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PubMed1987

Use of an exercise QRS score and radionuclide left ventricular ejection fraction in assessing prognosis after myocardial infarction.

We have compared the prognostic value of a predischarge post-infarction QRS score derived at rest and at submaximal exercise with ejection fraction measured by gated radionuclide left ventriculography in 65 patients. Seventeen patients died or had heart failure (group 1) and 48 were well or had angina (group 2) six months after infarction. The mean QRS score derived from the resting electrocardiogram for group 1 was significantly greater than that for group 2 (P less than 0.01) but the QRS scores at peak exercise did not differ significantly between the two groups. The mean ejection fraction for group 2 was significantly greater than that for group 1 (P less than 0.001). Both the rest and peak exercise QRS scores correlated weakly but significantly with ejection fraction (P less than 0.001). The QRS score at rest had a greater sensitivity and specificity in predicting cardiac death and heart failure than the QRS score at peak exercise. A sensitivity of 88% was achieved with a resting ejection fraction less than 50% and a resting QRS score greater than 4. At these values the specificities were 58% and 63% respectively. Combining the blood pressure response to exercise with the QRS score and ejection fraction improved the sensitivity of both with no loss of specificity. Therefore, the resting QRS score is comparable to ejection fraction as a predictor of serious cardiac events after infarction and the sensitivity of both may be improved by including an assessment of the blood pressure response to exercise. Because a 12-lead electrocardiogram is cheap and widely available, this QRS score may be used in risk stratification after infarction.

Adult↗
PubMed1996

[Estimation of left ventricular volumes and ejection fraction with acoustic quantification in myocardial infarction. Comparison with echocardiographic, angiographic and scintigraphic data].

The object of this study was to assess the reliability of measurements of left ventricular volumes and ejection fraction by acoustic quantification by the method of summation of discs in acute myocardial infarction. Thirty-two patients with an average age of 55.9 +/- 12 years were studied prospectively on average 6 +/- 2 days after the onset of myocardial infarction. Within 48 hours, the patients underwent TM echocardiography (Teichholz's method) two-dimensional echocardiography (Simpson's method on freeze frames and acoustic quantification) before left ventricular angiography and isotopic ventriculography, considered as the reference methods for comparing left ventricular volumes and ejection fractions. The data displayed in real time by acoustic quantification correlated well with the results of left ventricular angiography (r = 0.77; p = 0.0001) and moderately underestimated (+4.1 +/- 11.9%) the ejection fraction, but were relatively disappointing for estimating volumes. When compared with isotopic ejection fraction, the correlation coefficient was r = 0.71 (p = 0.0004) and the values were overestimated. In this study, acoustic quantification was the most reliable echocardiographic method of assessing the left ventricular ejection fraction with reference to contrast angiography (Teichholz: r = 0.56; p = 0.0014; Simpson: r = 0.76; p = 0.001). The authors conclude that assessing the left ventricular ejection fraction with acoustic quantification is reliable in acute myocardial infarction. However, the method is not very accurate in measuring end systolic and end diastolic volumes.

Acoustics↗
PubMed1994

Effects of early administration of enalapril on radionuclide left ventricular ejection fraction and plasma N-terminal atrial natriuretic peptide after acute myocardial infarction.

The effects of enalapril therapy on radionuclide ejection fraction and plasma N-terminal atrial natriuretic peptide were investigated in a randomized, double-blind, placebo-controlled study of 52 patients with acute myocardial infarction. The medication was begun intravenously within 24 hours of the onset of symptoms. At discharge and the end point of 6 months, the radiographic size of the heart was significantly smaller in patients receiving (n = 28) than in those not receiving (n = 24) enalapril therapy (p < 0.03 vs < 0.01). However, left ventricular ejection fraction decreased simultaneously from 50 +/- 10% to 47 +/- 11% in patients treated with enalapril, whereas it increased from 48 +/- 13% to 50 +/- 14% in control patients (p < 0.05 for the difference of the changes). The decrease in ejection fraction was most marked in the infarct-related region of the left ventricle (p < 0.01). During the in-hospital period, plasma N-terminal atrial natriuretic peptide was decreased in patients treated with enalapril, whereas it was increased in those treated with placebo with complicated acute myocardial infarction (p < 0.05). During the following 6 months, the differences remained insignificant. Early administration of enalapril significantly attenuated heart enlargement after myocardial infarction and probably improved hemodynamics during the acute phase of complicated infarction. The decrease in ejection fraction during recovery indicates an impairment of systolic function. The decrease in infarct-related regional ejection fraction suggests that the impairment may be due to poor healing of the infarction scar.

