左心室收缩功能对急性冠状动脉综合征患者经皮冠状动脉介入治疗临床转归的影响

目的探讨左心室射血分数减低的急性冠状动脉综合征患者进行经皮冠状动脉介入(PCI)治疗后的临床转归。方法110例急性冠状动脉综合征患者分为左心室射血分数正常(NEF)组和射血分数减低(DEF)组。NEF组共61例患者,男47例,女14例;DEF组共49例患者,男42例,女7例。记录PCI术后患者的重要心血管事件(包括心源性死亡、再次非致命性心肌梗死、再次心绞痛和心功能不全)。结果经过6～54个月随访发现,同NEF组相比,DEF组中术前急性广泛前壁心肌梗死多见,左心室收缩和舒张末期内径较大,高密度脂蛋白(HDL)胆固醇较低,差异有统计学意义。但二组间重要心血管事件发生率差异无统计学意义。结论对于左心室收缩功能减低的急性冠状动脉综合征患者经PCI和积极药物治疗后,近中期临床预后接近左心室收缩功能正常的患者。     

Recovery of left ventricular systolic function after left anterior descending coronary artery stenting

Our objective was to determine the factors affecting recovery of left ventricular (LV) contractility and myocardial perfusion after percutaneous coronary intervention (PCI). We selected 60 consecutive patients who underwent successful left anterior descending coronary artery (LAD) stenting. The mean stent diameter and length were 3.37+/-0.47 mm and 17.4+/-6 mm, respectively. Supporting a functional impact of successful PCI, myocardial perfusion and LV ejection fraction (LVEF) improved at 6+/-3 months after the procedure (48.8+/-11.6% vs 52.5+/-11.5%, P=0.05). Patient related factors such as diabetes mellitus, presentation with acute coronary syndrome, and age did not seem to affect LVEF change after the procedure. On univariate analysis, the change in LVEF after PCI was only related to the stent diameter. The increase in LVEF was higher in patients who received a stent>3 mm in diameter (P=0.041). There was a weak but statistically positive correlation between the stent diameter and the LVEF change after the procedure (R=0.267, P=0.049). Other procedure related factors such as multivessel PCI or stent length did not affect the percent ejection fraction change after stenting.     

Determinants of left ventricular systolic function after acute myocardial infarction: the role of residual myocardial ischaemia

BACKGROUND: Left ventricular systolic function (LVSF) is one of the major determinants of survival after acute myocardial infarction (AMI). Some factors such as the infarct size and localization, and the patency of the infarct-related artery are known determinants of LVSF. However, the long-term effect of myocardial ischaemia on LVSF has been poorly studied in clinical settings. OBJECTIVES: To assess the acute and long-term effects of myocardial ischaemia on LVSF in patients recovering from an AMI. METHODS: A cohort of 74 patients recovering from AMI was studied. Myocardial ischaemia was detected by means of ambulatory electrocardiogram (ECG) monitoring at recruitment (4+/-2 days after AMI), exercise ECG test and stress echocardiography at discharge (7+/-4 days after AMI). LVSF was studied by means of two-dimensional echocardiography at recruitment, at discharge, and at 1, 3, 6 and 12 months after AMI. RESULTS: Patients with myocardial ischaemia on ambulatory ECG monitoring and stress echocardiography had worse LVSF at recruitment than those without ischaemia. The presence of myocardial ischaemia on ambulatory ECG monitoring was an independent determinant of LVSF at recruitment together with infarct localization and size (assessed by creatine kinase MB isoenzyme (CK-MB) levels). Patients with signs of myocardial ischaemia on ambulatory ECG monitoring and stress echocardiography had a progressive left ventricular dysfunction compared with those without ischaemia. CONCLUSIONS: Residual ischaemia is an independent determinant of LVSF after AMI and its presence implied a progressive worsening of the LVSF. Because left ventricular systolic dysfunction is a major determinant of survival after AMI, its precursors, among them residual myocardial ischaemia, should be identified. Treatment of ischaemia is known to be associated with improved prognosis and improved LVSF.     

