Search PubMed⌕ Search

Biomedical subjects

P Probst

Publications and source records attributed to P Probst.

At least 37 records · Page 2Linked to original sources
PubMed1998

Comparison of transesophageal Doppler coronary flow reserve measurements with thallium-201 single-photon emission computed tomography imaging in assessment of left anterior descending artery stenoses.

BACKGROUND AND HYPOTHESIS: Recent studies demonstrate the feasibility of coronary flow reserve measurements by transesophageal echocardiographic (TEE) Doppler recordings of coronary sinus or left anterior descending (LAD) coronary artery flow velocity for detecting stenoses of the LAD artery. This study compares coronary flow reserve measurements by Doppler TEE with thallium-201 (201Tl) single-photon emission computed tomography (SPECT) in patients with proximal single-vessel LAD stenosis. METHODS: Nineteen patients with various degrees of LAD stenosis (mean area stenosis 71 +/- 24%; range 24-96%) were studied. Area stenosis by quantitative coronary angiography was < 75% in 7 patients and > 75% in 12 patients. Transesophageal LAD and coronary sinus Doppler measurements were performed at baseline and after intravenous dipyridamole. Coronary flow reserve was calculated as the ratio of hyperemic to baseline average peak velocities. Predefined coronary flow reserve cut-off values of 1.8 for the coronary sinus method and of 2.0 for the LAD method were used for diagnosis of significant LAD stenosis. Results were compared with qualitative 201Tl dipyridamole SPECT. RESULTS: Overall predictive accuracy for diagnosis of > 75% LAD stenosis was 79% for 201Tl SPECT, 77% for the transesophageal LAD and 79% for the transesophageal coronary sinus technique. Concordant results between 201Tl SPECT and the LAD and coronary sinus Doppler methods were observed in 79% and 71% of patients, respectively. CONCLUSIONS: Thallium-201 SPECT and transesophageal Doppler assessment of coronary flow reserve have similar accuracy for diagnosing significant proximal LAD stenosis. Therefore, both transesophageal Doppler techniques might constitute another widely available, noninvasive method for assessment of left coronary artery disease, if disease location is proximal.

Blood Flow Velocity↗
PubMed1998

Stent implantation in acute myocardial infarction using a heparin-coated stent: a pilot study as a preamble to a randomized trial comparing balloon angioplasty and stenting.

Preliminary experience with primary stenting in myocardial infarction has suggested a greater benefit in clinical outcome than has been obtained with direct balloon angioplasty. However, subacute thrombosis (SAT) remains a limitation for this new mode of therapy. In the BENESTENT II Pilot and main trials, the incidence of SAT with the heparin-coated Palmaz-Schatz stent was only 0.15%. Therefore, as a preamble to a large randomized trial, the feasibility and safety of the use of the Heparin-Coated Palmaz-Schatz trade mark Stent in Acute Myocardial Infarction (AMI) was tested in 101 patients enrolled between April and September 1996 in 18 clinical centres. In 101 stent-eligible AMI patients, as dictated by protocol, a heparin-coated stent was implanted. The primary objectives were to determine the in-hospital incidence of major adverse cardiac events (MACE: death, MI, target lesion revascularization) and bleeding complications, while the secondary objectives were the procedural success rate and the MACE, the restenosis and reocclusion rates at 6.5 months. Stent implantation (n 3 129 stents) was successful in 97 patients of the 101 who were included in this trial. During their hospital stay, two patients died and no patient experienced re-infarction, ischaemia prompting re-PTCA or CABG. Four patients suffered a bleeding complication, three major and one minor, of whom three required surgical repair. At 210 days follow-up, 81% of the patients were event free. At 6.5 months restenosis was documented in 18% of the 88 patients who underwent follow-up angiography, including three total occlusions. The results, both with respect to QCA and the occurrence of MACE, compare favourably with studies using elective stenting in both stable and unstable angina patients. As a result of this pilot study, a large randomized trial comparing direct balloon angioplasty with direct stenting in 900 patients with AMI was initiated in December 1996.

