Measurement of left ventricular ejection fraction in myocardial infarction by 2-dimensional echocardiography--comparison with radionuclide angiography

Left ventricular ejection fraction (LVEF) with 4 different algorithms (biplane and single-plane Simpson's rule and ellipsoid area-length method) was measured by 2-dimensional echocardiography (2 DE) in 42 patients with myocardial infarction (MI), and the results were compared with those with equilibrium radionuclide angiography (ERNA). The correlation coefficients were 0.98 for biplane Simpson's rule (apical 4 and 2 chamber view), 0.96 for biplane area-length method (apical 4 and 2 chamber view), 0.81 for single-plane Simpson's rule (apical 4 chamber view), and 0.77 for single-plane area-length method (apical 4 chamber view). The results indicated that biplane method is superior to single-plane method. Biplane area-length method is an alternative simple method for LVEF measurement in patients with MI.     

Serial measurements of left ventricular ejection fraction by radionuclide angiography early and late after myocardial infarction

The left ventricular ejection fraction was determined serially with radioisotope angiography in 63 patients with acute myocardial infarction. After the peripheral injection of a bolus of technetium-99m, precordial radioactivity was recorded with a gamma scintillation camera and the ejection fraction calculated from the high frequency left ventricular time-activity curve. Since this technique requires no assumptions with respect to left ventricular geometry, it is particularly useful in patients with segmental left ventricular dysfunction. Serial measurements during the first 5 days after hospital admission were made in 50 patients, 30 of whom were studied during the subsequent 2 to 39 months (mean 19.9 months). Late follow-up serial studies were also performed in an additional 13 patients who had only one measurement of the left ventricular ejection fraction during the early postinfarction period.Early after infarction, the left ventricular ejection fraction was normal (more than 0.52) in only 15 of the 63 patients, and averaged 0.52 ± 0.05 (standard deviation) in the 27 patients with an uncomplicated infarct. The ejection fraction was reduced in 24 patients with mild to moderate left ventricular failure (0.40 ± 0.05, P < 0.0001) and in the 12 patients with overt pulmonary edema (0.33 ± 0.07, P < 0.0001). In 35 patients the ejection fraction correlated with the mean pulmonary arterial wedge pressure (r = 0.72). In 15 patients with normal left ventricular wall motion by heart motion videotracking, the ejection fraction was significantly higher (0.53 ± 0.08) than in the 26 patients with regional left ventricular dysfunction (0.41 ± 0.10, P < 0.0001). During the early postinfarction period, the left ventricular ejection fraction improved in 55 percent of patients and remained unchanged or decreased in 45 percent. A further increase in the ejection fraction was noted in 61 percent of patients during the late follow-up period. Patients with an initially low or decreasing ejection fraction had a significantly greater incidence of early mortality and left ventricular dysfunction (P < 0.02) than those whose ejection fraction was normal or improved to normal early after infarction. These data indicate that the ejection fraction is a sensitive indicator of left ventricular function after acute myocardial infarction and that serial measurements are helpful in predicting early mortality and morbidity.     

Right ventricular ejection fraction. Validation of first-pass radionuclide studies by contrast angiography

The accuracy of first-pass radionuclide angiocardiography (FPRNA) in the assessment of right ventricular ejection fraction (RVEF) using a multicrystal scintillation camera in the right anterior oblique view has not been reported. To test the validity of this technique, RVEFs derived from first-pass time-activity curves with and without background correction were compared with those obtained from contrast ventriculography in 36 patients. Background regions-of-interest tested included tricuspid valve, free wall, and horseshoe-shaped approaches. The tricuspid valve approach yielded a mean RVEF of 0.485 +/- 0.100 (SD) which slightly underestimated the contrast mean value (0.553 +/- 0.099, p less than 0.05) but correlated well (r = 0.88). The horseshoe approach yielded a mean value of 0.548 +/- 0.100 which approximated the contrast mean value and also correlated well (r = 0.81). The free wall approach yielded a mean of 0.502 +/- 0.095 which did not differ from contrast data (p greater than 0.05) but correlated less well (r = 0.77). With the method without background correction, a much lower mean value (0.387 +/- 0.081, p less than 0.01) and less correlation (r = 0.77) were obtained. Thus, FPRNA using a multicrystal camera in the right anterior oblique view is a reliable technique for measuring RVEF when a tricuspid valve or horseshoe-shaped background approach is employed, but is less accurate if the time-activity curve without background correction is applied.     

