Sudden death in the year following myocardial infarction : Relation to ventricular premature contractions in the late hospital phase and left ventricular ejection fraction

Both depressed left ventricular ejection fraction and ventricular arrhythmias have been associated with a poor prognosis following acute myocardial infarction. To assess the relative role of each of these parameters in predicting mortality in the early period after hospitalization for myocardial infarction, 24 hour ambulatory electrocardiographic tape recordings and gated cardiac blood pool scans were obtained in 81 patients approximately two weeks after their admission to the hospital for myocardial infarction. Lown class 0 to II ventricular premature contractions during this period were classified as uncomplicated ventricular arrhythmias and Lown class III to V ventricular premature contractions were classified as complicated ventricular arrhythmias. Ejection fraction was calculated from biplane images of gated cardiac blood pool scans. In 36 patients the ejection fraction was ≥ 0.40; only three of these had complicated ventricular arrhythmias. In 45 patients the ejection fraction was < 0.40; 26 of these had complicated ventricular arrhythmias. Eight patients had documented ventricular fibrillation or instantaneous death during a mean 7.0 month (range 2 to 16 months) follow-up period outside the hospital. Although the number of patients studied was small, and there were only eight sudden deaths, life table analysis projected a one year mortality of 66 per cent in patients with complicated ventricular arrhythmias and 31 per cent in patients with an ejection fraction < 0.40. All eight patients who died suddenly were in the subgroup of 26 patients with an ejection fraction < 0.40 and complicated ventricular arrhythmias; none was in the subgroup of 19 patients with an ejection fraction < 0.40 and uncomplicated ventricular arrhythmias (p < 0.02). Although a low ejection fraction may suggest a poor prognosis following myocardial infarction, the presence of complicated ventricular arrhythmias significantly increases the risk of sudden cardiac death in the early period after hospitalization in patients with low ejection fraction.     

Long-term stepwise sustained improvement in left ventricular ejection fraction after myocardial infarction

Radionuclide left ventricular ejection fraction, end-diastolic volume, and exercise capacity were determined in 34 selected patients who survived a first Q wave anterior infarction. Patients were included in the study if they had no subsequent cardiac events (unstable angina or myocardial infarction) during the average follow-up period of 47 months (range = 36 to 70 months); none was treated with thrombolysis, coronary angioplasty, or bypass grafting. Overall, mean left ventricular ejection fraction increased from 28 +/- 10% 1 month after infarction to 33 +/- 10% at 3 years (p less than 0.01); mean end-diastolic volume decreased from 217 +/- 99 ml to 171 +/- 80 ml (p less than 0.002). Stepwise improvement in left ventricular ejection fraction occurred in 15 of these patients (group B) and was associated with a significant increase in exercise capacity. Mean ejection fraction in group B was 26 +/- 7% at 1 month and 41 +/- 10% at 3 years (p less than 0.001). In all of these patients there was improved regional wall motion in the noninfarct zone, whereas five patients also showed improvement in the infarct zone. The results indicate a progressive improvement in left ventricular function that occurs over time in some patients after first Q wave anterior infarction, independent of intervention.     

Effect of pulsatile and nonpulsatile flow during cardiopulmonary bypass on left ventricular ejection fraction early after aortocoronary bypass surgery