Journal Article↗
PubMed1998

[Social intelligence deficits in autistic children and adolescents--subjective theories of psychosocial health care professionals].

The paper is concerned with personal theories of health care professionals about deficiencies in social intelligence of autistic persons. In the component-model of social intelligence means the ability of individuals or groups, to interact with each other in social situations. This contains social perception, social behavior as well as social conceptions and refers to emotional, cognitive and normative aspects. 33 interviewees, working as psychologists or teachers in kindergartens, schools or therapy institutions, are questioned by a half-standardized single interview concerning their beliefs about nonverbal social abilities, social perspective taking, and construction of a theory of mind in autistic persons. The major finding is: The impairments can be found in all aspects of social intelligence. Especially emotional handicaps, which are quoted by more than 80% of the interviewees, and low cognitive preconditions of mastering social stimuli, which are quoted by nearly all interviewees, are relevant. The subjective theories of the interviewees are in accordance to the models of parents as well as the models of the leading experts. The professional relationship to autistic persons and the practical experiences of the health care professionals lead to their specific personal theories of deficiencies in social intelligence of autistic people with wide consequences in respect to the professional contact with the autistic children and young adults.

Adolescent↗
PubMed1997

Prognostic value of intracoronary flow velocity and diameter stenosis in assessing the short- and long-term outcomes of coronary balloon angioplasty: the DEBATE Study (Doppler Endpoints Balloon Angioplasty Trial Europe).

BACKGROUND: The aim of this prospective, multicenter study was the identification of Doppler flow velocity measurements predictive of clinical outcome of patients undergoing single-vessel balloon angioplasty with no previous Q-wave myocardial infarction. METHODS AND RESULTS: In 297 patients, a Doppler guidewire was used to measure basal and maximal hyperemic flow velocities proximal and distal to the stenosis before and after angioplasty. In 225 patients with an angiographically successful percutaneous transluminal coronary angioplasty (PTCA), postprocedural distal coronary flow reserve (CFR) and percent diameter stenosis (DS%) were correlated with symptoms and/or ischemia at 1 and 6 months, with the need for target lesion revascularization, and with angiographic restenosis (defined as DS > or = 50% at follow-up). Logistic regression and receiver operator characteristic curve analyses were applied to determine the prognostic cutoff value of CFR and DS separately and in combination. Optimal cutoff criteria for predictors of these clinical events were DS, 35%; CFR, 2.5. A distal CFR after angioplasty > 2.5 with a residual DS < or = 35% identified lesions with a low incidence of recurrence of symptoms at 1 month (10% versus 19%, P=.149) and at 6 months (23% versus 47%, P=.005), a low need for reintervention (16% versus 34%, P=.024), and a low restenosis rate (16% versus 41%, P=.002) compared with patients who did not meet these criteria. CONCLUSIONS: Measurements of distal CFR after PTCA, in combination with DS%, have a predictive value, albeit modest for the short- and long-term outcomes after PTCA, and thus may be used to identify patients who will or will not benefit from additional therapy such as stent implantation.

Aged↗
PubMed1997

A Leishmania protein that modulates interleukin (IL)-12, IL-10 and tumor necrosis factor-alpha production and expression of B7-1 in human monocyte-derived antigen-presenting cells.