Prognostic significance of persistent right ventricular dysfunction as assessed by radionuclide angiocardiography in patients with inferior wall acute myocardial infarction

We evaluated cardiac hemodynamics and long-term prognosis in patients with right ventricular (RV) acute myocardial infarction (AMI) using Fourier phase and amplitude analysis of radionuclide angiocardiographic scanning. In 143 patients with RV AMI, delayed phase and low amplitude in radionuclide RV images persisted in 54 patients (persistent RV dysfunction group) 3 months after AMI, but disappeared in the remaining 89 patients (improved RV function group). No significant differences were present in RV dimensions, left ventricular (LV) wall motion, LV ejection fraction, or RV ejection fraction between these groups during the acute phase. At 3 months, RV dimension and LV and RV wall motion indexes were significantly higher (p = 0.0292, p = 0.0124, p<0.0001, respectively), and LV and RV ejection fractions were lower (p = 0. 0174 and p = 0.0008, respectively) in the persistent RV dysfunction group. Percutaneous transluminal coronary angioplasty in the acute phase was performed in a smaller group of patients (15% vs. 34%, p = 0.0223), and the degree of residual stenosis in the proximal right coronary artery was significantly greater in the persistent RV dysfunction group than in the improved RV function group (82+/-22% vs. 53+/-30%, p<0.0001). The 8-year survival rate was significantly lower in the persistent RV dysfunction group (p<0.0001). Persistent abnormality of phase and amplitude in radionuclide RV images was a significant independent predictor of long-term survival (odds ratio 10.42; 95% confidence interval 3.65 to 29.71; p<0.0001). Radionuclide angiocardiographic Fourier phase and amplitude scanning can detect persistent RV dysfunction in patients with RV AMI and can predict patient outcome.     

Prognostic significance of right ventricular ejection fraction following inferior myocardial infarction

The prognostic significance of right ventricular ejection fraction, measured by radionuclide ventriculography, was assessed in 168 consecutive patients with inferior myocardial infarction. Right ventricular ejection fraction was 0.40 or less in 35 patients. Over a follow-up period of 40 months, there were 15 deaths in the total group of 168 patients, eight (23%) in the 35 with right ventricular ejection fraction of 0.40 or less, and seven (5%) in the remainder of the group. The one year survival of patients with right ventricular impairment (84 +/- 6%) was significantly worse (P less than 0.01) than those with a right ventricular ejection fraction over 0.40 (95 +/- 2%). A multivariate Cox model analysis showed age (P less than 0.001), left ventricular ejection fraction (P less than 0.01), and right ventricular ejection fraction (P less than 0.03) to be independent predictors of survival. Impaired right ventricular function is an adverse prognostic factor in patients with inferior infarction, particularly in those with impaired left ventricular function.     

Prognostic significance of left ventricular ejection fraction after acute myocardial infarction. A bedside radionuclide study

The prognostic significance of left ventricular ejection fraction measurements obtained at the bedside was assessed in 171 patients as soon as possible after acute myocardial infarction. Ejection fraction was measured with a radionuclide first pass portable probe method within a mean of 24 hours of the onset of major symptoms. The results were related prospectively to the subsequent incidence of ventricular fibrillation in hospital, and to hospital and postdischarge deaths in a mean follow up period of 15 (range 9-21) months. All eight episodes of primary ventricular fibrillation, all 12 deaths due to pump failure in hospital, and also 12 out of 13 postdischarge deaths occurred in that minority of 81 patients whose initial postinfarction left ventricular ejection fraction was less than 0.35. Multivariate correlation with clinical, enzymatic, and electrocardiographic indicators of myocardial infarction showed that the prognostic significance of these indicators could largely be explained by their association with low left ventricular ejection fractions. Left ventricular ejection fraction measured within the initial 24 hours after acute myocardial infarction predicts prognosis throughout the subsequent year.     

Relationship between radionuclide right ventricular ejection fraction and clinical status in patients with left ventricular dysfunction after myocardial infarction.

