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PubMed1998

First-pass radionuclide angiographic analysis with two regions of interest to improve left ventricular ejection fraction accuracy.

UNLABELLED: First-pass radionuclide angiographic (FPRNA) analysis, using the standard, single-fixed region of interest (ROI) drawn at end-diastole, often underestimates the left ventricular ejection fraction (LVEF) as determined by other standard techniques. This study examined the hypothesis that correction for the anatomic motion of the aortic valve plane toward the apex during systole, which results in improper inclusion of aortic counts within the single-fixed ROI, using a two-ROI method to compensate for this motion would eliminate this underestimation. METHODS: In 70 patients who underwent FPRNA and planar gated equilibrium radionuclide angiography (GERNA) on the same day, Fourier transform phase and amplitude images were used to generate functional maps of the aorta and the left ventricle on the FPRNA representative cycle. The region of low amplitude between the aorta and left ventricle, which corresponds to the degree of aortic valve plane motion, was used to guide the manual placement of two ROIs. The first was over the left ventricle at the end-diastole including the aortic valve plane area, and the second was a smaller end-systolic ROI drawn over the first ROI, excluding the valve plane area. RESULTS: Both the fixed- and dual-ROI FPRNA methods had excellent correlation with GERNA (r = 0.92 and 0.91, respectively). The mean FPRNA LVEF using a fixed ROI (45% +/- 14%) was significantly lower than GERNA (51% +/- 15%, p < 0.001), but the mean LVEF calculated from the dual-ROI (51% +/- 14%) was essentially identical to those obtained with GERNA. The method of manual placement of the two ROIs had extremely high levels of inter- and intraobserver reproducibility (r = 0.98 and 0.99, respectively). CONCLUSION: Despite good correlation, the standard, fixed-ROI method of FPRNA analysis systematically underestimates the LVEFs of GERNA. This problem can be eliminated by taking into account valve plane motion during the cardiac cycle by using Fourier-guided, dual-ROI analysis on FPRNA. These differences in methods and results should be considered when substituting or comparing LVEFs derived from these techniques.

Female↗

PubMed1997

Precision of the gallbladder ejection fraction obtained with Tc-99m-pyridoxyl-5-methyl-tryptophan (99mTc-PMT) hepatobiliary scintigraphy as compared with the contraction ratio in three-dimensional computed tomography.

UNLABELLED: The gallbladder ejection fraction (GBEF) obtained with Tc-99m-pyridoxyl-5-methyl-tryptophan (99mTc-PMT) hepatobiliary scintigraphy has been used as a parameter of gallbladder function. To determine the accuracy of GBEF, the relationship with the contraction ratio of the gallbladder (GBCR) obtained with three-dimensional helical computed tomography (3D-CT) was studied. PATIENTS AND METHODS: A normal volunteer, 8 patients suffering from cholecystolithiasis and a patient with gallbladder dyskinesia were examined. The percent initial dose (%ID) for the gallbladder and GBEF with hepatobiliary scintigraphy were used to compare the volume of the gallbladder and GBCR which was measured by 3D-CT. RESULTS: The %ID of the gallbladder was correlated with the volume of the gallbladder by 3D-CT (Y = 1.000X - 1.818, r = 0.928). GBEF was correlated well with GBCR by 3D-CT (Y = 0.916X + 6.296, r = 0.975). CONCLUSIONS: The %ID of the gallbladder obtained with hepatobiliary scintigraphy may be a good indicator of the volume of the gallbladder. The accuracy of GBEF was confirmed by comparison with 3D-CT examination. GBEF is considered a useful parameter of pathophysiological gallbladder function.

Adult↗

PubMed2006

Left ventricular filling hemodynamics in patients with pulmonary edema and preserved versus reduced left ventricular ejection fraction: a prospective Doppler echocardiographic study.