急性冠状动脉综合征患者窦性心率震荡与左心室功能的关系

目的 研究急性冠状动脉综合征(ACS)患者窦性心率震荡(HRT)现象的变化及与左心室收缩功能的关系.方法 103例ACS患者和62例健康者行24 h动态心电图检查,根据心电图检查结果计算HRT指标:震荡初始值(TO)、震荡斜率(TS)、心率变异(HRV)和全部窦性心搏RR间期的标准差(SDNN).测量左心室射血分数(LVEF)和左心室舒张末期直径(LVEDD).根据心肌酶及心电图的变化将ACS患者分为急性心肌梗死、不稳定心绞痛两个亚组.比较ACS组与对照组及ACS各亚组各变量的差异,分析HRT与LVEF及LVEDD的相关性.结果 (1)ACS组TO高于对照组(0.17±1.40)%与(-0.26±0.99)%,差异有统计学意义(P＜0.05);TS低于对照组[RR间期分别为(0.88±2.51)ms与(2.60±2.76)ms,差异有统计学意义(P＜0.01)].(2)ACS患者两亚组比较,TS、LVEF、LVEDD差异有统计学意义(均P＜0.01).(3)LVEF与TS呈正相关(r=0.21,P＜0.05);与TO负相关(r=-0.26,P＜0.05).结论 ACS患者窦性HRT减弱,提示ACS患者的心脏自主神经调节功能下降,HRT可作为一个评价左心室功能和预后的指标.

Abstract：

Objective To observe the change of sinus heart rate turbulence (HRT) and its relation to left ventricular systolic function (LVSF) in patients with acute coronary syndrome (ACS). Methods The 103 ACS patients and 62 healthy subjects were enrolled in this study, all of them received 24-hour Holter monitor. And the values of turbulence onset (TO), turbulence slope (TS)and heart rate variability (HRV) SDNN were calculated according the Holter records. The clinical information, left ventricular ejection fraction (LVEF) and left ventricular end diastolic diameter (LVEDD) were recorded. Then the ACS patients were divided into acute myocardial infarction (AMI)group and unable angina pectoris (UAP) group according to the cardiac enzymes and electrocardiogram. Results The value of TO was significantly higher in ACS group than in control group [(0.17±1.40)％ vs. (- 0.26±0.99)％, P＜0.05], and TS was significantly lower in ACS group than in control group [R-R interval:(0.88±2.51) ms vs. (2.60±2.76) ms, P＜0.01].There were significant differences in TS, LVEF and LVEDD between AMI group and UAP group (all P＜0.01), but there were no differences in HRV and TO between the two groups. TS was positively correlated with LVEF (r=0.21, P＜0.05), while TO was negatively correlated with LVEF (r=-0.26, P＜0.05) by Spearman correlation analysis. Conclusions HRT is significantly blunted in ACS patients and can evaluate cardiac autonomic function. It may be as a predictor of LVSF in ACS patients.     

Impaired left ventricular systolic function after a half-ironman race.

OBJECTIVE: To assess the effects of prolonged strenuous exercise in the form of a half-ironman (HI) race (2 km swim, 90 km bike ride and a 21 km run) on left ventricular systolic function. METHODS AND RESULTS: The study participants consisted of nine male triathletes (mean age +/- SD 32+/-5 years) who competed in the Great White North HI race. Two-dimensional transthoracic echocardiograms were obtained two to three days before the HI (prerace), immediately after completion of the HI (postrace) and 24 h after cessation of exercise. Compared with before the race, performing an HI was associated with a decline in systolic blood pressure (prerace 127.2+/-15.0 mmHg compared with after the race 116.1+/-10.2 mmHg, P<0.05), the systolic blood pressure to end-systolic cavity area ratio (a surrogate for left ventricular contractility - prerace 14.3+/-3.0 mmHg/cm(2) compared with postrace 11.0+/-2.2 mmHg/cm(2), P<0.05) and the fractional area change (prerace 54.1+/-3.8% compared with postrace 47.4+/-5.5%, P<0.05). There was also a concomitant increase in heart rate (prerace 56.3+/-9.4 beats/min compared with postrace 74.1+/-10.7 beats/min, P<0.05), the end-systolic cavity area (prerace 9.2+/-2.2 cm(2) compared with postrace 10.8+/-1.9 cm(2), P<0.05) and the end-systolic cavity area to end-systolic myocardial area ratio (prerace 0.39+/-0.08 compared with postrace 0.51+/-0.1, P<0.05), which returned toward baseline values 24 h after cessation of the HI. CONCLUSIONS: Performing an HI appears to be associated with a transient impairment in left ventricular contractility and a subsequent decline in left ventricular systolic function that tends to return toward normal values within 24 h after cessation of exercise.     

