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Biomedical subjects

A Salustri

Publications and source records attributed to A Salustri.

At least 37 records · Page 2Linked to original sources
PubMed1999

Effects of early treatment with captopril and metoprolol singly or together on six-month mortality and morbidity after acute myocardial infarction. Results of the RIMA (Rimodellamento Infarto Miocardico Acuto) study. The RIMA researchers.

UNLABELLED: The RIMA (Rimodellamento Infarto Miocardico Acuto) study was designed to assess the relative effects of angiotensin-converting enzyme (ACE) inhibition by captopril, beta-blocker therapy by metoprolol, and their combination in patients with a first acute myocardial infarction on: 1. echocardiographically detected left ventricular remodeling; 2. prognosis. The second goal will be the argument of the present paper. Two-hundred fifty < or = 75 years consecutive patients (mean age: 58 yrs, males = 203) with acute myocardial infarction were randomly allocated to receive for > or = 3 months captopril (up to 75 mg/day, Group 1), metoprolol (up to 200 mg/day, Group 2) or captopril + metoprolol (Group 3) starting in the first 24 hours after the onset of symptoms. Intravenous beta-blockers in the acute phase of myocardial infarction and all other cardioactive drugs were allowed. The effect of the randomized therapy at six months from admission to the coronary care unit was considered in relation to: 1. recurrence of spontaneous cardiac events and of elective revascularization procedures; 2. adverse reactions (hypotension, atrioventricular block, cough, allergy, need of beta-blockers in Group 1, need for ACE inhibition in Group 2) requiring treatment modification based on physician's decision. RESULTS: Definite follow-up data were available in 226 patients and 195/226 patients (86%) had a complete treatment period. In these patients (per protocol analysis), 37 spontaneous cardiac events occurred: cardiac death = 6, non-fatal reinfarction = 9, unstable angina requiring hospitalization = 16, congestive heart failure = 6. Moreover, seven patients received a coronary revascularization procedure. Events occurred in 11/67 patients from Group 1, 16/63 patients from Group 2, 10/65 patients from Group 3 (16% vs 25% vs 15%, p = 0.28). The multiple logistic regression analysis demonstrated an increased odds ratio (OR) for spontaneous cardiac events in patients from Group 2 (OR = 2.82, 95% Cl: 1.16-6.87: p < 0.05). Elective revascularization procedures were statistically less frequent in patients treated with metoprolol (Group 1 = 9%, Group 2 = 1.6%, Group 3 = 0%; Group 1 vs Groups 2 and 3; p = 0.03). The intention-to-treat analysis on the overall population (226 patients) confirmed the presence of a trend towards a higher risk in patients from Group 2 (OR = 2.1, 95% Cl: 0.96-4.59; p = 0.06). Adverse reactions were observed in 16 patients from Group 1, 6 patients from Group 2 and 15 patients from Group 3 (22% vs 10% vs 23%; Group 2 vs Groups 1 and 3; p = 0.08). At the multivariate regression analysis, a trend towards less adverse reactions in patients assigned to the beta-blocker therapy alone was confirmed (OR = 0.41, 95% Cl: 0.15-1.13; p = 0.07). CONCLUSIONS: In a randomized early post-infarction treatment strategy, ACE inhibition with captopril alone or in combination with metoprolol demonstrated an increased protection against spontaneous cardiac events at six months in comparison with metoprolol alone. On the other hand, the beta-blocker treatment was associated with a lower number of elective revascularization procedures and appeared better tolerated than ACE inhibition.

Adrenergic beta-Antagonists↗
PubMed1998

Prognostic value of myocardial viability in medically treated patients with global left ventricular dysfunction early after an acute uncomplicated myocardial infarction: a dobutamine stress echocardiographic study.

