Detection of occult left ventricular dysfunction in patients without prior clinical history of myocardial infarction by technetium-99m sestamibi myocardial perfusion gated single-photon emission computed tomography

BACKGROUND: In the absence of a prior history of myocardial infarction (MI), left ventricular (LV) dysfunction is commonly due to hypertension, valvular heart disease, or hibernating myocardium. HYPOTHESIS: Since technetium-99m sestamibi gated single-photon emission computed tomography (SPECT) may be used to determine both stress/rest myocardial perfusion and resting LV function, we attempted to evaluate the ability of gated SPECT imaging to detect occult LV dysfunction. METHODS: We evaluated the ability of this technique to detect occult LV dysfunction among 179 patients without history MI and angiographically documented coronary artery disease (CAD). All patients underwent both gated SPECT and cardiac catheterization within a 6-month time period. Left ventricular volume and ejection fraction (EF) values were determined according to a previously validated technique using Simpson's rule. Normal limit values for LV volumes and EF were derived from a control population of 93 patients with normal coronary angiograms. RESULTS: Based on normal limit-derived criteria, 15% of the CAD study cohort had occult LV dysfunction (> 2 standard deviations below gender-specific normal limit means for LVEF). Mean LV end-diastolic volume index (EDVi) was significantly increased (p < 0.05) and LVEF decreased (p < 0.05) in patients with triple-vessel CAD. End-diastolic volume index was also increased in the cohort of patients with both hypertension and LV hypertrophy (LVH) (p < 0.05). However, multivariate logistic regression analysis revealed that only CAD extent, but not hypertension or LVH, was a significant predictor of occult LV dysfunction (p = 0.009). CONCLUSION: Occult LV dysfunction can be detected in patients with CAD by gating technetium-99m sestamibi SPECT studies, and its presence may signify the presence of extensive CAD.     

Effect of recanalization of chronic total occlusions on global and regional left ventricular function in patients with or without previous myocardial infarction.

Previous studies have demonstrated improvement of regional wall motion and global left ventricular function after successful recanalization of chronic total occlusion in coronary artery. However, the difference of benefits of recanalization between infarct site and noninfarct site is unknown. This study assessed the changes in left ventricular ejection fraction, regional wall motion after successful angioplasty of chronic total occlusions with or without previous myocardial infarction. This study also evaluated the factors that influenced the outcome of left ventricular function. We retrospectively studied 75 patients with a successfully recanalized chronic total occlusion in native coronary artery. Left ventriculograms were obtained at baseline and after 6 months. Global and regional left ventricular function were determined. The patients were divided into two groups. Group 1 comprised patients without previous myocardial infarction in the territories of total occlusion vessel that was recanalized. Group 2 comprised patients with previous myocardial infarction in the territories of total occlusion vessel that was recanalized. Left ventricular ejection fraction increased from 53.2% +/- 16.3% at baseline to 57.3% +/- 20.1% at 6-month follow-up in the whole group (P = 0.001). In group 1 patients, the evolution of left ventricular (LV) ejection fraction increased from 59.5% +/- 13.7% to 67.3% +/- 14.6% (P < 0.001). In group 2 patients, the evolution of LV ejection fraction increased, but not significantly, from 48.9% +/- 16.2% to 50.5% +/- 16.9% (P = NS). The evolution of LV ejection fraction increased from 47.6% +/- 17.4% to 50.8% +/- 17.5% (P < 0.05) in the subgroup of recanalization in infarct-related vessel that had rich collateral circulation and had long-term patency. The regional wall motion all significantly improved in group 1 patients (P < 0.05). The regional wall motion did not change in group 2 patients (P = NS). The influence of recanalization of chronic coronary occlusions on the improvement of left ventricular global function was different between myocardial infarction and nonmyocardial infarction patients. The left ventricular function did not improve in myocardial infarction patient. Regional wall motion improved in patients without previous myocardial infarction. For reliable improvement of left ventricular function after recanalization of chronic total occlusions, evidence (not only by symptom or treadmill test) of viable myocardium in recanalized vessel is important. It is also important to keep patency of infarct-related vessel that has good collateral circulation for improving the left ventricular function.     

