Myocardial viability independently influences left ventricular diastolic function in the early phase after acute myocardial infarction

BACKGROUND: After acute myocardial infarction, a broad range of left ventricular (LV) end-diastolic pressure (LVEDP) is expected because of chamber remodeling. However, intrinsic characteristics of the infarcted tissue (necrosis or viability) may also play a role. We aimed to evaluate whether myocardial viability (Mviab) has an influence on LVEDP. METHODS: One hundred twenty-three consecutive patients with acute myocardial infarction underwent low-dose dobutamine echocardiography (5-10 microg/kg/min) to assess Mviab. Mviab was quantitatively evaluated by the variation of Delta wall motion score index. Patients underwent left heart catheterization with recording of LVEDP and a complete echocardiographic examination with measurement of LV volumes, ejection fraction, and mass. RESULTS: The overall population (81% male; mean age 58 +/- 10 years) was divided into 2 groups according to the presence (group 1; 66 patients) or absence (group 2; 57 patients) of Mviab. LVEDP was higher in patients without Mviab (16 +/- 8 vs 20 +/- 7 mm Hg; P =.02). The multivariate analysis showed that Delta wall motion score index correlated with LVEDP (P =.01) independent of wall motion score index and LV end-systolic volume. CONCLUSIONS: After acute myocardial infarction, LVEDP shows wide variability and is independently associated with Mviab.     

Myocardial contrast echocardiography predicts left ventricular remodelling after acute myocardial infarction.

BACKGROUND: We investigated whether the extent of residual myocardial viability demonstrated by myocardial contrast echocardiography (MCE) predicts the degree of left ventricular (LV) remodelling after acute myocardial infarction as assessed by cardiovascular magnetic resonance. METHODS: Accordingly, 25 patients underwent MCE 5 to 7 days after acute myocardial infarction followed by cardiovascular magnetic resonance assessment of LV end-diastolic volume, LV end-systolic volume, and LV ejection fraction. A contrast perfusion index was calculated within the infarct-related territory. RESULTS: LV end-diastolic and end-systolic volumes were significantly smaller (138 +/- 38 vs 188 +/- 43 mL, P =.008, and 86 +/- 35 vs 119 +/- 49 mL, P =.01, respectively) and LV ejection fraction was significantly higher (52 +/- 5.4 vs 31.5 +/- 3.2%, P> =.02) in patients showing good myocardial viability (contrast perfusion index 相似文献   

Myocardial global performance index as a predictor of in-hospital cardiac events in patients with first myocardial infarction.

OBJECTIVE: We sought to assess the ability of a Doppler index of global myocardial performance (MPI), measured at entry, to predict inhospital cardiac events in a series of patients with first acute myocardial infarction (AMI). METHODS: A complete 2-dimensional and Doppler echocardiographic examination was performed within 24 hours of arrival at the coronary care department in 96 patients (81 men and 15 women; mean age 58 +/- 9 years) with first AMI. Patients were divided a posteriori into 2 groups according to their inhospital course: group 1 comprised 75 patients with an uneventful course and group 2 comprised 21 patients with a complicated inhospital course (death, heart failure, arrhythmias, or post-AMI angina). RESULTS: There were no significant differences between the 2 groups with regard to history of hypertension, diabetes mellitus, hypercholesterolemia, site and size of infarction, and conventional parameters of diastolic function. However, patients with complications were significantly older (63 +/- 10 vs 55 +/- 8 years, P =.005) and had higher wall-motion score index and left ventricular end-systolic volume compared with patients without events (1.84 +/- 0.27 vs 1.52 +/- 0.30, P =.001; and 66 +/- 29 vs 47 +/- 21 mL, P =.009, respectively), whereas the ejection fraction was reduced (40 +/- 10% vs 52 +/- 10%, P =.0001). The mean value of the MPI was significantly higher in patients with cardiac events than in those without events (0.65 +/- 0.20 vs 0.43 +/- 0.16, P =.0001). A MPI >/= 0.47 showed a sensitivity of 90% and specificity of 68% for identifying patients with events, on the basis of the receiver operator curve. In a multivariable model, the MPI at admission remained independently predictive of inhospital cardiac events (odds ratio 15.6, 95% confidence interval 2.4-99, P =.003). CONCLUSION: These data suggest that in the acute phase of AMI, the MPI measured at entry may be useful to predict which patients are at high risk for inhospital cardiac events.     

