Combined Right Ventricular Dysfunction And Radial Dyssynchrony Predicts Response After Resynchronization Therapy

Background and ObjectiveEchocardiography plays an important role in the care of patients with chronic congestive heart failure treated with cardiac resynchronization therapy (CRT). In the past, a large number of clinical reports have utilized echocardiography before CRT implantation to assess abnormalities of mechanical activation, known as dyssynchrony, to potentially improve patient selection. Recently, right ventricular (RV) function is recognized as a cardinal prognostic marker in patients with heart failure. There is some smaller single-center studies show that RV function significantly affects response to CRT. Poor left ventricular (LV) reverse remodeling occurs after CRT in patients with heart failure having severe RV dysfunction at baseline. Little is known the relationships between RV function and left ventricular dyssynchrony. Whether RV dysfunction is associated with LV dyssynchrony in chronic congestive heart failure patients is still unclear. We sought to understand the relationships between RV contractility and LV dyssynchrony in chronic congestive heart failure patients by using speckle tracking image and echocardiography. To study the different of LV dyssynchrony between the normal RV function group and the RV dysfunction group.MethodsA total of72patients with congestive heart failure were analyzed by standard and two-dimensional strain echocardiography. Septal to posterior wall mechanical delay (SPWMD) obtained from2D radial strain, with a≥130ms threshold indicating LV dyssynchrony. RV function was evaluated using tricuspid annular plane systolic excursion (TAPSE), with a≤14mm threshold indicating severe RV impairment. Left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV) and ejection fraction (LVEF) were calculated from apical four-chamber views, according to the modified Simpson’s rule. RV end-diastolic area and RV end-systolic area were calculated from the apical four-chamber view, and the calculation of RV fractional area change used to determine global RV systolic function. ResultsOf72patients (mean age,59±12years),45(62.5%) were males and27(37.5%) were females. The etiology of heart failure was primarily ischemic (25%). Significant RV dysfunction was observed in22(30.56%) individuals and46(63.90%) patients showed LV dyssynchrony. Patients with RV dysfunction had.lower RFAC, TAPSE (P<0.001) and higher LVESV, LVEF (P<0.05) than those with normal RV function. Patients with RV dysfunction had no more LV dyssynchrony compared to those with preserved RV function (P=0.658). In the overall population,8had low TAPSE (≤14mm) and normal SPWMD,32had normal TAPSE and high SPWMD (≥130ms). TAPSE had no correlation with SPWMD (r=0.136, P=0.255).ConclusionRV function and LV dyssynchrony are not associated. Quantitative analysis of RV function is as important as assessing LV dyssynchrony in patients with congestive heart failure. Background and ObjectiveRandomized trials tell us that CRT can transform the lives of some patients with heart failure, improving cardiac function, symptoms, quality of life, morbidity and mortality. Recently, studies that used markers of right ventricular(RV) longitudinal axis function show that there is improvement in right ventricular function as a consequence of CRT, which is independent of the effect of CRT on left ventricular function. Studies found improvement in RV function at3-month follow-up independent of the cause of heart failure (ischemic vs. non-ischemic) or the severity of pulmonary hypertension at baseline. The improvement in RV function was independent of any RV reverse remodeling or decrease in pulmonary artery pressure; hence, RV function improvement was not attributable to changes in RV workload. However, little is known about there is improvement in RV systolic and diastolic function as an immediate consequence of CRT. The purpose of this research was to evaluate the early effects of cardiac resynchronization therapy (CRT) on right ventricular systolic and diastolic function using echocardiography and tissue Doppler imaging. Evaluate the different of right ventricular function before and after CRT between responders and non-responders.MethodsForty-four consecutive heart failure patients underwent echo examination at baseline, one week, and6months after CRT. RV function was assessed by RV Fractional area change (RFAC), tricuspid annulus plane systolic Excursion (TAPSE), and velocity (Vsr), tricuspid E/E’, RV myocardial performance index (RV-MPI). Clinical parameters and left ventricular volumes were also observed. Left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV) and ejection fraction (LVEF) were calculated from apical four-chamber