Estimating left ventricular ejection fraction after myocardial infarction by various clinical parameters

Establishment and validation of a prediction model for nonrecovery of left ventricular ejection fraction in acute myocardial infarction patients combined with decreased left ventricular ejection fraction

BACKGROUND

This study aimed to investigate the risk factors for nonrecovery of left ventricular ejection fraction (LVEF) during follow-up in patients with acute myocardial infarction (AMI) who underwent percutaneous coronary intervention (PCI) combined with reduced LVEF, and establish and verify a risk prediction model based on these factors.

METHODS

In this study, patients with AMI who underwent PCI in a high-volume PCI center between December 2018 and December 2021 were consecutively enrolled, screened, and randomly assigned to the model establishment and validation cohorts. A predictive model method based on least absolute shrinkage and selection operator regression was used for establishment and validation.

RESULTS

Cardiac troponin I, myoglobin, left ventricular end-diastolic dimension, multivessel disease, and no-reflow were identified as potential predictors of LVEF recovery failure. The areas under the curve were 0.703 and 0.665 in the model establishment and validation cohorts, respectively, proving that the prediction model had some predictive ability. The calibration curves of the two cohorts showed good agreement with those of the nomogram model. In addition, the decision curve analysis showed that the model had a net clinical benefit.

CONCLUSION

This prediction model can assess the risk of nonrecovery of LVEF in patients with AMI undergoing PCI combined with LVEF reduction during follow-up, and conveniently screen high-risk patients with nonrecoverable LVEF early.

Why do authors derive new cardiovascular clinical prediction rules in the presence of existing rules? A mixed methods study

Background

Researchers should examine existing evidence to determine the need for a new study. It is unknown whether developers evaluate existing evidence to justify new cardiovascular clinical prediction rules (CPRs).

Objective

We aimed to assess whether authors of cardiovascular CPRs cited existing CPRs, why some authors did not cite existing CPRs, and why they thought existing CPRs were insufficient.

Method

Derivation studies of cardiovascular CPRs from the International Register of Clinical Prediction Rules for Primary Care were evaluated. We reviewed the introduction sections to determine whether existing CPRs were cited. Using thematic content analysis, the stated reasons for determining existing cardiovascular CPRs insufficient were explored. Study authors were surveyed via e-mail and post. We asked whether they were aware of any existing cardiovascular CPRs at the time of derivation, how they searched for existing CPRs, and whether they thought it was important to cite existing CPRs.

Results

Of 85 derivation studies included, 48 (56.5%) cited existing CPRs, 33 (38.8%) did not cite any CPR, and four (4.7%) declared there was none to cite. Content analysis identified five categories of existing CPRs insufficiency related to: (1) derivation (5 studies; 11.4% of 44), (2) construct (31 studies; 70.5%), (3) performance (10 studies; 22.7%), (4) transferability (13 studies; 29.5%), and (5) evidence (8 studies; 18.2%). Authors of 54 derivation studies (71.1% of 76 authors contacted) responded to the survey. Twenty-five authors (46.3%) reported they were aware of existing CPR at the time of derivation. Twenty-nine authors (53.7%) declared they conducted a systematic search to identify existing CPRs. Most authors (90.7%) indicated citing existing CPRs was important.

Conclusion

Cardiovascular CPRs are often developed without citing existing CPRs although most authors agree it is important. Common justifications for new CPRs concerned construct, including choice of predictor variables or relevance of outcomes. Developers should clearly justify why new CPRs are needed with reference to existing CPRs to avoid unnecessary duplication.

Measurement of Ejection Fraction After Myocardial Infarction in the Population

OBJECTIVES

To assess the secular trends in left ventricular ejection fraction (LVEF) assessment after myocardial infarction (MI) and to identify the determinants of testing.

DESIGN

A population-based MI incidence cohort.

METHODS

The use of tests measuring LVEF (echocardiography, radionuclide, and left ventricular [LV] angiography) was examined among all consecutive residents of Olmsted County, MN, hospitalized for a validated incident MI between 1979 and 1998. Baseline characteristics and outcome were ascertained from community medical records.