LeIF, a gene homologue of the eukaryotic initiation factor 4A was first described as a leishmanial antigen that induced a Th1-type T cell response in peripheral blood mononuclear cells (PBMC) from leishmaniasis patients. Moreover, the interferon (IFN)-gamma production by PBMC was found to be interleukin (IL)-12 dependent. Herein, we characterize the effects of LeIF on cytokine production and expression of surface molecules by normal human monocytes as well as by monocyte-derived macrophages and dendritic cells (MoDC). LeIF was a strong inducer of IL-12 and, to a lesser extent, of IL-10 and tumor necrosis factor (TNF)-alpha in macrophages and MoDC. IL-12 production did not require CD40 triggering, confirming that the ability of LeIF to induce IL-12 was not mediated through an effect on T cells. However, addition of soluble CD40 ligand (L) synergistically augmented IL-12 production in macrophages and MoDC. The cytokine-inducing activity of LeIF is located in the N-terminal portion of the molecule and was both proteinase K sensitive and polymyxin B resistant. LeIF, lipopolysaccharide and fixed Staphylococcus aureus all induced comparable amounts of IL-12, validating the potent cytokine-inducing effects of LeIF. Moreover, of these stimuli, LeIF had the highest IL-12/IL-10 and IL-12/TNF-alpha ratio demonstrating the preference of LeIF for IL-12 induction. Studies investigating the expression of surface molecules showed that LeIF up-regulated B7-1 and CD54 (ICAM-1) on macrophages and MoDC. To our knowledge this is the first report describing IL-12 production, up-regulation of co-stimulatory and intercellular adhesion molecules by monocytic antigen-presenting cells in response to a protein from a pathogenic microorganism. These immunomodulatory characteristics of LeIF might be excellent properties for a Th1-type adjuvant.

Adjuvants, Immunologic↗
PubMed1997

Transesophageal versus intracoronary Doppler measurements for calculation of coronary flow reserve.

OBJECTIVE: The present study was performed to compare coronary flow reserve by transesophageal Doppler echocardiography and intracoronary Doppler flow wire measurements in patients with LAD disease. METHODS: 17 patients with various degree of LAD stenosis were studied. Intracoronary LAD Doppler measurements were performed at baseline and after intracoronary injection of 18 micrograms adenosine. Transesophageal coronary sinus and LAD Doppler measurements were performed at baseline and after intravenous dipyridamole (0.6 mg/kg/5 min). Coronary flow reserve was calculated as the ratio of hyperemic to baseline average peak velocities. RESULTS: Coronary flow reserve was 2.44 +/- 0.62 and 2.19 +/- 0.76 for proximal and distal intracoronary measurements and was 2.25 +/- 0.64 and 1.74 +/- 0.63 for transesophageal LAD- and coronary sinus measurements. Proximal intracoronary flow reserve significantly correlated with transesophageal coronary sinus (r = 0.73, p < or = 0.001) and LAD (r = 0.70, p < or = 0.005) measurements, whereas distal intracoronary flow reserve only correlated with transesophageal coronary sinus flow reserve (r = 0.56, p < or = 0.02). Receiver operating characteristic curve analysis demonstrated similar diagnostic accuracy of all applied techniques for detection of a significant LAD stenosis. CONCLUSIONS: Coronary flow reserve by both transesophageal techniques correlated with intracoronary Doppler flow wire measurements, however considerable discrepancies may occur in the individual patient.

Adenosine↗
PubMed1997

Use of a collagen plug versus manual compression for sealing arterial puncture site after cardiac catheterization.

The aim of the study was to investigate (1) the safety and efficacy of the application of a collagen plug (Vasoseal) at arterial puncture sites, (2) the hemostasis time, and (3) the comfort for the patient of a collagen plug (Vasoseal) when compared with manual compression. Sixty-two patients were randomized either for application of a collagen plug (Vasoseal, group A, n = 33) or manual compression (group B, n = 29) after cardiac catheterization. All patients were evaluated for subjective pain score ranging from 1 to 5 (1 = no pain up to 5 = very strong pain). In addition the authors measured the time until hemostasis could be achieved. The patients were evaluated by duplex sonography for complications at days 1 and 7 after the procedure. The pain score demonstrated a significantly lower score in group A when compared with group B (P = 0.01). The mean time for hemostasis was significantly lower in group A (mean 9.6 minutes) when compared with group B (mean 23.6 minutes) (P = 0.0001). Regarding the complication rate there was no significant difference between the groups (group A vs group B, P = 0.82). The authors conclude that the application of a collagen plug at the arterial puncture site is a safe and time-saving method. In addition it is less painful and therefore better tolerated than manual compression.