BACKGROUND: Residual viable myocardium identified by dobutamine stress after myocardial infarction may act as an unstable substrate for further events such as subsequent angina and reinfarction. However, in patients with severe global left ventricular dysfunction, viability might be protective rather than detrimental. The aim of this study was to assess the impact on survival of echocardiographically detected viability in medically treated patients with global left ventricular dysfunction evaluated after acute uncomplicated myocardial infarction. METHODS AND RESULTS: The data bank of the large-scale, prospective, multicenter, observational Echo Dobutamine International Cooperative (EDIC) study was interrogated to select 314 medically treated patients (271 men; age, 58+/-9 years) who underwent low-dose (</=10 microg x kg-1 x min-1) dobutamine for the detection of myocardial viability and high-dose dobutamine for the detection of myocardial ischemia (</=40 microg x kg-1 x min-1 with atropine </=1 mg) performed 12+/-6 days after an acute uncomplicated myocardial infarction and showing a moderate to severe resting left ventricular dysfunction (wall motion score index [WMSI] >1.6). Patients were followed up for 9+/-7 months. Low-dose dobutamine stress echocardiography identified myocardial viability in 130 patients (52%). Dobutamine-atropine stress echocardiography was positive for ischemia in 148 patients (47%) and negative in 166 patients (53%). During the follow-up, there were 12 cardiac deaths (3.8% of the total population). With the use of Cox proportional hazards model, delta low-dose WMSI (the variation between rest WMSI and low-dose WMSI) was shown to exert a protective effect by reducing cardiac death by 0.8 for each decrease in WMSI at low-dose dobutamine (coefficient, -0.2; hazard ratio, 0.8; P<0.03); WMSI at peak stress was the best predictor of cardiac death in this set of patients (hazard ratio, 14.9; P<0.0018). CONCLUSIONS: In medically treated patients with severe global left ventricular dysfunction early after acute uncomplicated myocardial infarction, the presence of myocardial viability identified as inotropic reserve after low-dose dobutamine is associated with a higher probability of survival. The higher the number of segments showing improvement of function, the better the impact is of myocardial viability on survival. The presence of inducible ischemia in this set of patients is the best predictor of cardiac death.

Aged↗
PubMed1998

Left ventricular ejection fraction in patients with normal and distorted left ventricular shape by three-dimensional echocardiographic methods: a comparison with radionuclide angiography.

BACKGROUND: Serial evaluation of left ventricular (LV) ejection fraction (EF) is important for the management and follow-up of cardiac patients. Our aim was to compare LVEF calculated from two three-dimensional echocardiographic (3DE) methods with multigated radionuclide angiography (RNA), in patients with normal and abnormally shaped ventricles. METHODS AND RESULTS: Forty-one consecutive patients referred for RNA underwent precordial rotational 3DE acquisition of 90 cut-planes. From the volumetric data set, LVEF was calculated by (a) Simpson's rule (3DS) through manual endocardial tracing of LV short-axis series at 3 mm slice distance and (b) apical biplane modified Simpson's method ( MS) in 29 patients by manual endocardial tracing of the apical four-chamber view and its computer-derived orthogonal view. Patients included three groups: A, 17 patients with LV segmental wall motion abnormalities; B, 13 patients with LV global hypokinesis; and C, 11 patients with normal LV wall motion. For all the 41 patients, there was excellent correlation, close limits of agreement, and nonsignificant difference between 3DS and RNA for LVEF calculation (r = 0.99, [-6.7, +6.9] and p = 0.9), respectively. For the 29 patients, excellent correlation and nonsignificant differences between LVEF calculated by both 3DS and BMS and values obtained by RNA were found (r = 0.99 and 0.97, p = 0.7 and p = 0.5, respectively). In addition, no significant difference existed between values of LVEF obtained from RNA, 3DS, and BMS by the analysis of variance (p = 0.6). The limits of agreement tended to be closer between 3DS and RNA (-6.8, +7.2) than between BMS and RNA (-8.3, +9.7). The intraobserver and inter-observer variability of RNA, 3DS, and BMS for calculating LVEF(%) were (0.8, 1.5), (1.3, 1.8), and (1.6, 2.6), respectively. There were closer limits of agreement between 3DS and RNA for LVEF calculation in A, B, and C patient subgroups [(-3.5, +5), (-8.4, +5.6), and (-7.8, +8.6)] than that between BMS and RNA [(-8.1, +10.7), (-11.9, +9.3), and (-9.1, +11.3)], respectively. CONCLUSIONS: No significant difference existed between RNA, 3DS, and BMS for LVEF calculation. 3DS has better correlation and closer limits of agreement than BMS with RNA for LVEF calculation, particularly in patients with segmental wall motion abnormalities and global hypokinesis. 3DS has a comparable observer variability with RNA. Therefore the use of 3DS for serial accurate LVEF calculation in cardiac patients is recommended.

