Relationship between right ventricular ejection fraction and pulmonary pressure in man]

This clinical study analysed the changes in right ventricular ejection fraction induced by changes in right ventricular afterload using a new thermodilution catheter linked to a rapid response computer which allowed instantaneous measurements of the right ventricular ejection fraction. The first group comprised 16 patients referred for coronary angioplasty with single vessel disease (isolated proximal stenosis of one of the two main branches of the left coronary artery) and a normal left ventricular ejection fraction (> or = 55%) and mean pulmonary artery pressure of < 25 mmHg: right ventricular ejection fraction and mean pulmonary artery pressure were measured under basal conditions and after 60 seconds' coronary occlusion with the balloon catheter in order to assess the effects of the reactional increase in afterload on the right ventricular ejection fraction. The second group comprised 11 patients with dilated primary cardiomyopathy with decreased left ventricular ejection fraction (< 50%) and mean pulmonary artery pressure > or = 25 mmHg: the right ventricular ejection fraction and mean pulmonary artery pressure were measured under basal conditions and after intravenous trinitrin (performed to evaluate the pulmonary reaction to vasodilators) in order to analyse the effects of the reduction of afterload on right ventricular ejection fraction. Negative linear correlations were observed between the right ventricular ejection fraction and mean pulmonary artery pressure under basal conditions (r = -0.72; p < 0.005) and between the right ventricular ejection fraction and mean pulmonary artery pressure after changing the conditions of afterload (r = -0.82; p < 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)     

Noninvasive diagnosis of pulmonary arterial hypertension in chronic obstructive pulmonary disease: right ventricular ejection fraction at rest

Because right ventricular ejection fraction (RVEF) depends on impedance to RV ejection, the hypothesis was tested that an abnormality in radionuclide-determined RVEF would be a useful noninvasive predictor of pulmonary artery (PA) hypertension in patients with chronic obstructive pulmonary disease (COPD). Simultaneous measurements of resting RVEF and PA pressure were made in 30 patients with COPD. All were stable and without clinical evidence of respiratory decompensation or congestive heart failure. Eleven patients had normal (less than 20 mm Hg) mean PA pressure and 19 patients had PA hypertension. The average RVEF was 41 +/- 7% (range 29 to 60%). Five patients had normal (greater than 45%) and 25 patients depressed RVEF. An inverse linear relation between mean PA pressure and RVEF was present (r = -0.74). In the group with normal PA pressure, RVEF averaged 48% (range 42 to 60%). In the group with PA hypertension, RVEF averaged 36% (range 29 to 44%). RVEF was significantly higher in the group with PA hypertension. Using RVEF less than 45% as an indicator of PA hypertension, the sensitivity was 100%, the specificity 55%, and the predictive accuracy of a positive result 79%. Using RVEF less than or equal to 40% as an indicator of PA hypertension, the sensitivity was 75%, the specificity 100%, and the predictive accuracy of a positive study 100%. Thus, radionuclide-determined RVEF using the first-pass technique and a multicrystal camera is a useful noninvasive test for diagnosing PA hypertension in patients with advanced COPD.     

Scintigraphic prediction of pulmonary arterial systolic pressure by regional right ventricular ejection fraction during the second half of systole

In 49 patients in whom gated equilibrium ventriculography and cardiac catheterization were performed within a 6 day interval, total and fractional portions of global and regional right ventricular ejection fraction (RVEF) were correlated with pulmonary arterial systolic pressure. Pulmonary arterial systolic pressure was normal (30 mm Hg or less) in 27 patients (Group I) and elevated (31 mm Hg or greater) in 22 patients (Group II). The second-half regional RVEF was 38 +/- 8% (mean +/- standard deviation) with a range of 30 to 54% for Group I and 22 +/- 6% with a range of 13 to 32% for Group II. The difference between the means was statistically significant (p less than 0.001). Use of a second-half regional RVEF of 30% as the criterion of elevated pulmonary arterial systolic pressure resulted in a sensitivity of 0.86 and a specificity of 1.00. A power curve fit in which pulmonary arterial systolic pressure = 10.91 (second-half regional RVEF)-0.87 allowed accurate estimation (r = -0.85) of pulmonary arterial systolic pressure from the second-half regional RVEF. It is concluded that second-half regional RVEF may be used to accurately detect pulmonary arterial hypertension and to estimate its extent.     

