Multivariate Analysis of Left Ventricular Mass Determinants in Adults

Echocardiographic left ventricular mass (LVM) estimates are strong predictors of subsequent mortality and cardiovascular events. It is known that blood pressure (BP), weight (WT), and age are significantly correlated with LVM. We hypothesized that stroke volume (SV) measured by Doppler echocardiography would also be correlated with LVM. Two hundred and thirteen patients referred for routine echocardiography had determination of LVM, cuff BP, and Doppler SV. Those with localized LV disease, valvular disease, or cor pulmonale were excluded. In both men and women, systolic BP (SBP) was more closely correlated with LVM than was diastolic blood pressure or mean arterial pressure, and SV was more closely correlated with LVM than cardiac output or cardiac index. Stepwise regression, followed by multiple regression showed that four variables (WT, SV, SBP, and AGE) explained 32.3% of the variability in LVM in men and 48.5% of the variability in LVM in women. WT and SV were significant determinants of LVM in both men and women. Age was also significant in men and SBP was also significant in women. For both men and women, SV was more significantly correlated with LVM than was SBP. The changes in LVM associated with 1 SD increments of SV and SBP, respectively, were 8 and 5 g for men and 13 and 11 g for women. We conclude that men and women have different patterns of variables influencing LVM. Doppler echocardiographic SV is a newly described determinant of LVM that has a greater correlation with LVM than does SBP. This study reemphasizes the importance of WT as the major determinant of LVM.     

左室重量指数与复杂性室性心律失常

目的探讨左室重量指数预测复杂性室性心律失常的临床价值。方法对１１６例轻、中度高血压病人行超声心动图和动态心电图监测。４０例健康人作对照组。结果复杂性室性心律失常发生率在左室重量指数法和左室实测值法左室肥厚组分别为３６．９％，１３．９％，二者差异显著（Ｐ＜０．０１）。结论左室重量指数法左室肥厚对预测复杂室性心律失常有重要价值。     

Determinants of Left Ventricular Mass and Hypertrophy in Hemodialysis Patients Assessed by Cardiac Magnetic Resonance Imaging

Background and objectives: Left ventricular hypertrophy (LVH) is an independent risk factor for premature cardiovascular death in hemodialysis (HD) patients and one of the three forms of uremic cardiomyopathy. Cardiovascular magnetic resonance (CMR) is a volume-independent technique to assess cardiac structure. We used CMR to assess the determinants of left ventricular mass (LVM) and LVH in HD patients.Design, setting, participants, & measurements: A total of 246 HD patients (63.8% male; mean age 51.5 ± 12.1 yr) underwent CMR on a postdialysis day. LVM was measured from a stack of cine loops and indexed for body surface area (LVM index [LVMI]). Demographic, past biochemical, hematologic, and dialysis data were collected by patient record review. Results up to 180 d before CMR were collected. LVH was defined as LVMI >84.1 g/m² (male) or >76.4 g/m² (female).Results: A total of 157 (63.8%) patients had LVH. LVH was more common in patients with higher predialysis systolic BP, predialysis pulse pressure, and calcium-phosphate product (Ca × PO₄). Furthermore, LVH was significantly associated with higher end-diastolic and systolic volumes and lower ejection fraction. There were positive correlations with LVMI and end-diastolic and systolic volumes. There were weak positive correlations among LVMI, mean volume of ultrafiltration, and Ca × PO₄. Using multivariate linear and logistic regression (entering one BP and cardiac variable), the independent predictors of LVMI and LVH were end-diastolic volume, predialysis systolic BP, and Ca × PO₄.Conclusions: The principal determinants of LVM and LVH in HD patients are end-diastolic LV volume, predialysis BP, and Ca × PO₄.Patients with ESRD, particularly those who require hemodialysis (HD), have an increased risk for premature cardiovascular disease (CVD) (1). Left ventricular hypertrophy (LVH) is a common feature of patients with ESRD, a component of uremic cardiomyopathy and an independent risk factor for sudden cardiac death, heart failure, and cardiac arrhythmias in the general population and HD patients (2–4).Studies that have assessed independent predictors of left ventricular mass index (LVMI; corrected for body surface area [BSA]) and LVH in patients with ESRD have used echocardiography and implicated factors such as hypertension, reduced blood vessel compliance, anemia, phosphate control, and dosage of dialysis (5–7); however, accurate echocardiographic estimation of LVMI in patients with ESRD is difficult because of large variation in intravascular (and hence intraventricular) volume during the interdialytic period and during dialysis. Geometric assumptions made during calculation of LVMI from conventional M-mode echocardiography dimensions result in greater inaccuracies as a result of geometric LV distortion in patients with LVH and ESRD.Cardiac magnetic resonance (CMR) imaging provides more detailed, volume-independent measurement of cardiac structure and has been thoroughly validated using human autopsy and animal specimens (8,9). This technique has been established as the most accurate noninvasive method of assessing ventricular dimensions in patients, including those with stage 5 chronic kidney disease (10,11). In particular, measurements obtained by echocardiography tend to overestimate LVMI, particularly at higher values, when compared with CMR (12). Furthermore, pilot studies in patients with ESRD, using CMR to identify myocardial changes of uremic cardiomyopathy, have so far shown a significant reduction in long-term survival similar to previous echocardiography findings (13 and unpublished data). Thus, the aim of this study was to assess by CMR the determinants of LVMI and LVH in a cohort of HD patients.     