RESULTS

Among 2,317 patients with incident MI, LVEF assessment increased from 1979 to 1986 (22 to 85%; p value for trend = 0.0001) to stabilize thereafter until 1998. During the most recent decade, LVEF was measured during the hospital stay in 81% of the patients. Characteristics associated with lesser use of tests included older age and measurement of ejection fraction within 1 year prior to the index MI. Larger MI size, prolonged hospital stay, and involvement of a cardiologist as a care provider were positively associated with determination of LVEF.

CONCLUSIONS

Measurement of LVEF after MI increased in the last 2 decades, but there continues to be a group of patients in whom it is not done. Given the potential benefits of LVEF measurement, including knowledge for risk stratification and therapeutic choices as underscored in recent practice guidelines, there may be additional opportunities for improving outcomes by ensuring its more consistent use. However, as testing for LVEF differs according to patient characteristics, reliance on selected clinically performed LVEF measurements will result in biased estimates of the prevalence of LV dysfunction after MI.

Acute myocardial infarction: differing preinfarction and clinical features according to infarct site and gender

While differences between anterior and inferior acute myocardial infarction have been observed, clinical features of lateral infarction are poorly investigated. However, the impact of gender on clinical course and prognosis after myocardial infarction is not fully understood. Electrocardiographically determined infarct site, demographic and clinical variables were prospectively recorded for 1623 consecutive patients admitted to Clinical Hospital Split between 1990 and 1994 due to a first Q-wave acute myocardial infarction. Anterior infarctions were correlated with a higher prevalence of diabetes (P=4 x 10(-6)) or pulmonary venous congestion (P=2 x 10(-12)); inferior infarctions were correlated with a lower prevalence of hypertension (P=0.001), hypercholesterolemia (P=0.02) or diabetes (P=10(-5)), and a higher prevalence of smoking (P=0.001); lateral infarctions were characterized by a smaller infarction size and lower prevalence of pulmonary congestion (P=0.002). Among men under the age of 50 with inferior infarction there were 90% smokers, which was significantly more than among their gender (P=0.005) or infarct site (P=2 x 10(-5)) counterparts. After adjustment for age and other confounding factors, the prevalence of inferior infarction was higher in men (P=0.002). Increased age (P=0.002), female gender (P=0.0006), anterior site (P=10(-5)), diabetes (P=0.0003), greater creatine kinase-MB fraction level (P=0.001) and pulmonary congestion (P=9 x 10(-6)) were independent predictors of an adverse hospital outcome. Each site of acute myocardial infarction has relatively specific preinfarction and clinical features. Our results suggest a greater importance of vasoconstriction in the pathophysiology of inferior infarction, especially in young male smokers, and greater importance of advanced atherosclerotic process in occurrence of anterior infarction.

Correlation between symptomatology and site of acute myocardial infarction

OBJECTIVE

We determined the occurrence of presenting symptoms in patients with different sites of acute myocardial infarction after controlling for age and conventional risk factors.

METHODS

Hospital-based study of patients hospitalized because of first anterior (n=731), inferior (n=719) and lateral (n=96) infarction in Clinical Hospital Split between 1990 and 1994. Data form about presenting symptoms and clinical profile was completed for each patient.

RESULTS

Anterior infarctions were more often presented by headache (adjusted odds ratio (OR)=1.67, 95% CI=1.06-2.62), weakness (OR=1.60, 95% CI=1.31-1.96), dyspnea (OR=1.40, 95% CI=1.14-1.72), cough (OR=2.24, 95% CI=1.59-3.16), vertigo (OR=2.04, 95% CI=1.40-2.99) and tinnitus (OR=2.09, 95%CI=1.06-4.14). Inferior infarctions were more often associated with epigastric (OR=1.71, 95%CI=1.30-2.24), neck (OR=1.47, 95% CI=1.10-1.98) and jaw pain (OR=2.16, 95% CI=1.42-3.27), sweating (OR=1.56, 95% CI=1.27-1.92), nausea (OR=2.01, 95%CI=l.64-2.46), vomiting (OR=1.55, 95% CI=1.22-1.97), belching (OR=1.57, 95% CI=1.21-2.03) and hiccups (OR=2.88, 95%CI=1.53-5.42). Patients with lateral infarctions were more likely to complain of left arm (OR=1.80, 95% CI=1.07-3.05), left shoulder (OR=1.82, 95% CI=1.19-2.79) and back pain (OR=2.40, 95% CI=1.28-4.46). Pain was less frequently reported by hypercholesterolemic (P=l.4x10(-7)), patients over 70 years (P=0.002), women (P=0.0007) and those with non-triggered infarction (P=0.0009), whereas those over 70 (P=1.7x10(-6)) and men (P=0.0003) were less likely to report other relevant symptoms.

