Initial Ejection Fraction Research Articles

Progression of aortic stenosis in adults: Newappraisal using doppler echocardiography

This study examined progression of aortic stenosis (AS) as assessed by Doppler echocardiography. One hundred twelve consecutive adult patients had calcific AS and underwent three examinations during a mean 25-month period (range 7 to 54 months). At the time of entry into the study, mean values for initial peak aortic velocity and ejection fraction (EF) were 2.9 +/- 0.7 m/sec and 63 +/- 10%, respectively; 52% of the patients were symptomatic. At the third examination the percentage of symptomatic patients increased to 65% (p = 0.0039 compared to baseline values), and the aortic peak velocity increased to 3.3 +/- 0.8 m/sec (p less than 0.001). Age, sex, and EF were not predictors of progression. Documented coronary artery disease (in 57 patients) did not affect progression, and neither did the aortic peak velocity at the time of entry into the study. Thirty-eight patients reported an increase in symptoms from the first to third examination, and their rate of progression was significantly different from that of the rest of the population: 0.33 +/- 0.50 m/sec/yr compared to 0.18 +/- 0.26 m/sec/yr (p less than 0.03).

Clinical safety profile of sotalol in patients with arrhythmias

Key safety parameters of sotalol were examined in 1,288 patients entered into recent controlled trials of ventricular (85% of patients) or supraventricular arrhythmias (15%). Most patients were middleaged male Caucasians with significant heart disease. The most serious adverse event was proarrhythmia, occurring in 56 patients (4.3%). Of these, 27 had hemodynamic compromise due to malignant ventricular arrhythmias. Most had a history of sustained ventricular tachycardia, myocardial infarction, congestive heart failure (CHF) or cardiomyopathy, or a combination of these. The other 29 had nonsevere events; 38% continued taking sotalol. Proarrhythmia was manifested by torsades de pointes in 24 of the 56 patients. No universal causal relation was found with commonly associated factors such as bradycardia, hypokalemia and long QT interval. The mean QT and QTc at baseline within 1 week of a severe proarrhythmic event were greater than those of patients not having proarrhythmia. Nineteen patients (1%) discontinued therapy with sotalol because of drug-related CHF. Predisposing conditions included low initial baseline ejection fraction, history of CHF, cardiomyopathy or cardiomegaly, or both, male gender and age >65 years. Heart failure usually occurred within 7 to 30 days of initiating therapy. The most common reason for premature discontinuation of the drug in patients treated for sustained ventricular tachycardia was ineffectiveness (39%), whereas adverse effects were the most common reasons among patients treated for complex ventricular ectopy (21%). Dyspnea and bradycardia were the most common cardiovascular effects, and fatigue, dizziness and asthenia the most common noncardiac, adverse effects. Although frequently reported, these adverse effects resulted in discontinuation of only 1 to 4% of the patients at risk. Considering the benefits of the antiarrhythmic and β-blocking effects of sotalol, its risk/benefit ratio is highly favorable for the treatment of ventricular and supraventricular arrhythmias.

Responses of left ventricular function in survivors and nonsurvivors of septic shock

In a previous study of 20 patients with septic shock, we demonstrated severe, but reversible depression of radionuclide-determined left ventricular ejection fraction. To further analyze the cardiovascular response to septic shock, we performed serial cardiovascular studies on 54 patients with blood culture-positive septic shock.The survivors had a mean initial ejection fraction (±SEM) of .40 ± .03 with a mean left ventricular end-diastolic volume index (EDVI) of 122 ± 8 mL/m 2, both significantly decreased and increased, respectively, from critically ill nonseptic control patients ( P < .02). These abnormalities persisted for two to five days and returned to normal within 2 weeks. The nonsurvivors had a mean initial ejection fraction of .47 ± .04 and a mean initial EDVI of 99 ± 9 mL/m 2; both are not different from control patients. On serial studies, the nonsurvivors exhibited one of two patterns: half of the nonsurvivors demonstrated a decreasing EDVI associated with a decreasing stroke volume index (SVI) and cardiac index, the other half of the nonsurvivors had an increasing EDVI associated with maintenance of the SVI and cardiac index. In the surviors, there a statistically significant negative correlation of the decreased ejection fraction with the increased EDVI, but no such correlation occurred in the nonsurvivors. Regarding serial cardiac performance during a 2-week period following shock onset, each patient's consecutive ejection fractions and EDVIs were correlated and the correlation coefficients were averaged. Comparing ejection fraction and EDVI, the survivors had a much greater correlation ( r= −.60) than the nonsurvivors ( r= −.14) ( P < .005). Based on the observations of these studies, the following mechanism is likely: during human septic shock, the cardiovascular system is stressed by both peripheral vascular abnormalities and direct depression of the myocardium, the latter manifested clinically by a depressed ejection fraction. In general, survivors respond on serial studies by ventricular dilation (increased preload) to maintain ventricular performance. A substantial subgroup of nonsurvivors fails to dilate, and succumbs (in part), with an inability to maintain serial ventricular function.