Intravenous myocardial contrast echocardiography predicts left ventricular remodeling in patients with acute myocardial infarction.

BACKGROUND: This study evaluated the ability of intravenous myocardial contrast echocardiography (MCE) performed in the setting of acute myocardial infarction for prediction of left ventricular (LV) remodeling. METHODS: Intravenous MCE was performed immediately before, 1 hour, and 24 hours after primary percutaneous transluminal coronary angioplasty (PTCA) in 35 patients with a first myocardial infarction. The MCE was used to define the relative perfusion defect size (in %; relMCD). Two-dimensional echocardiography was performed directly after angioplasty and after 4 weeks to determine LV end-diastolic volumes (LVEDV). The increase in LVEDV at 4 weeks defined a remodeling (> 15% increase) and a nonremodeling group (< or = 15% increase). RESULTS: Patients with remodeling had larger relMCD before (22.0 +/- 16.1 vs 8.0 +/- 11.9, P =.015), 1 hour (20.0 +/- 13.0 vs 4.9 +/- 11.6, P =.001), and 24 hours after PTCA (22.9 +/- 14.1 vs 1.2 +/- 2.8, P <.001). There was a significant correlation between relMCD 24 hours after PTCA and the increase in LVEDV at 4 weeks (r = 0.648; P <.001). Receiver operating characteristic (ROC) curve analysis revealed a relMCD at 24 hours of 5.1% or more to predict remodeling with a sensitivity of 94% and a specificity of 87% (area under ROC curve = 0.917; SE = 0.054). Multivariate analysis demonstrated relMCD at 24 hours to be the only predictor of remodeling (odds ratio = 173.4; P =.022). CONCLUSION: The size of the persistent MCE perfusion defect after revascularization for acute myocardial infarction has a high predictive value for LV remodeling during a 4-week follow-up period.     

Early changes in left ventricular volume and function are predictors for long-term remodeling in patients with acute transmural myocardial infarction and preserved systolic function.

BACKGROUND: We sought to describe the degree of long-term left ventricular (LV) remodeling after acute transmural myocardial infarction with preserved LV systolic function, and to evaluate whether Doppler echocardiographic parameters in the early phase could predict this process. METHODS: A total of 60 patients without heart failure and with LV ejection fraction > or = 0.40 (mean 0.48 +/- 0.054), were followed up with Doppler echocardiographic examinations at baseline, 3 months, and 1 and 2 years. RESULTS: There was a significant increase in LV end-diastolic volume index of 7% (P =.006) and LV end-systolic volume index of 8% (P =.03), and no change in ejection fraction. This remodeling was confined to 7 patients (12%) with a significant increase in LV end-diastolic volume index above 20 mL/m(2). There was also a significant increase in the deceleration time of both the early mitral filling wave (Delta early mitral filling wave = 58 milliseconds, P <.0005) and the diastolic forward component of pulmonary venous flow (Delta diastolic forward component of pulmonary venous flow = 61 milliseconds, P <.0005), and a shift in filling pattern with increasing prevalence of abnormal relaxation. Changes in end-diastolic volume index were predicted by baseline early mitral filling wave less than 100 milliseconds, but the most powerful predictors of 2-year remodeling were volume changes at 3 months. CONCLUSION: Twelve percent of patients with Q-wave infarction and ejection fraction > or = 0.40 experienced significant LV dilatation at 2 years, and this late remodeling was partly related to baseline filling characteristics.     

Index of myocardial performance after early phase of myocardial infarction in relation to its location.

To define the degree of heart derangement in recent myocardial infarction (MI) occurring in different wall locations of myocardium, we echocardiographically evaluated left ventricular volumes, ejection fraction, wall-motion score index, isovolumetric contraction and relaxation time, ejection time, and index of myocardial performance in 74 patients with MI. Participants were chosen among the patients with MI of comparable extent and interesting unlike zones of myocardial walls. Mean values of evaluated left ventricular end-diastolic and end-systolic volumes and ejection fraction were nearly alike in all patients, whereas wall-motion score index and index of myocardial performance were cleary prolonged in those with anterior MI in comparison with the values recorded in patients with lateral or inferior MI. The mean values of isovolumetric contraction and relaxation time suggest that a prevalent systolic dysfunction is present in the early phase of MI. In addition, the different index of myocardial performance prolongation in MI otherwise located suggests evidence that MI located in the anterior wall has more serious effect than lateral or inferior MI.     