Aged↗
PubMed1985

Left ventricular ejection fraction after acute coronary occlusion in conscious dogs: relation to the extent and site of myocardial infarction.

The change in left ventricular radionuclide ejection fraction after acute occlusion of the left anterior descending (LAD) or circumflex (LC) coronary artery was compared with the ultimate histologic extent of myocardial infarction in conscious dogs. The acute change in ejection fraction correlated with size of infarction in 14 dogs with occlusions of the LAD coronary artery (r = .89, y = 1.12x + 14.2) and in 27 dogs with occlusions of the LC coronary artery (r = .71, y = 0.73x + 7.9); the slope of the regression equation was greater (p less than .05) for those with LAD than for those with LC occlusions. Multivariate analysis revealed no independent contribution of left ventricular weight, the subendocardial extent of infarction, or change in heart rate to the acute change in ejection fraction. These data indicate that the decrease in ejection fraction after coronary occlusion is determined primarily by the size of the ischemic area, which also determines size of infarction. In dogs instrumented over a long term, infarcts in the LAD myocardial distribution result in greater decreases in ejection fraction than infarcts of comparable size in the LC distribution.

Animals↗
PubMedDate not supplied

Relationship between autonomic nervous system test results, ejection fraction and inducibility of sustained ventricular arrhythmias by means of electrophysiological studies.

Autonomic nervous system dysfunction and low left ventricular ejection fraction have been associated with an increased incidence of cardiac arrhythmias and sudden death. This research was conducted to determine whether Valsalva ratio (longest to shortest R-R interval during Valsalva manoeuvre), R-R variability (standard deviation of R-R intervals in a 60-second electrocardiographic recording strip), and corrected QT interval permit the identification of those patients with an inducible sustained ventricular arrhythmia when submitted to electrophysiological studies. We also evaluated the ejection fraction as a predictive index of inducibility. We studied 42 patients (21 males), 38 +/- 19 years old, who were submitted to an electrophysiological study in order to evaluate supraventricular (control group: n = 16) or ventricular arrhythmias (n = 26). The patients studied for the evaluation of ventricular arrhythmias presented structural and functional cardiac damage. Their ejection fraction (0.41 +/- 0.17) was significantly reduced (p = 0.01) when compared to that of the control group (0.61 +/- 0.08). The patients with cardiac damage had abnormal autonomic nervous system test results. None of the measurements was significantly related to the inducibility of sustained ventricular tachyarrhythmias in the group of patients who had structural and functional involvement. The finding of abnormal cardiac autonomic nervous system indices and low ejection fraction can be related to structural heart disease, but neither the abnormal cardiac autonomic nervous system indices nor the low ejection fraction allows us to identify the patients who will develop inducible sustained ventricular tachyarrhythmias when submitted to electrophysiological study.

Adult↗
PubMed1989

The value of the left ventricular ejection fraction in the treatment of angina pectoris following acute myocardial infarction: a randomized double blind study.

Radionuclide determination of left ventricular ejection fraction was performed at hospital discharge and one month later in 60 patients who had suffered acute myocardial infarction. At the first determination, the patients were randomized into two groups. In the first group, the cardiologist who cared for the patients was provided with the result of the determination of the ejection fraction whereas, in the second group, the result was withheld. At a 'blinded' evaluation two months after hospital discharge, 7 of those patients (24%) from the group where the cardiologist knew the ejection fraction and 11 of the patients (38%) in whom this result was withheld complained of angina pectoris on exertion (ns). The medication of the patients did not differ in the two groups. No significant difference was found in the values of the ejection fraction in patients with and without angina pectoris. In this controlled study, we were not able to document a clinical effect by routinely determinating left ventricular ejection fraction in patients with acute myocardial infarction in the treatment of angina pectoris.

Adrenergic beta-Antagonists↗
PubMed1982

Ejection fraction derived using dye dilution and angiographic methods.