Quantitation of left ventricular wall motion in normal subjects: Comparison of various methods

Computer-assisted analysis of percent change in the square root of area in each of 12 consecutive 30-degree, pie-shaped ventricular segments was obtained in 48 normal subjects who underwent cardiac catheterization and left ventriculography. The information obtained permitted establishment of objective confidence limits for normal left ventricular regional wall motion. As an index of dynamic changes in segmental wall motion, the percent change in the square root of area method compared favorably with existing radius, area, hemichord, and chord methods. It also possessed a variety of theoretical advantages over these techniques: 1) large numbers of points were analyzed, 2) wall motion disorders in all areas except base were evaluated, 3) taking the square root of area's percent change provided both area information with least splay and an average measure of radius.     

Comparison of echocardiography and radionuclide ventriculography in the follow-up of left ventricular systolic function in adult lymphoma patients during doxorubicin therapy

OBJECTIVES: To compare echocardiography (ECHO) and radionuclide ventriculography (RVG) in the monitoring of left ventricular systolic function during doxorubicin therapy in adult lymphoma patients. DESIGN: Prospective study. SETTINGS: University hospital. SUBJECTS: A total of 28 adult patients who received doxorubicin to a cumulative dose of 400-500 mg m(-2). MAIN OUTCOME MEASURES: ECHO and RVG were performed at baseline and after cumulative doxorubicin doses of 200, 400 and 500 mg m(-2). RESULTS: At baseline, the mean (+/-SE) left ventricular ejection fractions (LVEF) were 58 +/- 1.3, 71 +/- 1.8 and 58 +/- 1.7% as determined by RVG, M-mode ECHO and two-dimensional (2D) ECHO, respectively. After the cumulative doxorubicin dose of 500 mg m(-2) LVEF decreased to 49.6 +/- 1.7% (RVG) (P < 0.001), 62 +/- 1.6% (M-mode) (P=0.006) and 52.5 +/- 1.3% (2D ECHO) (P=0.036). Although a significant correlation between LVEF determined by RVG and M-mode ECHO (r=0.615, P=0.002) and a trend between RVG and 2D ECHO (r=0.364, P=0.096) were observed, there were substantial differences in the results of individual patients. In the agreement analysis using the method of Bland and Altman there was a mean difference of 12% units with the upper limit of agreement +26% units and the lower limit of agreement -2.1% units for LVEF determinations with M-mode ECHO and RVG, and a mean difference of 3.3% units with upper and lower limits of agreement +19.6 and -13.1% units for LVEF determinations with 2D ECHO and RVG, respectively. CONCLUSION: We found only a moderate agreement between left ventricular systolic function determined by ECHO and RVG methods. Thus, in the follow-up of left ventricular function in adult patients during doxorubicin therapy, the guidelines based on LVEF measurement by RVG cannot be applied to ECHO. Consequently, RVG remains the method of choice in this context.     

Comparison of intravenous digital subtraction cineangiocardiography with conventional contrast ventriculography for the determination of the left ventricular volume at rest and during exercise

Left ventricular volumes were determined by means of digitalsubtraction cineangiocardiography (DSA) which was performedin the right anterior oblique projection after contrast agentinjection into the superior vena cava. Monoplane end-diastolic(EDV), end-systolic volumes (ESV), and ejection fraction (EF)were calculated using the ‘area–length’ methodand were compared with the same parameters obtained by conventionalleft ventricular cineangiocardiography. A first group of 20patients was studied at rest and a second group of 10 patientsduring bicycle exercise at a work load of 64 watts during 2min, by DSA and conventional cineangiocardiography. Three differentsubtraction modes were evaluated: (1) mask mode subtraction(MMS), (2) time interval difference (TID) method and (3) a combinationof MMS and TID called MMS+TID method. With the MMS method goodcorrelations were obtained for EDV, ESV and EF at rest (r>0.91)and during exercise (r>0.91). The TID method showed onlymoderate correlations for patients at rest (r>0.86) and duringexercise (r>0.79). Similar results as with MMS were achievedby the combined method (MMS+TID) at rest (r>0.91) and duringexercise (r>0.91). Interobserver variability indicated ahigh reproducibility for all methods except for TID during exercise.Itis concluded that DSA is an accurate technique for left ventricularvolume determination not only at rest but also during exercise.The best results are obtained with MMS or MMS+TID methods, whileleft ventricular contour detection is easier and more convenientwith MMS+TID.     