CONCLUSIONS

Our study suggests a linkage between different infarction sites and specific groups of symptoms. Furthermore, coronary patients should give their full attention to non-specific symptoms and any kind of discomfort.

Risk assessment of left ventricular systolic dysfunction in primary care: cross sectional study evaluating a range of diagnostic tests

OBJECTIVES

To assess the probability of left ventricular systolic dysfunction without echocardiography in patients from general practice.

DESIGN

Cross sectional study using multivariate regression models to examine the relation between clinical variables and left ventricular systolic dysfunction as determined by echocardiography.

SETTING

Three general practices in Copenhagen.

SUBJECTS

2158 patients aged >40 years were screened by questionnaires and case record reviews; 357 patients with past or present signs or symptoms of heart disease were identified, of whom 126 were eligible for and consented to examination.

MAIN OUTCOME MEASURES

Clinical variables that were significantly (P<0.05) related to ejection fraction </=0.45 and their predictive value for left ventricular systolic dysfunction.

RESULTS

15 patients (12%) had left ventricular systolic dysfunction. The prevalence was significantly related to three questions: does the electrocardiogram have Q waves, left bundle branch block, or ST-T segment changes? (P=0.012); is resting supine heart rate greater than the simultaneous diastolic blood pressure? (P=0.002); and is plasma N-terminal atrial natriuretic peptide>0.8 nmol/l? (P=0.040)? Only one of 60 patients with a normal electrocardiogram had systolic dysfunction (2%, 95% confidence interval 0% to 9%) regardless of response to the other two questions. The risk of dysfunction was appreciable in patients with a yes answer to two or three questions (50%, 27% to 73%).

CONCLUSIONS

A normal electrocardiogram implies a low risk of left ventricular systolic dysfunction. Patients can be identified for echocardiography on the basis of an abnormal electrocardiogram combined with increased natriuretic peptide concentration or a heart rate greater than diastolic blood pressure, or both.

Left ventricular atrioventricular plane displacement: an echocardiographic technique for rapid assessment of prognosis in heart failure

OBJECTIVE

To assess the prognostic value of atrioventricular plane displacement in heart failure patients.

DESIGN

Patients were followed prospectively for one year after atrioventricular plane displacement determination.

SETTING

Malmö University Hospital, with a primary catchment area of 250,000 inhabitants.

PATIENTS

181 patients with a clinical diagnosis of heart failure; age 75.7 (SD 5.2) years, duration of heart failure 2.7 (5.7) years; 100 men, 81 women.

MAIN OUTCOME MEASURES

Mortality in relation to atrioventricular plane displacement.

RESULTS

Total mortality was 22.7% (41/181), and was highly significantly (P = 0.001) related to atrioventricular plane displacement. Mortality within prospectively defined categories of displacement was: > or = 10.0 mm, 0% (0/19); 8.2 to 9.9 mm, 10.3% (3/29); 6.4 to 8.1 mm, 19.4% (12/62); and < 6.4 mm, 36.6% (26/71). The groups were similar in age, sex, angiotensin converting enzyme inhibitor and beta blocker treatment, and cause and duration of heart failure.

CONCLUSIONS

Mortality in heart failure is strongly related to atrioventricular plane displacement.

Simplified echocardiography in the diagnosis of heart failure

Echocardiography is essential in the diagnosis of heart failure, but insufficient resources limit its use. We compared swift (five minutes) simplified echocardiography, using elementary equipment, with standard echocardiography (45 minutes), using advanced equipment. Visual semi-quantification of cardiac dimensions, valvular stenosis, and left ventricular ejection fraction (LVEF) was performed in 100 consecutive patients with suspected or known heart failure. Agreement between simplified and standard echocardiography was 78-89% regarding semi-quantification of cardiac dimensions, and 95-98% for valvular stenosis (present/not present). Sensitivity and specificity for simplified echocardiography to identify patients with LVEF < 0.40 was 86 and 89%, respectively. Simplified echocardiography using elementary equipment could be an alternative to standard echocardiography in the diagnosis of heart failure. The cost and time saved by using simplified echocardiography allows for more patients to be examined, which should be weighed against its accuracy.

