539 GOING BEYOND CRT NON-RESPONSE: ECHO-GUIDED LEFT BUNDLE-BRANCH PACING


 We present the case of a 56-year-old man affected by heart failure (HF) with reduced ejection fraction (HFrEF) and permanent atrial fibrillation, who previously underwent a CRT-D implant with left ventricular stimulation delivered by an epicardial pacing lead due to an unfavourable CS anatomy. We upgraded this system to left bundle branch pacing. The LBB lead was connected to the atrial plug in of the device in order to deliver multisite left ventricular pacing. The device was programmed in DDDR mode and the delay between the two LV pacing sites was chosen (modifying atrioventricular delay) after multimodality assessment (both electrocardiographic and echocardiographic) to obtain the best resynchronization and systolic performance.