Cardiac Strains for Optimization of CRT in Non-Responders

"The previously implanted, ineffective CRT-D is reprogrammed under supervision of Trans-Thoracic Echocardiography (TTE) to:~1. adjust the atrioventricular interval so that E and A waves do not overlap~2. the interventricular interval is subsequently optimized to yield maximum improvement of the sum of longitudinal+radial+circumferential strains."

"This intervention relates to the determination of strains and atrioventricular interval and supplies data for reprogramming the ineffective CRT-D~Transthoracic echocardiography performed to determine the left ventricular ejection fraction as an outcome measure is not considered intervention here (as it is also performed in the control group and that would cause an error cross-referencing."