Non-invasive prognostic factors in chronic heart failure. One-year survival of 300 patients with a diagnosis of chronic heart failure due to ischemic heart disease or dilated cardiomyopathy

The prognosis and clinical findings related to prognosis were examined in 300 patients with congestive heart failure in a prospective study. The diagnosis was based on case history data (NYHA class II or III), depressed ejection fraction (< or = 40%) and/or increased cardiothoracic ratio (> or = 50%). Forty-eight (16%) patients died within 1 year after the entry examination. Non-invasive baseline parameters of survivors and non-survivors were compared. All necessary medication was allowed. At the entry of the study three parameters independently predicted an increased mortality on a high significance level (P < 0.01): cardiothoracic ratio, signs of lung congestion on the chest X-ray (four grade classification), and plasma urea level; other three parameters did so on a lower significance level (P < 0.05): plasma natrium, creatinine value and endsystolic volume. Other parameters such as age, ejection fraction, NYHA class or exercise tolerance duration were not statistically different in survivors and non-survivors. Our modification (a four grade classification) of the signs of lung changes on the chest X-ray enables a more accurate determination of the prognosis in patients with chronic heart failure.

How well can the chest radiograph diagnose left ventricular dysfunction?

OBJECTIVES

To review the diagnostic utility of the chest radiograph for left ventricular dysfunction.

DATA SOURCES

Structured MEDLINE searches, citation reviews of relevant primary research, review articles, and textbooks, personal files, and data from experts.

STUDY SELECTION

Studies of patients without valvular disease that allowed calculation of the sensitivity and specificity of selected radiographic signs compared with a criterion standard of increased left ventricular preload or reduced ejection fraction.

DATA EXTRACTION

Two independent readers reviewed 29 studies. Studies were pooled after stratification by radiographic finding, criterion standard, and clinical setting.

MAIN RESULTS

Redistribution best diagnosed increased preload with a sensitivity of 65% (95% confidence interval [CI] 55%, 75%) and specificity 67% (95% CI 53%, 79%). Cardiomegaly best diagnosed decreased ejection fraction with a sensitivity of of 51% (95% CI 43%, 60%) and specificity of 79% (95% CI 71%, 85%). Interrater reliability was fair to moderate for redistribution and moderate for cardiomegaly. The clinical setting affected results by decreasing the specificity of cardiomegaly to 8% in detecting increased preload in patients with severe systolic dysfunction. The absence of redistribution could only exclude increased preload in situations in which the suspicion (pretest probability) of disease was less than 9%, whereas redistribution could confirm increased preload when the pretest probability was greater than 91%. The absence of cardiomegaly could only exclude a reduced ejection fraction if the pretest probability was less than 8%, whereas cardiomegaly could confirm a reduced ejection fraction if the pretest probability was greater than 87%.

CONCLUSIONS

Redistribution and cardiomegaly are the best chest radiographic findings for diagnosing increased preload and reduced ejection fraction, respectively. Unfortunately, neither finding alone can adequately exclude or confirm left ventricular dysfunction in usual clinical settings. Redistribution is not always reliably interpreted.

Detection of left ventricular dysfunction after acute myocardial infarction: comparison of clinical, echocardiographic, and neurohormonal methods

OBJECTIVE

The SAVE study showed that captopril improves mortality in patients with left ventricular dysfunction after myocardial infarction and that this benefit occurred even in patients with no clinically overt heart failure. On the basis of this, it seems important to identify correctly which patients have left ventricular dysfunction after a myocardial infarction. The objective was to compare various methods of identifying patients with left ventricular dysfunction (left ventricular ejection fraction, LVEF, < or = 40%) after acute myocardial infarction. The methods compared were echocardiography (quantitative and qualitative visual assessment), clinical evaluation (subjective assessment and three clinical score methods), and measurement of plasma concentrations of cardiac natriuretic peptide hormones (atrial and brain natriuretic peptides, ANP and BNP).