BACKGROUND: Objective evidence of elevated left ventricular (LV) filling pressures is infrequently demonstrated in clinical practice in patients with heart failure (HF) and preserved LV ejection fraction (LVEF) and the clinical diagnosis of HF is commonly questionable in these patients. The objective of this study was to examine whether elevated LV filling pressures can be demonstrated noninvasively in consecutive patients with HF and preserved (vs reduced) LVEF. METHODS: Echocardiography was performed in 141 patients hospitalized with acute pulmonary edema (within 3 days of admission in 83.6%). LV filling was assessed in 116 patients without significant valve disease (median age 76 years; 51.7% men) and LV filling pressures were estimated based on mitral and pulmonary venous flow patterns and mitral annular diastolic velocities. RESULTS: LVEF was preserved (> or =45%) in 49 patients (42.2%) and reduced (<45%) in 67 patients (57.8%). In patients with in sinus rhythm, normal LV filling pattern and abnormal relaxation, pseudonormal, and restrictive LV filling patterns (the latter two patterns associated with elevated LV filling pressures) were evident in 8, 1, 11, and 9 patients with preserved LVEF, versus 5, 11, 15, and 23 patients with reduced LVEF, respectively (P = .01) (LV filling pattern was nonconclusive in 12 patients). In patients with atrial arrhythmias, elevated LV filling pressures were evident in 4 of 14 patients with preserved LVEF and 3 of 4 patients with reduced LVEF. Overall, elevated LV filling pressures were demonstrable in 24 patients with preserved LVEF (49.0%) and in 41 patients with reduced LVEF (68.3%) (P = .26). CONCLUSIONS: Elevated LV filling pressures are frequently evident by Doppler echocardiography in patients with HF and preserved or reduced LVEF. Thus, Doppler echocardiography can provide objective noninvasive evidence of abnormal LV filling in a large proportion of patients with HF and preserved LVEF.

Aged↗

PubMed2005

Effects of candesartan on cardiac sympathetic nerve activity in patients with congestive heart failure and preserved left ventricular ejection fraction.

OBJECTIVES: We sought to evaluate the effects of angiotensin receptor blocker (ARB) on cardiac sympathetic nerve activity (CSNA) in patients with congestive heart failure (CHF) with a preserved left ventricular ejection fraction (LVEF). BACKGROUND: Approximately 50% of patients with CHF have preserved LVEF. It is reported that ARB therapy improves CSNA in CHF patients and reduced LVEF. However, the effect of ARB therapy on CSNA evaluated by iodine-123 meta-iodobenzylguanidine ((123)I-MIBG) scintigraphy has not been determined in CHF patients with preserved LVEF. METHODS: We selected 50 patients with nonischemic CHF and LVEF >40% who were treated with standard therapy. Twenty-five patients were randomized to also receive candesartan, whereas the remaining 25 patients received placebo. The delayed heart/mediastinum count (H/M) ratio, delayed total defect score (TDS), and washout rate (WR) were determined by (123)I-MIBG scintigraphy before and six months after treatment. The LV end-diastolic volume and LVEF were determined by echocardiography, and the plasma brain natriuretic peptide (BNP) concentration was also measured. RESULTS: In patients receiving candesartan, (123)I-MIBG scintigraphic and echocardiographic parameters were significantly improved after treatment. In contrast, there were no significant changes in these parameters in patients receiving placebo. There was a significant correlation between the changes in (123)I-MIBG scintigraphic findings and the percent change in BNP from baseline to six months in patients receiving candesartan (TDS: r = 0.587, p < 0.005; H/M ratio: r = -0.509, p < 0.01; WR: r = 0.602, p < 0.005). CONCLUSIONS: Adding candesartan to standard therapy can improve CSNA and LV performance in CHF patients with preserved LVEF.

3-Iodobenzylguanidine↗

PubMed1998

Measurements and day-to-day variabilities of left ventricular volumes and ejection fraction by three-dimensional echocardiography and comparison with magnetic resonance imaging.