Survival and cardiac event rates in the first year after emergency coronary angioplasty for acute myocardial infarction

One year survival and event-free survival rates were analyzed in 342 patients with acute myocardial infarction who were consecutively enrolled in a treatment protocol of early intravenous thrombolytic therapy followed by emergency coronary angioplasty. Ninety-four percent of the patients achieved successful reperfusion, including 4% with failed angioplasty whose perfusion was maintained by means of a reperfusion catheter before emergency bypass surgery. The procedural mortality rate was 1.2% and the total in-hospital mortality rate was 11%. Ninety-two percent of surviving nonsurgical patients who underwent repeat cardiac catheterization were discharged from the hospital with an open infarct-related artery. The related cumulative 1 year survival rate for all patients managed with this treatment strategy was 87%, and the cardiac event-free survival rate was 84%. The 1 year survival for hospital survivors was 98% and the infarct-free survival rate was 94%.Multivariable analysis identified the following factors as independent predictors of subsequent cardiovascular death: cardiogenic shock, greater age, lower ejection fraction, female gender and a closed infarct-related vessel on the initial coronary angiogram. Among patients with cardiogenic shock, despite a 42% in-hospital mortality rate, only 4% died during the first year after hospital discharge. Similarly, the in-hospital and 1 year postdischarge mortality rates were 19 and 4%, respectively, for patients with an initial ejection fraction <40, and 25 and 3%, respectively, for patients > 65 years. An aggressive treatment strategy including early thrombolytic therapy, emergency cardiac catheterization, coronary angioplasty and, when necessary, bypass surgery resulted in a high rate of infarct vessel patency. Long-term mortality and reinfarction rates after hospital discharge were low, even for patients in high risk subgroups.

Hemodynamic Effect of Propafenone and the Experience in Patients with Congestive Heart Failure

The effects of propafenone on left ventricular function and hemodynamics are presented in this study. In one group of 13 patients who underwent electrophysiological testing and subsequent chronic oral therapy with propafenone, eight had left ventricular ejection fractions determined by nuclear study before and during therapy with the drug. Initial measurements ranged from 22% to 39% (mean 30%), while those on chronic therapy showed no statistical difference and ranged from 22% to 48% (mean 30%). In a separate dose titration study of 14 patients, left ventricular ejection fraction showed a modest but significant decrease (52%± 9% to 48%± 11%; p &lt; 0.05). This change was more marked in patients with an initial low ejection fraction. Propafenone appears to be safe in these patients but should be administered with caution in patients with particularly low ejection fractions.

Factors that predict improvement in left ventricular ejection fraction after coronary angioplasty for acute myocardial infarction.

Acute and follow-up angiograms were analyzed in 75 patients with acute myocardial infarction treated with emergency coronary angioplasty to determine factors that might predict improvement in left ventricular ejection fraction. Ejection fraction improved 8.4 +/- 8.2% in 60 patients who maintained patent infarct vessels at follow-up angiography, compared with -4.1 +/- 6.0% in 15 patients who developed reocclusion (p less than .001). In patients with patent infarct vessels, univariate analysis revealed the following significant predictors of improvement in ejection fraction: initial ejection fraction (r = -.38, p less than .003) subtotal vs total stenosis (12.9 +/- 9.3% vs 6.9 +/- 7.3%, p less than .02), infarct vessel (left anterior descending 11.0 +/- 8.4%, right 6.8 +/- 6.4%, circumflex 2.6 +/- 7.5%, p less than .02), and time to follow-up study (less than or equal to 15 days vs greater than 15 days) (4.8 +/- 5.8% vs 9.8 +/- 8.6%, p less than .03). Reperfusion time (less than or equal to 2 hr vs greater than 2 hr) predicted improvement when subtotal stenoses and stuttering infarctions were excluded (10.6 +/- 7.0% vs 4.9 +/- 6.9, p less than .03). Multivariate analysis showed initial ejection fraction and subtotal vs total stenosis to be independent predictors. Patients with anterior infarctions, low initial ejection fractions, and subtotal stenoses or reperfusion times less than or equal to 2 hr are likely to benefit most from coronary angioplasty for acute myocardial infarction.