DESIGN

Cross sectional study of left ventricular function in patients two to eight days after acute myocardial infarction.

SETTING

Coronary care unit of a teaching hospital.

PATIENTS

75 survivors of a recent myocardial infarction aged 40 to 88 with no history of cardiac failure and without cardiogenic shock at the time of entry to the study.

MAIN OUTCOME MEASURES

Sensitivities and specificities of the various methods of detecting left ventricular dysfunction were calculated by comparing them with a cross sectional echocardiographic algorithm for LVEF.

RESULTS

Clinical impression was poor at identifying LVEF < 40% (sensitivity 46%). Clinical scoring improved this figure somewhat (modified Peel index sensitivity 64%). Qualitative visual assessment echocardiography was a more sensitive method (sensitivity 82%) for detecting LVEF < 40%. Plasma BNP concentration was also a sensitive measure for detecting left ventricular dysfunction (sensitivity 84%) but plasma ANP concentration was much poorer (sensitivity 64%).

CONCLUSION

Left ventricular dysfunction is easily and reliably detected by echocardiographic measurement of LVEF and also by a quick qualitative echocardiographic assessment but is likely to be missed by clinical assessment alone. High concentrations of plasma BNP maybe another useful indicator of left ventricular dysfunction, particularly in hospitals where not all patients can be screened by echocardiography or radionuclide ventriculography after myocardial infarction.

Acute myocardial infarction size and myoglobin release into serum

The kinetics of myoglobin release after acute myocardial infarction were studied. Various algorithms for calculation of infarct size, based on immunonephelometric determination of myoglobin and cumulative myoglobin release into the circulation were compared. The cumulative myoglobin release and maximal serum myoglobin concentration were compared with various measures of infarct size: cumulative release of creatine kinase, electrocardiographic changes, and left ventricular ejection fraction. After acute myocardial infarction, time to peak for myoglobin in serum was correlated with time to peak for creatine kinase (r = 0.645). On average, the myoglobin concentration peaked 8.8 h earlier than creatine kinase activity. The rate of elimination of myoglobin showed a large variation (0.041-0.628 h-1) and was not correlated with the elimination rate of creatine kinase. The elimination rate of myoglobin after acute myocardial infarction was shown to depend on the patient's age and infarct size. The elimination constant of myoglobin is preferably estimated on an individual basis in large and complicated infarctions. Cumulative myoglobin release correlated with algorithms based on the cumulative release of creatine kinase (r = 0.622) and its isoenzyme MB (r = 0.660), and to a lesser extent with the residual left ventricular ejection fraction (r = 0.513) and the sum of ST-segment deviations on electrocardiography (r = 0.469). Maximal myoglobin values in serum correlated moderately with the calculated infarct size (r = 0.488; based on creatine kinase-MB) and electrocardiographic changes (r = 0.554). In combination with fast immunological methods for myoglobin determination, myoglobin peak height offers the advantage of providing reliable results within 12 h after onset of symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Sensitivity and specificity of echocardiographic identification of patients eligible for safe early discharge after acute myocardial infarction

In a prospective clinical trial of 195 consecutive unselected patients with acute myocardial infarction (AMI), systematic blinded clinical and echocardiographic examinations were performed by two observers on day 5. The purpose was to define low-risk patients with regard to in-hospital and 2-month mortality and predict the potential costs (lost patient lives) and benefits (saved in-patient days) if as a routine procedure these low-risk patients were discharged earlier. By design, low-risk patients as defined by clinical criteria were allocated to discharge on days 7 to 10 and by echocardiographic criteria on days 5 to 7 after AMI. The sensitivity of the echocardiographic low-risk identification procedure was more than twofold higher than the sensitivity of clinical low-risk identification (49% vs 24%). Both procedures were safe with a specificity of 100% for cardiac mortality. Optimal identification of low-risk patients was provided by combining data from echocardiographic and clinical evaluations (sensitivity 59%). Results of the study suggest that a bedside echocardiographic approach to estimation of global left ventricular function is more sensitive and equally specific and therefore more efficient for risk stratification on post-AMI day 5 than clinical examination alone. Thus echocardiographic examination allows identification of a larger subset of patients with AMI (greater than 40% of the population alive on day 5) who can be discharged earlier and safely, with a potential saving of in-patient days of 436 days in 87 low-risk patients minus the cost of echocardiographic studies in 195 patients. However, the best prediction was obtained by combining clinical and echocardiographic examination.(ABSTRACT TRUNCATED AT 250 WORDS)