Force-frequency relationship in the echocardiography laboratory: a noninvasive assessment of Bowditch treppe?

BACKGROUND: Estimation of contractility of the left ventricle is an important, and as yet elusive, goal with noninvasive techniques. OBJECTIVE: We sought to assess the feasibility of a totally noninvasive estimation of force-frequency relation (FFR) during exercise stress in the echocardiography laboratory. METHODS: We enrolled 13 healthy control patients (12 men, age 38 +/- 15 years) as group I, and 50 patients (38 men, age 64 +/- 11 years) referred for exercise echocardiography as group II. To build the FFR, the force was determined at each step as the ratio of the systolic pressure (cuff sphygmomanometer)/end-systolic volume index (biplane Simpson's rule/body surface area). The slope of the relationship was calculated with the linear best fit of the FFR. RESULTS: Noninvasive systolic pressure/end-systolic volume ratio was obtained in all patients. The slope of the linear best fit of the force-frequency curve was lower in group II compared with group I (group II = 10.1 +/- 9.3 x 10(-2) vs group I = 14.9 +/- 9.9 x 10(-2) group I, P =.04). By regional wall-motion analysis, 2 subgroups were identified in group II: group IIA (n = 8) had a positive echocardiogram; and group IIB (n = 42) had a negative echocardiogram. The slope of the force-frequency curve was lower in patients with ischemia compared with those without (group IIA = 3.5 +/- 4.2 x 10(-2) vs group IIB = 11.4 +/- 9.5 x 10(-2); P =.012). Heart rate-systolic pressure/end-systolic volume index relation was biphasic, with an initial positive slope and a subsequent negative slope in 1 patient of group I, 4 patients of group IIA, and 15 patients of group IIB (P <.05 vs group I). CONCLUSION: A noninvasive estimation of FFR can be easily determined during exercise echocardiography. This index of global contractility is theoretically appealing for identification of limited contractile reserve and latent global left ventricular dysfunction.     

The myocardial performance index during low-dose dobutamine echocardiography in control subjects and patients with a recent myocardial infarction: a new index of left ventricular functional reserve?

BACKGROUND: Wall-motion analysis during low-dose dobutamine echocardiography (LDDE) is a semiquantitative measure of left ventricular contractile reserve after myocardial infarction (MI). The Doppler echocardiographic myocardial performance index (MPI) is a quantitative measure of combined left ventricular systolic and diastolic function. We sought to characterize the changes in MPI during LDDE in control subjects and patients with MI, and to describe the relation of these changes to changes in regional systolic function. METHODS: MPI was obtained at rest and during LDDE (10 microg/kg/min) in 25 healthy volunteers (group 1) and 50 patients with a recent MI. Patients were divided into two subsets; those with (n = 23; group 2A) and those without (n = 27; group 2B) a contractile reserve defined as an improvement of wall motion in more than two contiguous infarct-zone segments during LDDE. DeltaMPI was defined as the change from rest to LDDE. RESULTS: MPI decreased significantly during LDDE in groups 1 and 2A, whereas MPI increased in group 2B (DeltaMPI = 0.12 +/- 0.04 and 0.10 +/- 0.08 vs -0.03 +/- 0.08, P <.0001). On multivariate analysis, Deltawall-motion score index predicted DeltaMPI (beta = 0.65, P <.0001) independently of age, sex, and the dobutamine-induced change in heart rate and systolic blood pressure. CONCLUSIONS: Data suggest that the change in MPI during LDDE may provide a simple and quantitative measure of overall left ventricular functional reserve in patients with a recent MI.     

Assessment of myocardial viability in prior myocardial infarction by intravenous bolus microbubble injection: a new time domain index to estimate regional relative myocardial blood volume.

