Imaging to improve the results of cardiac resynchronization therapy

摘要

So far, the indication for CRT is based on ECG criteria with QRS width >=120 ms. Reliable measure of mechanical dyssynchrony is expected to improve selection of appropriate candidates [2]. In this respect, a myriad of echocardiographic techniques have been suggested to accomplish this task [5]. Their detailed analysis is beyond the scope of this review.They include conventional blood-derived Doppler parameters, such as the difference of pre-ejection periods of aortic and pulmonary outflow, delay between septal and posterior wall motion assessed by M-mode echocardio-graphy, and various techniques of Tissue Doppler Imaging [5].