The aim of this study was to assess day-to-day variability of left ventricular (LV) volume and ejection fraction (EF) calculated from 3-dimensional echocardiography (3-DE) and to compare the reproducibility of the measurement with magnetic resonance imaging. Forty-six subjects were examined including 15 normal volunteers (group A) and 31 patients with LV dysfunction (group B). Precordial 3-DE acquisition was performed at 2 degrees rotational intervals and repeated 1 week later. Magnetic resonance imaging was performed at 0.5 T. End-diastolic and end-systolic LV volumes were derived using Simpson's rule by manual endocardial tracing of 8 equidistant parallel LV short-axis slices with 3-DE, whereas 9-mm slices were used with magnetic resonance imaging. The mean +/- SD of end-diastolic and end-systolic LV volumes (ml) and EF (%) from magnetic resonance imaging were 182 +/- 75, 121 +/- 76, and 39 +/- 18, whereas those from 3-DE were 182 +/- 76, 121 +/- 77, and 39 +/- 18 respectively. Day-to-day measurements of end-diastolic and end-systolic LV volumes, and EF on 3-DE were not significantly different as assessed with SEE (2.7, 1.1, and 2.4, respectively). Intra- and interobserver SEE for calculating end-diastolic and end-systolic LV volumes and EF for magnetic resonance imaging were 6.3, 4.7, and 2.1 and 13.6, 11.5, and 4.7, respectively, whereas those for 3-DE were 3.1, 4.4, and 2.2 and 6.2, 3.8, and 3.6, respectively. Day-to-day variability of LV volume and EF calculation on 3-DE were small and not significantly different for normal and dysfunctional left ventricles. Observer variabilities of 3-DE were fewer than those of magnetic resonance imaging. Therefore, 3-DE is recommended for serial assessment of LV volume and EF in normal and abnormally shaped ventricles.

Adult↗

PubMed1998

Administration of an intravenous perfluorocarbon contrast agent improves echocardiographic determination of left ventricular volumes and ejection fraction: comparison with cine magnetic resonance imaging.

OBJECTIVES: The purpose of this study was to determine whether contrast-enhanced transthoracic echocardiography improves the evaluation of left ventricular (LV) volumes and ejection fraction (EF). BACKGROUND: Echocardiographic assessment of LV volumes and EF is widely used but may be inaccurate when the endocardium is not completely visualized. Recently the intravenous (i.v.) administration of perfluorocarbon microbubbles has been shown to enhance opacification of the LV cavity, but the utility of these agents to improve the echocardiographic assessment of LV systolic function is unknown. METHODS: In 40 subjects (29 men and 11 women, aged 24 to 81 years) an assessment of LV volumes and EF was performed with a magnetic resonance imaging examination, followed immediately by a transthoracic echocardiogram before and after the intravenous administration of 2% dodecafluoropentane emulsion (EchoGen; Sonus Pharmaceuticals, Bothell, Washington). RESULTS: Contrast enhanced the echocardiographic assessment of LV end diastolic volume (p < 0.02), end systolic volume (p < 0.01) and LVEF (p < 0.03). The percentage of subjects in whom the correct echocardiographic classification EF was normal, mild to moderately depressed or severely reduced improved significantly after contrast enhancement (from 71% before contrast to 94% after, p < 0.03). These findings were most striking in the subjects with two or more adjacent endocardial segments not visualized at baseline. CONCLUSIONS: Administration of an intravenous contrast agent improves the ability to accurately assess LV volumes and EF in humans. Contrast enhancement is most useful in subjects with two or more adjacent endocardial segments not seen at baseline.

Adult↗

PubMedDate not supplied

An investigation of the estimation of ejection fractions and cardiac volumes by a quantitative gated SPECT software package in simulated gated SPECT images.