We tested whether the duration of myocardial opacification by harmonic power Doppler imaging after intravenous bolus microbubble injection (with a definition of "the end of opacification") would reflect the remaining vascular bed in infarcted segments. In 28 patients with previous myocardial infarction and 20 control patients, we performed harmonic power Doppler imaging after intravenous bolus injection of 1.5 g of Levovist. Using multiframe trigger mode in which 4 consecutive frames were imaged at every sixth end systole, which formed 1 "burst," we recorded anterior/septal and inferior/posterior walls separately on the center of each apical view with individual boluses. The duration of segmental opacification was measured as the number of "bursts" in which color signals persisted until the fourth frame. The duration was similar between the anterior/septal and inferior/posterior walls (13 +/- 3 vs 13 +/- 3 bursts, not significant) in the control group. In myocardial infarction patients, the duration was significantly shorter in the infarcted than in the control segments (6 +/- 6 vs 14 +/- 3 bursts, P < .001) and their ratio and difference exhibited significant correlations (r = 0.82, P < .001 and r = 0.91, P < .001, respectively) with the activity ratio on thallium Tl 201 single-photon emission computed tomography at rest. Thus, the duration of opacification by harmonic power Doppler imaging after intravenous bolus microbubble injection, the measurement of which was standardized by using multiframe trigger mode, may be useful in assessing regional myocardial viability in patients with previous myocardial infarction.     

Complicated acute myocardial infarction requiring mechanical ventilation in the intensive care unit: prognostic factors of clinical outcome in a series of 157 patients

OBJECTIVE: To determine prognostic factors associated with death in patients with complicated acute myocardial infarction requiring mechanical ventilation. DESIGN: Retrospective chart-based analysis. SETTING: A 22-bed medical intensive care unit in a university hospital. PATIENTS: A total of 157 consecutive patients with acute myocardial infarction requiring endotracheal intubation and mechanical ventilation admitted to an intensive care unit during a 6-yr period. INTERVENTIONS: Coronary reperfusion strategy within 12 hrs following symptom onset. MEASUREMENTS AND MAIN RESULTS: Clinical characteristics at admission of survivors (n = 77) and nonsurvivors (n = 80) were similar regarding demographics, medical history, and Glasgow Coma Scale score. Twenty-eight-day intensive care unit mortality rate was 51%. The following criteria were higher for nonsurvivors: Simplified Acute Severity Score II, 79 +/- 18 vs. 64 +/- 17 (p <.0001); Acute Physiology and Chronic Health Evaluation (APACHE) II, 33 +/- 13 vs. 25 +/- 6 (p <.0001); incidence of cardiogenic shock (p =.0085) and failing organs (p <.0001); coronary artery disease extension (p =.045); and delay between symptom onset and coronary reperfusion (p =.0348). Nonsurvivors also had higher serum urea and creatinine and lower urine output, arterial pH, and left ventricular ejection fraction (p <.05). Mortality rate was higher in patients with PaO2/FiO2 ratio <200 than in patients with PaO2/FiO2 ratio >200 at admission (log-rank, 5.016; p =.0251). By multivariate analysis, only three factors were independently associated with death: APACHE II >29 (odds ratio, 1.132; 95% confidence interval, 1.013-1.265, p =.0287), serum creatinine >180 micromol/L (odds ratio, 6.151; 95% confidence interval, 1.446-26.166, p =.0139), and initial left ventricular ejection fraction <0.4 (odds ratio, 1.121; 95% confidence interval, 1.049-1.347, p =.0316). Overall, good discrimination was achieved for the risk score model (c-index, 0.852). CONCLUSIONS: We confirmed the high mortality rate of patients admitted to an intensive care unit with acute myocardial infarction requiring mechanical ventilation. In these patients, the main risk factors for death found, namely high APACHE II, early development of acute renal failure, and low resting left ventricular function, reflected the severity of the myocardial infarction.     

Assessment of left ventricular systolic and diastolic function by Doppler tissue imaging in patients with preinfarction angina.

