| Both of the left ventricular inferior wall and the right ventricular (RV) lateral wall receive blood flow from the right coronary artery (RCA). As a result, RV involvements occurred commonly when RCA was the culprit. RV ischemic dysfunction is associated with increased morbidity and mortality of the inferior wall myocardial infarction patient. However, limited imaging techniques could effectively and efficiently detect the RV impairment.Recent advances in echocardiography with speckle-tracking imaging which have been widely used in evaluating left ventricular systolic function immediately and during follow-up provide revived expectations for assessment of the RV systolic function. Speckle-tracking technique is based on tracking the movements of myocardial speckles and is not geographic dependent. Recently, speckle-tracking imaging is also introduced to evaluate the RV function.Our study aimed to use speckle tracking right ventricular longitudinal strain parameters to assess the RV systolic function of the inferior wall myocardial infarction patients, exploring the feasibility and validity of the new methods. Furthermore, the RV function recovery and RV remodeling were estimated with primary discussion about the relative determinants. Part I Assessment of the right ventricular systolic function after inferior wall and right ventricular myocardial infarction by two-dimensional speckle tracking echocardiographyObjective To assess right ventricular (RV) systolic function in patients with acute right ventricular myocardial infarction (RVMI) in association with inferior myocardial infarction (INFMI) by applying 2-dimensional (2D) speckle tracking imaging (STI) longitudinal strain (LS) and strain rate (LSr) parameters.Methods 17 consecutive patients diagnosed with INFMI in association with RVMI were included in our study.21 INFMI patients without RVMI were also included to match the RVMI group. RVMI group and INFMI group were called acute myocardial infarction (AMI) group, all of them were diagnosed AMI the first time.24 chest pain patients admitted consecutively at the same time but with negative results in the selective coronary angiography were served as blank control. Echocardiography were performed within 48 hours. The RVLS parameters, whichinclude LS and LSr were then analyzed off line.Results The RV global LS (RVGLS), the LS of the basal and mid segments of the free wall and septum, the LSr of the basal and mid segments of the free wall were lower than control group in the AMI group (P<0.05). Compared to INFMI group, the RVGLS, the LS of the mid and apical segments of the free wall and the LSr of the mid segments of the septum were lower in the RVMI group (P<0.05). In the single parameter mode of ROC curve analysis, the diagnosis efficiency of RV free wall LS (RVFWLS) and RVGLS were higher than other parameters. The cut-off value of RVFWLS and RVGLS were-18.26% and -16.27% respectively (sensitivity were 100% and 100%, respectively, specificity were 65.5% and 72.4%, respectively).Conclusions The 2D-STI RVLS parameters precisely reflect the impaired RV systolic function in the INFMI and RVMI patients, the RV global systolic function are even worse when RVMI involved, mainly for the RV free wall. RVLS parameters are good predictors of RVMI which could provide more references for the early diagnosis and functional evaluation of RV in acute INFMI patients with RVMI.Part Ⅱ Evaluation of the short time prognosis of the right ventricular systolic function after percutaneous coronary intervention in patients with inferior wall and right ventricular myocardial infarctionObjective The aim of the study is to assess the short time recoveryof the right ventricular systolic function in inferior wall infarction patients with or without right ventricular (RV) myocardial infarction (MI) after percutaneous coronary intervention (PCI) by using 2-dimensionalspeckle tracking imaging (2D-STI) longitudinal strain (LS) parameters and to explore if combining RVMI is an factor that could influence the recovery of the right ventricle.Methods 22 consecutive patients diagnosed with inferior wall myocardial infarction (IWMI) and treated with percutaneous coronary intervention were included in our study. 