Although aortocoronary bypass graft has successfully relieved angina in most patients, concern has been expressed about possible deterioration or failure of improvement of left ventricular performance. With use of intraaortic balloon pumping to produce pulsatile flow during cardiopulmonary bypass, left ventricular ejection fraction and end-diastolic volume index were compared in a consecutive series of 40 men undergoing elective aortocoronary bypass, 20 of whom had pulsatile flow and 20 who had mean flow during cardiopulmonary bypass. Left ventricular ejection fraction and end-diastolic volume index were measured before and 1 to 12 days after operation using a collimated scintillation probe and indium^113m. In the group receiving nonpulsatile flow the ejection fraction decreased from 52.2 ± 2.9 percent (mean ± standard error of the mean) to 38.7 ± 3.2 percent on the first postoperative day and 43.0 ± 3.4 percent on the 10th day (P < 0.001). In the group receiving pulsatile flow, the ejection fraction increased from 51.4 ± 3.0 percent to 61.6 ± 3.4 percent on day 1 and 65.8 ± 2.9 percent on day 10 (P < 0.001). Three of 20 (15 percent) in the group with nonpulsatile flow had an increase of ejection fraction compared with 17 of 20 (85 percent) in the group given pulsatile flow. Left ventricular end-diastolic volume index was not significantly altered in either group. Two men (10 percent) in each group had post-operative myocardial infarction. The ejection fraction increased despite infarction in both patients given pulsatile flow but decreased in both patients with infarction given mean flow. In a series of 235 patients intraoperative infarction occurred in 8 of 109 patients given pulsatile flow (incidence 7.3 percent) but in 14 of 126 patients given mean flow (incidence 11.1 percent) (P < 0.05). These results suggest that pulsatile flow during cardiopulmonary bypass (1) improves left ventricular ejection fraction in the early postoperative period in patients undergoing aortocoronary bypass and (2) may enhance myocardial preservation in these patients.     

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.     

Effect of rapid mobilization on ejection fractions and ventricular volumes after acute myocardial infarction

Despite the current practice of early mobilization and early hospital discharge after uncomplicated acute myocardial infarction (AMI), physicians are reluctant to permit normal physical and social activity for several weeks after the AMI "to allow the heart to heal." This study tested whether it was possible to identify a low risk group of patients on day 3 after AMI, and whether vigorous early mobilization from days 4 through 7 affected left ventricular function and volumes (studied by gated blood pool scan on days 4 and 14). There was 1 death in 3 months in 45 patients with uncomplicated AMI suitable for randomization to activity (group A) compared with 11 deaths in 55 patients unsuitable for rapid early mobilization (group B) (p less than 0.01). Early vigorous mobilization in 24 of the group A patients compared with sedentary care in 20 did not affect change in ejection fraction, end-diastolic volume, end systolic-volume, stroke volume, heart rate or cardiac output between days 4 and 14. A very low risk group suitable for early vigorous mobilization can be defined on day 3 after AMI; further, vigorous early mobilization does not affect left ventricular function or volumes. Early return to physical, social and occupational activity after uncomplicated AMI should result in marked reduction in direct and indirect costs of AMI.     

Two-dimensional echocardiographic estimation of right ventricular ejection fraction in patients with coronary artery disease

Two-dimensional echocardiographic determination of right ventricular ejection fraction was compared with right ventricular ejection fraction obtained by first pass radionuclide angiography in 39 patients with coronary artery disease. Apical four chamber and two chamber right ventricular views were obtained in 34 (87%) of the 39 patients, while a subcostal four chamber view was obtained in 31 patients (80%). Right ventricular ejection fraction by two-dimensional echocardiography was calculated by the biplane area-length and Simpson's rule methods using two paired orthogonal views and utilizing a computerized light-pen method for tracing the right ventricular endocardium. A good correlation (r = 0.74 to 0.78) was found between radionuclide angiographic and two-dimensional echocardiographic right ventricular ejection fraction for each method used. Patients with acute inferior myocardial infarction had the lowest right ventricular ejection fraction by radionuclide angiography and two-dimensional echocardiography (p less than 0.05 compared with patients with right coronary artery obstruction and no infarction). There were no differences in right ventricular ejection fraction between patients with acute and old inferior myocardial infarction by both techniques. No correlation was found between left and right ventricular ejection fraction by radionuclide angiography (r = 0.16). It is concluded that 1) right ventricular ejection fraction by two-dimensional echocardiography correlates well with radionuclide angiographic measurements and can reliably evaluate right ventricular function in coronary artery disease, 2) patients with inferior myocardial infarction have reduced right ventricular ejection fraction, and 3) changes in left ventricular ejection fraction do not directly influence right ventricular function.     

