Endomyocardial delivery in the setting of active left ventricular assist device (LVAD) support has rarely been studied. The objective was to establish a protocol for endomyocardial injections during LVAD support without compromising mechanical circulation. LVAD implantation was performed in four pigs. A curved needle catheter was percutaneously inserted into the right carotid artery and positioned into the left ventricle under fluoroscopic guidance. In the setting of increasing LVAD flows (2.3-3.1 l/min), percutaneous methylene blue dye administration into the myocardium proceeded without complications in all pigs. Transection of excised hearts revealed an anterior, lateral, inferior, and septal wall distribution of methylene blue documenting injections in all four regions of the left ventricle. Ex vivo, the catheter could be maneuvered close to the LVAD inflow cannula despite augmentation of LVAD flow up to 5 l/min. Endomyocardial injections during LVAD support was found to be feasible and safe with the curved needle catheter.