10 of them were combined with right ventricular myocardial infarction (RVMI group), the rest were included in the INFMI group.24 chest pain patients admitted at the same time but with negative results in the selective coronary angiography were served as blank control. Echocardiography were performed at baseline and before discharged from the hospital (4.7±1.8 days). Right ventricular LS were then analyzed off line. Traditional echocardiographic parameters like right ventricular fractional area change (RVFAC), tricuspid annular plane systolic excursion (TAPSE) and tissue Doppler imaging derived mechanic performance index (TDI-MPI) were measured.Results For all of the patients, compared with control group at baseline, the RVFAC, TAPSE, right ventricular global longitudinal strain (RVGLS), most of the septal LS and all of the free wall LS were lower, furthermore RVFAC and TDI-MPI of the RVMI group were worse (P<0.05, respectively). Compared withcontrol group at discharge, theRVFAC, RVGLS andfree wall basal LS were lower in the myocardial infarction patients, the TAPSE, all of the septal LS and most of the free wall LS were lower in the RVMI group (P<0.05, respectively). Compared with baseline, the RVGLS, free wallLS, TAPSE and TDI-MPI of INFMI group were better at discharge (P<0.05,respectively), the RVGLS, free wall basal LS were higher in the RVMI group (P<0.05,respectively). The recovery trend of RVGLS, septal basal LS, free wall mean and mid LS and TDI-MPI were slower in the RVMI group than INFMI group (P<0.05,respectively).Conclusions The 2D-STI RVLS parameters precisely reflected the impaired RV systolic function and rapid recovery course in the INFMI and RVMI patients, however, the RV systolic function in RVMI group recovered slower than in INFMI group. The study demonstrated that RVLS parameters could provide earlier diagnostic and prognostic information of RV dysfunction in acute INFMI patients with and without RVMI. After successful PCI, right ventricular systolic function could recover rapidly in only few days.Part Ⅲ Evaluation of the right ventricular systolic function recovery and remodeling after percutaneous coronary intervention in patients with inferior wall and right ventricular myocardial infarctionObjective The aim of the study is to evaluate the recovery of the right ventricular systolic function and the remodeling of the right ventricle after percutaneous coronary intervention (PCI) in inferior wall infarction patients by using 2-dimensional speckle tracking imaging (2D-STI) longitudinal strain (LS) parameters and to explore the prevalence and determinants of the right ventricular remodeling.Methods 26 patients diagnosed with inferior wall myocardial infarction (IWMI) and treated with percutaneous coronary intervention were included in our study.11 of them were combined with right ventricular myocardial infarction (RVMI group), the rest were included in the INFMI group. Echocardiography were performed at baseline, before discharged from the hospital (4.7+1.8 days) and 3-6 months after discharged (4.6±1.8 months). Right ventricular 2D longitudinal strain (LS) and traditional parameters were then analyzed off line.RV remodeling was defined as an increase in RV end-diastolic area ≥20% from baseline to 6 months follow-up and patients were then divided into remodeling group and non-remodeling group.Results For the total patients, compared with baseline, the right ventricular global longitudinal strain (RVGLS), all of the free wall LS (FWLS), tricuspid annular plane systolic excursion (TAPSE) andtissue Doppler imaging derived mechanic performance index (TDI-MPI) were better at discharge, furthermore all of the septal LS and right ventricular fractional area change (RVFAC) at 3-6 months later were better (P<0.05, respectively). Compared with the values at discharge, theRVGLS, most of the FWLS and septal basal LS patients were higher at few months later (P<0.05, respectively).The recovery trends of the RVGLS, septal basal LS, most of the FWLS and TAPSE were slower than the INFMI group in the RVMI group (P<0.05, respectively).On admission, the TAPSE of the remodeling group were lower than the non-remodeling group (P<0.05). At discharge, the RVGLS, all of the septal LS and TAPSE were lower in the remodeling group (P<0.05, respectively).3-6months later, only the RV free wall mean and apicalLS were lower in the remodeling group (P< 0.05, respectively).Compared with the non-remodeling group, only the differences of the recovery trends of all the septal LS were significant (P<0.05, respectively), manifesting that these values in non-remodeling group recovered more rapidly than in the remodeling group.Conclusions The 2D-STI RVLS parameters precisely reflected the impaired RV systolic function in the INFMI, and appeared to be superior to traditional echocardiographic parameters for the risk stratification of the INFMI patients. Moreover, the recovery of the septum appeared to be associated with the right ventricular remodeling, the slower the septum recovered, the more the right ventricular prone to remodel. |
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