Aged↗
PubMed1996

Synthesis of the CC-chemokines MIP-1alpha, MIP-1beta, and RANTES is associated with a type 1 immune response.

Lymphocytes regulate the immune response by secreting cytokines that control the activity and function of effector cells. Chemokine subsets are ideal candidates for recruitment of specific effector cells to inflammatory sites or to other lesions because of their selective chemoattractant activities. Given the Th1-Th2 model of immune regulation and the particular role of leukocyte recruitment for the outcome of the response, we analyzed whether a subset of human chemokines is associated with a specific type of immune response. Therefore, we have analyzed the human T cell response to Ags prepared from Yersinia enterocolitica and Ascaris suum with respect to cytokine mRNA-synthesis and secretion. For the Gram-negative bacterium Y. enterocolitica, induction of a type 1 response is indicated by IL-2 and IFN-gamma production, and for the nematode A. suum, a type 2 response is based on IL-4 and IL-5 production. Interestingly, expression of three CC-chemokines (i.e., MIP-1alpha, MIP-1beta, and RANTES) correlated with the type 1 response induced by Y. enterocolitica Ag. Chemokine secretion is not restricted to T lymphocytes; therefore, synthesis of MIP-1alpha, MIP-1beta, and RANTES was also characterized in human T cell clones that display a cytokine pattern indicative of the Th2, Th0, or Th1 phenotype. Again CC-chemokine secretion correlated with the Th1-like phenotype. In six analyzed IL-2- and IFN-gamma- secreting Th1 clones and in two Th0 clones, MIP-1alpha, MIP-1beta, and RANTES were detected, while none or only minimal secretion of these CC-chemokines was observed in three IL-4- and IL-5-producing Th2 cell clones.

Animals↗
PubMed1996

Assessment of left ventricular function: comparison between radionuclide angiography and semiquantitative two-dimensional echocardiographic analysis.

Measurement of global left ventricular function is important in the follow-up of cardiac patients and is a good prognostic indicator in acute cardiac situations. We compared quantitative measurements of global left ventricular function made with radionuclide angiography (RNA) and contrast cardiac ventriculography (CVG) to visual semiquantitative estimates from two-dimensional echocardiographic images (2D-echo). Three hundred and thirty-nine consecutive patients who underwent RNA were assessed with 2D-echo within 3 months. In addition, 92 of these patients also underwent CVG (correlation of ejection fraction between CVG and RNA: r=0.82; P<0.0001). The RNA mean ejection fractions in the four 2D-echo groups (0=normal, 1=slightly, 2=moderate, or 3=severe reduced left ventricular function) differed markedly (P<0.0001); however, there was overlapping among the groups (2D-echo score/RNA ejection fraction: 0=57.3%+/-12.8%; 1=46.0%+/-12.9%; 2=29.6%+/- 12.2%; and 3=24.6%+/-11. 5%) and the difference between 2D-echo scores 2 and 3 was not significant. 2D-echo showed a good concordance in RNA classes (0=>/=505; 1=35%-49%; 2=21%-34%; and 3=</=20% ejection fraction) 0 (133/166; 80%) and 3 (18/30; 60%) but low concordance in classes 1 (27/82; 33%) and 2 (21/61; 34%). For accurate assessment of global left ventricular ejection fraction, visual semiquantitative judgement of a 2D echocardiographic image is limited in comparison to CVG or RNA, especially in patients with a slight or moderate reduction in left ventricular ejection fraction.

Cardiac Catheterization↗
PubMed1996

Relationship between intrahepatic vessels and computer-generated hepatic scissurae: an in vitro assay.

