Abstract
In spite of improvements in heart failure management and increasing utilization of cardiac resynchronization therapy (CRT), approximately 30–40% of CRT patients remain nonresponders and 50% or more are echocardiographic nonresponders (defined as less than 15% reduction in left ventricular end systolic volume post-CRT). Optimization guided by echocardiography has been studied as one of the methods to improve the nonresponder rate to CRT. Echo-guided biventricular (Biv) pacemaker optimization has been associated with improvement in acute cardiac hemodynamics and improvement in functional class. In this review, the authors discuss various methods to optimize Biv pacemaker by echocardiography, recent advances in pacemaker optimization and the limitations of echocardiography. The authors also demonstrate complex hemodynamic derangements in heart failure via multiple case examples highlighting the role of comprehensive echo Doppler in elucidating cardiac hemodynamics encountered in CRT nonresponders, as well as tailoring of Biv pacemaker optimization to the underlying physiologic derangement.
Financial & competing interests disclosure
TZ Naqvi serves as a consultant to St Jude Medical and has received research grants from Medtronic and St Jude Medical. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.
No writing assistance was utilized in the production of this manuscript.
Notes
AV: Atrioventricular; LV: Left ventricle; MR: Mitral regurgitation; PW: Pulsed wave; RV: Right ventricle; TDI: Tissue Doppler imaging.
LV: Left ventricle; PW: Pulsed wave; VTI: Velocity time integral.
AV: Atrioventricular; VV: Interventricular.