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 stratification of survivors of lst myocardial infarction: evaluation of regional kinetics and ejection fraction by bidimensional echocardiography

To determine the prognostic value of some echocardiographic indices of left ventricular function (ejection fraction, wall motion score index, left ventricular dimension) in the first year after acute myocardial infarction, we studied prospectively 162 consecutive patients (mean age: 61 +/- 11) who survived the hospital phase of a first acute myocardial infarction. Two-dimensional echocardiography was performed at hospital discharge (mean: 20 +/- 3 days after admission). For the analysis of wall motion, an 11 segment model of the left ventricle was used; from the scoring system of segmental ventricular function (1 = normal, 2 = hypokinetic, 3 = akinetic, 4 = dyskinetic, 5 = aneurysmal) we derived the wall motion score index (sum of assigned number to each segment/11). The echocardiographic ejection fraction was determined using the monoplane ellipsoid formula for the calculation of end diastolic and end systolic volumes in apical four-chamber and two-chamber views; the assumed ejection fraction was the mean value resulting from values of ejection fraction calculated in the two views. The follow-up was protracted from 13 to 36 months (mean: 22 months). Fourteen patients (9%) died as a result of cardiac events within 13 months of myocardial infarction. Of the patients with ejection fraction greater than or equal to 45% (81/162 = 50%) two died (first year mortality = 2.4%); of those with 35-45% ejection fraction (58/162 = 35%) two died (first year mortality = 3.5%); while of those with less than or equal to 35% ejection fraction (25/162 = 15%) ten died (first year mortality = 40%). Of the patients with wall motion score index less than 1.5 (76/162 = 47%) none died in the follow-up period; of those with score index between 1.5 and 1.9 (61/162 = 37%) four died (first year mortality = 7%); of those with score index greater than or equal to 1.9 (25/162 = 15%) ten died (first year mortality = 40%). Thus, ejection fraction and score index have the same predictive value for mortality in the first year after a first acute myocardial infarction. However, an interesting datum is that in the sub-group of patients with less than or equal to 35% ejection fraction and score index less than 1.9 the first year mortality was 15%, while in the sub-group with less than or equal to 35% but score index greater than or equal to 1.9 the first year mortality was 57%.(ABSTRACT TRUNCATED AT 400 WORDS)     

Effect of oral alcohol on left ventricular ejection fraction, volumes, and segmental wall motion in normals and in patients with recent myocardial infarction

A first-pass nuclear angiogram and a multiple-gated acquisition study were obtained in 10 normal physicians and in 10 patients with a 7-to-10 day old transmural myocardial infarction. After the scan the subjects drank 2 oz. of whiskey. After 60 minutes, the multiple-gated acquisition study was repeated. In the normal group the left ventricular ejection fraction was 68% before and 72% after alcohol. The left ventricular end-diastolic volume increased from 89 to 97 ml while the left ventricular end-systolic volume decreased from 29 to 27 ml. The stroke volume rose from 61 to 70 ml/beat (p less than 0.05). The cardiac output increased from 4.0 to 5.0 l/min (p less than 0.05). In the infarction group, the left ventricular ejection fraction was 58% before and 56% after alcohol administration. The left ventricular end-diastolic volume fell from 111 to 96 ml, while the left ventricular end-systolic volume declined from 50 to 44 ml. The stroke volume fell from 61 to 52 ml/beat, while the cardiac output fell from 4.5 to 3.8 l/min. In the left ventricular infarction zones, alcohol produced in 9 of the 10 cardiac patients a decline in the left ventricular regional ejection fraction. In the normal group, alcohol produced no significant changes in the regional ejection fraction. The normal and the postinfarction patients responded differently to alcohol.     

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.     

Relationship between the changes in myocardial perfusion and left ventricular ejection fraction after acute myocardial infarction. Study with myocardial contrast echocardiography.