BACKGROUND: The aim of this study was assessment of left ventricular (LV) systolic and diastolic function by pulsed wave Doppler tissue imaging (DTI) in patients with or without preinfarction angina in acute myocardial infarction. METHODS: We prospectively evaluated 31 consecutive patients (4 women, 27 men; age 58 +/- 10 years) with a first acute myocardial infarction. LV systolic and diastolic function was assessed by classic methods and DTI on the third day during acute myocardial infarction. Patients were divided into 2 groups according to the presence (group 1; n = 10) or absence (group 2; n = 21) of preinfarction angina. Mitral inflow velocities and early diastolic mitral annular velocity (Em), late diastolic mitral annular velocity (Am), peak systolic mitral annular velocity, Em/Am, the ratio of early diastolic mitral inflow velocity (E) to Em, and myocardial performance index were calculated by DTI. RESULTS: Group 1 had significantly higher Em and Em/Am than group 2 (11.3 +/- 3.34 cm/s vs 7.4 +/- 2.07 cm/s, P <.0001; 1.01 +/- 0.38 cm/s vs 0.6 +/- 0.2 cm/s, P =.001, respectively). The E/Em ratio and myocardial performance index were significantly lower in group 1 than in group 2 (5.1 +/- 2.92 vs 8.10 +/- 3.15, P=.018; 0.49 +/- 0.15 vs 0.65 +/- 0.24, P =.042, respectively). Wall-motion score index was lower in those with preinfarction angina than in those without (1.6 +/- 0.36 vs 1.9 +/- 0.39; P =.04, respectively). Peak systolic mitral annular velocity and Am were not statistically different between groups (9.4 +/- 1.84 vs 8.3 +/- 2.03, P =.172; 11.7 +/- 3.07 vs 12.1 +/- 3.34, P =.72, respectively). There were no significant differences between the 2 groups regarding transmitral E velocity, atrial contraction mitral inflow velocity (A), E/A ratio, isovolumetric relaxation time, and deceleration time of the mitral E wave (P =.91, P =.08, P =.58, P =.81, and P =.71, respectively). CONCLUSION: LV diastolic function was better in patients with preinfarction angina than in patients without. This condition could not be detected by conventional mitral inflow Doppler velocities, but could be detected by DTI. This preliminary evidence shows that DTI is better than conventional mitral Doppler indices in the assessment of a favorable LV diastolic function in patients with preinfarction angina.     

Enoximone very low-dose dobutamine stress echocardiography: a new test for detecting viability in severe myocardial dysfunction after acute myocardial infarction.

Relying on the synergistic action on contractility of enoximone and dobutamine when concomitantly infused, 25 patients with their first acute Q-wave anterior myocardial infarctions underwent conventional low-dose dobutamine echocardiography (LDE) and enoximone very-LDE to assess myocardial viability in severely dysfunctioning areas. Images were recorded at peak of pharmacodynamic effect of drugs and 4 months after revascularization. At peak-dose stage of LDE and enoximone very-LDE the regional infarct zone wall-motion score significantly decreased from the basal value of 25.6 +/- 2.9 to 16 +/- 6.0 (P <.001) and to 14.5 +/- 5.2 (P <.001), respectively. A high correlation was found by comparing the wall-motion score of each patient calculated at peak effect of combined drug administration with follow-up values (r(s) = 0.9). Enoximone very-LDE has proven to be a new test useful to evaluate viability in asynergic segments especially when the results of conventional tests are questionable.     