BACKGROUND: The purpose of this investigation was to determine the accuracy of the estimation of ejection fractions (EFs) and left ventricular volumes from a commercially available software package (Quantitative Gated SPECT [QGS]) as a function of different true EFs, count level in the acquisitions, severity and location of perfusion defects, increasing hepatic activity, and modified wall motion. METHODS AND RESULTS: The dynamic mathematic cardiac-torso digital phantom was used to create three-dimensional source and attenuation maps representing the distribution of a technetium-99m-labeled cardiac perfusion agent in the chest. Three hearts with varying end-systolic volumes were used to investigate different EFs. Perfusion defects were created as localized uptake within selected portions of the cardiac walls, scaled to the desired fraction of the normal wall uptake, and subtracted from the normal distribution. The hepatic uptake was increased up to five times of the normal heart uptake to investigate the influence of a "hot" liver. Alteration of lateral wall motion was also investigated. A three-dimensional projector that included the influence of distance-dependent spatial resolution and nonuniform attenuation was then used to create projection images. The projections were scaled to the desired acquisition count level, and Poisson noise was added. Automatic determination of EF slightly overestimated the true EF for normal count levels by 3% to 7% of the true EF and underestimated the true EF by up to 9% for very low count levels for 180-degree reconstructions. The accuracy for determining the volumes was not as high as for the EFs (an average error of 12% was observed). The calculated EFs were relatively accurate for perfusion defects of 50% or less. When perfusion defects exceeded 50%, extracardiac counts were included in the heart contours, causing larger underestimations of EF. With removal of the extracardiac counts, the EFs increased. With a hepatic uptake of two or more times the heart uptake, no meaningful EF could be obtained. Either drawing a single region of interest for every slice or use of the manual mode with constrain option could remarkably improve the estimation. The accuracy of the calculation of EF and volumes for the heart with stationary wall was fairly high but decreased significantly when coupled with perfusion defects. CONCLUSION: It is concluded that the QGS program evaluates the functional parameter of EF accurately. The biggest limitations occurred in determining the appropriate cardiac contour if areas with very high extracardiac counts were present in the heart slices, and when a greater than 50% decrease occurred in uptake for perfusion defects.

Cardiac Volume↗

PubMed2002

Decrease in heart ventricular ejection fraction during multiple sclerosis.

Recent studies have shown that mitoxantrone is effective in patients with active multiple sclerosis (MS) and that cardiac monitoring is usually required. However, right and left ventricular ejection fractions (VEFs) have never been studied in MS patients as compared with control subjects. Radionuclide angiocardiography (RA) was performed to assess right and left VEFs at rest in 40 consecutive patients with active definite MS [15 men and 25 women; mean age 33.9 +/- 10 years; mean disease duration 8 +/- 6.5 years; 18 had relapsing-remitting and 22 had secondary progressive forms of the disease; mean Expanded Disability Status Scale (EDSS) score 4.8 +/- 1.9]. The control group consisted of 40 subjects free of neurological or cardiovascular disease (17 men and 23 women; 44.6 +/- 13.4 years of age). The VEF values obtained in the control group defined the normal limits (right VEF 32-54%; left VEF 50-74%). A statistically significant decrease of right (P=0.02) and left (P < 0.0001) VEFs was found in MS patients as compared with control subjects. RA showed pathological results for right (7.5%), left (10%) and both (7.5%) VEFs in 25% of MS patients. No correlation was found between VEF and sex, age, disease duration, disease course, EDSS score or previous treatment. Autonomic impairment, which frequently occurs in MS patients, may have accounted for the decrease in VEFs. Further physiological studies are required to determine factor responsible for the decrease of VEFs in MS.

Adolescent↗

PubMed1987

Nuclear ejection fraction measurements with a small crystal detector: methodological investigations.

A series of studies were performed with a single crystal detector system, nuclear stethoscope (N.S.) (Bios) used for measuring left ventricular function (ejection fraction [EF]). Counting capacity, validity, reproducibility, effect of repositioning of the instrument and of different operators were investigated. Counting capacity was found to be approximately linear up to a count rate of 40.000 cps. Validity was studied by comparing measurements in the same subject using the N.S. with those obtained by a gamma-camera computer system with software using a background subtraction similar to that in the N.S. The mean difference in EF (0.01) was not significant. Maximum emptying and filling velocity measurements with the two instruments were also compared r = 0.86 and r = 0.89, respectively, and a coefficient of variation of 18.1% and 17.9%. Reproducibility was determined from duplicate determinations under identical conditions. The standard error of a single determination was 5%. Repositioning by the same operator increased the variation to 9.1% without any systematic difference. Comparison between two operators did not increase the coefficient of variation (8.8%). There was a systematic difference between measurements using the two acquisition modes, ventricular function mode and position monitor mode. Beat-to-beat variation of EF values during 12 s in 25 patients with coronary heart disease studied under standardized resting conditions was 11.9%.