Assessment of left ventricular function by electrocardiogram-gated myocardial single photon emission computed tomography using quantitative gated single photon emission computed tomography software]

Electrocardiogram (ECG)-gated myocardial single photon emission computed tomography (SPECT) can assess left ventricular (LV) perfusion and function easily using quantitative gated SPECT (QGS) software. ECG-gated SPECT was performed in 44 patients with coronary artery disease under post-stress and resting conditions to assess the values of LV functional parameters, by comparison to LV ejection fraction derived from gated blood pool scan and myocardial characteristics. A good correlation was obtained between ejection fraction using QGS and that using cardiac blood pool scan (r = 0.812). Some patients with myocardial ischemia had lower ejection fraction under post-stress compared to resting conditions, indicating post-stress LV dysfunction. LV wall motion and wall thickening were significantly impaired in ischemic and infarcted myocardium, and the degree of abnormality in the infarcted areas was greater than in the ischemic area. LV functional parameters derived using QGS were useful to assess post-stress LV dysfunction and myocardial viability. In conclusion, ECG-gated myocardial SPECT permits simultaneous quantitative assessment of myocardial perfusion and function.     

Sensitivity of cross-sectional echocardiography in detection of impaired global and regional left ventricular function: prospective study

In order to establish the sensitivity and specificity of cross-sectional echocardiography for detection of global and regional left ventricular function a prospective study was performed in 80 patients suspected of having coronary artery disease. Twenty four hours before heart catheterization, cross-sectional echocardiograms were recorded in the apical RAO-equivalent view and high quality echocardiograms were obtained in 71/80 patients (89%). M-mode echocardiograms of the left ventricle could be performed in 56/71 patients (79%). Based on normal values sensitivity and specificity of cross-sectional echocardiography were calculated in comparison to cineventriculography. For fractional shortening (normal value greater than 25%) sensitivity measured 46% and specificity 93%, and when the E-point septal separation was measured (normal value less than 7 mm), sensitivity increased to 73% and specificity was 84%. For detection of increased end-diastolic volume (less than 155 ml) sensitivity reached 84% and specificity 98% and for increased end-systolic (less than 70 ml) volume it was 86 and 97%, respectively. A depressed left ventricular ejection fraction (greater than 49%) was found with a sensitivity of 93% and specificity of 100%. Regional left ventricular wall motion, analyzed by an area method, revealed for anterior wall motion a sensitivity of 68% and a specificity of 94%, whereas for posterior wall motion sensitivity reached 80% and specificity 96%. Regression equation between the number of pathological segments and left ventricular ejection fraction for cineventriculography was given by Y = -4.06 X + 73.4, r = 0.93 and for cross-sectional echocardiography by Y = -3.69 X + 62.6, r = 0.85. We conclude that cross-sectional echocardiography can be used as a screening method to detect impaired left ventricular function. It is superior to M-mode echocardiography. Reduced regional function of the posterior wall can be found with high sensitivity, but depressed motion of the anterior wall may be overlooked.     

ECToolbox软件测量99Tcm-MIBI门控心肌显像左室射血分数临床研究

目的评价ECToolbox软件测量门控心肌显像左室射血分数（LVEF）的临床价值。方法使用ECToolbox软件,将58例99Tcm-MIBI门控心肌显像患者按左室舒张末容积（EDV）分为〈70 ml、70～100 ml及≥100 ml三组,分别测量并记录其R0、R1及R2的LVEF,并于1周内行门控心血池显像,比较两种显像LVEF测量值的相关性和一致性。结果 EDV〈70 ml时门控心肌显像与心血池测量值没有相关性,3种测量值均被显著高估,R1值相对最接近门控心血池测量值。EDV在70～100 ml时,门控心肌显像与心血池显像测量值具有相关性,R1值与心血池显像测量值无显著差异。EDV≥100 ml时,门控心肌显像与心血池显像测量值具有极强的相关性,R0值与心血池显像测量值无显著差异。R0在EDV〈70 ml和EDV≥100 ml时以及R1在各组中对心脏收缩功能是否正常的判断与心血池显像的一致性较好。结论门控心肌显像ECToolbox软件LVEF测量值与心血池显像的相关性与一致性均与EDV大小有关,EDV〈100 ml时应使用R1值,但当EDV〈70 ml时误差可能较大,EDV≥100 ml时应该使用R0值。     