左室质量比值和左室质量指数对高血压左室重构识别的比较

目的 比较左室质量比值(％PLM)和左室质量指数(LVMI)对左室重构识别的价值。方法 对187例高血压患者进行超声心动图检查，测量其心脏结构和功能。结果 左室质量适宜(aLVM)、过高(iLVM)和不足的分布分别占48.1％、48．7％和3．2％。％PLM与左室收缩功能的相关系数高于LVMI与左室收缩功能的相关系数。左室肥厚(LVH)时，iLVM的左室射血分数、左室短轴缩短率低于aLVM(P＜0．01)。但在aLVM或iLVM中．LVH和无LVH两组间的左室收缩功能无明显差异(P＞0．05)。结论 ％PLM识别左室重构比LVMI更符合生理情况，更能精确地对高血压患者进行危险分层。     

Plasma Norepinephrine and Hemorheology in Essential Hypertensive Patients with Different Patterns of Left Ventricular Hypertrophy

对80例不同类型高血压左室肥厚（LVH）患者的血浆去甲肾上腺素（NE）和血液流变学改变进行观察。结果显示，（1）向心性肥厚组（CH）高切变率下全血粘度（WBV230）显著升高；（2）不对称性室间隔肥厚组（ASH）血浆NE和收缩末期室壁应力（ESS）增高较明显；（3）多元回归分析显示，SBP，ESS和血浆NE是影响相对室壁厚度的重要因素。提示CH是一种对压力负荷过重而产生的代偿形式；ASH的形成除了负荷因素外血浆NE可能起更重要的作用。     

左室质量比值和左室质量指数对高血压左室重构识别的比较

目的比较左室质量比值(%PLM)和左室质量指数(LVMI)对左室重构识别的价值.方法对187例高血压患者进行超声心动图检查,测量其心脏结构和功能.结果左室质量适宜(aLVM)、过高(iLVM)和不足的分布分别占48.1%、48.7%和3.2%.%PLM与左室收缩功能的相关系数高于LVMI与左室收缩功能的相关系数.左室肥厚(LVH)时, iLVM的左室射血分数、左室短轴缩短率低于aLVM(P<0.01).但在aLVM或iLVM中,LVH和无LVH两组间的左室收缩功能无明显差异(P>0.05).结论 %PLM识别左室重构比LVMI更符合生理情况,更能精确地对高血压患者进行危险分层.     

Echocardiographic Quantification of Left Ventricular Mass: Prognostic Implications

Left ventricular hypertrophy (LVH) has been shown to be an independent risk factor for adverse cardiac and cerebrovascular events. Despite this well-known association, the lack of a standardized approach for the quantification and the monitoring of LVH regression has limited its use as a primary risk factor that can be easily clinically targeted. Echocardiography has become the most widespread tool used for the quantification of LVH. With advances in this technology, echocardiographic quantification of LVH has improved and reference standards are being used to determine the clinical implications of LVH regression. In this article, we aim to provide a current appraisal of LVH with a focus on presenting the current clinical methods used to accurately detect LVH, the prognostic implications of these findings, and help develop a therapeutic target for clinicians.     

高血压左室构型与左室中层力学的关系

目的:用室壁应力-左室中层缩短率关系做为评价心肌收缩性的指标,研究高血压不同左室构型患者心肌收缩性的改变与心功能变化的关系.方法:应用超声心动图计算左室重量指数(LVMI)和相对室壁厚度(RWT),按LVMI和RWT将左心室分为四种构型.对117例原发性高血压病人和45例健康人左心室结构按左室室壁应力(MESS)和室壁中层缩短率(mFS)来估计心功能情况.结果:以射血分数、左室短轴缩短率和左室中层缩短率表示的收缩功能离心性肥厚受损最重,以室壁应力-左室中层缩短率关系表示的心肌收缩性,向心性肥厚最重.以EF斜率等表示的心脏舒张功能高血压不同左室构型患者损害不同,舒张功能的改变与心肌收缩性的损害成正相关.结论:高血压不同左室构型患者心肌收缩性损害不同,左室构型向向心性发展在一定阶段上代偿了心肌收缩性的下降,以保持心脏收缩排血功能的正常.     

