engleski

The role of echocardiography in surgical CRT device implantation and optimization of LV lead placement

Beside multiple clinical benefits, cardiac resynchronization therapy (CRT) is linked to 30% of non-responders, due to the underlying disease not being influenced by the electrical therapy, or suboptimal therapy delivery. In case of inadequate coronary veins anatomy or failed coronary sinus lead placement, mini-thoracotomy is advocated as an alternative approach. It is known that CRT induces acute changes in haemodynamics and that lead placement can influence the amount of response. While TEE is regularly used during valve surgery, little attention is paid to using echo guided CRT implantation and monitoring acute response of differential LV lead positioning. 10 patents (3F/7M, 54±14 years) referred for surgical CRT implantation via a mini-thoracotomy were analyzed. Intraoperative TEE including Doppler myocardial imaging data were acquired pre- and post-CRT device activation. The right atrial and ventricular leads were placed transvenously, the LV screw-in lead was positioned epicardially on the lateral wall via an anterolateral mini-thoracotomy. Selective LV lead pacing was performed on 4 sites (basal and apical anterior/posterior wall), analysing acute changes in LV dimensions, mechanics and haemodynamics. Optimisation criteria included the septal flash reduction, the decrease in end-systolic volume (LVESV) and the increase in dP/dt and EF. The septal flash was defined as an early inward and outward ventricular septal motion within the isovolumic contraction period, imaged by gray-scale or Tissue Doppler colour (anatomical) M-mode. dP/dt was measured from the mitral regurgitation CW Doppler traces. Reverse remodelling was defined as a reduction of LVESV ≥10%. Assessing the acute response to CRT was feasible in all patients. The LV pacing site with optimal response was the basal anterior wall (50% of pts), followed by the basal posterior (30% of pts), apical anterior and apical posterior wall (10% of pts each). Such LV lead positioning lead to a significant LVESV reduction (172±91 ml vs.136±75 ml, p=0.0003) and EF increase (22±9% vs. 32±8%, p=0.0001) immediately following pacemaker activation, with reverse LV remodelling and septal flash resolution occurring in all patients. A significant increase of post-implantation dP/dt was also noted in all patients (333.5±64.4 mmHg/s vs. 633.6±196.9 mmHg/s, p=0.001). Conclusion: Intraoperative echocardiography is a feasible tool which can be used to assess acute response to CRT and to guide optimal LV lead placement based on septal flash reduction and increase in dP/dt, leading to immediate LV reverse remodelling.

echocardiography; surgical CRT device implantation; optimization of LV lead placement

doi: 10.1093/ejechocard/jeq136