Delayed recovery of left ventricular function after recanalization of a chronic coronary occlusion.

An unusually prolonged course of recovery of severely impaired left ventricular (LV) function (EF 32%) was observed in a patient after recanalization of a chronically occluded LAD. Despite persistent vessel patency, LV function remained depressed for almost 2 years after the percutaneous transluminal coronary angioplasty until complete recovery (EF 82%) could be observed. The possibility of a delayed recovery should be considered when assessing new therapeutic strategies to improve LV function of chronically ischemic myocardium.     

Effects of captopril on left ventricular systolic and diastolic function after acute myocardial infarction.

The left ventricle progressively dilates in some patients after acute myocardial infarction (AMI). Both systolic and diastolic left ventricular (LV) dysfunction can be of significance in the development of heart failure. Captopril has been shown to prevent dilatation, but the effect on LV diastolic function is unknown. In a placebo-controlled double-blind parallel study, 58 AMI patients with heart failure or low ejection fraction, or both, were consecutively randomized at day 7 to either placebo or captopril (25 mg twice daily). No differences were present between the groups at baseline. Fifty-three patients completed the 6-month study period. Both LV diastolic and systolic volume indexes increased significantly in the placebo group (17 and 14%, respectively); in the captopril group there was no change in LV diastolic volume index, but a 13% reduction in LV systolic volume index. Ejection fraction increased significantly in the captopril group. The peak flow velocities of the early and atrial filling phases were measured, and the ratio between the velocities was calculated. A significant reduction was observed during the study period in early peak flow velocity (65 to 52 cm/s) and in the ratio between early and atrial peak flow velocity (1.3 to 0.8) in the placebo group (p less than 0.05), but no significant changes occurred in the captopril group. No correlation was found between dilatation of the left ventricle and reduction in early peak flow velocity or the ratio between early and atrial peak flow velocity. In conclusion, captopril prevented LV dilatation, improved ejection fraction and prevented LV diastolic dysfunction in AMI patients with early signs of LV systolic dysfunction.     

Usefulness of coronary angiography for assessing left ventricular systolic function

OBJECTIVE: In previous echocardiographic studies, a correlation between ejection fraction of the left ventricle and change in the movement of the mitral annular ring was found. In the light of these studies, we planned to investigate the relationship between systolic shortening (SS) and percent of systolic shortening (PSS), calculated from the long axis frame in coronary angiography and left ventricular systolic function. METHODS AND RESULTS: One hundred and thirty-eight patients (40 men and 98 women; mean age 58 +/- 10 years) who had been referred for coronary angiography and left ventriculography were included in the study. Ejection fraction (EF) was calculated from left ventriculography obtained from 30 degrees right anterior oblique projection. Distance from the lower border of the ostium of the left coronary artery to the most apical border of the left anterior descending (LAD) artery was measured at end-systole (ES) and end-diastole (ED) using coronary angiography obtained from the same projection. SS as ED-ES and PSS as SS/ED were calculated. Correlation of SS and PSS with EF was calculated (EF = 13.7 + 4.8 x SS, r = 0.91, p < 0.001 and EF = 14.2 + 6.5 x PSS, r = 0.90, p < 0.01). SS < 7 mm (criterion A) and PSS < 6% (criterion B) suggested that left ventricle EF was less than 50%, with a sensitivity, specificity and diagnostic accuracy of 83%, 100%, 95%; 95%, 86% and 88%, respectively. CONCLUSION: SS and PSS highly significantly correlate with left ventricular EF. Therefore, left ventriculography could be omitted in selected patients undergoing coronary angiography if it is not necessary to define the anatomic structure of the left ventricle.     

