Left ventricular endocardial pacing improves the clinical efficacy in a non-responder to cardiac resynchronization therapy: role of acute haemodynamic testing

Recently, emphasis has been shifted from patient selection to more optimal pacing sites in non-responders to cardiac resynchronization therapy (CRT). We present a patient who was a non-responder during both acute haemodynamic testing at implant as well as clinically thereafter. After first demonstrating acute haemodynamic improvement using LV d P /d tmax during a temporary left ventricular (LV) endocardial pacing setup, a permanent LV endocardial lead was transseptally implanted with substantial and persistent clinical improvement.