Echocardiographic algorithms for admission and predischarge prediction of mortality in acute myocardial infarction

To develop improved prognostic algorithms for routine bedside use in acute myocardial infarction (AMI), the prognostic value concerning 2- and 12-month mortality of an early (within 72 hours after AMI) resting echocardiogram was defined in 201 consecutive patients. The relation between (1) the clinical variables (age, sex, prior and repeat AMI, arrhythmias, cardiac arrest, early [less than 72 hours after AMI] and late heart failure, early and maximal in-hospital Killip class, and maximal creatine kinase-MB isoenzyme), (2) early myocardial performance by echocardiography, and (3) mortality was characterized by Kaplan-Meier survival curves and receiver-operating characteristic curves based on Cox regression model. Only age and clinical heart failure in terms of the maximal in-hospital Killip class had independent predictive value of death (p less than 0.05) when an early echocardiographic estimate of left ventricular ejection fraction (LVEF) was included in the multivariate statistical models. The following 2 optimized algorithms for admission and predischarge calculation of risk of mortality at 2 and 12 months were developed based on the Cox model, using combinations of age, maximal Killip class and early echocardiographic LVEF: mortality at 2 months = 1 - exp - [0.051 x exp [0.044 x (age -60) - (0.117 x (LVEF - 40)]]; and mortality at 1 year = 1 - exp - [0.101 x exp [0.408 x (maxKillip - 1) - (0.061 x (LVEF - 40)]]. Discriminative power for prediction of mortality of the predischarge algorithm in an independent population of 195 patients 5 days after AMI compared favorably with that obtained in the original population, confirming the validity of the proposed method of prognostication.

Bedside diagnosis of preserved versus impaired left ventricular systolic function in heart failure

The importance of recognizing symptomatic heart failure with preserved left ventricular (LV) systolic function has only recently been appreciated. To determine its frequency and identify clinical features that make the bedside diagnosis likely, 82 patients admitted for decompensated heart failure were classified into 2 groups based on their LV systolic performance, as defined by fractional shortening (FS): group I (n = 59), with impaired systolic function (fractional shortening less than 24%), and group II (n = 23) with preserved systolic function (fractional shortening greater than or equal to 24%). Mean fractional shortening was 15 +/- 5% and 39 +/- 1% for groups I and II, respectively. Female gender (p less than 0.05), obesity (p less than 0.01) and diastolic blood pressure greater than or equal to 105 mm Hg (p less than 0.05) predominated in group II. Jugular venous distention was identified more frequently in group I (p less than 0.05). No statistically significant difference between the 2 groups was noted among various demographic variables (age, duration of symptoms, history of hypertension, ischemic heart disease and heavy alcohol drinking) or physical findings (S3 gallop, edema, cardiomegaly, pulmonary congestion and pulmonary edema). Echocardiographic mean left ventricular dimension measured 6.6 +/- 1 versus 5.0 +/- 1 cm (p less than 0.01) and mean posterior wall thickness 1.1 +/- 0.3 versus 1.4 +/- 0.4 cm (p less than 0.01) in group I and II, respectively. The combination of diastolic blood pressure greater than or equal to 105 mm Hg and an absence of jugular venous distention had a high specificity and positive predictive value (100%) for identifying group II patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Superiority of visual versus computerized echocardiographic estimation of radionuclide left ventricular ejection fraction