OBJECTIVE: To evaluate the influence of right ventricular (RV) function, determined by RV ejection fraction, on the clinical status of patients with ischemic heart disease and left ventricular (LV) EF under 40%. BACKGROUND: The role of RV function as a marker of prognosis in heart failure has been debated. We hypothesized that the degree of RV dysfunction is a determinant of the clinical status and outcome of patients with LV dysfunction after myocardial infarction. PATIENTS AND METHODS: 30 patients, 25 male, with previous myocardial infarction, more than 6 months age, were studied by equilibrium radionuclide angiography. Functional capacity was evaluated by cardiopulmonary exercise test with Naughton protocol. Patients were followed during a 12 month period for major clinical events: death or hospitalisation for congestive heart failure. Two groups of patients were considered according the value of RVEF (< or = 30% and > 30%). RESULTS: The values of EF were: LV = 25 +/- 7% and RV = 35 +/- 9%. Maximum oxygen consumption correlated with RVEF (r = 0.78, p < 0.001) but not with LVEF (r = 0.12, NS). The group of patients with RVEF > 30% had a greater exercise time (712 +/- 229 versus 441 +/- 208 seconds, p = 0.003), higher oxygen consumption (19.8 +/- 5.3 versus 13.5 +/- 3.3 ml/kg/min, p = 0.001) and oxygen consumption in relation to the maximum predicted for age and sex (71 +/- 19 versus 50 +/- 13%, p = 0.002). Cumulative frequency of major clinical events was greater in the group with RVEF < or = 30% (58% vs 6%, relative risk 3.14, 95% CI 1.23 to 5.05). There was no correlation between the values of LVEF and outcome. CONCLUSIONS: In this setting of ischemic LV dysfunction, the RVEF correlates with functional capacity in cardio-pulmonary exercise test and the presence of RV dysfunction is associated to a higher incidence of clinical events.     

Estimation of left ventricular ejection fraction from Doppler derived myocardial performance index in patients with acute myocardial infarction: agreement with echocardiographic and radionuclide measurements

OBJECTIVE: The aim of the study was to validate a previously published method to calculate left ventricular ejection fraction (EF) from the myocardial performance index (MPI or Tei-index) in patients with acute myocardial infarction (MI). METHODS: Sixty-one patients in sinus rhythm without overt heart failure were examined between 2 and 7 days after the acute MI. Doppler tracings from mitral inflow and left ventricular outflow were recorded together with two-dimensional echocardiographic (2DE) recordings. MPI was calculated from the Doppler tracings, and EF measured with the biplane Simpson's method. From MPI the EF was calculated by the formula EF = 0.60 - (0.34 x MPI). Radionuclide angiographic (RNA) measurements of EF were performed within 1 day of the Doppler echocardiography. RESULTS: Compared with radionuclide EF, MPI derived EF significantly underestimated EF by 0.03 (+/-0.013; P = 0.027), whereas there was no significant difference in mean EF between 2DE and RNA. There was no statistically significant difference in the agreement between MPI derived EF relative to RNA, or 2DE relative to RNA. The agreement between the three methods was only moderate with wide limits of agreement (+/-0.17). The relationship expressed by the proposed formula for calculating EF from MPI was not statistically significant in regression analysis in this patient population. CONCLUSIONS: No statistically significant relationship was found between MPI and EF by radionuclide angiography. However, MPI derived EF was as accurate as biplane echocardiographic measurements of EF when compared with radionuclide EF, but the agreement between methods was only moderate.     

Effects of coronary thrombolysis on left ventricular ejection fraction in patients with acute myocardial infarction

Left ventriculograms were performed on 65 patients with acute myocardial infarction, once upon admission and again 3 months later. In 29 cases urokinase was injected intravenously and/or intracoronarily. The other 17 were treated without urokinase. In 8 out of 29 patients whose infarct-related coronary arteries remained completely occluded following urokinase therapy, the global ejection fraction was reduced from 54 +/- 3% during the acute stage to 46 +/- 5% during the chronic stage (p less than 0.001). However, for the 21 patients whose coronary arteries were successfully recanalized, the 2 values were the same (52 +/- 2%). The highest global ejection fractions were seen in 19 spontaneously recanalized patients (acute: 54 +/- 2%, chronic: 55 +/- 2%). For the 8 unsuccessful patients, the regional ejection fraction for the infarcted portion was reduced from 20 +/- 5% during the acute stage to 18 +/- 6% during the chronic stage. But for the successful patients there was an improvement from 22 +/- 2% during the acute stage to 27 +/- 2% during the chronic stage. Again, the regional ejection fraction was the highest for the spontaneously recanalized group, being 31 +/- 2% and 36 +/- 3% during the acute and chronic stages, respectively. These results indicate that if the coronary artery remains occluded during the acute stage the reduced left ventricular function continues to deteriorate even more during the chronic stage. Successful coronary thrombolysis, however, might salvage the infarcted myocardium as well as preserve the function of the left ventricle.     