Effect of thrombolysis (streptokinase) on left ventricular function during acute myocardial infarction

One hundred ninety-two consecutive patients with acute myocardial infarction were enrolled in a prospective trial of coronary thrombolysis in which either intracoronary or intravenous streptokinase was administered. First-pass radionuclide ejection fraction (EF) was measured early (within 24 hours of admission) and late (10 to 14 days after admission) to assess changes in left ventricular (LV) function. In 68 patients in whom reperfusion was successful, mean EF increased from 39 +/- 11% early to 47 +/- 13% late. In 36 patients in whom reperfusion was not successful, the mean EF increase was significantly smaller (from 38 +/- 10% to 42 +/- 11%, p less than 0.025). Patients in whom reperfusion was successful were then grouped according to extent of LV functional change. The extent of EF change (delta EF) was not significantly influenced by time to lysis at intervals up to 7 hours (delta EF = 9.1 +/- 10% at 2 to 3 hours, 8.7 +/- 12% at 3 to 4 hours, 10 +/- 10% at 4 to 5 hours, and 7.0 +/- 10% at 5 to 7 hours; difference not significant [NS]), location of the infarct (delta EF = 8.9 +/- 11% for inferior and 5.7 +/- 8.0% for anterior, NS), or presence of Q waves on the initial electrocardiogram (delta EF = 8.8 +/- 11% in patients with and 7.8 +/- 9.9% in patients without Q waves). Only the initial EF was predictive of subsequent EF change.(ABSTRACT TRUNCATED AT 250 WORDS)

Spontaneous changes in regional wall motion abnormalities in acute myocardial infarction

The incidence of improvement in regional wall motion of segments with severe contractile abnormalities in the first 10 days after a first acute myocardial infarction (AMI) was assessed with serial gated blood pool scans in 95 patients who received standard medical therapy. Regional wall motion was quantitatively assessed as percent chord shortening in 4 segments in the anterior view and 4 segments in the 45 ° left anterior oblique view. Among 237 segments with ho more than 15% shortening (severely hypokinetic or akinetic [SH/A] segments), 59 (25%) improved at least 15% at 10 days, 166 (70%) did not change and 12 (5%) deteriorated by at least 15%. Among 91 patients who had SH/A segments, 37 (41%) had improvement in at least 1 SH/A segment (group 1) and 54 had no improvement in SH/A segments (group 2). Group 1 had a higher initial ejection fraction (EF) (50 ± 12%) than group 2 (45 ± 13%, p < 0.05). The changes in percent shortening of SH/A segments were compared with coronary anatomy in 37 patients who underwent coronary angiography. The 17 patients with 1-vessel coronary artery disease (CAD) had significantly improved wall motion (8.2 ± 13.4%, p < 0.005), in contrast to the 20 patients with multivessel CAD (1.8 ± 11.5%, difference not significant). Among patients with 1-vessel CAD, the improvement was greater in patients with right coronary or left circumflex artery disease (12.8 ± 14.4%) than in those with left anterior descending disease (4.1 ± 13.4%, p < 0.05). These data indicated that improved wall motion is seen in initially SH/A segments in 41% of AMI patients with akinesia. Patients with a higher initial EF and less severe CAD usually involving the inferoposterior wall are more likely to have improved wall motion in SH/A segments.

Early prediction of mortality in patients with acute myocardial infarction: a prospective study of clinical and radionuclide risk factors

To examine the prognostic value of early radionuclide imaging in patients with transmural acute myocardial infarction, 222 patients in Killip class I and II were studied prospectively within 24 hours of the onset of symptoms. The 30-day mortality rate for the entire group was 11% (25 of 222). Univariate analysis indicated that an initial radionuclide left ventricular ejection fraction (EF) of less than 0.30 was associated with the greatest relative risk (RR = 6.6), although the percent of abnormally contracting regions (RR = 3.9) and thallium-201 defect index (RR = 3.3) were also significant risk factors. Stepwise logistic regression Indicated that addition of EF resulted in the greatest improvement over the best clinical model (Killip class and chest radiographic findings) for the prediction of 30-day mortality ( χ 2 improvement = 12.8, p < 0.0005). Using the optimal model for prediction of mortality (EF and Killip class), a high-risk group with a 30-day mortality rate of 39% (90-day mortality 47%) and a low-risk group with a 30-day mortality rate of 3% (90-day mortality 4%) was identified. In clinically stable patients with transmural acute myocardial infarction, early assessment of EF in conjunction with clinical evaluation, is a valuable method for early identification of high-risk subsets.