Radionuclide assessment of regional differences in left ventricular wall motion and myocardial perfusion in idiopathic dilated cardiomyopathy

Regional variations in left ventricular contractility and myocardialperfusion are frequent in idiopathic dilated cardiomyopathyand might result from an increase in left ventricular wall stressresponsible for regional wall motion abnormalities. The aimof the study was to perform radionuclide studies in patientswith idiopathic dilated cardiomyopathy to assess regional leftventricular wall motion and myocardial perfusion abnormalitiesin this myocardial disease. We studied 29 men referred withidiopathic dilated cardiomyopathy and normal coronary angiograms.Rest radionuclide left ventriculography and exercise thallium-201tomography were performed in all patients. The thallium-201tomograms were divided into 20 segments for each patient. Meanleft ventricular ejection fraction was 27±11%; 17 patientshad diffuse hypokinesia (mean left ventricular ejection fraction:24±9%) and 12 patients had predominant regional hypokinesia(mean left ventricular ejection fraction: 32±12%). Ofall 580 tomographic segments, 186 had a reduction of thallium-201uptake at exercise. Among them, reversibility was found in 53%.On the whole, 68% (158/232) of anterior, inferior and apicalsegments had a perfusion abnormality, compared with 8% (28/348)of septal and lateral segments (P<0.0001). Left ventricular wall motion and myocardial perfusion abnormalitiesare heterogeneous and not evenly distributed in dilated cardiomyopathy.The alterations are predominant on the myocardial regions delineatingthe antero-posterior axis of the left ventricle. These findingssuggest the possible role of increased left ventricular wallstress on this axis.     

The prevalence and prognosis of ventricular dyskinesis after myocardial infarction using radionuclide ventriculography

To assess the prevalence and prognosis of ventricular dyskinesis,radionuclide ventriculography was performed on 100 consecutivepatients just before discharge from hospital following theirfirst myocardial infarction; thereafter follow-up studies wereperformed after one and four months. Dyskinesis of the leftventricle was seen in 25 patients who had sustained transmuralinfarction which was anterior in 19 and inferolateral in six.Clinical examination poorly predicted dyskinesis; 20 patientsexhibited persisting ST segment elevation on the electrocardiogram,but only 10 had radiological cardiomegaly at the time of discharge.Mean left ventricular ejection fraction (LVEF) was significantlyreduced at discharge (0.23 ± 0.07, mean ± 1 S.D)and for the group failed to improve four months after infarction.However, 10 patients remained free from cardiac failure duringfollow-up and could be distinguished by otherwise good leftventricular regional wall movement.     

Simultaneous contrast imaging of the left ventricle by two-dimensional echocardiography and standard ventriculography

Simultaneous contrast two-dimensional echocardiograms and contrast ventriculograms were analyzed for 19 cardiac cycles in 6 patients. Ventriculographic volume was underestimated by 40 ± 4.5% (p <.001) by the contrast echocardiograms, despite good correlation (r = 0.88). Discrepancies could not be assigned to changes in volume between studies nor to a lack of precise endocardial definition. Simultaneous imaging demonstrated that the ultrasonic transducer was located 33° cephalad to the cardiac apex. Although angiographic volume was severely underestimated, ejection fraction (r = 0.93) and stroke volume (r = 0.90) could be calculated from two-dimensional echocardiograms using regression equations.     