实时心肌超声造影微泡再充盈参数评价心肌梗死患者心肌灌注

目的 应用实时心肌超声造影分析收缩末期与舒张末期再充盈参数,探讨其评价心肌梗死患者心肌微循环灌注的可行性.方法 对21例陈旧性心肌梗死及急性心肌梗死亚急性期的患者及6例正常对照组进行实时心肌超声造影.用时间强度曲线分析左室各节段收缩末期及舒张末期的微气泡再充盈过程.根据灌注的函数公式y(t)=A[1 - e-kt]+B,脱机心电图触发方式选择收缩末期(T波结束)帧和舒张末期(R波顶点)帧分别执行灌注曲线拟合,得到微气泡信号强度增加的高度(A值)、信号强度增加的速率(k值)并计算A×k值,比较收缩末期与舒张末期相应节段心肌血容量、心肌血流速度、心肌血流量的差异.结果 正常对照组中收缩末期的A值、k值及A×k值均小于舒张末期各值,差异有统计学意义[分别为(6.21±2.69)dB对(7.93±3.66)dB,P＜0.05;0.36±0.15对0.42±0.19,P＜0.01;2.88±1.29对3.39±1.61,P＜0.05].与收缩末期相比,舒张末期A值,k值及A×k值具有更大的变异性(变异系数分别为A值46.2％对43.3％,k值45.2％对41.4％,A×k值47.5％对44.8％,P值均＜0.05).病例组中梗死相关冠状动脉供血节段心肌的收缩末期再充盈参数明显小于非梗死冠状动脉供血心肌各参数值,差异有统计学意义[A值、k值及A×k值分别为(3.99±1.02) dB对(4.77±1.24)dB,P＜0.05;0.31±0.13对0.35±0.16,P＜0.05;1.25±0.74对2.39±1.11,P＜0.01].结论 收缩末期与舒张末期再充盈参数可以评价心肌微循环灌注,收缩末期各参数值具有更小的变异性,其中收缩末期k值是一个较好的评价指标.然而,显著的变异性提示这些指标适用于自身前后对照研究.     

Global longitudinal strain: a novel index of left ventricular systolic function.

BACKGROUND: Echocardiographic estimation of global left ventricular (LV) function is subjective and time consuming. Our aim was to develop a novel approach for assessment of global LV function from 2-dimensional echocardiographic images METHODS: Novel computer software for tissue tracking was developed and applied as follows: digital loops were acquired from apical 2-, 3-, and 4-chamber views and a line was loosely traced along the LV endocardium at the frame wherein it was best defined. Around this line, the software selected natural acoustic markers moving with the tissue. Automatic frame-by-frame tracking of these markers during the heart cycle yielded a measure of contractility along the selected region of interest. Global longitudinal strain (GLS) and GLS rate (GLSR) were calculated for the entire U-shaped length of LV myocardium (basal, mid, and apical segments of 2 opposite walls in each view). To test this software, computer-derived GLS and GLSR were analyzed by a nonechocardiographer, blinded to the echocardiographic interpretation, in 27 consecutive patients after myocardial infarction (MI) (age 64.4 +/- 12.9 years; 19 men; mean wall-motion score index of 1.79 +/- 0.44) and compared with those obtained in 12 consecutive control patients (age 59.0 +/- 9.7 years; 8 women), with a normal echocardiographic study. RESULTS: GLS and GLSR, averaged from the 3 apical views, differed significantly in patients post-MI compared with control patients (GLS -14.7 +/- 5.1% vs -24.1 +/- 2.9% and GLSR -0.57 +/- 0.21/s vs -1.02 +/- 0.09/s for patients post-MI vs control patients, respectively; both P <.0001). There was a good linear correlation between the wall-motion score index and the GLS and GLSR (R = 0.68 and R = 0.67, respectively; both P <.0001). A cut-off value for GLS of -21% had 92% sensitivity and 89% specificity and a cut-off value for GLSR -0.9/s had 92% sensitivity and 96% specificity for the detection of patients post-MI. CONCLUSIONS: GLS and GLSR are novel indices for assessment of global LV function from 2-dimensional echocardiographic images. Early validation studies with the method are suggestive of high sensitivity and specificity in the detection of LV systolic dysfunction in patients post-MI.     

组织速度成像定量评价大鼠急性心肌梗死后左室重构的左室收缩功能

目的应用定量组织速度成像结合二维超声心动图对大鼠急性心肌梗死(Acute Myocardial Infarction,AMI) 后左室重构的左室收缩功能进行评价,以探讨定量组织速度成像评价大鼠AMI后左室重构的应用价值.方法 AMI组雌性SD大鼠(n＝12)为样本,正常组大鼠(n＝10)作对照,4周后2组均行超声心动图检查.结果与正常组相比,AMI组的左室舒张末期内径、舒张末期容积显著增加(P＜0.01);左室射血分数、左室后壁增厚率、球形指数、梗死区变薄指数等显著降低(P＜0.01);心脏长轴方向上AMI组二尖瓣环、左室侧壁各节段,短轴方向上前间隔及后壁的基底部、中部定量组织速度成像收缩期峰值速度明显下降(P＜0.05);二尖瓣环收缩期平均峰值速度与左室射血分数、球形指数等呈线性相关(r值分别为0.84 、0.70,P＜0.001).结论定量组织速度成像结合二维超声心动图能较全面、定量和无创性地评价大鼠AMI后左室重构的左室收缩功能.     