Intracoronary thrombolytic therapy in acute myocardial infarction: A prospective, randomized, controlled trial

A prospective, randomized trial was designed to assess the efficacy of intracoronary thrombolytic therapy with streptokinase (STK) in acute myocardial infarction. Sixty-four patients with acute myocardial infarction were randomized within 6 hours of onset of symptoms to 1 of 3 groups. Sixteen patients were treated by conventional means (control group). Nineteen patients underwent coronary arteriography and received corticosteroids and intracoronary and intravenous nitroglycerin (NTG group). Twenty-nine patients received management identical to that of the NTG group, with the addition of intracoronary STK therapy (STK group). Recanalization was demonstrated in 21 of 29 patients (72%) in the STK group. Global and regional ejection fraction (EF) was determined by radionuclide ventriculography before any intervention and 7 to 10 days later. No significant improvement in global EF was achieved in the control and NTG groups. In STK patients as a group, global EF did not increase significantly; however, in patients recanalized with STK, EF improved from 42 ± 17% to 49 ± 16% (p − 0.023). All groups showed wide variability of response. Improvement in global EF of more than 5% was noted in 44% of patients recanalized with STK. When subgrouped on the basis of initial global EF of 45% or less or more than 45%, only patients recanalized with STK with an initial EF of 45% or less had an improved global EF (from 30 ± 10% to 42 ± 10%, p = 0.015). Regional EF of all involved infarct regions was improved only in the STK group (from 34 ± 19% to 42 ± 23%, p = 0.027) and STK-recanalized subgroup (from 33 ±18% to 45 ± 24%, p = 0.003). When only the most involved infarct regions were analyzed, control, NTG and STK groups improved, with patients recanalized with STK showing the greatest degree of improvement. Thus, this trial demonstrates a beneficial effect of thrombolytic therapy in global and, more strikingly, in regional function in patients in whom recanalization with STK is successful, with predominant benefit in those with initially depressed 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.

Assessment of potentially salvageable myocardium during acute myocardial infarction: Use of postextrasystolic potentiation

Twenty-three patients with evolving acute myocardial infarction (AMI) undergoing catheterization for thrombolytic therapy had interventional contrast ventriculography using programmed atrial stimulation. Postextrasystolic (PES) potentiation was present in 67% of infarct-related segments up to 9 hours after the onset of AMI. The presence of segmental potentiation was not related to time from onset of pain to ventriculography, initial ejection fraction, presence of collaterals, left ventricular end-diastolic pressure or the PES delay. In 18 patients reperfusion was successful using intracoronary streptokinase an average of 6.2 hours after the onset of AMI; in these patients repeat contrast ventriculography was performed an average of 11 days after AMI. Improved chronic segmental ventricular function was predicted by the presence of collaterals to the infarct-related artery at the time of acute catheterization (p = 0.02), but was best predicted by analysis of acute PES potentiation (p less than 0.0001). The predictive value of PES analysis was highest in segments without collaterals. Thus, atrial stimulation is safe during AMI and analysis of segmental ventricular function shows potentially viable myocardium up to 9 hours after the onset of AMI. In addition, analysis of PES segmental function can predict chronic function if reperfusion is successful, especially in segments without collaterals. PES ventriculographic analysis may allow prospective determination of which patients during AMI are most likely to benefit from acute thrombolytic therapy.

Profound but reversible myocardial depression in patients with septic shock.

To characterize the role of cardiac function in septic shock, serial radionuclide cineangiographic and hemodynamic evaluations were done on 20 patients with documented septic shock. Although all patients had a normal or elevated cardiac index, 10 patients had moderate to severe depression of their ejection fraction with values below 0.40. Thirteen of twenty patients survived their episode. Paradoxically, 10 of 13 survivors, but none of the 7 nonsurvivors, had an initial ejection fraction less than 0.40 (p less than 0.005). The mean initial ejection fraction for the survivors was 0.32 +/- 0.04, and their mean end systolic and end diastolic ventricular volumes were substantially increased with a normal stroke volume. The survivors' serial scans showed a gradual return to normal ejection fraction and ventricular volume by 10 days after the onset of shock. Nonsurvivors had normal initial ejection fractions and ventricular volumes that did not change during serial studies.