Adult↗
PubMed1997

Coding sequence, exon-intron structure and chromosomal localization of murine TNF-stimulated gene 6 that is specifically expressed by expanding cumulus cell-oocyte complexes.

Tumor necrosis factor stimulated gene-6 (TSG-6) has been previously shown to be induced in vitro in several cell types by proinflammatory cytokines, and in vivo in pathological conditions such as rheumatoid arthritis. In this study, we report the complete coding sequence for the mouse TSG-6 protein, and the exon intron structure and the chromosomal localization of the gene. We have identified a 1605 nt cDNA sequence from mouse cumulus cell oocyte complexes (COCs) induced to expand in vivo. The sequence contains an open reading frame of 825 nt that codes for the 275 amino acid TSG-6 protein. The gene contains six exons separated by 1.1-5.8 kb introns and has been localized to the murine chromosome 2 by linkage analysis. Comparative reverse transcription-polymerase chain reaction studies have revealed that TSG-6 mRNA is specifically expressed after COC expansion induced in vivo, identifying the first non-pathological process in which TSG-6 may play an important role. Since TSG-6 binds to hyaluronan and interacts with inter-alpha-trypsin inhibitor (IalphaI), molecules that are essential for matrix formation by COCs, this protein may have a structural role in the matrix or may enhance the antiproteolytic effect of IalphaI to protect the matrix from degradation.

Amino Acid Sequence↗
PubMed1997

Cardiac imaging for risk stratification with dobutamine-atropine stress testing in patients with chest pain. Echocardiography, perfusion scintigraphy, or both?

BACKGROUND: Pharmacological stress echocardiography and myocardial perfusion scintigraphy are used frequently for risk stratification in patients with suspected myocardial ischemia. However, their relative prognostic strength has never been explored. METHODS AND RESULTS: Two hundred twenty consecutive patients with chest pain (mean age, 60 +/- 12 years; 124 men, 115 with previous myocardial infarction) were studied with dobutamine-atropine stress echocardiography (ECHO) and simultaneous 99mTc sestamibi single photon emission computed tomography imaging (MIBI). Ischemia was defined as deterioration in left ventricular wall motion and reversible perfusion defects, respectively. ECHO was positive for ischemia in 76 and MIBI in 91 patients (agreement, 77%; kappa = .51). During follow-up of 31 +/- 15 months, 24 patients had hard cardiac events (nonfatal myocardial infarction or cardiac death). By univariate analysis, age, history of congestive heart failure, and any abnormality or ischemia on ECHO or MIBI were associated with cardiac events. Multivariate analysis revealed that age, abnormal ECHO (odds ratio [OR], 18.9; 95% CI, 2.5 to 146.0) or MIBI (OR, 12.8; 95% CI, 1.7 to 98.3), and ischemia on ECHO (OR, 4.0; 95% CI, 1.6 to 9.9) or MIBI (OR, 3.0; 95% CI, 1.2 to 7.4) had independent predictive values. When ECHO was used as a first option, the addition of MIBI to all nonischemic ECHO studies decreased the OR from 4.0 (95% CI, 1.6 to 9.9) to 3.8 (95% CI, 1.4 to 10.2). Addition of MIBI confined to nonischemic ECHO studies in which target heart rate was not attained (nondiagnostic studies) increased the OR to a maximal 5.7 (95% CI, 2.2 to 15.0). In contrast, the addition of ECHO to nondiagnostic MIBI studies was not useful. CONCLUSIONS: Dobutamine-atropine ECHO and MIBI provide comparable prognostic information. The addition of MIBI to ECHO may be useful in patients with nondiagnostic ECHO studies.

Aged↗
PubMed1997

Hyaluronan synthesis by mouse cumulus cells is regulated by interactions between follicle-stimulating hormone (or epidermal growth factor) and a soluble oocyte factor (or transforming growth factor beta1).