Usefulness of coronary angiography for assessing left ventricular systolic function

In previous echocardiographic studies, a correlation between ejection fraction of the left ventricle and change in the movement of mitral annular ring was found. In the light of these studies we planned this study to investigate the relationship between systolic shortening (SS) and percent of systolic shortening (PSS), calculated from long axis frame in coronary angiography and left ventricular systolic functions. One hundred and thirty eight patients (40 women and 98 men; mean age 58±10 years) who had been referred for coronary angiography and left ventriculography were included in the study. Ejection fraction (EF) was calculated from left ventriculography obtained from 30° right anterior oblique projection. Distance from lower border of the ostium of left coronary artery to the most apical border of left anterior descending (LAD) artery was measured at end-systole (ES) and end-diastole (ED) using coronary angiography obtained from the same projection. SS as ED-ES and PSS as SS/ED were calculated. Correlation of SS and PSS with EF was calculated (EF=13.7+4.9×SS, r=0.91 and EF=14.2+6.5×PSS, r=0.90). SS<7 mm and PSS<6% indicated that left ventricle EF was less than 50%, with a sensitivity, specificity and diagnostic accuracy 83%, 100%, 95%; 95%, 86% and 88%, respectively. In conclusion, SS and PSS calculated from coronary angiography have high correlation with left ventricular EF. Therefore, left ventriculography can be omitted in selected patients undergoing coronary angiography if it is not necessary to define the anatomic structure of left ventricle.     

Long-term recovery of left ventricular function after primary angioplasty for acute myocardial infarction.

AIMS: To investigate changes in left ventricular function in the first 6 months after acute myocardial infarction treated with primary angioplasty. To assess clinical variables, associated with recovery of left ventricular function after acute myocardial infarction. METHODS: Changes in left ventricular function were studied in 600 consecutive patients with acute myocardial infarction, all treated with primary angioplasty. Left ventricular ejection fraction was measured by radionuclide ventriculography in survivors at day 4 and after 6 months. Patients with a recurrent myocardial infarction within the 6 months were excluded. RESULTS: Successful reperfusion (TIMI 3 flow) by primary angioplasty was achieved in 89% of patients. The mean ejection fraction at discharge was 43.7%+/-11.4, whereas the mean ejection fraction after 6 months was 46.3%+/-11.5 (P<0.01). During the 6 months, the mean relative improvement in left ventricular ejection fraction was 6%. An improvement in left ventricular function was observed in 48% of the patients; 25% of the patients had a decrease, whereas in the remaining patients there was no change. After univariate and multivariate analysis, an anterior infarction location, an ejection fraction at discharge < or =40% and single-vessel disease were significant predictors of left ventricular improvement during the 6 months. CONCLUSIONS: After acute myocardial infarction treated with primary angioplasty there was a significant recovery of left ventricular function during the first 6 months after the infarction. An anterior myocardial infarction, single-vessel coronary artery disease, and an initially depressed left ventricular function were independently associated with recovery of left ventricular function. Multivessel disease was associated with absence of functional recovery. Additional studies, investigating complete revascularization are needed, as this approach may potentially improve long-term left ventricular function.     