BACKGROUND AND OBJECTIVE: Myocardial contrast echocardiography has recently been proposed as a valid technique in the evaluation of myocardial perfusion after myocardial infarction. The objective of this study was to evaluate the relation between changes in myocardial perfusion assessed by myocardial contrast echocardiography and left ventricular ejection fraction after myocardial infarction. PATIENTS AND METHODS: We prospectively studied 17 patients with acute myocardial infarction, on whom two echocardiographic studies were performed, at 48-72 hours and at 6 months. Left ventricular ejection fraction and myocardial perfusion were evaluated with myocardial contrast echocardiography (Multiple-Frame Triggering and Harmonic Angio). Basal, medial and distal segments of the interventricular septum (anterior location infarction) and inferior wall (inferior infarction) were assessed. Myocardial perfusion was classified semi-quantitatively as grade 0, 1 or 2 (absent, heterogeneous or homogeneous opacification, respectively), giving a perfusion score. RESULTS: Left ventricular ejection fraction improved in 9 patients (53%), the proportion of grade 0 segments decreasing by 11 +/- 17%; by contrast, this proportion increased by 9 +/- 13% in patients with no improvement in ejection fraction (p = 0.028). Additionally, a significant correlation was observed between changes in ejection fraction and both perfusion score (r = 0.625; p = 0.007) and the proportion of grade 2 segments (r = 0.649; p = 0.005). CONCLUSION: After myocardial infarction, there is a significant relation between changes in left ventricular ejection fraction and myocardial perfusion assessed by myocardial contrast echocardiography with i.v. agents.     

Increase in radionuclide left ventricular ejection fraction after cardioversion of chronic atrial fibrillation in idiopathic dilated cardiomyopathy.

To assess the potential improvement in left ventricular ejection fraction after cardioversion of chronic atrial fibrillation to sinus rhythm in idiopathic dilated cardiomyopathy, we studied prospectively 17 patients, aged 58 +/- 6 years, by radionuclide angiocardiography at rest. Left ventricular ejection fraction was determined before treatment and at a mean delay of 4.7 months after cardioversion. Return to sinus rhythm was obtained in 12 patients, pharmacologically or by electrical cardioversion. Five patients remained in atrial fibrillation. No clinical, echocardiographic or haemodynamic finding could predict the success of cardioversion. In chronic atrial fibrillation, the ejection fraction did not change significantly: 30.0 +/- 9.1% (19 to 44%) at the first evaluation and 29.5 +/- 8.3% (22 to 41%) after 4.7 months. After successful cardioversion, left ventricular ejection fraction improved from 32.1 +/- 5.3% (24 to 41%) to 52.9 +/- 9.7% (37 to 71%) (P less than 0.001). The difference was 20.8 +/- 11.3% and left ventricular ejection fraction was normalized in 50% (6/12) of the patients. There was a significant reduction in the cardiothoracic ratio on chest X-rays and of the left ventricular end-diastolic diameter on echocardiography; fractional shortening increased (27.7 +/- 4.3% vs 20.3 +/- 2.7%, P less than 0.01). A third evaluation was realized after a mean delay of 11.7 months in the patients with successful cardioversion. Sinus rhythm was present in 83% (10/12) of the patients: seven patients were reevaluated by radionuclide angiography. The improvement in left ventricular function observed at the 4.7 months evaluation was still present. In two patients with recurrence of atrial fibrillation, there was a severe deterioration of left ventricular systolic function.(ABSTRACT TRUNCATED AT 250 WORDS)     

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.     

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.     