Expansion of the cumulus cell-oocyte complex (COC) in the preovulatory mammalian follicle requires a transient induction of hyaluronan (HA) synthesis by the cumulus cells. We studied the interactions of known factors that regulate this process by isolating compact COCs from mice and inducing their expansion in vitro. Maximum HA synthesis requires either follicle-stimulating hormone (FSH) or epidermal growth factor (EGF) in combination with either a soluble factor(s) produced by the oocyte or transforming growth factor beta1. FSH (or EGF) exerts its effects during the first 2 h of incubation, before HA synthesis actually begins. The oocyte factor(s) (or transforming growth factor beta1) exerts its effects from 2 h onwards and must be continuously present throughout the subsequent approximately 10 h to achieve a maximum level of HA synthesis. FSH stimulates intracellular cAMP synthesis, which correlates with net HA production up to approximately 14 fmol/COC at 5 ng/ml FSH; however, higher concentrations of FSH increase cAMP levels approximately 10-fold higher with no additional effect on HA synthesis. EGF at saturating concentrations for HA synthesis does not stimulate cAMP above basal levels. Tyrosine kinase inhibitors genistein and tyrphostin AG18 nearly abolish the HA synthesis response to EGF and inhibit the response to FSH by approximately 60%, suggesting that a tyrosine kinase activity is involved for both factors, whereas FSH also operates partially through another signaling pathway. Actinomycin D abolishes HA synthesis if added at the beginning of culture and reduces HA synthesis by approximately 50% if added between 6-12 h when HA synthesis is normally maximal. The results suggest that regulation of HA synthesis is primarily controlled at the transcriptional level.

Animals↗
PubMed1997

Coding sequence of a hyaluronan synthase homologue expressed during expansion of the mouse cumulus-oocyte complex.

Maturation of mammalian cumulus cell-oocyte complex in the preovulatory follicle involves the deposition of a hyaluronan-rich extracellular matrix by the cumulus cells. In this study, we report the complete coding sequence of a novel mouse hyaluronan synthase homologue expressed in cumulus cell-oocyte complexes induced to expand in vivo. The time frame of mRNA expression of this molecule correlates well with previous biochemical and immunohistochemical findings on the initiation of hyaluronan synthesis in maturing preovulatory follicles. Evolutionary comparison of the vertebrate hyaluronan synthase homologues indicates that there are at least two genes that code for these proteins.

Amino Acid Sequence↗
PubMed1997

Prognostic value of dobutamine echocardiography early after uncomplicated acute myocardial infarction: a comparison with exercise electrocardiography.

OBJECTIVES: This study sought to assess the relative prognostic power of dobutamine echocardiography and exercise electrocardiography after acute myocardial infarction. BACKGROUND: The prognostic value of dobutamine echocardiography early after acute myocardial infarction has not yet been reported. METHODS: One hundred seventy-eight patients (mean age 58 +/- 9 years) with a first uncomplicated acute myocardial infarction underwent predischarge dobutamine echocardiography (5 to 40 micrograms/kg body weight per min, plus atropine if needed) and symptom-limited bicycle exercise electrocardiography and were followed up for 17 +/- 13 months. Stress-induced dyssynergy and ST segment depression > 1 mm were considered criteria of positivity for dobutamine echocardiography and exercise electrocardiography, respectively. RESULTS: Dobutamine echocardiography was positive in 83 patients and exercise electrocardiography in 60. At follow-up there were 5 deaths, 6 nonfatal myocardial infarctions (11 hard events) and 20 cases of unstable angina. Dobutamine echocardiography and exercise electrocardiography had similar negative predictive values both for all events (88% and 86%, respectively) and for hard events (98% and 95%, respectively). The hard events rate was significantly higher in patients with positive rather than negative dobutamine echocardiography (relative risk [RR] 5.15, 95% confidence interval [CI] 1.14 to 23.16), although there was no difference between patients with positive and negative exercise electrocardiograms. When Cox analysis was performed, dobutamine echocardiography had an independent prognostic value both for all events (RR 2.88, 95% CI 1.37 to 6.08) and for hard events (RR 6.56, 95% CI 1.42 to 30.46). CONCLUSIONS: After uncomplicated acute myocardial infarction, dobutamine echocardiography and exercise electrocardiography have a similar high negative predictive value for both all events and hard events only. Positive dobutamine echocardiography, but not positive exercise electrocardiography, identifies a group of patients at higher risk of subsequent cardiac events.