高血压左室构型与左室中层力学的关系

目的：用室壁应力－左室中层缩短率关系做为评价心肌收缩性的指标,研究高血压不同左室构患者心肌收缩性的改变与心功能变化的关系。方法：应用超声心动图计算左室重量指数（ＬＶＭＩ）和相对室壁厚度（ＲＷＴ）,按ＬＶＭＩ和ＲＷＴ将左心室分为四种构型。对１１７例原发性高血压病人和４５例健康人左心室结构按左室室壁应力（ＭＥＳＳ）和室壁中层缩短率（ｍＦＳ）来估计心功能情况。结果：以射血分数、左室短轴缩短率和左室中层缩短率表示的收缩功能离心性肥厚受损严重,以室壁应力－左室中层缩短率关系表示的心肌收缩性,向心性肥厚最重。以ＥＦ斜率等表示的心脏舒张功能高血压不同左室构型患者损害不同,舒张功能的改变与心肌收缩必的损害成正相关。结论：高血压不同左室构型患者心肌收缩性损害不同,左室构型向向心性发展在一定阶段上代偿了心肌收缩性的下降,以保持心脏     

Left Ventricular Relative Wall Thickness Versus Left Ventricular Mass Index in Non-Cardioembolic Stroke Patients

In non-cardioembolic stroke patients, the cardiac manifestations of high blood pressure are of particular interest. Emerging data suggest that echocardiographically determined left ventricular hypertrophy is independently associated with risk of ischemic stroke.The primary objective of this study was to evaluate the frequency of different patterns of left ventricular (LV) remodeling and hypertrophy in a group of consecutive patients admitted with non-cardioembolic stroke or transient ischemic attack (TIA). In particular, we were interested in how often the relative wall thickness (RWT) was abnormal in patients with normal LV mass index (LVMI). As both abnormal RWT and LVMI indicate altered LV remodeling, the secondary objective of this research was to study whether a significant number of patients would be missing the diagnosis of LV remodeling if the RWT is not measured.All patients were referred within 48 hours after a stroke or a TIA for a clinically indicated transthoracic echocardiogram. The echocardiographic findings of consecutive patients with non-cardioembolic stroke or TIA were analyzed.All necessary measurements were performed in 368 patients, who were enrolled in the study. Mean age was 63.7 ± 12.5 years, 64.4% men. Concentric remodeling carried the highest frequency, 49.2%, followed by concentric hypertrophy, 30.7%, normal pattern, 15.5%, and eccentric hypertrophy, 4.1%. The frequency of abnormal left ventricular RWT (80.4%) was significantly higher than that of abnormal LVMI (35.3%), (McNemar P < 0.05).In this group of non-cardioembolic stroke patients, abnormal LV remodeling as assessed by relative wall thickness is very frequent. As RWT was often found without increased LV mass, the abnormal left ventricular geometry may be missed if RWT is not measured or reported.     

Left Ventricular Strain Examination of Different Aged Adults with 3D Speckle Tracking Echocardiography

The purpose of this study was to identify traits of the left ventricular (LV) global longitudinal strain (GLS), global radial strain (GRS), global circular strain (GCS), and global area tracking (GAT) with three‐dimensional speckle tracking echocardiography (3DSTE), and to determine the relationship between strain and age in healthy adults of different ages. A total of 153 volunteers were divided into young adult, middle‐aged, and elderly groups, and examined with echocardiography to obtain general data and live two‐dimensional (2D) images of the apical four‐chamber view, which were assembled to obtain the full volume view of the LV. The images were then analyzed with 3DSTE software. Compared with the young adult and middle‐aged groups, elderly adults demonstrated lower GLS, GRS, GCS, and GAT. Significant differences were not noted in GLS, GRS, and GCS between the young adult and middle‐aged groups; however, the GAT of the middle‐aged group was lower than that of the young adult group. The longitudinal strain (LS), radial strain (RS), and area tracking (AT) of 16 LV segments of the young adult group decreased gradually in level from the mitral valve to the apex, and increased in circular strain (CS). The LS, RS, CS, and AT of the middle‐aged group also decreased gradually. The LS, RS, CS, and AT of the elderly people were highest from the mitral valve to the apex level and lowest at the papillary muscle. The results of this study demonstrated that LV GLS, GRS, GCS, and GAT decrease with age.     

Left Ventricular Size and Shape: Determinants of Mechanical Signal Transduction Pathways

Heart failure may be viewed as a progressive disorder that is impelled, at least in part, by progressive left ventricular (LV) remodeling. In the present discussion we will review the role of LV remodeling in the pathogenesis of heart failure, with a focus on the contribution that changes in LV size and shape play in the development and progression of the progression of heart failure. The clinical implication of this review is that existing neurohormonal strategies may not completely prevent disease progression in the failing heart, and that adjunctive strategies that are designed to specifically prevent and/or attenuate LV remodeling may play an important role in the clinical treatment of heart failure.