Apical Rocking and cardiomyopathy

Current attempts of improving patient selection in cardiac resynchronization therapy (CRT) are mainly based onechocardiographic timing of myocardial velocity peaks. Regional myocardial function is neglected. Apical transversemotion (ATM) is a new parameter to quantify apical rocking as an integrative surrogate of both temporal and functionalinhomogeneities within the left ventricle. In this study, we tested the predictive value of apical rocking forresponse to CRT.Methodsand resultsSixty-nine patients eligible for CRT were assessed by echocardiography before and 11+5 months after pacemakerimplantation. Response was defined as left ventricular (LV) end-systolic volume decrease .15%. Rocking was quantified(ATM) and visually assessed by four blinded readers. Predictive value for CRT response of both assessmentswas compared with conventional dyssynchrony parameters. ATM in the four-chamber view plane differentiatedbest between responders and non-responders (2.2+1.5 vs. 0.06+1.9 mm, P , 0.0001). Quantified ATM predictedreverse remodelling with a sensitivity, specificity, and accuracy of 75, 96, and 83% whereas visual rocking assessmentresulted in 89, 75, and 83%, respectively. The accuracy of conventional parameters was significantly lower.Conclusion Apical rocking is a new marker to assess LV dyssynchrony and predict CRT response. It is superior to conventionalparameters. Even its simple visual assessment may be sufficiently accurate in the clinical setting.- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Acut-off of 1.5 mm distinguished between responders and nonresponderswith a sensitivity, specificity, and accuracy of 75, 96,and 83%, respectively (Figure 2A).

Contradicting reports have been published regarding the relation between a dobutamine-induced increase in eithercardiac dyssynchrony or left-ventricular ejection fraction (LVEF) and the response to cardiac resynchronizationtherapy (CRT). Using apical rocking (ApRock) as surrogate dyssynchrony parameter, we investigated the dobutaminestress echocardiography (DSE)-induced changes in left-ventricular (LV) dyssynchrony and LVEF and their potentialpathophysiological interdependence.Methodsand resultsFifty-eight guideline-selected CRT candidates were prospectively enrolled for low-dose DSE. Dyssynchrony was quantifiedby the amplitude of ApRock. An LVEF increase during stress of .5% was regarded significant. Scar burden wasassessed by magnetic resonance imaging. Mean follow-up after CRT implantation was 41+13 months for the occurrenceof cardiac death. ApRock during DSE predicted CRT response (AUC 0.88, 95% CI 0.77–0.99, P , 0.001) and correlatedinversely with changes in EF (r 1/4 20.6, P , 0.001). Left-ventricular ejection fraction changes duringDSEwere notassociated with CRT response (P 1/4 0.082). Linear regression analysis revealed an inverse association of LVEF changesduring DSE with both, total scar burden (B 1/4 22.67, 95CI 23.77 to 21.56, P , 0.001) and the DSE-induced changein ApRock amplitude (B 1/4 21.23, 95% CI 21.53 to 20.94, P , 0.001). Kaplan–Meier analysis revealed that DSEinducedincrease in ApRock, but not LVEF, was associated with improved long-term survival.Conclusion During low-dose DSE in CRT candidates with baseline dyssynchrony, myocardial contractile reserve predominantlyresults in more dyssynchrony, but less in an increase in LVEF. Dyssynchrony at baseline and its dobutamine-inducedchanges are predictive of both response and long-term survival following CRT.

1,5 mm !!

Current imaging techniques attempt to identify responders to cardiac resynchronization therapy (CRT). However,because CRT response may depend upon several factors, it may be clinically more useful to identify patients forwhom CRT would not be beneficial even under optimal conditions. We aimed to determine the negative predictivevalue of a composite echocardiographic index evaluating atrial-ventricular dyssynchrony (AV-DYS) and intraventriculardyssynchrony.Methodsand resultsSubjects with standard indications for CRT underwent echo before and during the month following device implantation.AV-DYS was defined as a percentage of left ventricular (LV) filling time over the cardiac cycle. AV-DYS, whichproduces a characteristic rocking of the LV apex, was quantified as the percentage of the cardiac cycle over whichtissue Doppler-derived displacement curves of the septal and lateral walls showed discordance. CRT responderstatus was determined based on the early haemodynamic response to CRT (intra-individual improvement .25%in the Doppler-derived LV dP/dt).Among 40 patients, optimal cut-points predicting CRT response were 31% for LV apical rocking and 39% forAV-DYS. The presence of either apical rocking .31% or AV-DYS ≤39% had a sensitivity of 95%, specificity of80%, positive predictive value of 83%, and a negative predictive value of 94% for CRT response.Conclusion After pre-selection of candidates for CRT by QRS duration, application of a simple composite echocardiographicindex may exclude patients who would be non-responders to CRT and thus improve the global rate of therapy

Normal apical kinetics

% de temps en oppositionCutt of à 31% du RR

%Avdystemps diastolique/RR *100

% Ap rocking>31% % Av dys <36%