Ventriculographically derived ejection fraction (EF-V) is the most frequently used method to measure left ventricular (LV) function, However, significant error may result in the measurement of end-systolic volume (ESV), which is used to calculate EF-V. This error is ascribed to the variable, irregular, nonellipsoidal geometry of the end-systolic ventricular chamber. Since stroke volume (SV) is determined more accurately by dilution methods than by ventriculography, an improved measure of ESV can be calculated by subtracting green dye determined SV from the ventriculographic determined end-diastolic volume (EDV). The purpose of this study was to measure a correlated ejection fraction (EF-C) using EDV by ventriculography and SV derived using green dye. In eight anesthesized dogs cardiac outputs (COs) were calculated by green dye and left ventriculography. CO determined by ventriculography was greater than that measured by green dye (p less than 0.005). EF-V (55 +/- 15%) was always greater than EF-C (32 +/- 12%) (p less than 0.005). These studies (1) may partially explain the discrepancy in CO calculated from the use of dilution methods and ventriculography and (2) present a method to improve the calculation of LV ejection fraction.

Animals↗
PubMed1977

Effects of noise on the determination of ejection fraction from left ventricular time-activity curves.

The effects of Poisson noise on three estimates of ejection fraction made from left-ventricular time-activity curves have been investigated. All three methods are based on a sinusoidal model of left-ventricular volume changes. The first, developed by Schelbert et al., overestimates the ejection fraction for low-activity levels and low ejection fractions. The second estimate, which is merely a first-order correction for the contribution of Poisson noise to the first estimate, appears to be more accurate when both estimators are applied to simulated time-activity curves, and the resulting ejection fractions are compared. A third, "maximum likelihood" estimator, when applied to the same data, is apparently more accurate than the first two.

Heart Function Tests↗
PubMed1996

Clinical characteristics, left and right ventricular ejection fraction, and long-term prognosis in patients with non-insulin-dependent diabetes surviving an acute myocardial infarction.

Patients with diabetes mellitus have a high morbidity and mortality from acute myocardial infarction, the reason for which is not fully understood. The relationship between congestive heart failure symptoms, left ventricular ejection fraction, and long-term mortality was examined in 578 hospital survivors of acute myocardial infarction, 47 of whom had Type 2 (non-insulin-dependent) diabetes mellitus. None of the patients were treated with insulin. The prevalence of congestive heart failure during hospitalization was similar in patients with and without diabetes, although mean diuretic dose was higher in the former patients. Left and right ventricular ejection fraction was measured with radionuclide ventriculography in the second week after acute myocardial infarction. At discharge from the coronary care unit, patients with and without diabetes had similar left ventricular ejection fraction (with diabetes: median 46% vs without diabetes: median 43%; p = 0.89). Median right ventricular ejection fraction (62%) was within normal limits in both groups and did not differ statistically. Survival data were obtained for all patients. The 5-year mortality was increased in patients with diabetes compared with non-diabetic patients independent of left ventricular ejection fraction. Univariate analysis showed that the cumulative 5-year mortality rate was 53% in the group with diabetes compared with 43% in the non-diabetic group (p = 0.007). Using multivariate regression analysis presence of diabetes was found to have a significant association with long-term mortality after myocardial infarction, that was independent of age, history of hypertension, congestive heart failure symptoms during hospitalization or of either left or right ventricular ejection fractions at discharge. We conclude that the excess mortality in patients with non-insulin-dependent diabetes mellitus is not explained by available risk markers after myocardial infarction. Even though left ventricular ejection fraction and serum creatinine did not differ significantly, the apparent higher dose of Frusemide in patients with than without non-insulin-dependent diabetes mellitus might indicate that heart failure, it present, is more severe in patients with than in those without diabetes. The importance of diastolic dysfunction in this context needs to be determined.

Adult↗
PubMed1979

First-pass or single-pass radionuclide angiography evaluation of left ventricular ejection fraction using a microcomputer system.

Left ventricular ejection fractions of 31 patients determined from first-pass or single-pass radionuclide angiography from the anterior position using a microcomputer system and floppy disc were compared to angiographic catheterization data obtained from the right anterior oblique position. This study demonstrated a good correlation with r = 0.91. To our knowledge, this is the first report of comparative first-pass left ventricular ejection fraction data and contrast angiography using a microcomputer system and a floppy disc.

Albumins↗
PubMed2002

Can the estimation of ejection fraction during gated single photon emission computed tomography at rest add information to the cardiac perfusion study?