Aged↗
PubMed1997

Accurate assessment of mitral valve area in patients with mitral stenosis by three-dimensional echocardiography.

The accuracy of measurements of mitral valve orifice area (MVA) from three-dimensional echocardiographic (3DE) image data sets obtained by a transthoracic or transesophageal rotational imaging probe was studied in 15 patients with native mitral stenosis. The smallest MVA was identified from a set of eight parallel short-axis cut planes of the mitral valve between the anulus and the tips of leaflets (paraplane echocardiography) and measured by planimetry. In addition, MVA was measured from the two-dimensional short-axis view (2DE). Values of MVA measured by 3DE and 2DE were compared with those calculated from Doppler pressure half-time (PHT) as a gold standard. Observer variabilities were studied for 3DE. MVA measured from PHT ranged between 0.55 and 3.19 cm2 (mean +/- SD 1.57 +/- 0.73 cm2), from 3DE between 0.83 and 3.23 cm2 (mean +/- SD 1.55 +/- 0.67 cm2), and from 2DE between 1.27 and 4.08 cm2 (mean +/- SD 1.9 +/- 0.7 cm2). The variability of intraobserver and interobserver measurements for 3DE measurements was not significantly different (p = 0.79 and p = 0.68, respectively); for interobserver variability, standard error of the estimate = 0.25. There was excellent correlation, close limits of agreement (mean difference +/- 2 SD), and nonsignificant differences between 3DE and PHT for MVA measurements (r = 0.98 [0.02 +/- 0.3] and p = 0.6), respectively. There was moderate correlation, wider limits of agreement, and significant difference between 2DE and PHT for MVA measurements (r = 0.89 [0.32 +/- 0.66] and p = 0.002), respectively. This may be related to the difficulties in visualization of the smallest orifice in precordial short-axis views. This study suggests that three-dimensional image data sets, by providing the possibility of "computer slicing" to generate equidistant parallel cross sections of the mitral valve independently from physically dictated ultrasonic windows, allow accurate and reproducible measurement of the MVA.

Adult↗
PubMed1997

Should the diagnosis of coronary artery disease be based on the evaluation of myocardial function or perfusion?

The aim of this review was to define the place of stress (exercise, dobutamine, and vasodilator) echocardiography in the context of perfusion scintigraphic techniques for the detection of coronary artery disease. Echocardiography and nuclear imaging have their strong and weak points. Echocardiography has the benefit of widespread availability, relatively low cost, portability, absence of radiation, safety, and determination of ischaemic threshold. However, echocardiographic imaging cannot be performed during treadmill exercise, the echocardiographic windows are variable with sometimes poor echogenicity, and interpretation is subjective and requires an important learning curve. Diagnostic comparisons were focused on studies involving echocardiographic and nuclear imaging in the same patients. These direct comparisons show that exercise or dobutamine echocardiography and perfusion imaging have similar accuracies for the detection and localization of coronary artery disease. Perfusion imaging may be more sensitive in the detection of mild coronary artery disease; echocardiography, however, has a better specificity. Vasodilator perfusion imaging is superior to vasodilator echocardiography, although the new dipyridamole-atropine echocardiography test will make future reassessment necessary. Once the condition of adequate echocardiographic training is fulfilled, we believe that the selection of one or other test should be tailored to clinical circumstances rather than be a uniform decision.

Cardiotonic Agents↗
PubMed1997

Hemodynamic changes, plasma catecholamine responses, and echocardiographically detected contractile reserve during two different dobutamine-infusion protocols.