Liver segmentation is a matter of increasing importance for radiologists, in particular with respect to accurate preoperative localisation of focal hepatic lesions. Procedures for delineating the segmental anatomy from CT or MR images are therefore much in demand. In this context, a convenient technique for generating the intersegmental scissurae by computer has recently been proposed [9]. The procedure, however, seemed questionable from an anatomical point of view. We therefore checked its relevance using anatomical vascular casts of post mortem livers and comparing the computer-generated scissurae with the actual course of the intrahepatic vessels. The results presented in this paper confirm that a rigid application of flat scissural planes is not able to render the real intrahepatic compartmentation. Only techniques considering the effective individual vascular anatomy can provide a correct determination of the hepatic segments.

Aged↗
PubMed1996

Cyclic flow variations after angioplasty: a rare phenomenon predictive of immediate complications. DEBATE Investigator's Group.

Experimental studies and studies in human beings have indicated that cyclic flow variation (CFV) is a reliable marker of the formation of platelet aggregates and thus may be predictive of immediate complications after coronary angioplasty. In this study, the incidence and clinical relevance of CFV in a large patient population after elective percutaneous transluminal coronary angioplasty (PTCA) was assessed. One hundred two patients with one-vessel disease and no previous Q-wave myocardial infarction underwent angiographically successful PTCA of a single lesion of a major coronary artery. A Doppler guide wire inserted distal to the stenosis was used to monitor flow velocity continuously after PTCA for 15 minutes. In 94 (92%) of 102 patients, a stable and reliable Doppler signal could be recorded for 15 minutes after the procedure. CFV, defined as gradual decline in flow over several minutes followed by a sudden restoration to higher values, was observed in 4 patients. In 3 of these 4 patients, the occurrence of CFV was predictive of immediate complications (2 intracoronary thrombosis and 1 acute closure), whereas none of the patients without CFV (n = 90) showed acute closure during hospital stay. In conclusion, CFVs in patients after angiographically successful elective PTCA are rare (4.3%) but highly sensitive for the prediction of abrupt occlusion.

Aged↗
PubMed1996

Assessing coronary stenosis. Quantitative coronary angiography versus visual estimation from cine-film or pharmacological stress perfusion images.

UNLABELLED: Visual judgment of stenosis severity from cine-film or single-photon emission computed tomographic dipyridamole perfusion images was compared to assessment of stenosis severity as measured with digital quantitative coronary angiography. Thirty patients with angiographically verified single-vessel disease underwent dipyridamole thallium stress testing within 90 days of angiography. RESULTS: A percent diameter stenosis of > or = 50%, a percent area stenosis of > or = 75%, and a stenotic flow reserve of < 3.75 measured by quantitative coronary angiography (CMS, version 1.1, Medis Inc.) corresponded to haemodynamically significant stenosis as evaluated by visual estimates from cine-film or perfusion images. Quantitative coronary angiography percent diameter stenosis (51.2% +/- 12.6%) correlated closely (r = 0.74) but underestimated significantly visual assessment of stenosis severity from cine-film (69.3% +/- 21.2%; P = 0.0001). However, quantitative coronary angiography percent area stenosis (74.7% +/- 11.7%) more closely reflected visual estimates from cine-film (P = 0.19). Quantitative coronary angiography stenotic flow reserve showed the highest positive and negative predictive value regarding visual estimates from cine-film (88%, 86%) or perfusion images (88%, 64%) followed by percent diameter stenosis (86%, 75% 86%, 56%) and percent area stenosis (87%, 80%, 87%, 60%), respectively. CONCLUSION: Evaluation of coronary lesions by quantitative coronary angiography corresponds closely with visual estimates from cine-film and haemodynamic significance as evaluated by dipyridamole perfusion images.

Adult↗
PubMed1996

[Quality assurance in invasive and interventional cardiology in Austria in 1994. Commissioned by the Interventional Cardiology Working Group of the Austrian Cardiology Society].