Left ventricular function is an important prognostic indicator in patients with coronary artery disease. The electrocardiogram gated, myocardial, single photon emission tomography (SPECT) program is coming into wide use. This program permits measurement of end diastolic volume, end systolic volume, and ejection fraction. This study was designed to show whether the measurement of ejection fraction by using (99c)Tc tetrofosmin gated SPECT at rest could give additional information to the interpretation of perfusion. Exercise 99mTc tetrofosmin SPECT and gated (99c)Tc tetrofosmin SPECT at rest were performed in 33 patients with or suspected of having coronary artery disease. Left ventricular ejection fraction was calculated from reconstructed gated SPECT at rest with a software quantitative gated SPECT. The results showed a poor correlation between segmental ejection fraction and segmental perfusion in stress and rest. There was an increasing probability of reversibility as the ejection fraction increased, while there was a greater chance of a fixed defect as the ejection fraction decreased. It is concluded that gated SPECT using (99c)Tc tetrofosmin provides clinically satisfactory functional data that, in combination with the perfusion information, will improve diagnostic and prognostic accuracy without an increase in cost or radiation dose to patients.

Adult↗
PubMed1985

[Aortic stenosis with low preoperative ejection fraction. Long-term postoperative hemodynamic and angiographic studies].

Twenty-two patients underwent aortic valve replacement for aortic stenosis with a preoperative ejection fraction less than 45%. Three patients died peroperatively and a fourth patient died 18 months later before the haemodynamic control. The other 18 patients were systematically reinvestigated, on average 16 months after surgery. Sixteen had a remarkable functional improvement and a significant increase in ejection fraction at haemodynamic control: 32 +/- 6% to 61 +/- 8%, p less than 0.001. They were surgical successes (Group I). In this group, the 7 patients with the most severe alteration of ventricular function and an average ejection fraction of: 26 +/- 3%, also improved to near normal function with a postoperative fraction of 62 +/- 11%. There was no significant improvement of the ejection fraction in 2 patients, and they were classified with the fatalities as surgical failures (Group II). The clinical, electrocardiographic, radiological, haemodynamic and angiographic data of these two populations were compared to try and identify preoperative indices of prognostic value. Only the angiographic left ventricular myocardial mass index (LVMI) was significantly higher in Group II (253 +/- 98 g/m2) than in Group I (156 +/- 56 g/m2, p less than 0.05). A discriminating analysis showed that the most important parameters to separate the 2 groups of patients were the LVMI and the thickness of the left ventricular wall. The marked increase of the postoperative ejection fraction in 3/4 of our patients confirmed the clinical value of valvular replacement justifying the indication for surgery in patients with severe aortic stenosis in spite of a severe alteration of left ventricular function.

Aged↗
PubMed1983

The accuracy of radionuclide ventriculography in the analysis of left ventricular ejection fraction.

To assess the reliability of using ejection fraction values derived from gated blood pools scans as a way to classify patients, we reviewed 76 radionuclide studies. Each study was processed in 10 different ways (varying or fixed left ventricular region of interest in association with 5 different backgrounds), and compared with contrast ventriculograms performed within one week of the radionuclide study. Correlation values with contrast results varied from 0.76 to 0.94 (mean 0.84 +/- 0.06, +/- 1 SD), and linear fit slopes varied from 0.39 to 0.90 (mean 0.75 +/- 0.15). Based on contrast results, patients were divided first into four groups (severely reduced, reduced, normal, and high ejection fractions). Predictive accuracy of the radionuclide estimates for these four groups was poor, ranging from 0.39 +/- 0.08 to 0.82 +/- 0.06%. Sensitivity was somewhat better (range 0.53 +/- 0.11 to 0.78 +/- 0.08%), and specificity better yet (0.78 +/- 0.08 to 0.95 +/- 0.02%). The results were better with techniques resulting in higher correlation values, and further improved when patients were regrouped into two populations (normal or reduced), though 90% of subjects were correctly identified only when correlation values exceeded 0.90. We conclude that care must be taken in the identification of patients using radionuclide angiography who have normal and abnormal left ventricular function; it can be done with confidence only when linear fits with contrast ventriculographic results have high correlation coefficients. Stratification attempts should be reduced to a minimum, as multiple population subgroups result in substantial patient mislabeling.

Adult↗
PubMed1995

Preserved right ventricular ejection fraction predicts exercise capacity and survival in advanced heart failure.