We studied hemodynamic changes, catecholamine responses, and the occurrence of improved wall thickening by echocardiography during two different dobutamine-infusion protocols. Forty-three patients were studied by using a stepwise incremental dobutamine dose-infusion protocol (10-40 microg/kg/min, 3-min intervals); a subgroup of 11 patients also underwent a continuous dobutamine-infusion protocol (10 microg/kg/min for 12 min) in random order. No patient used beta-blockers. At 3-min intervals, blood pressure, heart rate, and plasma concentrations of dobutamine, epinephrine, and norepinephrine were measured. The echocardiographic improvement of wall thickening was analyzed only in paired protocols by visual assessment in left ventricular regions with normal wall motion at rest. The mean heart rate increased in the continuous and stepwise protocols from 73 to 99 and 74 to 132 beats/min. There was no significant change in blood pressure response between the two protocols. The mean plasma dobutamine concentrations during the continuous and stepwise protocols at 0, 3, 6, 9, and 12 min were 0/0; 31/38; 80/203; 106/448; and 120/692 ng/ml, respectively. In each patient, a response curve was constructed for the plasma dobutamine concentration versus heart rate. The heart rate increment and dobutamine concentration at which wall thickening was detected were similar with both protocols (14 +/- 5 vs. 12 +/- 7 beats/min) and (80 +/- 40 vs. 92 +/- 48 ng/ml; mean +/- SD). Wall thickening was noted in two of 11 patients between 0 and 3 min and 11 of 11 patients between 3 and 6 min in both protocols. Catecholamine responses during the continuous and stepwise protocols were epinephrine, 23 versus 28/28 versus 36, and norepinephrine 301 versus 323/347 versus 519. Only norepinephrine plasma concentrations increased significantly during the stepwise protocol. A 6-min dobutamine infusion was sufficient during both protocols to reach an adequate plasma dobutamine concentration, which induced a detectable increase of wall thickening in all patients. There is a significant differences between the two protocols with regard to the plasma catecholamine changes, so some of the hemodynamic effects during the stepwise dobutamine-infusion protocol may be mediated through release of endogenous catecholamines.

Adrenergic beta-Agonists↗
PubMed1997

Cardiac arrest during dobutamine stress echocardiography.

In this report, we describe the case of a woman with normal coronary arteries who experienced a cardiac arrest during a dobutamine stress test. The patient was successfully treated with external cardiac massage. The possible mechanisms underlying this unusual life-threatening side effect of dobutamine infusion are discussed.

Adrenergic beta-Agonists↗
PubMed1997

[Three-dimensional transesophageal echocardiography: a new cardiologic diagnostic tool. Initial experience with 150 patients].

BACKGROUND: Three-dimensional transesophageal echocardiography is a new diagnostic tool and its potential has been investigated mainly in international centers dealing with research in the field of cardiac pathologies. The clinical usefulness and the potential additional information over multiplane transesophageal echocardiography in daily clinical practice have not been exstensively studied. OBJECTIVES: This study sought to assess the feasibility and to define the potential role of three-dimensional technique in a clinical cardiology department. POPULATION AND METHODS: One hundred-fifty patients (73 males, 77 females) aged 17-82 underwent a three-dimensional transesophageal echocardiographic study. Indications for the study were the following: 39 mitral (26%), 13 aortic (8%) and 4 tricuspidal (2%) valvulopathies, 23 valvular prostheses (15%), 6 aortic diseases (4%), 16 sources of embolism (10%), 16 congenital heart diseases (10%), 14 ischemic heart diseases (9.3%), 14 cardiomyopathies (9%), 5 other pathologies (3%). The 3 D examination quality was graded as insufficient, sufficient and good. The information obtained by "volume rendered" and "anyplane" three-dimensional echocardiography were compared with the traditional two-dimensional images to determine whether they provided additional information. RESULTS: A total of 288 acquisitions were obtained in the 150 patients (1.9 acquisitions per patient). Examinations were graded of good quality in 99 patients (61%), sufficient in 36 (24%) and insufficient in 15 patients (10%). Additional informations were obtained in 33 patients (22%) by "volume rendered" echocardiography and by "anyplane echocardiography", including mitral regurgitation or repair for valvular prolapse (11 patients), aortic valve malformations and endocarditis (4 patients), congenital heart diseases (9 patients), right ventricular dysplasia (6 patients) or hypertrophic cardiomyopathy (1 patient), tricuspid regurgitation (2 patients). The additional information were obtained in patients in the group of good 3 D reconstructions quality in all but two cases. CONCLUSIONS: The diagnostic use of the transesophageal technique with 3 D facilities permitted to obtain an overall 22% of additional information. These results will stimulate further study to evaluate the advantages of the three-dimensional technique in specific clinical fields of application.