Physiologic correlates of right ventricular ejection fraction in chronic obstructive pulmonary disease: A combined radionuclide and hemodynamic study

The pathophysiologic correlates of right ventricular ejection fraction, as well as its relation to contractile function as assessed by systolic pressure-volume data, were evaluated in 20 patients with chronic obstructive pulmonary disease. Radionuclide and hemodynamic measurements were obtained simultaneously. Baseline determinations were obtained in all patients. In seven patients, studies were repeated after intravenous administration of sodium nitroprusside. This procedure allowed characterization of right ventricular performance at decreased afterload and provided two points necessary for definition of the right ventricular systolic pressure-volume relation. Seventeen of the 20 patients had a depressed right ventricular ejection fraction (less than 45 percent). There was a strong inverse linear correlation between right ventricular ejection fraction and afterload as assessed by peak or mean pulmonary arterial pressure (r = ?0.81) and pulmonary vascular resistance index (r = ?0.73). Right ventricular ejection fraction also correlated, although less strongly, with preload as assessed by right ventricular end-diastolic volume index (r = ?0.56) and mean right atrial pressure (r = ?0.51). It did not correlate with cardiac index, the ratio of peak pulmonary arterial pressure to right ventricular end-systolic volume index, arterial oxygen tension or left ventricular ejection fraction. After nitroprusside administration, mean arterial pressure, peak pulmonary arterial systolic pressure and pulmonary vascular resistance index decreased significantly. The slope (E) and the volume intercept (V₀) of each pressure-volume line were determined. Administration of dobutamine resulted in a leftward shift from the endsystolic pressure-volume line. There were poor correlations between E and right ventricular ejection fraction, as well as between E and the control ratio between pulmonary arterial systolic pressure and end-systolic volume index.These data demonstrate that, in addition to intrinsic contractile influences, right ventricular ejection fraction is highly dependent on afterload, but less dependent on preload. Right ventricular ejection fraction is a poor indicator of the slope of the systolic pressure-volume relation, raising questions concerning its use as an independent index of chamber contractility.     

Relation of right ventricular ejection fraction to exercise capacity in chronic left ventricular failure

Although the left ventricle is traditionally viewed as the heart's main pumping chamber, no correlation has been shown between left ventricular (LV) ejection fraction (EF) at rest and exercise capacity in patients with chronic LV failure. Because vasodilators with venodilating activity increase exercise capacity more than predominant arterial dilators in patients with LV failure, right ventricular (RV) function may relate to exercise capacity in these patients. In 25 patients with chronic LV failure, caused by coronary artery disease in 12 patients and idiopathic dilated cardiomyopathy in 13 patients, RVEF and LVEF at rest were measured by radionuclide angiography. Maximal upright bicycle exercise testing was also performed to determine maximal oxygen consumption, which averaged only 13 ± 4 ml/min/kg. The LVEF at rest was 26 ± 10% and did not correlate with maximal oxygen consumption (r = 0.08). However, the RVEF was 41 ± 12% and correlated with maximal oxygen consumption (r = 0.70, p < 0.001) in the same patients. The correlation was stronger (r = 0.88) in patients with coronary artery disease than in those with idiopathic dilated cardiomyopathy (r = 0.60). Thus, RVEF at rest is more predictive of exercise capacity than LVEF in the same patients with chronic LV failure. These results are consistent with the clinical observation that only venodilating agents increase exercise capacity of patients with chronic LV failure.     

Thermodilution measurement of the right ventricular ejection fraction

This study addressed the clinical reproducibility and validity of the thermodilution (TD) measurement of the right ventricular ejection fraction (RVEF). Forty-one patients underwent right heart catheterization, including TD RVEF, within 2 h of gated first pass (GFP) and gated blood pool (GBP) radionuclide ventriculography; 21 had single plane contrast right ventricular angiography (ANGIO) during the same catheterization. Analysis of variance showed no difference among three successive TD RVEF measurements. (table; see text) Stroke volume by RV ANGIO correlated with Fick (n = 10, r = .86) and thermodilution stroke volume (n = 21, r = .88). It is concluded that although the thermodilution method is an accurate way to measure flow, it is not an accurate way to measure right ventricular ejection fraction, and by inference, ventricular volumes. The most likely explanation for this finding is incomplete mixing as in previous studies of indicator methods of measuring left ventricular volumes.     