Tissue doppler imaging predicts recovery of left ventricular function after recanalization of an occluded coronary artery

OBJECTIVES: We tested the hypothesis that the tissue Doppler imaging (TDI)-derived positive preejection velocity (+VIC) can predict the recovery of contractile function after revascularization in patients with a recent myocardial infarction. BACKGROUND: In experimental studies, the presence and extent of TDI-derived +VIC correlated with the extent of viable myocardium. METHODS: Forty-three patients with a large myocardial infarction and an occluded left anterior descending (n = 38) or dominant right coronary (n = 5) artery were selected. The median duration of occlusion was 24 h. Longitudinal myocardial velocities were recorded at rest by pulsed-wave TDI echocardiography 6 +/- 2 h after revascularization. Functional recovery was defined as an increase in segmental chordal shortening > or =10% at three-month follow-up left ventricular angiogram as compared with baseline. RESULTS: A good quality TDI signal was obtained in 309 of 324 analyzed segments (95.4%). Severe dysfunction was present in 198 segments of which 126 (64%) showed recovery at three-month follow-up. Sampling of all dysfunctional segments lasted 11 +/- 4 min per patient. Sensitivity, specificity, and accuracy of the +VIC to predict segmental recovery were 91%, 71%, and 84%, respectively. The percentage of segments that were dysfunctional at angiography but showed a +VIC correlated with improvement of both global left ventricular ejection fraction (r = 0.60, p = 0.001) and wall motion score index (r = -0.78, p < 0.0001) at follow-up. CONCLUSIONS: Assessment of +VIC by pulsed-wave TDI is a simple and accurate method that predicts recovery of contractile function after revascularization in patients with a recent myocardial infarction.     

Determinants of improved left ventricular function after thrombolytic therapy in acute myocardial infarction

Many studies have been performed to evaluate the efficacy of thrombolytic therapy in achieving reperfusion, salvaging myocardium and enhancing survival. This review discusses the concordance between the results of these clinical studies and the observations made in experimental animals of the effect of reperfusion on the recovery of left ventricular function. The evaluation of functional recovery is affected by the timing of the measurement and the sensitivity of the method for detecting regional abnormalities. In addition, the underlying coronary anatomy also determines outcome, so that infarct location, collateral circulation and the degree of coronary obstruction merit consideration. Two factors are of paramount importance in determining the amount of myocardium salvaged, the recovery of left ventricular function and the reduction in mortality. These factors are: the time delay until reperfusion is achieved and the adequacy of the coronary reflow. The close agreement between studies measuring the effect of reperfusion on left ventricular function and studies with mortality as the end point provides indirect evidence that enhancement of survival in patients treated with thrombolytic agents is mediated by recovery of ventricular function.     

Determinants of left ventricular function one year after cardiac transplantation.

Left ventricular systolic function was assessed by radionuclide angiography in 107 consecutive transplant recipients who were alive one year after operation. Mean (SEM) ejection fraction was 62.4 (4.6) at rest and 68.8 (5.4) on exercise. The influence of donor-related factors (donor age and sex, ischaemia time), recipient-related factors (recipient age and sex, frequency of acute rejection), type of immunosuppression (cyclosporin/azathioprine or prednisolone/azathioprine), and frequency of hypertension on left ventricular function one year after operation was examined by univariate and multivariate analysis. There was a close association both at rest and on exercise between a higher ejection fraction and treatment with cyclosporin/azathioprine. There was a trend for lower donor and recipient age, shorter ischaemia time, and fewer rejection episodes to be associated with better left ventricular function, but this was not statistically significant. Left ventricular systolic function was well maintained in most patients a year after cardiac transplantation. The type of immunosuppression used had a strong influence on the left ventricular systolic function of the transplanted heart.     

Right ventricular systolic function and ventricular interaction during acute embolisation of the left anterior descending coronary artery in sheep.