Adult↗

PubMed1991

Left ventricular ejection fraction in obstructive sleep apnea. Effects of long-term treatment with nasal continuous positive airway pressure.

The effects of treatment with nasal continuous positive airway pressure (CPAP) on left ventricular ejection fraction (LVEF) were assessed in 29 patients with obstructive sleep apnea (OSA) in a prospective study using multiple gated equilibrium radionuclide angiocardiography. All patients were evaluated before CPAP treatment was initiated and were reevaluated after one year (mean +/- SE, 415 +/- 6 days), of home treatment with nasal CPAP. The mean LVEF increased from 59 +/- 1 percent to 63 +/- 1 percent (p less than 0.005). The degree of improvement in LVEF was correlated with baseline LVEF (r = 0.54; p less than 0.003), meaning that the lower the baseline value, the greater the increase with treatment. The changes were not different when subgroups of medicated and unmedicated patients were considered separately. These results show that long-term nasal CPAP treatment results in improved left ventricular function in OSA.

Evaluation Studies as Topic↗

PubMed2004

Mitral valve repair in patients with low left ventricular ejection fractions: early and late results.

STUDY OBJECTIVES: This retrospective study was performed to examine the outcome of mitral valve repair (ie, mitral valvuloplasty [MVP]) in relation to preoperative low left ventricular ejection fraction (LVEF). DESIGN AND SETTINGS: From our series of 338 consecutive patients who underwent MVP between 1983 and 2001, we compared the course of 302 patients with preoperative LVEF of > 35% (group I) to that of 36 patients with LVEF of </= 35% (group II). RESULTS: Preoperatively, group II patients were more likely to be associated with ischemic heart disease (IHD) [p < 0.0002], and to have undergone emergency surgery (p < 0.02) and concomitant coronary artery bypass graft surgery (CABG) [p < 0.02]. The perioperative mortality rate was 8% for group II and 2% for group I (p < 0.03). On multivariate analysis, predictors of increased operative mortality were emergent operation (p < 0.001) and preoperative New York Heart Association (NYHA) class IV (p < 0.02). Predictors of overall mortality (early and late) included emergency operation (p < 0.02), preoperative NYHA class IV (p < 0.002), and IHD (p < 0.0001). Postoperatively, 78% of patients from both groups were in NYHA class I/II. The 5-year rate of freedom from reoperation was 89%. The estimated overall 5-year survival rate (early and late) was 82% for group I and 54% for group II (p < 0.02), and when associated with prior CABG, prior myocardial infarction, or concomitant CABG, it was 0%, 37%, and 63%, respectively, in group II. CONCLUSIONS: Good symptomatic relief and acceptable overall survival can be obtained in patients in both groups after they have undergone MVP, in the absence of serious comorbidities. Preoperative NYHA class IV and end-stage IHD increase early and late mortality, particularly in group II patients, in whom surgery may be a salvage effort only. Prognosis is dismal in group II patients who have previously undergone CABG. In chronic cases, an early referral for MVP electively before deterioration to end-stage heart disease would improve survival even in patients with low LVEF.

Adolescent↗

PubMed1992

Calculation of a gallbladder ejection fraction: advantage of continuous sincalide infusion over the three-minute infusion method.

The purpose of this study was to investigate alternative methods of infusing sincalide for calculation of a gallbladder ejection fraction (GBEF) during cholescintigraphy (5 mCi 99mTc-mebrofenin). After gallbladder filling, three methods of infusion were compared in 23 normal volunteers: (1) 0.02 microgram/kg as a 3-min infusion, (2) 0.02 microgram/kg as a 30-min infusion, and (3) 0.01 microgram/kg as a 30-min infusion (14 subjects), all performed on separate days. With the 3-min infusion, the emptying pattern was usually exponential and completed in 15 min. The mean (GBEF) was 52% +/- 26% at 20 min and 56% +/- 27% at 30 min (range 0%-100%). GBEFs were less than 35% in six subjects and 35%-38% in four. Side effects were noted by 11/23 subjects. With the slow infusions, emptying was linear; no side effects were noted. With 0.02 microgram/kg, the mean GBEF was 50% +/- 27% at 20 min and 70% +/- 22% at 30 min (range 26%-95%). Similar results were seen with 0.01 microgram/kg, but the data were more limited. The 30-min infusion had a higher normalcy rate than the 3-min method (91% versus 74%). Females had significantly lower GBEFs than males (p less than 0.05%). We conclude that the slow infusion method is preferable; it is more physiological, results in more complete emptying, has no side effects, has less normal variability, and should improve the specificity of this test. The lower mean female GBEF may have pathophysiological significance.

