A critical comparison of echocardiographic measurements used for optimizing cardiac resynchronization therapy: stroke distance is best

Abstract

AimsDyssynchrony assessment in cardiac resynchronization therapy (CRT) is controversial, and there are no standard protocols for optimizing treatment. We studied the feasibility and reproducibility of several echocardiographic measures to optimize CRT pacemaker settings. We also assessed the utility of 'stroke distance' [left ventricular outflow tract velocity-time integral (LVOT VTI)] in performing this function. Methods and resultsThirty patients underwent the following functional assessments; 6 min walk test distance, peak VO 2 consumption on cardiopulmonary exercise testing (VO 2 peak), quality-of-life scoring, and echocardiography; before and at 3 and 6 months after implantation of the CRT device. At 3 months, patients received LVOT VTI-guided optimization of interventricular (VV) and atrioventricular (AV) delays. The feasibility and reproducibility of each optimization measurement was statistically analysed, and the functional benefits of optimization examined. Left ventricular outflow tract VTI, interventricular mechanical delay (IVMD), and tissue Doppler lateral-septal delay showed good feasibility (.90%), whereas LVOT VTI, IVMD, and the 12-segment tissue Doppler dyssynchrony index showed good reproducibility (coefficient of variation ,20%). The most feasible and reproducible measure was LVOT VTI. Our optimization protocol necessitated alteration of AV and/or VV delays in 60% of patients at 3 months and was associated with a 50% improvement in functional responder status between 3 and 6 months. ConclusionLeft ventricular outflow tract VTI provides us with a single, direct measure of global LV function which is robust, and easily applicable in routine clinical practice, and which is effective at improving response to CRT.--

Echocardiography versus intracardiac electrocardiography-based optimization for cardiac resynchronization therapy

“…Although there are sparse and conflicting data on the long-term effect of echoguided AV and VV delay optimization echocardiography remains the most frequently used method for tailoring CRT in clinical practice [5,31]. Thus new methods like the IEGM-based algorithm remains to be compared against this standard, not only with respect to acute hemodynamic effects but also with respect to long-term outcome.…”

Optimizing the Atrioventricular Delay in Dual Chamber Pacemakers; Is It Worth?

“…Several studies from single centers have shown improvement in cardiac output by echo Doppler-guided AVD optimization [11][12][13]. Doppler parameters used for echoguided optimization include aortic VTI [14,15]; diastolic mitral flow pattern by Ritter's method [16]; iterative method [17]; diastolic filling time [13]; VTI of mitral inflow [18]; Dopplerderived dP/dt [7]; tissue Doppler imaging [11,12]; LV and right ventricular (RV) pre-ejection delays; and myocardial performance index [19].…”

Impact of Echocardiographic Optimization of Resynchronization Pace-Maker Using Different Pacing Modalities and Atrioventricular Delays on Acute Hemodynamic Response and Long Term Prognosis

“…Measurement of stroke volume derived from the left ventricular outflow tract velocity-time integral (VTI) of left ventricular outflow tract (LVOT VTI) has been proposed for optimizing both AV and VV delays [32]. On Figure 3 is echocardiographic presentation of AV optimization and on Figure 4 is shown echocardiographic presentation of VV optimization.…”