OBJECTIVE: Regional LV ischemia involving the septum affects LV systolic function and geometry. We investigated the effects of these changes on RV function and geometry. METHODS: In six closed-chest sheep end-systolic pressure-volume relationships (ESPVRs) were constructed from ventricular volumes, measured with magnetic resonance imaging (MRI) and matching intraventricular pressures, before and after selective embolisation of the left anterior descending coronary artery (LAD). The extent of myocardial ischemia was assessed post-mortem by coronary perfusion with Evans-Blue. Alterations in septal geometry were studied by measuring the curvature, segmental length and thickness of the septum in two midventricular (short-axis) MRI slices before and during ischemia. From these data, changes in LV and RV free wall segmental lengths were calculated. RESULTS: Selective embolisation of the LAD resulted in left ventricular ischemia (15 +/- 2.1% of the total LV) with 23% of the septum involved. Stroke volume did not change significantly, while LV systolic pressure decreased by 24 mmHg (p < 0.05). Although RV systolic function decreased to a significantly lesser extent than LV function (p < 0.01), systolic function of both ventricles diminished significantly as indicated by substantial rightward shifts of the ESPVRs: 121% for LV and 41% for RV (both p < 0.01). At mid-ventricular level and end-systole, the septum showed significant increases in its radius of curvature and segmental length (both p < 0.05), and a significant wall thinning (p < 0.01). Calculated end-systolic lengths of LV and RV free walls also increased, by 57 and 14% respectively. CONCLUSIONS: LAD embolisation not only results in a significantly diminished LV systolic function but also causes RV systolic function to decline significantly. Regional dysfunction by necessity entails global dysfunction as well. Analysis of ventricular geometry reveals that both the septum and the RV free wall increase their length, which plays an important role in the pathophysiology of diminished RV systolic function concomitant with reduced LV function.     

冠状动脉粥样硬化程度与左室收缩功能的关系

目的：探讨冠状动脉粥样硬化程度与左室收缩功能之间的关系。方法：回顾性分析复旦大学附属中山医院心导管室的冠状动脉造影病例205例，将其冠脉病变程度按Gensini积分系统进行评定，将Gensini积分及各危险因素与短轴缩短分数，左室射血分数之间行二变量的Spearman相关性分析及控制影响Gensini积分与短轴缩短分数、左室射血分数相关的其它变量的偏相关分析，再将左室射血分数与Gensini积分及各危险因素作多元逐步回归分析。结果：Gensini积分与短轴缩短分数（r=一0．32，P〈0．01），左室射血分数（r=一0．33，P〈0．01）之间呈负相关，在控制了影响相关的其它变量后Gensini积分仍与短轴缩短分数（r=一0．26，P〈0．01），左室射血分数（r=一0．28，P〈0．01）之间呈负相关，多元逐步回归显示冠状动脉粥样硬化程度为左室收缩功能的独立影响因子（B=一0．378，P〈0．01）。结论：冠状动脉粥样硬化程度与左室收缩功能是独立相关的。     

Specific tissue Doppler predictors of preserved systolic and diastolic left ventricular function after an acute anterior myocardial infarction

The degree of left ventricular (LV) dysfunction determines the outcome of patients suffering an acute anterior myocardial infarction (AAMI). Many recent studies have utilized tissue Doppler echocardiography (TDE) parameters in the assessment of LV function. We sought to investigate whether some variables easily obtained from TDE profiles of mitral annulus corners would predict a relatively preserved LV global function traditionally assessed with ejection fraction (EF) and deceleration time (DT), within the acute phase of AAMI. Included were 50 consecutive patients with a first AAMI. Standard echocardiography and TDE of mitral annulus were performed within 36 hours of admission. Pulsed wave sample volumes were set at the septal, lateral, anterior, and inferior corners of the mitral annulus. Preserved LV function was defined as an EF > 40% together with a DT > or = 140 ms and < 220 ms. An inferior annular systolic velocity of > 7.5 cm/s predicts preserved global left ventricular function with a sensitivity of 81% and specificity of 71%. An anterior mitral annular early diastolic velocity of > 8cm/s had a sensitivity of 69% and specificity of 85%. When these two velocities both exceed the limits above, such a combined index yielded a sensitivity of 69%, specificity of 94%, and an overall diagnostic accuracy of 86% for the estimation of preserved LV global function. The parameters derived from TDE profiles of inferior and anterior mitral annulus comers provide valuable information to predict preserved global left ventricular function during the early period of AAMI.