Comparison of measurement of left ventricular ejection fraction by Tc-99m sestamibi first-pass angiography with electron beam computed tomography in patients with anterior wall acute myocardial infarction

The goal of this study was to compare measurements of left ventricular (LV) ejection fraction (EF) by first-pass radionuclide angiography ("first-pass angiography") using technetium-99m (Tc-99m) sestamibi with those by contrast-enhanced electron beam computed tomography ("electron beam tomography") as a reference technique in patients with an anterior wall acute myocardial infarction (AMI). Twenty-five patients with first Q-wave anterior wall AMI underwent paired electron beam tomographic and first-pass angiographic studies (mean, 1 day apart). Fourteen patients had 2 sets of measurements of the LVEF obtained by both methods (separated by at least 6 weeks), for a total of 39 paired measurements. LVEF by electron beam tomography was calculated from absolute systolic and diastolic LV chamber volumes. LV volumes by electron beam tomography were 199 +/- 51 ml at end-diastole and 111 +/- 42 ml at end-systole. Mean LVEF was 45 +/- 11% by first-pass tomography and 46 +/- 9% by electron beam tomography. The linear correlation coefficient between both methods was 0.82 (p <0.0001), with slope = 1.0, y-intercept = -1.1, and SEE = 6.1. The mean difference between the 2 methods was -0.7 +/- 6.0 EF units (p = 0.75). The correlation between the differences and means of both methods was 0.34 (p = 0.04), indicating a trend for first-pass angiography to overestimate LVEF in the higher range. LVEFs measured by first-pass angiography in patients with abnormal LV geometry and contraction patterns caused by anterior wall AMI agree well with those measured by electron beam tomography in the clinically relevant range.     

急性心肌梗死患者左心室射血分数与糖化血红蛋白水平的相关性

目的观察急性心肌梗死患者左心室射血分数(LVEF)与糖化血红蛋白(HbAlc)水平的市H关性。方法入选首次急性心肌梗死患者共161例,入院后24h内空腹静脉血测定HbAlc,根据HbAlc水平分为HbAlc正常组(6.5%)与HbAlc升高组(≥6.5%),所有患者分别于发病后72h内、发病后30d行超声心动图检查测量LVEF。结果 HbAlc升高组入院时及30d随访时的LVEF明显低于HbAlc正常组[入院时:(47.9%±7.7%)比(51.3%±7.8%),P=0.008;30d随访时:(51.1%±7.6%)比(55.1%±7.9%),P=0.002]。结论 HbAlc升高的急性心肌梗死患者LVEF在急性期和30d时较HbAlc正常者降低更为明显。     

Right ventricular and left ventricular ejection fraction in pediatric patients with normal hearts: first-pass radionuclide angiocardiography

First-pass radionuclide angiocardiography was used to estimate right ventricular (RV) ejection fraction (EF) and left ventricular (LV) EF in infants, children, and teenagers with normal hearts. The right ventricle was analyzed in 74 patients and the left ventricle in 72 patients. Mean RVEF for the group was 0.53 +/- 0.06 (range 0.43 to 0.73); mean LVEF for the group was 0.68 +/- 0.09 (range 0.49 to 0.86). Lower values tended to be present in younger patients. However, there was no statistical difference in EFs between age groups and no linear correlation between magnitude of EF and age or EF and heart rate for either ventricle. Data obtained demonstrated that RVEF and LVEF in children with normal hearts are similar to those in adults with normal cardiovascular systems. A RVEF of 0.41 to 0.47 or a LVEF of 0.50 to 0.59 would suggest borderline systolic function; a RVEF less than 0.41 (mean -2 SD) or LVEF less than 0.50 (mean -2 SD) would be considered abnormal when this technique of first-pass radionuclide angiocardiography is used.     