Comparison of single plane videodensitometry-based right ventricular ejection fraction in right and left anterior oblique views to biplane geometry-based right ventricular ejection fraction

To evaluate the reliability of the videodensitometric assessment of right ventricular ejection fraction, 38 patients were studied during diagnostic cardiac catheterization. Digital subtraction images of the right ventricle were obtained in both the right anterior oblique and the left anterior oblique views, using direct intraventricular injection of dilute contrast medium. From the end-diastolic and end-systolic images obtained in each view, analysis of the relative brightness values generated a videodensitometry-based right ventricular ejection fraction for both the right and the left anterior oblique views. These values were compared with those generated by applying the geometry-based Simpson's rule to the orthogonal images. Right ventricular ejection fraction ranged from 22 to 88%. Videodensitometric ejection fraction in the right anterior oblique view correlated well with that in the left anterior oblique view (r = 0.88) and each correlated well with geometry-based ejection fraction (r = 0.91 and 0.82, respectively). In a subset of 18 patients without significant cardiac disease, mean videodensitometric right ventricular ejection fraction was 68% (versus 61% in the abnormal subset), and it correlated closely with left ventricular ejection fraction (r = 0.82). Videodensitometric analysis of digital subtraction images provides a reliable method for calculating right ventricular ejection fraction that is independent of geometry and reliably separates normal from abnormal values. Application of videodensitometric techniques should simplify analysis of the response of the right ventricle to different interventions in patients with cardiac disease.     

Corticosteroids in chronic bronchitis and pulmonary emphysema.

Chronic bronchitis and emphysema (chronic obstructive pulmonary disease [COPD]) represent a major health problem in this country. Corticosteroids have provided an important advance in the management of bronchial asthma, but the role of these drugs in the therapy for COPD has not been defined clearly. To gain further insight into this problem, an overview of the pharmacologic properties and mechanisms of action of corticosteroids on the cellular systems of the lung and a critical analysis of the 17 studies evaluating the efficacy of therapy with corticosteroids in COPD were done. There are several theoretic reasons why corticosteroids might be useful in treating COPD; however the majority of studies have not demonstrated a positive effect, yet individual patients have attained marked improvement. An objectively monitored, finite trial of therapy with corticosteroids in the patient with COPD who has worsening symptoms is warranted, as the benefit is high in responsive individuals and the risk is low in nonresponders.     

Evaluation of right ventricular performance with a right ventricular ejection fraction thermodilution catheter and MRI in patients with pulmonary hypertension

STUDY OBJECTIVES: We sought to compare catheter studies using a right ventricular ejection fraction (REF) catheter together with echocardiography and MRI in patients with pulmonary hypertension. Patients and methods: We compared hemodynamic findings, echocardiography, and MRI studies in 16 patients with pulmonary hypertension. Six healthy volunteers served as control subjects for the MRI studies. RESULTS: MRI imaging provided accurate assessment of cardiac output in all but two patients. As compared with MRI, the REF catheter constantly underestimated the REF and overestimated right ventricular volumes in patients with pulmonary hypertension. REF, end-systolic and end-diastolic right ventricular volumes, and right ventricular muscle mass, as determined by MRI, were almost identical in patients with preserved cardiac function and those with low-output failure. The only factor that was different in both groups was the severity of tricuspid regurgitation. CONCLUSION: Right ventricular dimensions and muscle mass do not differ in patients with pulmonary hypertension who have low cardiac output and those who do not. According to our results, the major determinant of cardiac output in these patients appears to be the severity of tricuspid regurgitation. The REF catheter provides invalid data on right ventricular dimensions in patients with pulmonary hypertension.     

Angiographic assessment of right ventricular volumes and ejection fraction

Since the advent of cardiovascular angiography only a few decades ago (1), a massive number of data related to the ventricular function have been accumulated. Specifically, left ventricular (LV) geometry, volumes, and patterns of contractility have been extensively investigated (2–7), especially in patients with coronary artery disease (8–11). In contrast, much less attention has been given to the characteristics of the right ventricle (RV). This has been due partially to the fact that the LV was always considered to be the more important chamber of the heart. The relative neglect of RV performance has been further compounded by difficulties in analyzing the geometry of the RV chamber: while the LV configuration approximately resembles an ellipsoid of revolution (and therefore lends itself to relatively simple mathematical analysis), the RV has always been considered a somewhat amorphous structure that does not yield to simple geometric manipulation. In this review, recent approaches to the angiographic measurements of RV volumes and ejection fraction are examined.     