Serial Doppler echocardiographic assessment of left and right ventricular performance after a first myocardial infarction.

We sought to investigate the relation between left ventricular (LV) and right ventricular (RV) function assessed with the Doppler-derived myocardial performance index (MPI), to assess serial changes, and to investigate the prognostic value of biventricular assessment of cardiac function after a first myocardial infarction (MI). To do so, serial Doppler echocardiography was performed in 77 consecutive patients with a first MI. Right ventricular MPI correlated significantly with LV MPI (r = 0.51, P <.0001). In patients with echocardiographic signs of RV MI, the RV MPI was significantly higher (0.59 +/- 0.18 versus 0.44 +/- 0.19, P =.001), whereas no difference in LV MPI was seen (0.55 +/- 0.19 versus 0.56 +/- 0.13, P = not significant). Right ventricular MPI showed a rapid normalization during follow-up, whereas LV MPI did not decrease. During follow-up, 23 patients died of cardiac causes or were readmitted because of worsening heart failure. Multivariate Cox analysis indicated LV MPI (relative risk 4.9 [95% CI 1.8-13.5], P =.002) and RV MPI (relative risk 3.8 [1.3-17.0], P =.01) to be predictors of cardiac events. Thus the RV MPI is frequently abnormal after a first MI but normalizes rapidly on follow-up, and biventricular assessment of cardiac function may improve the prognostic accuracy compared with LV assessment alone.     

Early assessment of coronary flow reserve by transthoracic Doppler echocardiography predicts late remodeling in reperfused anterior myocardial infarction.

BACKGROUND: Microvascular integrity is an essential determinant of favorable late outcome in reperfused myocardial infarction. Coronary flow reserve (CFR) can be assessed by transthoracic Doppler echocardiography and provides a functional estimate of microvascular integrity downstream from the patent infarct-related vessel. OBJECTIVE: We sought to assess the effects of CFR in predicting late left ventricular (LV) remodeling in patients with reperfused acute anterior myocardial infarction treated with primary angioplasty. METHODS: In all, 31 patients admitted with acute anterior myocardial infarction underwent primary angioplasty of the infarct-related vessel. After angioplasty, angiographic thrombosis in myocardial infarction (TIMI) grade and myocardial blush were scored. On the first day, all underwent stress echocardiography and CFR evaluation of left anterior descending coronary artery by transthoracic Doppler. All patients had resting 2-dimensional echocardiography at 1, 3, and 6 months for assessment of LV function. RESULTS: CFR could be successfully assessed in 31 patients. After 6 months 5 patients showed LV dilatation (group I), whereas 26 patients did not show significant variation (group II). On day 1, CFR was higher (group I = 1.43 +/- 0.11 vs group II = 1.67 +/- 0.26, P =.005) and the deceleration time of diastolic left anterior descending coronary artery flow velocity was longer (group I = 212 +/- 41.4 milliseconds vs group II = 286 +/- 106.7 milliseconds, P <.02) in patients without, compared with those with LV remodeling, whereas there was no difference in angiographic parameters. CONCLUSION: Early assessment of CFR and the pattern of baseline diastolic coronary flow velocity by transthoracic Doppler echocardiography is feasible, safe, and more useful than angiographic indices in identifying patients at high risk of remodeling in spite of successful primary angioplasty.     

Diagnosis of viable myocardium using velocity data of Doppler myocardial imaging: comparison with positron emission tomography.