核素心室造影评价不同部位心肌梗死患者的左室整体和局部功能

目的应用放射性核素心室造影技术对不同部位的左室心肌梗死（MI）患者进行左室整体和局部收缩和舒张功能参数的对比分析。方法选择对照组15例、下壁MI组24例、前壁MI组29例,利用放射性核素心室造影技术评价3组的左室整体和局部的收缩与舒张功能参数。结果①左室整体收缩功能,在左室射血分数和峰射血率二个参数中,下壁MI组与对照组相比有显著下降（P<0.05）,前壁MI组与对照组和下壁MI组相比,分别有显著下降（P<0.05）。②左室整体舒张功能,在峰充盈率和前1/3充盈分数二个参数中,前壁MI组与对照组和下壁MI组相比分别有显著下降（P<0.05）。③左室局部收缩功能,在以左室局部射血分数为参数时,下壁MI组在4个节段与对照组相比有显著下降（P<0.05）,前壁MI组在4个节段与对照组相比有显著下降（P<0.05）,前壁MI组在2个节段比下壁MI组有显著下降（P<0.05）。④左室局部舒张功能,在以LVR1/3FF为参数时,下壁MI组和前壁MI组分别与对照组相比在4个节段上有显著下降（P<0.05）,前壁MI组在2个节段上比下壁MI组有显著下降（P<0.05）。结论前壁MI对左室整体和局部收缩与舒张功能的损害重于下壁MI。     

平衡法门控心血池显像评价不同分级前壁心肌梗死患者左室收缩及舒张功能

目的我们应用平衡法门控心血池显像技术对不同Killip分级的前壁心肌梗死患者进行左室总体和局部收缩和舒张功能参数的对比分析。方法对照组15例（G0）,前壁心肌梗死KillipⅠ级17例（G1）,前壁心肌梗死KillipⅡⅢ级12例（G2）。利用平衡法门控心血池显像技术评价3组的左室总体和局部的收缩与舒张功能。结果①左室整体收缩功能,在LVEF,ESC 2个参数中,G1比G0有显著差异（P<0.05）,G2分别比G1和G0有显著差异（P<0.05）。在PER、1/3EF、1/3ER 3个参数中,G2分别比G1和G0显著下降（P<0.05）。②左室总体舒张功能,在PFR、1/3FF、1/3FR、EDC中,G1比G0有显著差异（P<0.05）,G2分别比G1和G0有显著差异（P<0.05）。③左室局部收缩功能,在以LVREF为参数时,G1在4个节段比G0显著差异（P<0.05）,G2在所有6个节段中比G1和G0均显著下降（P<0.05）。④左室局部舒张功能,在以LVR1/3FF为参数时,G1在4个节段比G0显著下降（P<0.05）,G2在所有6个节段比G0和G1均显著下降（P<0.05）。结论前壁心肌梗死后出现心功能受损或心力衰竭的主要原因为左室重构。     

Low-dose dobutamine radionuclide ventriculography for prediction of myocardial viability: quantitative analysis of regional left ventricular function

BACKGROUND: It is important to distinguish viable myocardium from necrotic tissue in order to decide upon therapy in patients with ischemic heart disease. HYPOTHESIS: We verified the hypothesis that quantitative analysis of regional left ventricular function using low-dose dobutamine radionuclide ventriculography (RNV) can sensitively predict myocardial viability and compared its usefulness with thallium-201 (201Tl) single-photon emission computed tomography (201Tl-SPECT). METHODS: Radionuclide ventriculography at rest and during low-dose dobutamine infusion (5 micrograms/kg/min), 201Tl-SPECT, and coronary angiography were performed in 51 subjects with severe ischemia-related stenosis of coronary arteries and 3 subjects without coronary artery disease. 201Tl uptake was assessed as normal (control), low perfusion (LP), or defect. We compared the response of regional function to dobutamine with the regional 201Tl uptake. The accuracy of both methods for identifying viable myocardium was investigated in 17 patients who underwent successful coronary revascularization, with a resulting improvement in wall motion. RESULTS: The increase in regional ejection fraction (delta r-EF) in response to dobutamine was significantly greater in the control (12 +/- 6%) and LP (16 +/- 11%) regions than in the defect (5 +/- 10%) regions. The increase in one-third regional ejection fraction (delta r-1/3EF) was also significantly higher in the control (14 +/- 7%) and LP (10 +/- 8%) regions than in the defect regions (5 +/- 6%). We defined myocardial viability as a delta r-EF > 5% or a delta r-1/3EF > 2%. The sensitivity and specificity of the delta r-EF for identification of myocardial viability were 91.4 and 55.5%, respectively. The sensitivity and specificity of the delta r-1/3EF were 91.4 and 66.6%, respectively; the corresponding values for 201Tl SPECT were 74.2 and 77.8%. CONCLUSION: Low-dose dobutamine RNV with quantitative analysis of regional left ventricular function was more sensitive for identification of viable myocardium than 201Tl-SPECT.     

