Fig. 1
From: ECG optimisation for CRT systems in the era of automatic algorithms: a comprehensive review
Left ventricle capture confirmation by “EffectivCRT” algorithm. Dedicated unipolar LV EGM (LV cathode–RV coil EGM) during biventricular or LV pacing; until the third paced beat a “Qr” morphology indicate the effective LV capture; the fourth beat represent a kind of fusion and the further beats are represented by an “rS” morphology indicating the loss of LV capture. (with permission by Medtronic). LV left ventricle; RV right ventricle; Y LV effective OK; N loss of LV effective capture; AS atrial sense; Ab atrial blanking; VS ventricular