To test whether velocity data of Doppler myocardial imaging (DMI) at rest is useful for diagnosis of myocardial viability, 25 consecutive patients (age 64 +/- 10 years) with regional wall-motion abnormalities at the left anterior descending coronary artery territory and left ventricular dysfunction (ejection fraction: 31 +/- 7%) underwent both DMI at rest and positron emission tomography. The peak systolic velocity (Vpeak) and postsystolic thickening (PST) velocity were measured in myocardial segments of left anterior descending coronary artery territory from apical views. A total of 71 segments were classified by positron emission tomography as normal or viable in 38 (group A) and nonviable in 33 (group B). Although Vpeak did not show any difference between groups (1.81 +/- 1.77 vs 1.29 +/- 0.94 cm/s, P =.107), PST velocity was significantly higher in group A (2.48 +/- 1.68 vs 0.89 +/- 0.72 cm/s, P <.001). The sensitivity and specificity of PST velocity > 2.0 cm/s for diagnosis of viability were 61% (23/38) and 97% (32/33), respectively. In segments with PST velocity was < or =2.0 cm/s, Vpeak > 1.8 cm/s could discriminate group A from B with a sensitivity of 67% (10/15) and a specificity of 91% (29/32). The algorithm using both PST velocity and Vpeak of DMI showed sensitivity and specificity of 87% and 88%, respectively, for diagnosis of myocardial viability. Velocity data of DMI at rest provides robust information regarding viability in selected patients, and an advantage of this technique is that no stress testing is needed.     

常量卡维地洛对急性心肌梗死近期左心室功能的影响

目的　用超声心动图评价常量卡维地洛对急性心肌梗死后近期左心室功能的影响。方法　 74例急性心肌梗死患者 ,在用药前、用药 6个月后进行超声心动图检查。用修改的Simpson法经心尖四腔和二腔切面测定左心室收缩末容量、舒张末期容量和左室射血分数。结果　卡维地洛组心率比安慰剂组减慢 ,而安慰剂组左心室舒张末期容量和收缩末期容量增加 ,卡维地洛组容量减少。卡维地洛组左心室舒张末期容量指数比安慰剂组显著减少 (t =2 .470 ,P <0 .0 5 ) ;左心室收缩末期容量指数明显减少 (t =2 .6 86 ,P <0 .0 1) ,左心室射血分数增加 (t =2 .5 45 ,P<0 .0 5 )。结论　常量卡维地洛治疗急性心肌梗死 6个月 ,减少左心室容量 ,增加LVEF。     

Comparison of myocardial tissue Doppler with transmitral flow Doppler in left ventricular hypertrophy

We sought to determine the most useful echocardiographic measurements for assessment of diastolic function in patients with left ventricular hypertrophy (LVH) and normal systolic function. We compared myocardial Doppler velocities of the basal inferoposterior wall with mitral inflow pulsed wave Doppler velocities in 11 healthy volunteers (age, 36 +/- 6 years), 25 patients (age, 64 +/- 14 years) without LVH, and 37 patients (age, 67 +/- 14 years) with LVH and otherwise normal echocardiograms. The discriminatory measurements were myocardial A-wave duration (120 +/- 18 versus 98 +/- 20 and 92 +/- 12 ms, P <.0001), myocardial isovolumetric relaxation time (124 +/- 45 versus 95 +/- 48 and 78 +/- 25 ms, P =.0035), mitral A-wave velocity (0.98 +/- 0.37 versus 0.73 +/- 0.28 m/s and 0.61 +/- 0.22 m/s, P =.009), and mitral E-wave deceleration time (257 +/- 93 versus 201 +/- 85 ms and 184 +/- 83 ms, P =.015), which were significantly increased, and myocardial E-wave velocity (0.84 +/- 0.04 m/s versus 0.13 +/- 0.03 m/s and 0.14 +/- 0.03 m/s, P <.0001), which was significantly decreased, in patients with LVH compared with patients without LVH and normal volunteers, respectively. Left ventricular posterior wall thickness correlated with myocardial isovolumetric relaxation time (r = 0.52, P <.0001) and myocardial A-wave duration (r = 0.59, P <.0001), negatively with myocardial E wave (r = -0.43, P <.0001), and showed no correlation with mitral inflow parameters except mitral inflow A wave (r = 0.43, P =.002). On multivariate analysis using these variables, myocardial isovolumetric relaxation time (P =.0014) and A-wave duration (P =.001) were the only 2 variables that correlated with posterior wall thickness (multiple R = 0.71). In the presence of LVH and preserved left ventricular systolic function, myocardial relaxation time and velocities are more sensitive than mitral Doppler inflow parameters in detecting abnormal left ventricular relaxation.