Effects of hemoglobin on pulmonary arterial pressure and pulmonary vascular resistance in patients with chronic emphysema

BACKGROUND: The increase in viscosity caused by secondary polycythemia is thought to be one of the major causes of pulmonary hypertension secondary to chronic emphysema. However, very few clinical studies considered the relation between pulmonary hypertension and polycythemia in the case of chronic obstructive pulmonary disease. OBJECTIVE: The purpose of this study is to elucidate the relative contribution of an increase in hemoglobin level (Hb) to mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance (PVR). Methods: We retrospectively investigated 41 patients with chronic emphysema who had undergone a right heart catheterization. Multiple-regression analysis and F test were performed to investigate both direct effects of Hb and PaO(2) as independent variables on mPAP and PVR as dependent variables. RESULTS: Significant correlations were found between PaO(2) and mPAP (or PVR), or Hb and mPAP (or PVR), indicating that both Hb and PaO(2) are contributory to mPAP and PVR. The F test demonstrated that Hb and PaO(2) could directly affect the level of either mPAP or PVR. CONCLUSIONS: It was concluded that Hb had a direct effect on mPAP and PVR, independently of hypoxia in patients with chronic emphysema.     

Inter- and intrasubject variability of the thermodilution measurement of right ventricular ejection fraction and volume in patients with chronic obstructive pulmonary disease

STUDY OBJECTIVE--To determine the spontaneous changes in volumetric indices of right ventricular function assessed by thermodilution. DESIGN--The study involved measurements of inter- and intraindividual variation of right ventricular function in human subjects at rest and at two different levels of low load supine bicycle exercise. SUBJECTS-- The subjects were 23 patients with chronic obstructive pulmonary disease, referred for evaluation by right heart catheterisation. Mean (SEM) age was 55.4 (2.2) years and all were in sinus rhythm. MEASUREMENTS and RESULTS--Successive measurements of ejection fraction and right ventricular end diastolic and end systolic volumes were made by thermodilution with a fast response thermistor mounted in a Swan-Ganz catheter. Five measurements were made at rest (R), and three measurements during each of two levels of exercise (E1, E2). Group average values for each period showed no significant changes with time; interindividual variability was expressed as the coefficient of variation (VC1 = SD/means), intraindividual variability (VC2) as square root of mean value of individual variances. Interindividual variability increased from rest to exercise, while intraindividual variability was lower during exercise, presumably because the variables were more steady. For ejection fraction, VC1, was 23% at rest, 29% for E1 and 32% for E2, while VC2 was 21%, 12% and 15% respectively; for right ventricular end diastolic volume, VC1 was 23% at rest, 29% and 28% during exercise, and VC2 was 17%, 12% and 11% respectively. In some patients cold injection induced bradycardia and spuriously high values of ejection fraction. CONCLUSIONS - It is important to monitor heart rate before and during thermodilution measurements and to take into account only those made with stable heart rate. Injectate temperature should be above 10 degrees C.     

Effect of almitrine administration on pulmonary arterial pressure in resting and exercising dogs

In addition to its well-known ventilatory effect, a small rise in pulmonary arterial pressure or pulmonary vascular resistance is occasionally observed with chronic administration of almitrine. In order to test the hypothesis of enhancement of exercise pulmonary vasoconstriction by almitrine, mongrel dogs were studied at rest and during submaximal exercise before and after 4 weeks of chronic ingestion of almitrine (10 mg/kg). It was shown that resting pulmonary arterial pressure (PAP) remained unchanged by almitrine treatment. However, when exercise was superimposed on almitrine medication, PAP was significantly increased throughout the exercise bout. Thus, the rise in PAP during the 20th min of exercise averaged 8.7 +/- 3.4 mm Hg after almitrine treatment while PAP increased by only 1.3 +/- 1.7 mm Hg before medication. The exaggerated exercise-induced PAP response in conjunction with the enhanced secretion of norepinephrine that we observed during almitrine treatment suggests that catecholamine could be involved in the pulmonary haemodynamic adjustments. Furthermore, mixed-venous PO2 (PvO2) both during rest and exercise declined with the prolongation of almitrine ingestion, suggesting that PvO2 might possibly be implicated in the pulmonary haemodynamic response to almitrine, in the same way as it is involved in the hypoxia-induced pulmonary vasoconstriction. These findings demonstrate that almitrine medication, even at a high dose, does not have any deleterious effect on pulmonary vasculature in resting conditions, but prolonged submaximal exercise should be proscribed in patients on a long-term therapy.