An optimal method for determining left ventricular ejection fraction (LVEF) by echocardiography should be rapid, reliable, and widely applicable in order to be utilized routinely in a busy clinical laboratory. Most methods reported in the literature are reliable in selected, high-quality echocardiograms. Most require off-line computer analysis and are time-consuming and poorly suited to the routine of a busy laboratory. We compared in a blinded manner several echocardiographic methods of LVEF determination with the ejection fraction obtained by equilibrium radionuclide angiography (ERNA) in 44 patients unselected for image quality. Echocardiographic methods included: [1] cubed M-mode formula; [2] Teichholz M-mode formula; [3] subjective estimation of LVEF from two-dimensional echocardiographic videotape; [4] area-length method in one four-chamber view; [5] average of area-length method in three four-chamber views; [6] average of area-length method in four-chamber and two-chamber views (one beat each); [7] subjective estimation from stored videoloop of four-chamber and two-chamber view. In 30 cases M-mode tracings were available for analysis. In only 23 of the 44 patients were the apical views suitable for quantitative analysis. The ERNA ejection fraction was 44 +/- 17% (mean +/- 1 SD). The best echocardiographic correlation with ERNA ejection fraction in each patient subgroup studied was obtained by method 3. We concluded that subjective analysis of the videotaped study by an experienced cardiologist/echocardiographer provided the best estimation of ERNA ejection fraction. More time-consuming and costly computer techniques yielded a worse estimate.

Interobserver agreement and accuracy of bedside estimation of right and left ventricular ejection fraction in acute myocardial infarction

Ninety-eight patients with acute myocardial infarction were examined by 3 clinicians who, independently of each other, gave an estimate of left ventricular (LV) and right ventricular (RV) ejection fraction (EF) in each patient. Their estimates were based on physical examination, chest x-ray, electrocardiogram, patient history and clinical course during admission. Ejection fractions were estimated as belonging to 1 of 4 categories: normal (LVEF greater than or equal to 0.53, RVEF greater than or equal to 0.57), mildly reduced (LVEF 0.40 to 0.52, RVEF 0.45 to 0.56), moderately reduced (LVEF 0.30 to 0.39, RVEF 0.35 to 0.44) or severely reduced (LVEF less than 0.30, RVEF less than 0.35). Radionuclide ventriculography was carried out immediately after the physical examination. LVEF was correctly estimated in 43% of all examinations, deviated from radionuclide LVEF by 1 LVEF category in 45% and by 2 LVEF categories in 12%. The 3 clinicians agreed on estimated LVEF in only 32% of the patients. RVEF was correctly estimated in 67% of the examinations, but none of the clinicians identified greater than 43% of the relatively few patients with reduced radionuclide RVEF and they greatly disagreed as to who among the patients had a reduced RVEF. Previous myocardial infarction, electrocardiographic infarct location, Killip class, physical signs of left- and right-sided heart failure, radiographic pulmonary congestion and cardiomegaly were analyzed to determine which were the most helpful in predicting LVEF and RVEF. The results disclosed that several variables, traditionally believed to be reliable indexes of reduced ventricular function, were surprisingly poor predictors of LVEF and RVEF.

Prediction of left ventricular ejection fraction using a unique method of chest x-ray and ECG analysis: a noninvasive index of cardiac performance based on the concept of heart volume and mass interrelationship

A reasonably accurate, simple, inexpensive, noninvasive method of determining ejection fraction (EF) is necessary to evaluate left ventricular function in epidemiologic studies and individual patients. Using the concepts of left ventricular mass reflected by precordial R wave summation (M) and left ventricular volume (V) estimated by chest roentgenography in 114 patients with myocardial disease undergoing left ventriculography, EF was predicted with the formula: EF = 63.74 - (2.16.V) + (0.34.M); R2 = 0.69; standard error of the estimate (SEE) = 11. Because angiographic inferior wall motion (IWM) abnormalities significantly affected the results, but inferior Q waves were usually only present in patients having one infarct, a noninvasive technique to predict the presence of inferior wall motion abnormality (IMA) in patients having multiple infarcts was developed and based on the relationship of precordial R wave summation (M) and roentgenographic heart volumenometry (V). By combining V, M, and IMA (which predicted IWM) to determine EF, multiple linear regression analysis showed that EF = 67.30 - (1.56.V) + (0.23.M) - (14.18 IMA) (R2 = 0.77; SEE = 9). Prospective validation of the formula was then done in 139 consecutive individuals, with R2 = 0.49 and SEE = 9. This study demonstrates that routinely performed, simple, inexpensive clinical tests provide data that can be combined by multiple regression analysis to predict resting EF in patients with heart disease affecting the left ventricle. This unique method may allow inexpensive ventricular function screening in large population studies and in addition might provide an independent index of myocardial performance for clinical use, since it reflects the amount of contractile mass per unit of left ventricular volume.(ABSTRACT TRUNCATED AT 250 WORDS)