views, according to the modified Simpson’s rule. CRT responders were defined as those with≥15%decrease in LV end-systolic volume at6months.ResultsOf44patients (mean age,61±10years),31(70.5%) were males and13(29.5%) were females. The etiology of heart failure was primarily ischemic (29.5%).29(66%) were CRT responders which were defined as those with>15%decrease in LV end-systolic volume at6months,15(34%) were non-responders. Compare to the responders, non-responders had lower baseline RV systolic and diastolic function, such as lower RFAC, TAPSE, Vsr and higher E/E’(P<0.05). Within one week of CRT, there was an early improvement in LV function as demonstrated by an increase in LVEDV, LVESV and LVEF (P<0.05) in responders, but not in non-responders. Within one week of CRT, there was an early improvement in RV function as demonstrated by an increase in RFAC and TAPSE and Vsr, and a decrease in RV-E/E’ and RV-MPI(P<0.05) in all subjects. Responders, compared with non-responders, were more likely to have slightly higher improvement in RV systolic and diastolic function.ConclusionCompare to the responders, non-responders had lower baseline RV systolic and diastolic function. RV systolic and diastolic function improved not only in responders, but also in non-responders after CRT. It showed more improvement in RV systolic and diastolic function in responders compared with non-responders. Background and ObjectivesCardiac resynchronization therapy (CRT) has been proven unequivocally beneficial for patients with advanced chronic heart failure with prolonged QRS complexes. Despite enthusiasm of giving this therapy to patients who fulfilled the current recommendation, nonresponse was observed in about one-third of patients who may not show clinical or left ventricular(LV) reverse remodeling response.Numerous recent published reports have utilized echocardiographic techniques to potentially aide in patient selection for CRT prior to implantation. However, no ideal approach has yet been found. Different echocardiography-based imaging modalities have been used to assess this intraventricular dyssynchrony. However, all approaches for assessing intra-LV dyssynchrony have individually given disappointing results, especially in the PROSPECT study. Recently, right ventricular (RV) function is recognized as a cardinal prognostic marker in patients with heart failure. The purpose of this study was to test the hypothesis that a combined echocardiographic assessment of RV dysfunction and LV radial dyssynchrony by speckle-tracking strain may predict response to CRT.MethodsWe studied60heart failure patients before and6months after CRT. Septal to posterior wall mechanical delay (SPWMD) obtained from speckle-tracking radial strain, with a>130ms threshold indicating LV dyssynchrony. RV dysfunction was assessed by M-mode for tricuspid annulus plane systolic Excursion (TAPSE), and severe RV dysfunction was defined as TAPSE<14mm. CRT responders were defined as those with>15%decrease in LV end-systolic volume at6months. The combined approach for the whole group, using a SPWMD>130ms radial strain cut-off and TAPSE>14mm RV function cut-off, named Both-responder. Others named Both-nonresponder. Receiver operating characteristic (ROC) curves were constructed first for LV dyssynchrony and RV dysfunction individually to determine optimal sensitivities and specificities and then for the combined approach with areas under the ROC curves initially compared by logistic regression analysis.ResultsOf60patients (mean age,60.2±9.3years),34were males and26were females. The etiology of HF was primarily ischemic (25%).39(65%) were CRT responders which were defined as those with≥15%decrease in LV end-systolic volume at6months,21(35%) were non-responders。 The responder and nonresponder groups were similar with respect to age, gender distribution and the etiology of heart failure(P>0.05). Compare to the responders, non-responders had lager LVEDV, LVESV, slightly LV dyssynchrony and lower baseline RV systolic function (P<0.05). SPWMD is relatively valuable in predicting CRT responders(AUC=0.676, P=0.026; SPWMD>130ms has the relatively high sensitivity of92.3%and low specificity of42.9%), TAPSE is also relatively valuable in predicting CRT responders(AUC=0.749, P=0.002; TAPSE≤14mm has the relatively high sensitivity of97.4%and low specificity of52.4%), Combined RV dysfunction and LV radial dyssynchrony predicted CRT response with89.7%sensitivity and76.2%specificity, which was significantly better than either technique alone (AUC=0.842, P<0.001).ConclusionsCombined RV dysfunction and LV radial dyssynchrony permits accurate echo prediction of response to CRT. To predict reverse remodeling after CRT, it should analysis RV dysfunction as well as LV radial dyssynchrony.