Acute and long-term hemodynamic effects of oral pirbuterol in patients with chronic severe congestive heart failure: Randomized double-blind trial

In 20 patients with severe congestive heart failure (CHF), we studied the effects of the beta-adrenergic agonist pirbuterol compared to placebo in both an acute double-blind randomized trial and after long-term treatment. Acutely, pirbuterol patients (n = 10) demonstrated a significant rise in cardiac index (2.2 ± 0.14 to 3.2 ± 0.32 L/min/m 2), stroke index (26 ± 2.6 to 35 ± 2.9 ml/beat/m 2), stroke work index (22 ± 2.4 to 30 ± 2.7 gm · m/m 2), and ejection fraction (22 ± 4 to 30 ± 5%). These hemodynamic variables did not significantly change in placebo patients (n = 10). After 3 weeks of pirbuterol therapy, 14 patients (70%) were symptomatically improved and were continued on the drug for another 3 weeks; 13 of 14 patients who were symptomatically improved underwent restudy. Compared to pretreatment baseline, there was continued improvement in cardiac index (2.5 ± 0.16 to 3.2 ± 0.24 L/min/m 2), stroke index (30 ± 2.5 to 38 ± 2.9 ml/beat/m 2), stroke work index (26 ± 2.3 to 35 ± 3.1 gm · m/m 2), and ejection fraction (24 ± 1 to 28 ± 4%). Patients more frequently improved were those with nonischemic cardiomyopathy and those with higher initial ejection fractions. These results demonstrate the acute beneficial effects of oral pirbuterol versus placebo in a double-blind randomized trial. Improvement was maintained during long-term therapy in the majority of CHF patients.

Unstable angina and progression of coronary atherosclerosis.

We studied the progression of atherosclerotic coronary lesions in 38 patients who had previously undergone angiography and were later hospitalized for an episode of unstable angina pectoris, and in 38 matched patients with stable angina who had also undergone prior catheterization. Patients with unstable angina and those with stable angina were similar in terms of age (mean, 49 and 50 years, respectively), number of risk factors (1.5 per patient in both groups), interval between studies (mean +/- S.D., 44 +/- 31 and 35 +/- 31 months, respectively), number of diseased vessels on the first angiogram (1.52 in both groups), and initial ejection fraction (65 and 63 per cent, respectively). Progression of coronary lesions was demonstrated in 29 of the 38 patients with unstable angina, as compared with 12 of the 38 with stable angina (P less than 0.0005). Progression to 70 per cent or more stenosis was recorded in 21 of the patients with unstable angina but in only 5 of those with stable angina (P less than 0.0005). Also more frequent in the patients with unstable angina were multifocal progression (11 vs. 2, P less than 0.01) and progression of the left main or preseptal left anterior descending artery or both (9 vs. 1, P less than 0.01). Thus, we have demonstrated by angiography that unstable angina is associated with progression in the extent and severity of coronary atherosclerosis.

Cardiovascular physiology in a case of heterotopic cardiac transplantation

Successful heterotopic cardiac transplantation in a 24 year old man with end stage cardiomyopathy provided an opportunity to study cardiovascular physiology. The donor and native hearts, functioning independently in parallel, were studied by serial physical examination, electrocardiography, echocardiography, nuclear angiography and cardiac catheterization. Results indicated that the donor left heart assumed the predominant role in supplying systemic output, possibly contributing to decreasing function of the patient's own (native) heart. Analysis of serial nuclear angiograms revealed an initial postoperative ejection fraction of 52 and 21 percent in the donor and the native left ventricle, respectively; repeat studies 3 months postoperatively showed values of 50 and 9 percent, respectively, indicating significant deterioration in native left ventricular cardiac function. Observation of valve motion of the native heart showed major irregularities of the aortic valve in contrast to seemingly normal, regular mitral valve motion. These data raise interesting questions regarding interpretation of valve motion as an indicator of ventricular function.

Digitalis and myocardial infarction in man.