Adolescent↗
PubMed1997

[Prognostic stratification after acute uncomplicated myocardial infarction: exercise test, echo-dobutamine test or both?].

OBJECTIVES: The aims of this study were: 1) to assess the relative prognostic value of predischarge dobutamine echocardiography (DE) and exercise electrocardiography (EE) in patients after a first uncomplicated acute myocardial infarction (AMI), and 2) to evaluate the optimal prognostic strategy by using the two tests in different combinations. METHODS: DE (dobutamine infusion 5 to 40 micrograms/kg/min plus atropine 0.25 to 1 mg, if needed) and symptom-limited bicycle EE were performed in 208 patients (mean age 58 +/- 9 years, 90% males), on different days and in random order, 12 +/- 4 days after a first uncomplicated AMI and after pharmacological washout. A stress-induced dyssynergy and ST segment depression > 1 mm were considered criteria of positivity for DE and EE, respectively. Only spontaneous cardiac events were considered: cardiac death, reinfarction (= hard events), and unstable angina requiring hospitalization (= soft events). RESULTS: Thirty-eight events occurred during follow-up (16 +/- 13 months; range: 1-44 months); 5 cardiac deaths, 6 reinfarctions and 27 unstable angina. Patients with a positive DE had a twofold increase in all event rates (26 vs 12%, p < 0.01) and a fourfold increase in the rate of hard events (9 vs 2%, p < 0.05). In contrast, no statistically significant difference was observed in the distribution of the same events between patients with positive and negative EE. Both tests showed similar negative (DE 88%, EE 85%) and positive (DE 26%, EE 24%) predictive values. Among six different strategies (performing either DE or EE only in all patients; EE in all patients; EE in all patients and DE only in those with a positive EE; and DE only in those with a negative EE; EE in all patients and DE only in those with anterior AMI), EE only in patients with inferior or non-Q AMI and DE only in those with anterior AMI), performing DE only in patients with a positive EE gave the highest predictive accuracy-74% (95% confidence intervals 68 to 80) for all events and 77% (95% confidence intervals 71 to 83) for hard events. CONCLUSIONS: In patients with a first uncomplicated AMI, DE is useful in identifying patients at high and low risk of future spontaneous cardiac events. The optimal strategy for prognostication of these patients is to perform EE in all and DE only in the ones with a positive EE.

Acute Disease↗
PubMed1996

Assessment of left ventricular outflow in hypertrophic cardiomyopathy using anyplane and paraplane analysis of three-dimensional echocardiography.

This study analyzes the alterations in size and geometry of the left ventricular (LV) outflow tract that occur in hypertrophic cardiomyopathy (HC) using transthoracic 3-dimensional echocardiography. Transthoracic 3-dimensional echocardiography was performed in 17 patients with HC (4 after myectomy) and in 10 normal subjects. Images were acquired with the rotational approach, with electrocardiographic and respiratory gating. From the 3-dimensional datasets, short-axis parallel slicing of the LV outflow tract at a 1mm distance was performed at the onset of systole. For each slice, cross-sectional area and maximal and minimal diameter were calculated. Reconstruction of the LV outflow tract could be displayed in 3 dimensions in all patients, allowing orientation and clear definition of the irregular geometry. In patients with HC, the minimal LV outflow tract cross-sectional area was smaller than in normal subjects (2.3 +/- 1.0 vs 5.0 +/- 0.9 cm(2), p < 0.0001). The ratio between maximal and minimal cross-sectional areas was higher in patients with HC than in normal subjects (2.6 +/- 0.9 vs 1.4 +/- 0.2, p <0.0001). The ratio between maximal and minimal diameter of the smallest cross section of the LV outflow tract was also significantly higher in patients with HC than in normal subjects (1.6 +/- 0.3 vs, 1.2 +/- 0. 1, p <0.001); a value of 1.36 separated normal subjects from HC patients without previous myectomy. In conclusion, precordial 3-dimensional echocardiography allows detailed qualitative and quantitative information on the LV outflow tract. Patients with HC are characterized by a highly eccentric and asymmetric shape of the LV outflow tract, and by a smaller minimal cross-sectional area than that seen in normal subjects.