OBJECTIVES: This study was undertaken to determine which exercise and radionuclide ventriculographic variables predict prognosis in advanced heart failure. BACKGROUND: Although cardiopulmonary exercise testing is frequently used to predict prognosis in patients with advanced heart failure, little is known about the prognostic significance of ventriculographic variables. METHODS: The results of maximal symptom-limited cardiopulmonary exercise testing and first-pass radionuclide ventriculography in patients with advanced heart failure referred for evaluation for cardiac transplantation were analyzed. RESULTS: Sixty-seven patients with advanced heart failure (mean [+/- SD]; age 51 +/- 10 years, New York Heart Association functional classes III (58%) and IV (18%); mean left ventricular ejection fraction 0.22 +/- 0.07) underwent simultaneous upright bicycle ergometric cardiopulmonary exercise testing and first-pass rest/exercise radionuclide ventriculography. Mean peak oxygen consumption (VO2) was 11.8 +/- 4.2 ml/kg per min, and mean peak age- and gender-adjusted percent predicted oxygen consumption (%VO2) was 38 +/- 11.9%. Univariate predictors of overall survival included right ventricular ejection fraction > or = 0.35 at rest and > or = 0.35 at exercise and %VO2 > or = 45% (all p < 0.05). In a multivariate proportional hazards survival model, right ventricular ejection fraction > or = 0.35 at exercise (p < 0.01) and %VO2 > or = 45% (p = 0.01) were selected as independent predictors of overall survival. Univariate predictors of event-free survival included right ventricular ejection fraction > or = 0.35 at rest (p = 0.01) and > or = 0.35 at exercise (p < 0.01), functional class II (p < 0.05) and %VO2 > or = 45% (p = 0.05). Right ventricular ejection fraction > or = 0.35 at exercise (p = 0.01) was the only independent predictor of event-free survival in a multivariate proportional hazards model. Cardiac index at rest, VO2, left ventricular ejection fraction at rest, and exercise-related increase or decrease > 0.05 in left or right ventricular ejection fraction were not predictive of overall or event-free survival in any univariate or multivariate analysis. CONCLUSIONS: 1) Right ventricular ejection fraction > or = 0.35 at rest and exercise is a more potent predictor of survival in advanced heart failure than VO2 or %VO2; 2) %VO2 rather than VO2 predicts survival in advanced heart failure; 3) neither %VO2 nor VO2 predicts survival to the combined end point of death or admission for inotropic or mechanical support in patients with advanced heart failure.

Disease-Free Survival↗
PubMed1983

The acute effects of low flow oxygen and isosorbide dinitrate on left and right ventricular ejection fractions in chronic obstructive pulmonary disease.

The objectives of this study were to determine the effects of low flow oxygen and isosorbide dinitrate on rest and exercise biventricular ejection fractions in patients with chronic obstructive pulmonary disease and to relate these ejection fraction responses to changes in pressure and flow. Nine patients with stable, moderate to severe chronic obstructive pulmonary disease who had no prior history of heart failure performed supine exercise with simultaneous hemodynamic and radionuclide ventriculographic monitoring. Eight patients performed a second exercise during low flow oxygen breathing and five performed a third exercise after ingesting 10 mg oral isosorbide. Oxygen led to a decrease in exercise pulmonary artery pressure in all subjects and a decline in total pulmonary resistance in five of the seven in whom it was measured. Right ventricular ejection fraction increased 0.05 or more only in subjects who had a decrease in total pulmonary resistance. Isosorbide fed to an increase in rest and exercise right and left ventricular ejection fractions with simultaneous decreases in pulmonary artery pressure, total pulmonary resistance, blood pressure and arterial oxygen tension. These results suggest that in patients with chronic obstructive pulmonary disease but without a history of right heart failure, the right ventricular systolic functional response to low flow oxygen and isosorbide at rest and exercise is, in part, determined by changes in total pulmonary resistance. The chronic relation between right ventricular ejection fraction and pulmonary hemodynamics in patients with chronic obstructive pulmonary disease remains to be evaluated.

Blood Pressure↗
PubMed1995

Mitral regurgitation in patients with coronary artery disease and low left ventricular ejection fractions. How should it be treated?