Value of the QRS complex in assessing left ventricular ejection fraction

The relation between electrocardiographic findings and the angiographic left ventricular ejection fraction and the augmented ejection fraction after a premature ventricular contraction was investigated in 73 patients with documented chronic coronary artery disease. The patients were separated into four groups according to the presence or absence of abnormal Q waves. Twenty-four patients had diaphragmatic myocardial infarction, 21 had anterior myocardial infarction, 15 had both and 13 had no myocardial infarction. There were no statistically significant differences in cardiac index, left ventricular end-diastolic pressure or number of coronary vessels showing critical narrowing in the four groups. The sum of R waves (in mv) in leads aVL, aVF and V₁ to V₆ (ΣR) was correlated with the ejection fraction (EF) and the augmented ejection fraction (EFa). EF in percent = 6.6 ΣR mv + 9.4 (no. = 73, r = 0.61); and EFa in percent = 8.6 ΣR mv + 11.0 (no. = 73, r = 0.77). Among patients with ΣR of less than 4.0 mv, augmented ejection fraction was less than 0.45 in 73 percent; among patients with ΣR of 4.0 mv or more the augmented ejection fraction was greater than 0.45 in 93 percent (P < 0.001). Thus, the ΣR, calculated from six precordial and two augmented leads in patients with chronic coronary artery disease, correlated with both ejection fraction and augmented ejection fraction. The electrocardiogram in patients with coronary artery disease may prove useful as a simple, readily available and noninvasive guide in the assessment of left ventricular function in patients with coronary artery disease.     

The significance of lowered ejection fraction on prognosis after myocardial infarction

The subject of this study was a group of 757 patients hospitalized because of acute myocardial infarction in years 1992-1996, who survived the in-hospital course and were under observation for 2-6 years after the infarction. During the 14-18th day of the hospital stay they were made an echocardiographic test, including the ejection fraction (EF). The aim of this study was to define the influence of the ejection fraction value lowered below 40% on the long-term prognosis in patients after acute myocardial infarction. We compared two groups of patients; group I, consisting of 130 (17.2%) patients with EF lowered below 40% and group II, which included 627 patients with EF over 40%. To estimate the statistic significance we used the chi-square and t-Student test. The morbidity curves were made with the Kaplan-Meier method. The course of the myocardial infarction was much more grave in group I than in group II, what is confirmed by a more often anterior ventricular infarction and the quantity of dangerous complications which occurred during the in-hospital phase. The multi-factor regressive analysis showed that the ejection fraction lowered below 40% raises 2.47 times (95% confidence interval 1.50-4.07) (p < 0.001) the risk of death during the first year after myocardial infarction and nearly two times during the 5 year follow-up, compared to patients with a higher EF value. The influence of the EF value lowered below 40% on the creation of an infarction was not significant. The EF value lowered below 40% in patients after acute myocardial infarction was a significant risk factor in the long-term prognosis. More than 40% of deaths during the long-term prognosis in this group were caused by heart failure.     

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.     

Angiographic study of the ejection fraction by thirds of systole in coronary patients

The parameters of myocardial function in the initial phase of ventricular ejection are theoretically more sensitive than the indices calculated over the total systolic ejection period. The object of this study was to evaluate whether the calculation of the ejection fraction by thirds of systole, giving a separate assessment of left ventricular performance at the beginning, the middle and end of ejection, could reliably detect minor changes in ventricular function unrecognised by the usual holosystolic indices. Seventy left ventricular angiograms were analysed in 20 normal subjects (Group I) and 50 patients with coronary artery disease whose ventricular function estimated by the usual parameters was either decreased (Group II, 20 patients) or normal (Group III, 30 patients). In Group I, the ejection fraction in the first third of systole (FE1/3) was much higher than the ejection fraction in the second third (FE2/3). On the other hand, in Groups II and III, all patients had a FE1/3 lower than the FE2/3 (specificity: 100 p. 100). In these two groups, the reduction of FE1/3 and the increase of FE2/3 were very significant compared to Groupe I (p less than 0,001). The ejection fraction of the lest third was identical in the 3 groups. This abnormal distribution of ejection was detected in all coronary patients and was the only alteration of ventricular performance in each of the 30 patients in Group III. In this group, this abnormality was detected equally in patients with triple vessel disease (Subgroup III a, 20 patients) and in patients with isolated left anterior descending disease (Subgroup III b, 10 patients) illustrating the high sensitivity of this index for the detection of a minor abnormality of myocardial function.