A complete National Database is the prerequisite for quality control, quality management and improvement. In Austria, we have been reaching for this goal since more than three years. 21 094 diagnostic coronary angiographies (CA) and 4934 PTCAs were performed in all 27 centers (out of which 17 perform PTCA) in Austria during the year 1994. This is a reduction of 3.2% concerning CA and an 8.6% increase in PTCA compared to 1993. 48% of all PTCAs were done during the diagnostic study (CA), multivessel PTCA in 11%, direct PTCA for ongoing infarction in 2.3%. Concerning "new devices", 437 stents (182 during the year 1993) were implanted in 1994; also all 73 cases with rotablator, 105 with intracoronary ultrasound, and 26 directional coronary atherectomies (DCA) are documented. Hospital mortality after PTCA was 0.5% (unchanged from the years 1992 and 1993), emergency bypass surgery rate after PTCA was 1.2% (0.7% during the year 1993), and 1.4% of the patients suffered a myocardial infarction in the cathlab (1.2% during 1993). International comparison shows Austria among the top nations with 2637 CA and 617 PTCA per million inhabitants, corresponding to a ratio of 23% PTCA per 100 CA. Risk adjustment (exercise stress test pre PTCA documented in six cath-labs in 1993, compared to 11 in 1994. Type of stenosis (A, B, C) in five labs in 1993 and in 12 labs in 1994) and outcome control (exercise stress test 3 months after PTCA documented in five cath-labs in 1993, compared to 10 in 1994) are subject to constant improvement of our yearly monitor visits and feedback reaction. Austria is the only nation worldwide to support a complete national database with controlled numbers and parameters since more than 3 years, including yearly monitor visits (Internet address for the 1995 data: http@info.uibk.ac.at/gin/org/i_iik.stu/i_iik+ ++.htm) and feedback reports. We experienced no single negative reaction to our activities, but find them necessary for further quality management targets.

Angioplasty, Balloon, Coronary↗
PubMed1996

[Quality assurance in invasive and interventional cardiology in Austria for the 1995 calendar year].

A complete national database is the prerequisite for quality control, quality management and improvement. In Austria, we are reaching for this goal since more than 3 years. 23969 diagnostic coronary angiographies (CA) and 5898 PTCA were performed in all 25 adult-centers (out of which 18 perform PTCA) in Austria during the year 1995. This is an increase of 13.6% concerning CA and a 19.5% increase in PTCA compared to 1994. 50% of all PTCA were done during the diagnostic study (CA), direct PTCA for ongoing infarction in 2.8%. Concerning "new devices", 1572 stents (27% of the PTCA cases) were implanted in 1995. Hospital mortality after PTCA was 0.5% (unchanged to the years 1992 and 1993), emergency bypass surgery rate after PTCA was 0.8% (0.7% during the year 1993), and 1.3% of the patients suffered a myocardial infarction due to PTCA in the cath-lab (1.4% during 1994). International comparison shows Austria under the top nations with 2996 CA and 737 PTCA per million inhabitants, corresponding to a ratio of 41% PTCA and CABG per 100 CA. Out of 18 centers with PTCA-activity ischemia was proven to be present before PTCA in 2729 patients within 11 centers, primary-success-rate was documented in 14 centers concerning 3703 patients and a controlling exercise stress test within 3 months after PTCA was reported by 8 centers for 1555 patients. Local logbooks with continuous readings of complications, guidelines and monitor visits (audits) within all cath-labs in Austria turned out to be a better tool for quality control than computer-databases. But additional electronic databases will be necessary in the future. Austria is the only nation worldwide to support a complete national database with controlled numbers and parameters since more than three years, including complete yearly monitor visits and feedback reports. We experienced no single negative reaction to our activities, but find them necessary for further quality management targets.

Angioplasty, Balloon, Coronary↗
PubMed1995

TH2-type infiltrating T cells in nickel-induced contact dermatitis.