Use of intravenous digital subtraction ventriculography in the evaluation of left ventricle volumes and ejection fraction

Although intravenous digital subtraction ventriculography (IDSV) is increasingly used to estimate end-diastolic left ventricular volume (EDV), end-systolic left ventricular volume (ESV) and left ventricular ejection fraction (EF), its ability to reproduce the precise estimates provided by left ventricle cineangiography (LVCA) and its role in clinical cardiology have not been unequivocally established. In 32 patients subjected to cardiac catheterization for a variety of cardiac disorders and a normal or reduced left ventricular function the EDV, ESV and EF provided by a 30 degrees right anterior oblique LVCA were compared with those provided by a 30 degrees right anterior oblique IDSV. The mean EDV, ESV and EF obtained by IDSV in the 32 patients were superimposable on those obtained by LVCA. The individual EDV, ESV and EF values provided by the two methods were all related in a close linear fashion. For EF the correlation coefficient was 0.98 and the 90% confidence interval of the mean difference between the two series of values was +/- 6.1%, i.e. +/- 10% error compared to the mean EF provided by LVCA. Thus IDSV is a reliable and not too invasive method for estimating left ventricle volumes and ejection fraction. It might provide serial estimations with a better assessment of the evolution of a patient's disease and the effect of treatment.     

Echocardiographic assessment of ejection fraction in left ventricular hypertrophy

OBJECTIVE: To investigate the value of Simpson's rule, Teichholz's formula, and recording of mitral ring motion in assessing left ventricular ejection fraction (EF) in patients with left ventricular hypertrophy. DESIGN: Left ventricular ejection fraction calculated by Simpson's rule and by Techholz's formula and estimated by mitral ring motion was compared with values obtained by radionuclide angiography. SETTING: Secondary referral centre. PATIENTS: 16 patients with left ventricular hypertrophy and a clinical diagnosis of hypertrophic cardiomyopathy or hypertension. RESULTS: Calculation by Teichholz's formula overestimated left ventricular ejection fraction by 10% (p = 0.002) and estimation based on mitral ring motion-that is, long axis measurements-underestimated ejection fraction by 19% (p = 0.002), without significant correlation between ring motion and ejection fraction. There was no significant difference between mean values of ejection fraction calculated by Simpson's rule and measured by the reference method, but a considerable scatter about the regression line with a standard error of the estimate of 9.3 EF%. CONCLUSIONS: In patients with left ventricular hypertrophy the ejection fraction, calculated by Teichholz's formula or Simpson's rule, is a poor measure of left ventricular function. When mitral ring motion is used for the assessment in these patients the function should be expressed in ways other than by the ejection fraction.     

The value of the QRS scoring system in assessing regional and global left ventricular ejection fraction early after myocardial infarction

In 71 patients with a myocardial infarction (MI) (anterior in27, inferior in 44 patients) global (GEF) and regional (REF)left ventricular ejection fractions were determined by radionuclideventriculography and estimated from a 12 lead electrocardiogram(ECG), using Selvester's QRS score, during the early phase ofa MI (15 to 21 days following MI). Global ejection fractionsdetermined by radionuclide ventriculography and from ECG usingPalmeri's method were: for all M140.8 ± 12.6% vs 39.6± 11.4%; in the group of anterior M132.0 ± 10.0%vs 30.0 ± 9.7% and in the group of inferior MI 48.9±12.0%vs 45.1 ± 8.2%. A good correlation was found betweenglobal ejection fractions determined by radionuclide ventriculographyand ECG, as well as between radionuclide GEF and ECG score.A weaker correlation was found between radionuclide GEF andenzymes among all MIs and in the group of anterior MI, whilein the group of inferior MI this correlation was insignificant.The analysis of REF determined by radionuclide ventriculographyand ECG showed the greatest abnormalities in the infarct region,but in the group of anterior MI, dysfunction was present inthe whole left ventricle. The comparison of infarct-relatedREF derived from radionuclide ventriculography, with the QRSscore showed a significantly higher correlation than the comparisonwith enzymes. ECG estimation of REF from a modified Palmeri'sequation showed a better correlation with radionuclide REF thandid GEF derived from the standard Palmeri's equation: anteriorMI; r = 0.90 vs r = 0.82, inferior MI; r = 0.84 vs r = 0.69,respectively. Our results underline the value of relativelysimple ECG methods for the assessment of left ventricular globalfunction, and new possibilities for the estimation of regionalfunction in patients with myocardial infarction.     