Adult↗

PubMed2004

Mitral effective regurgitant orifice area versus left ventricular ejection fraction as prognostic indicators in patients with dilated cardiomyopathy and heart failure.

BACKGROUND: This study aimed at investigating the relative powers of the quantitative evaluation of functional mitral regurgitation (FMR) and ejection fraction (EF) in predicting the clinical changes and prognosis of dilated cardiomyopathy (DCM) with severe systolic dysfunction. METHODS: A total of 81 patients with DCM, EF < 0.40 and at least mild FMR were prospectively evaluated during a mean follow-up of 24 +/- 7 months. Twenty cardiac deaths were recorded. At the time of enrolment all patients underwent echocardiographic evaluation of the effective regurgitant orifice area (ERO), EF, left atrial area, and tenting area. In 42/81 patients, the data obtained at enrolment were compared to those measured at a mean follow-up of 10 +/- 2 months. A multivariate analysis was performed to determine the best predictor of NYHA class and mortality. RESULTS: There was a correlation between the NYHA class and the ERO (chi2 = 26.1, p = 0.0001) but not with EF (chi2 = 4.3, p = 0.22) and at multivariate analysis, the ERO was found to be the main determinant of the NYHA class (r = 0.64, standard error 0.6, p = 0.0001). The NYHA class remained unchanged or improved in 28/42 (67%) and deteriorated in 14/42 (33%) patients. In the first group, the ERO increased from 22.3 +/- 10 to 30.2 +/- 16.4 mm2 (p = 0.05) and the tenting area from 5.8 +/- 1.8 to 6.8 +/- 1.8 cm2 (p = 0.001); in the second group, the ERO increased from 25.1 +/- 5.6 to 39.0 +/- 14.5 mm2 (p = 0.04) and the tenting area from 5.9 +/- 2.1 to 7.6 +/- 1.8 cm2 (p = 0.0001), in both groups without significant changes in EF. The mortality was 8.1% in patients with an ERO < 21 mm2, 30.3% in patients with an ERO of 21-30 mm2, and 50% in those with an ERO > 30 mm2. The EF was similar in the three subgroups. At Cox multivariate analysis the best predictors of mortality were the ERO (chi2 = 13.83, p = 0.0001), EF (chi2 = 5.48, p = 0.019), and left atrial area (chi2 = 4.52, p = 0.04). CONCLUSIONS: FMR in DCM well correlated with the clinical status of the patients and its worsening was suggestive of progression of the disease. The ERO was found to be the best predictor of the NYHA class and mortality.

Aged↗

PubMed1994

Right ventricular volume overload results in depression of left ventricular ejection fraction. Implications for the surgical management of tricuspid valve disease.

BACKGROUND: Right ventricular volume overload (RVVO) occurring in conditions such as Ebstein's anomaly may result in depression of left ventricular ejection fraction (LVEF). This study tests this hypothesis by measuring LVEF in 10 patients with RVVO due to tricuspid valve resection for isolated tricuspid valve endocarditis and in 10 age-matched healthy persons. METHODS AND RESULTS: When the modified Simpson's rule was applied to echocardiographic images, LVEF for patients with RVVO measured significantly lower than for age-matched healthy subjects (51 +/- 4% versus 60 +/- 4%, P < .0001). Depression of LVEF does not result simply from reduced venous return to the left ventricle, since left ventricular end-diastolic volume was not significantly different between patients with RVVO and age-matched healthy persons (84 +/- 26 versus 77 +/- 20 mL, NS). Possible explanations for the depression in LVEF may relate to the decreased relative contribution of left atrial systole to left ventricular filling (demonstrated by transmitral pulsed Doppler) or to the mechanical effects of ventricular septal paradox (demonstrated by the abnormal leftward ventricular septal flattening and increase in short-axis cavity eccentricity at end diastole, which returns to normal at end systole) in patients with RVVO. CONCLUSIONS: These findings suggest that surgical excision of the tricuspid valve results in isolated RVVO, which creates not only diastolic overload of the right heart but also depression of LVEF.

