LV relies on placement of a pacing lead in one of the tributaries of the coronary sinus (CS). 2 , 3 Previous studies have shown that CRT improves heart failure symptoms, cardiac function, and reduces mortality. 1 , 4 , 5 Despite these findings, an estimated 30%–40% of patients receiving CRT do not respond to the treatment or even experience a clinical deterioration.…”

“…Several steps must be completed to achieve successful LVL placement, including localization and cannulation of the CS, creation of access to the target branch, and introduction of the LVL into the target branch. 2 , 12 , 13 Delivery and placement of the LVL represents the most challenging step in CRT and may cause several obstacles for the implanting physician, especially in cases with anatomic abnormalities or variations. 12 , 13 , 14 In 7.5%–10% of cases, LVL placement through the CS fails, possibly due to lack of operator experience in using traditional tools.…”

“… 12 , 13 , 14 In 7.5%–10% of cases, LVL placement through the CS fails, possibly due to lack of operator experience in using traditional tools. 2 …”

“…A new approach, interventional cardiac resynchronization therapy (I-CRT), integrates new methods for CS cannulation and LVL placement. 2 , 6 , 13 , 14 The I-CRT approach relies on a catheter-based system. This technique originally was invented by interventional cardiologists and radiologists.…”