The T cell response to nickel-modified endogenous peptides is involved in the immunopathogenesis of nickel-induced contact dermatitis. Nickel-reactive T cells described so far display a TH1 lymphokine secretion pattern characterized by high amounts of IFN gamma, but little or no IL-4 and IL-5. In this paper we demonstrate that nickel-reactive T cells can belong to the TH0 and even to the TH2 CD4+ T cell subset. Nickel-reactive T cell clones (TCC) were derived from the lesion of a patient with nickel contact dermatitis. These TCC responded to nickel with the production of high levels of IL-5 and variable amounts of IFN-gamma and IL-4 resembling TH2- or TH0-like cytokine secretion pattern. None of the nickel-reactive TCC showed a clear cut TH1 profile. We show that IL-4 was a growth factor for the TH2 and some of the TH0 TCC. We conclude that nickel is able to induce TH2 cells and that in this patient with a typical nickel-induced contact dermatitis TH2 cells are prevalent and might contribute to the immunopathogenesis of contact dermatitis.

Cell Line, Transformed↗
PubMed1995

Phenol sulfotransferases: candidate genes for Batten disease.

Batten disease (juvenile-onset neuronal ceroid lipofuscinosis; JNCL) is an autosomal recessive neurodegenerative disorder, characterized by the cytosomal accumulation of autofluorescent proteolipopigments in neurons and other cell types. The Batten disease gene (CLN3) has not yet been identified, but has been mapped to a small region of human chromosome area 16p12.1-p11.2. We recently reported the fortuitous discovery that the cytosolic phenol sulfotransferase gene (STP) is located within this same interval of chromosome 16p. Since phenol sulfotransferase is expressed in neurons, can sulfate lipophilic phenolic compounds, and is mapped near CLN3, STP is considered as a candidate gene for Batten disease. YAC and cosmid cloning results have further substantiated the close proximity of STP and a highly related sulfotransferase (STM), encoding the catecholamine-preferring enzyme, to the CLN3 region of chromosome 16p. In this report, we summarize some of the recent progress in the identification of two phenol sulfotransferase genes (STP and STM) as positional candidate genes for Batten disease.

Arylsulfotransferase↗
PubMed1995

Estimation of coronary flow reserve by transesophageal coronary sinus Doppler measurements in patients with syndrome X and patients with significant left coronary artery disease.

OBJECTIVES: This study sought to determine the feasibility of coronary sinus flow velocity analysis by transesophageal Doppler echocardiography for estimation of coronary flow reserve in patients with syndrome X and patients with coronary artery disease. BACKGROUND: Coronary flow reserve provides useful information in patients with coronary artery disease and patients with syndrome X. Current methods of measuring coronary flow reserve are invasive or require extensive laboratory equipment, or both. Transesophageal Doppler recordings of coronary sinus flow velocity before and after vasodilator application may allow noninvasive determination of coronary flow reserve. METHODS: We obtained coronary sinus flow velocity recordings before and after dipyridamole administration (0.6 mg/kg body weight per 5 min) in 9 patients with syndrome X, 14 with significant left coronary artery disease and 22 age-matched control patients. We used the formula anterograde minus retrograde flow velocity time integral times heart rate as an index of coronary sinus flow. Coronary flow reserve was calculated by dividing coronary sinus flow variables after dipyridamole administration by the respective baseline values. RESULTS: Technically adequate recordings were obtained in 44 (98%) of 45 patients. Compared with that in the control group (2.78 +/- 0.95 [mean +/- SD]), coronary flow reserve was significantly lower in patients with syndrome X (1.21 +/- 0.23, p < or = 0.001) as well as in those with coronary artery disease (1.47 +/- 0.7, p < or = 0.001). Using a cutoff coronary flow reserve value of 1.8, sensitivity, specificity and overall predictive value of coronary flow reserve determinations were, respectively, 100%, 91% and 94% for syndrome X and 86%, 91% and 89% for coronary artery disease. CONCLUSIONS: Coronary flow reserve calculation by transesophageal coronary sinus flow velocity recordings is feasible in a large proportion of patients and might be useful for the noninvasive evaluation of patients with syndrome X and patients with severe left coronary artery disease.

Blood Flow Velocity↗