Prognostic significance of left ventricular ejection fraction after acute myocardial infarction. A bedside radionuclide study.

The prognostic significance of left ventricular ejection fraction measurements obtained at the bedside was assessed in 171 patients as soon as possible after acute myocardial infarction. Ejection fraction was measured with a radionuclide first pass portable probe method within a mean of 24 hours of the onset of major symptoms. The results were related prospectively to the subsequent incidence of ventricular fibrillation in hospital, and to hospital and postdischarge deaths in a mean follow up period of 15 (range 9-21) months. All eight episodes of primary ventricular fibrillation, all 12 deaths due to pump failure in hospital, and also 12 out of 13 postdischarge deaths occurred in that minority of 81 patients whose initial postinfarction left ventricular ejection fraction was less than 0.35. Multivariate correlation with clinical, enzymatic, and electrocardiographic indicators of myocardial infarction showed that the prognostic significance of these indicators could largely be explained by their association with low left ventricular ejection fractions. Left ventricular ejection fraction measured within the initial 24 hours after acute myocardial infarction predicts prognosis throughout the subsequent year.     

Serial left ventricular ejection fraction in acute myocardial infarction by cross-sectional echocardiography: correlation of changing ejection fraction with clinical course

Left ventricular volume and ejection fraction were measuredin 22 survivors of acute myocardial infarction by means of two-dimensionalechocardiography and using a Simpson's rule algorithm. Ten ofthe 22 patients experienced complications. For the group as a whole, there were no significant trends inleft ventricular volume and ejection fraction between the firstand third days and the third month after infarction. In thesubgroups with uncomplicated and complicated infarction, therewere trends towards increasing and decreasing ejection fractions,respectively, which Jailed to attain statistical significance,however. The difference in ejection fraction between both subgroupshad become significant at 3 months; 55.2+11.1% in uncomplicatedv. 41.3±6.9% in complicated cases (P>0.0l). Individualchanges in ejection fraction falling outside the limits of reproducibilityof the method as assessed previously were observed between day1 and day 3 in only 2 patients with uncomplicated and in 2 patientswith complicated infarction. Between day 1 and 3 months suchchanges occurred in 8 patients with uncomplicated infarction(upward in 5 and downward in 3), and in 8 patients with complicatedinfarcts (upward in 3 and downward in 5) We conclude that changes in ejection fraction as measured bytwo-dimensional echocardiography lend to correlate with complications.     

Hemodynamic correlates of right ventricular ejection fraction measured with gated radionuclide angiography

Right ventricular function was studied in 60 patients with equilibrium gated radionuclide angiography. The mean (± standard deviation) right ventricular ejection fraction in 20 normal subjects was 53 ± 6 percent, a value in agreement with previous data from both radionuclide and contrast angiographie studies. This value was similar (55 ± 7 percent) in 11 patients with coronary artery disease but normal left ventricular function.Radionuclide measurements of right ventricular ejection fraction were correlated with right heart hemodynamics. There was a significant negative linear correlation between right ventricular ejection fraction and mean pulmonary arterial pressure (r = ?0.82) and between right ventricular ejection fraction and right ventricular end-diastolic pressure (r = ?0.67). Furthermore, patients with elevated right ventricular enddiastolic pressure and mean pulmonary arterial pressure had a more severely depressed ejection fraction than did those with an elevated mean pulmonary arterial pressure alone.Thus, an abnormal value for right ventricular ejection fraction by gated radionuclide angiography in the absence of primary right ventricular volume overload suggests abnormal right heart pressures, whereas a normal value excludes severe pulmonary arterial hypertension or an elevated right ventricular end-diastolic pressure.     

Regional left ventricular function assessed by contrast angiography in acute myocardial infarction.