Radionuclide assessment of a normal left ventricular response to exercise in patients without evidence of heart disease

The aim of this study was to define normal left ventricularperformance at rest and during supine bicycle exercise withequilibrium radionuclide ventriculography in a normal populationother than young healthy volunteers. Thirty-one patients (meanage 45 years ± 9 SD) with chest pain of varying originandno evidence of heart disease proven by means of noninvasiveand invasive techniques were studied. Left ventricular ejectionfraction (LVEF) at rest averaged 0.64 ± 007 SD and increasedwith peak exercise to 0.73 ± 008 SD (P<0.005). Changein LVEF from rest to maximum exercise ranged within 0–0.19.Six patients (19%) failed to augment LVEF with exercise to morethan 0.05; none of the patients dropped LVEF during exercise.Multivariate analysis revealed no significant predictors ofLVEF response to exercise. However, there was a tendency thatresting LVEF and enddiastolic volume index with exercise mightinfluence LVEF response to exercise. Peak left ventricular ejectionrate (LVER) at rest averaged 3.3s^–1 ± 0.6 SD andincreased to 51 s^–1 ± 11 SD (P<0.005) with exercise.Peak left ventricular early filling rate (LVFR) was 2.8s^–1± 0.6 SD at rest and was measured 5.5 s^–1 ±l.3 SD at maximum exercise (P<0.005). Left ventricular enddiastolicvolume (EDV) did not change significantly from rest to maximumexercise, whereas left ventricular endsystolic volume (ESV)decreased to 79% ± 19 SD (P<0.01) of the value atrest. In conclusion, in a normal population other than healthy youngvolunteers LVEF does not necessarily have to increase with exercise.Moreover, besides an augmentation of heart rate a normal leftventricular response to supine exercise is associated with anincrease of LVER and LVFR, a decrease in ESV and no significantchange in EDV, suggesting augmented contractility and a virtuallynegligible role of the Frank-Starling mechanism during exercise.     

急性心肌梗死患者室壁运动及心功能损害与发病-超声检查时间的关系

目的 探索急性心肌梗死患者室壁运动及心功能损害与发病-超声检查时间的关系.方法 收集初发急性心肌梗死患者219例,均已排除陈旧性心肌梗死、早期心肌再梗死、严重的瓣膜性心脏病、先天性心脏病、心肌病等影响室壁运动及心功能的疾病.所有患者均在予冠状动脉介入干预前行经胸超声心动图检查,采用二维超声等方法测量或（和）计算左心室舒张末期内径（left ventricular diameters in diastasis,LVDd）、收缩末期内径（left ventricular diameters in systole,LVDs）、左心室射血分数（left ventricular ejection fraction,LVEF）、室壁运动计分指数（wall motion index,WMI）及运动正常节段（fragments with normal wall motion,FM）百分比等参数,并精确记录发病-超声检查时间.结果 WMI、LVDd、LVDs、LVEF、FM百分比与发病-超声检查时间的相关关系均有统计学意义（P＜0.05）,相关系数分别为0.167,0.235,0.258,-0.196,-0.144.在WMI的多重线性回归分析结果显示,变量FM百分比、LVEF、左回旋支和（或）右冠状动脉进入方程（R2=0.878,justed R2=0.876）,偏回归系数分别为-1.103,-0.030,-0.001.结论 对于未予冠状动脉介入干预的急性心肌梗死患者,其室壁运动及心功能均随发病-超声检查时间的增加而减弱.