In recent years, coronary artery bypass grafting has been extended to include patients with very low left ventricular ejection fractions. Should concomitant mitral valve regurgitation be corrected simultaneously? Between January 1990 and July 1994, 43 patients with preoperative left ventricular ejection fractions < or = 25% and echocardiographic evidence of concomitant mitral valve regurgitation (grade I, 18 patients; II, 19 patients; and III, 6 patients) underwent primary coronary artery bypass grafting. None of these patients underwent simultaneous mitral valve surgery. Twenty-four patients (56%) had pulmonary artery pressures > or = 40 mmHg (pulmonary hypertension). The mean preoperative left ventricular ejection fraction was 18.7% +/- 4.4% (range, 10% to 25%), and the mean pulmonary artery pressure was 45.6 +/- 15.8 mmHg. The average of number of grafts per patient was 4.5 +/- 1.5. Five patients underwent simultaneous repair of a left ventricular aneurysm. The hospital mortality rate was 4.7% (2/43). Transient low cardiac output occurred postoperatively in 13 patients (30%). Sixteen patients (37%) had no postoperative complications. The average follow-up of the 41 hospital survivors was 6 months (range, 1 to 32 months). One patient died 8 months after surgery for an overall mortality rate of 7%. Another 2 patients had graft occlusions that did not require reoperation. In the 40 surviving patients, follow-up echocardiography revealed that 37 patients (93%) had either no mitral valve regurgitation or only very mild mitral valve regurgitation (grade I). Three patients had grade II mitral valve regurgitation, but none required mitral valve surgery. The New York Heart Association functional class improved significantly in all hospital survivors (from 3.4 +/- 0.6 to 1.7 +/- 0.7; p > 0.001), and left ventricular ejection fractions rose from 19.0% +/- 4.6% to 42.0% +/- 8.3%. Coronary artery bypass grafting is possible in patients with very low left ventricular ejection fractions who present with 2- or 3-vessel disease, significant coronary artery stenoses (less than or equal 70%), and angina. The mortality rate is acceptable and morbidity is low. If there is no rupture of papillary muscle or chordae, concomitant ischemic mitral regurgitation (grades I through III) seems to return to normal after coronary artery bypass grafting and, therefore, does not need to be corrected surgically during the primary operation.

Adult↗
PubMed1998

Normal left ventricular ejection fraction in older persons with congestive heart failure.

STUDY OBJECTIVES: To investigate in older patients with congestive heart failure (CHF) associated with prior myocardial infarction or hypertension the relationship between normal left ventricular (LV) ejection fraction and age, gender, hypertension, prior myocardial infarction, and atrial fibrillation. DESIGN: A prospective study was performed in 572 older patients (age >60 years) with CHF associated with prior myocardial infarction or hypertension and technically adequate two-dimensional echocardiograms for measuring LV ejection fraction. SETTING: A long-term health-care facility. PATIENTS: One hundred seventy-seven men and 395 women, mean age 82+/-8 years, with CHF associated with prior myocardial infarction or hypertension. MEASUREMENTS AND RESULTS: Normal LV ejection fraction (> or = 50%) occurred in 66 of 177 men (37%) and in 221 of 395 women (56%) (p<0.0001). Multiple logistic regression analysis showed that independent risk factors for normal LV ejection fraction in patients with CHF were no prior myocardial infarction (p=0.0001; odds ratio=3.048), female gender (p=0.0004; odds ratio=1.978), and age (p=0.016; odds ratio=1.029). CONCLUSIONS: Normal LV ejection fraction occurred in 50% of 572 older patients with CHF associated with prior myocardial infarction or hypertension. Independent risk factors for normal LV ejection fraction in patients with CHF were no prior myocardial infarction, female gender, and age.

Aged↗
PubMed1980

First pass radionuclide assessment of right and left ventricular ejection fraction in chronic pulmonary disease. Effect of oxygen upon exercise response.

Right and left ventricular ejection fraction (RVEF; LVEF) were determined in patients with severe chronic pulmonary disease (mean +/- SEM [FEV1 percent predicted 36 +/- 3%; PaO2: 64 +/- 3 mm Hg]), utilizing first pass radionuclide angiocardiography. RVEF and LVEF were measured at rest and again during upright bicycle exercise while patients breathed room air, and again during low flow oxygen (O2) administration. Mean RVEF was abnormal (less than 45%) at rest and did not increase with exercise while subjects breathed room air (44 +/- 2 percent vs 44 +/- 3 percent, P = ns), but improved significantly during exercise while patients breathed O2 (45 +/- 5 percent vs 51 +/- 3 percent, P less than .05). Breathing room air, RV exercise ejection fraction was abnormal (less than 5 percent increase in absolute RVEF) in 15 of 18 patients, but only 5 of 10 patients were abnormal during O2 administration. LVEF at rest was normal in all subjects. These data suggest: 1) RV exercise ejection fraction is abnormal in most patients with chronic pulmonary disease; 2) while low flow O2 does not alter RV performance at rest, it improves RV exercise ejection fraction in some patients.

Aged↗