Adult↗

PubMed1997

[Calculation of left ventricular volume and ejection fraction from ECG-gated myocardial SPECT: automatic detection of endocardial borders by threshold method].

A new method which calculate end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (LVEF) of the left ventricle from myocardial short axis images of ECG-gated SPECT using 99mTc myocardial perfusion tracer has been designed. Eight frames per cardiac cycle ECG-gated 180 degrees SPECT was performed. Threshold method was used to detect myocardial borders automatically. The optimal threshold was 45% by myocardial SPECT phantom. To determine if EDV, ESV and LVEF can also be calculated by this method, 12 patients were correlated ventriculography (LVG) for 10 days each. The correlation coefficient with LVG was 0.918 (EDV), 0.935 (ESV) and 0.900 (LVEF). This method is excellent at objectivity and reproductivity because of the automatic detection of myocardial borders. It also provides useful information on heart function in addition to myocardial perfusion.

Electrocardiography↗

PubMedDate not supplied

Laparoscopic cholecystectomy in a cardiac transplant candidate with an ejection fraction of less than 15%.

BACKGROUND AND OBJECTIVES: Laparoscopic procedures are becoming increasingly popular, even in the severely ill patient. We present a case of a cardiac transplant candidate with an ejection fraction of less than 15% who underwent a laparoscopic cholecystectomy. This is the first case in which intraoperative hemodynamic measurements were recorded in a patient with cardiopulmonary disease this severe. METHODS: The patient underwent the procedure while measurements were made at crucial intervals (baseline, with incremental insufflation, reverse Trendelenberg, at desufflation) using a pulmonary artery catheter, transesophageal echocardiography with fractional area measurements, radial arterial line, as well as standard monitoring. RESULTS: This patient showed hemodynamic changes consistent with a person without severe heart disease. There was a rise in mean arterial and systemic vascular resistance with insufflation to 10 mm Hg, which was further exaggerated by reverse Trendelenberg. Heart rate and pulmonary artery wedge pressure increased slightly. The cardiac output and fractional area change declined minimally. CONCLUSIONS: We conclude that if a patient with congestive heart failure is medically optimized, and intra-abdominal pressures and surgical times are minimized, laparoscopic cholecystectomy may be performed with minimal risk to the patient.

Cardiac Output, Low↗

PubMed1984

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 less than 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.

Cardiac Output↗

PubMed1984

Digital processing of contrast echocardiograms: a new technique for measuring right ventricular ejection fraction.

Imaging of the right ventricle with 2-dimensional echocardiography (2-D echo) is hampered by trabeculation of the right ventricular (RV) endocardial surface and by limited echocardiographic resolution. Determination of RV ejection fraction (EF) is thus often an inconsistent and tedious procedure. The process of digital subtraction contrast echocardiography was developed to maximize echocardiographic definition of the right ventricle and to assess RVEF with minimal operator interaction. Videotaped 2-D echocardiograms recorded during i.v. injection of agitated saline were digitized. Masks were constructed from end-systolic and end-diastolic apical 4-chamber and parasternal RV short-axis images. Masks were subtracted from corresponding images recorded with contrast in the right ventricle; images of the contrast alone were extracted and their areas determined. EF was calculated from raw area measurements and after conversion to volume. Comparison with RVEF measured by first-pass radionuclide angiography yielded the following correlation coefficients: 4-chamber RV area, r = 0.79; parasternal short-axis RV area, r = 0.59; ellipsoid approximation RV volume, r = 0.84; pyramidal RV volume, r = 0.79; and Simpson's rule triangular cylinder RV volume, r = 0.62. Digital subtraction contrast echocardiography is a new method that can be used for semiautomated determination of RVEF. Further studies to assess the clinical values of digital image processing of 2-D echocardiograms to measure RV function appear warranted.

Aged↗