The relationship of segmental left ventricular (LV) wall motion abnormalities to LV function 2-6 days after acute transmural myocardial infarction (MI) was investigated in 45 patients by quantitative contrast ventriculography. Patients were divided into four classes according to the MIRU criteria. Segmental wall motion was assessed by determining the percentage of systolic shortening (deltaS) along nine hemiaxes and the extent of akinetic or dyskinetic abnormally contracting segments (% ACS) expressed as a percentage of end-diastolic perimeter. When compared with that in 17 normal control-subjects, the LV end-diastolic volume was increased only in patients in class III and class IV; the LV end-systolic volume increased progressively from normal through class IV. Ejection fraction had a negative linear correlation with %ACS (r = 0.97). The size of ACS was larger in anterior (34 +/- 14%) than in inferior MIs (23 +/- 7%), resulting in greater LV dysfunction. However, for a comparable size of ACS, infarct location alone did not influence LV function parameters. In the noninfarcted zone, deltaS was increased when the size of ACS was less than 25% and reduced when the size of ACS was greater than 25%. Thus, the size of ACS is a major determinant of LV dysfunction in acute MI. The compensatory mechanisms operate either through an augmented mechanical function of residual myocardium when the infarct is small, or through the Frank-Starling mechanism when the infarct is large.     

Echocardiographic determinants of left ventricular ejection fraction after acute myocardial infarction

OBJECTIVE: This study was performed to determine if factors other than the size of regional dysfunction influence the global left ventricular ejection fraction after acute myocardial infarction. BACKGROUND: Left ventricular ejection fraction is an important prognostic variable after acute myocardial infarction. Although infarct size is known to affect the subsequent global left ventricular ejection fraction, it remains unclear whether other factors such as site or severity of the wall motion abnormality influence the ejection fraction after acute myocardial infarction. METHODS: Sixty-nine consecutive patients (mean age 61 +/- 14 years, 46 [67%] male) who did not receive thrombolytic therapy or undergo early revascularization were studied by echocardiography 1 week after Q-wave myocardial infarction. The absolute size of the region of abnormal wall motion (AWM) and the percentage of the endocardium involved (%AWM) were quantitated along with the wall motion score. A severity index was then derived as the mean wall motion score within the region of AWM. Site of myocardial infarction was classified as either anterior or inferior from the endocardial map. Left ventricular ejection fraction was measured by Simpson's method with 2 apical views. RESULTS: Twenty-nine (42%) patients had anterior and 40 had inferior myocardial infarction. The mean left ventricular ejection fraction was significantly lower in anterior than in inferior myocardial infarction (44.8% +/- 11.5% vs 53% +/- 8.6%; P =. 001). The mean %AWM was greater in anterior than in inferior myocardial infarction (32.1 +/- 15.5 vs 22.4 +/- 14.1; P =.01). The mean wall motion score was greater in anterior than in inferior myocardial infarction (9.8 +/- 6.4 vs 6.4 +/- 4.4; P =.01). The mean severity index did not differ by site. Multiple regression analysis demonstrated that, in descending order of importance, %AWM, extent of apical involvement, and site of myocardial infarction were independent determinants of global left ventricular ejection fraction. CONCLUSIONS: For myocardial infarctions of similar size, left ventricular ejection fraction is lower when apical involvement is extensive and the site of infarction is anterior. This site-dependent difference may be related to characteristics specific to the apex.     

Right ventricular ischemia mimicking acute anterior myocardial infarction.

Isolated right ventricular ischemia in combination with myocardial infarction (MI) is uncommon, accounting for fewer than 3% of all MI cases. A young man who presented with acute right ventricular ischemia from occlusion of a codominant right coronary artery proximal to an acute marginal branch is presented. His presenting electrocardiogram (ECG) showed ST segment elevation in V1 to V4 mimicking acute anterior MI. ECG criteria for isolated right ventricular ischemia are discussed.     

Pacemaker-induced ventricular tachycardia in patients with acute inferior myocardial infarction

We analysed a group of 35 consecutive patients with acute myocardial infarction—23 of the inferior, 12 of the anterior wall—who needed temporary pacing for bradycardiac arrhythmias. We observed in three patients ventricular tachycardias induced by pacemaker stimuli falling onto the vulnerable part of the cardiac cycle due to improper sensing. All three had an inferior myocardial infarction involving the right ventricle. Because the pacemaker electrode in this condition lies in the vicinity of the infarcted myocardium sensing problems occur more frequently and re-entry tachy-cardias can be triggered more easily. It represents a possible risk of pacemaker treatment in this group of patients who, on the other hand, often need cardiac pacing in the acute phase following the development of transient AV-block.