Adult↗
PubMed1996

Accurate measurement of left ventricular ejection fraction by three-dimensional echocardiography. A comparison with radionuclide angiography.

BACKGROUND: Three-dimensional echocardiography is a promising technique for calculation of left ventricular ejection fraction, because it allows its measurement without geometric assumptions. However, few data exist that study its reproducibility and accuracy in patients. METHODS AND RESULTS: Twenty-five patients underwent radionuclide angiography and three-dimensional echocardiography that used the rotational technique (2 degrees interval and ECG and respiratory gating). Left ventricular volume and ejection fraction were calculated by use of Simpson's rule at a slice thickness of 3 mm. Analyses were performed to define the largest slice thickness required for accurate calculation of left ventricular volume and ejection fraction. Three-dimensional echocardiography showed excellent correlation with radionuclide angiography for calculation of left ventricular ejection fraction (mean +/- SD, 38.9 +/- 19.8 and 38.5 +/- 18.0, respectively; r = .99); their mean difference was not significant (0.03 +/- 0.17; P = .3), and they had a close limit of agreement (-0.385, 0.315). Intraobserver variability for radionuclide angiography and three-dimensional echocardiography was 4.2% and 2.6%, respectively, whereas interobserver variability was 6.2% and 5.3%, respectively. There was no significant difference between left ventricular volume and ejection fraction calculated at a slice thickness of 3 mm and that calculated at different slice thicknesses up to 24 mm. However, the standard deviation of the mean difference showed a stepwise increase, particularly at thicknesses > 15 mm. At a slice thickness of 15 mm, the probability of three-dimensional echocardiography to detect > or = 6% difference in ejection fraction was 80%. CONCLUSIONS: Three-dimensional echocardiography has excellent correlation with radionuclide angiography for calculation of left ventricular ejection fraction in patients and has an observer variability similar to that of radionuclide angiography. We recommend the use of a 15-mm-thick slice for accurate and rapid measurement of left ventricular volume and ejection fraction.

Adult↗
PubMed1996

Proteoglycans and proteins in the extracellular matrix of mouse cumulus cell-oocyte complexes.

In the preovulatory follicle, the oocyte is surrounded by approximately 1000 closely associated cumulus cells forming the compact form of the cumulus cell-oocyte complex (COC). In response to the gonadotropin surge, the COC in a follicle destined for ovulation undergoes expansion when the cumulus cells synthesize and organize an extensive extracellular matrix enriched in hyaluronan. Successful expansion of the COC appears to be essential for ovulation and ultimately for fertilization. We studied this process in vitro by isolating compact COCs from preovulatory mouse follicles and incubating them under conditions which promote COC expansion by retention of newly synthesized hyaluronan (HA in the extracellular matrix around the cells. [3H]-Leucine and [35S]sulfate were used as precursors to label macromolecules synthesized by the cells that may be necessary for organizing the HA in this matrix. After labeling, expanded COCs were washed to remove medium and any labeled molecules that were not associated with the matrix. Macromolecules selectively associated with the matrix were then solubilized by digesting the expanded COCs briefly with Streptomyces hyaluronidase, an enzyme that specifically cleaves HA. Cells were removed by centrifugation, and the digest supernate was analyzed by molecular sieve chromatography and SDS-PAGE. A dermatan sulfate proteoglycan of large hydrodynamic size ( > 1 million Da) and a approximately 46-kDa protein were the predominant labeled species identified. The proteoglycan has properties similar to proteoglycans such as aggrecan and versican which interact specifically with HA. The approximately 46-kDa protein has the same molecular size as the link protein which interacts with HA and HA-binding proteoglycans to form stable ternary complexes in a variety of extracellular matrices. We propose that the dermatan sulfate proteoglycan and the approximately 46-kDa protein synthesized by the cumulus cells form similar ternary complexes that are necessary for retaining HA in the COC matrix and hence are required for successful COC expansion.

Animals↗