The use of digitalis after acute myocardial infarction is controversial. The effect of digoxin on computer-quantitated thallium-201 perfusion scintigrams (Tl-201), left ventricular (LV) ejection fraction (EF), and percentage of abnormally contracting LV regions (% ACR) was determined in 23 patients. A correlation was established between creatine kinase MB isoenzyme release and initial radionuclide-gated blood pool wall motion estimates of EF (r = -0.73) and % ACR (r = 0.71). After radionuclide assessments, 14 patients received digoxin 18 +/- 23 hours (mean +/- SD) after the rise in CK-MB from baseline, while the remaining nine patients served as controls. In the control group, the mean EF was 0.33 +/- 0.12 on the first study and 0.30 +/- 0.08 on the second study (p = NS). In the digoxin group, the EF after digoxin administration (mean 0.33 +/- 0.11) was significantly different from the initial EF (mean 0.29 +/- 0.09, p less than 0.03); however, digoxin had no apparent effect on infarct size as assessed by sequential % ACR and Tl-201 perfusion data. These data indicate that digoxin resulted in a minimal but significant improvement in EF that did not occur at the expense of LV perfusion or regional wall motion.

Left ventricular ejection fraction determined by radionuclide ventriculography in early stages of first transmural myocardial infarction: Relation to short-term prognosis

Left ventricular ejection fraction was determined with multiple gated equilibrium cardiac blood pool scintigraphy within 24 hours of the onset of symptoms of a first acute transmural myocardial infarction in 56 patients (23 with anterior and 33 with inferior infarction). A depressed ejection fraction (less than 0.54) was more frequent in patients with anterior (96 percent) than in those with inferior (61 percent) infarction (p <0.001); the mean ejection fraction was lower in patients with anterior (0.34 ± 0.09 standard deviation) than in those with inferior (0.50 ± 0.14) infarction (p <0.001). Of the 33 patients with inferior infarction, 19 had concomitant S-T segment depression in the precordial leads; the mean ejection fraction was lower in this subgroup than in the remaining 14 without such S-T depression (0.41 ± 0.11 versus 0.61 ± 0.08, p <0.05). During the subsequent hospital course, one or more complications (congestive failure, hypotension, shock, postinfarction angina, death) developed in 27 patients. The mean ejection fraction was lower in this group (0.34 ± 0.10) than in the remaining 29 patients whose hospital course was uncomplicated (0.52 ± 0.13) (p <0.001). Seven patients (12 percent) died (six from pump failure and one from ventricular arrhythmias) 2 to 14 days after the onset of infarction. The initial ejection fraction was lower in nonsurvivors (0.27 ± 0.11) than in survivors (0.46 ± 0.13) (p <0.001). Death due to pump failure occurred in 6 of 11 patients (55 percent) with an ejection fraction of 0.30 or less; in contrast, only 1 of the 45 patients with a higher ejection fraction died in the hospital (p <0.001). The overall data thus indicate that left ventricular ejection fraction is significantly reduced in acute anterior myocardial infarction but not in inferior infarction except in patients with associated precordial S-T segment depression. An ejection fraction of 0.30 or less is of prognostic value in predicting a high risk of hospital morbidity and mortality from pump failure in patients with a first acute transmural infarction.

Reproducibility of Ejection Fraction and Ventricular Volume by Gated Radionuclide Angiography After Myocardial Infarction

To validate the repeated use of radionuclide equilibrium angiography for determining left ventricular (LV) ejection fraction (EF) and end-diastolic and end-systolic volumes (EDV and ESV), 25 patients were studied on an hourly basis an average of 9.1 days after acute myocardial infarction. Data were processed with a semi-automatic computer program which develops an averaged-volume curve from an assigned LV region-of-interest. LV EDV and ESV were derived from a previously described method which correlates well with contrast angiography (r = 0.977, y = 0.0255x - 0.121). Comparison between initial and subsequent equilibrium EF and between initial and subsequent volumes showed excellent correlation. Excluding three anginal episodes, the EF variation between studies averaged 0.03 +/- 0.02.

Serial Radionuclide Determinations of the Ejection Fraction with99mTc-Labeled Red Blood Cells

The reproducibility of area/length ejection fraction determinations was evaluated in 21 subjects using 99mTc-labeled red blood cells (99mTc-RBCs). The ejection fraction was determined within 30 minutes and 3-5 hours after a single injection of 99mTc-RBCs. The mean absolute difference between the initial and subsequent ejection fractions was 7% (maximum, 15%) (r = 0.90). 99mTc-RBCs offer a reproducible method of determining the ejection fraction which is suitable for serial noninvasive evaluations of left ventricular function.