Biomedical subjects

S Pfleger

Publications and source records attributed to S Pfleger.

17 recordsLinked to original sources

PubMed2005

Diagnostic value of stress echocardiography for the detection of restenosis after PTCA.

Stress echocardiography (SE) has become a widely accepted clinical tool for the non-invasive diagnosis of coronary artery disease (CAD). Previous studies have confirmed that SE has superior diagnostic value compared to exercise ECG testing. SE has also emerged as a cost-effective alternative to nuclear imaging techniques in patients where symptoms and/or conventional ECG stress testing have provided ambiguous results. Several studies have investigated the value of SE to detect significant restenosis after PTCA. However, in these studies, different methods have been used to induce cardiovascular stress such as physical exercise by bicycle or treadmill, pharmacologic stress testing (with dipyridamole or dobutamine) or transoesphageal atrial pacing. This review evaluates the published database of SE to detect restenosis in patients after successful PTCA. It includes 13 studies with a total of 989 patients performed at 3-6 months after the primary intervention. The diagnostic value, utility and limitations of SE is presented and discussed. The data show that SE has a high diagnostic value for detecting significant restenosis after PTCA. Mean sensitivity of SE was 74% (CI 69-79%), mean specificity was 87% (CI 84-89%). The positive predictive value (PPV) of SE was 83%, the overall negative predictive value (NPV) 97%. We conclude that, in the follow-up of patients after PTCA, SE has distinct advantages over other non-invasive methods and is a recommended method for the detection of those to be considered for repeat angiography.

Angioplasty, Balloon, Coronary↗

PubMed2005

Automated impedance cardiography for detecting ischemic left ventricular dysfunction during exercise testing.

UNLABELLED: Automated impedance cardiography (ICG) is an attractive method for noninvasive hemodynamic evaluation. The objective of our study was to evaluate the feasibility and diagnostic value automated ICG in patients with suspected coronary artery disease (CAD). We measured stroke index (SI) and cardiac index (CI) in 65 patients with suspected CAD at rest and during bicycle exercise testing. All patients underwent subsequent cardiac catheterization including coronary angiography (CA). Depending on the results of CA, patients were divided into three groups, patients without significant CAD (group 0), single vessel disease (group 1) or multivessel disease (group 2-3). In a subset of 20 patients, automated ICG was compared to measurements of CI by the thermodilution (TD) method. RESULTS: There were no significant differences in SI and CI at baseline between the three groups. At 75- and 100-watt exercise, patients in group 2-3 showed significantly lower mean values of SI and CI as compared to patients of group 0 and group 1 (all p < 0.05), indicating exercise-induced ischaemic left ventricular (LV) dysfunction. Three patients had to be excluded because of inappropriate quality of the ICG signals during exercise. Comparison of automated ICG with TD measurements of CI showed good correlations between both methods at rest (r = 0.73) and during exercise (r = 0.89-0.91). CONCLUSIONS: We conclude that hemodynamic monitoring by automated ICG is both feasible and practical during exercise testing. Automated ICG can provide reliable and valuable additional diagnostic information on LV function during exercise which is helpful for selecting those patients for angiography who are likely to benefit from coronary interventions.

Adult↗

PubMed2004

[Atypical encephalitis in a 20-year-old soldier].

We report a patient with encephalitis who had been diagnosed with an unspecific aetiology. During follow-up, pneumonia was identified due to Mycoplasma pneumoniae infection that could also be confirmed as causal for the brain inflammation. Despite the initially critical clinical situation, the patient's condition improved under specific antibiotic treatment. Pathophysiologic, differential diagnostic, and therapeutic implications are discussed, and guidelines for diagnosis are proposed.

Adult↗

PubMed2004

Microbicidal efficacy of an advanced oxidation process using ozone/hydrogen peroxide in water treatment.

The combined application of ozone and hydrogen peroxide represents a kind of advanced oxidation for water treatment. The radicals that are generated during the process are used for the degradation of organic pollutants from groundwater and industrial effluents. The aim of our study was to evaluate the possible microbicidal, and particularly virucidal, efficacy of such a process, since no substantial data were available. The investigations were performed at a pilot plant installed for the elimination of perchloroethylene from polluted groundwater (reduction efficacy for perchloroethylene from 26 microg/L to 5 microg/L). To enable a reliable evaluation of the microbicidal effect, a set of alternate test organisms was used. As model viruses we chose bacteriophages MS2 (F+ specific, single-stranded RNA), phiX174 (single-stranded DNA) and PRD-1 (coated, double-stranded DNA). Furthermore, spores of Bacillus subtilis were included as possible surrogates for protozoa and Escherichia coli as representative for traditional indicator bacteria used in water analysis. The microbicidal efficiency was compared to the inactivation by means of ozone under two standard conditions (20 degrees C): (a) 0.4 mg/L residual after 4 min and (b) 0.1 mg/L residual after 10 min. Surprisingly, a good microbicidal effect of the ozone/hydrogen peroxide process was found. This was somewhat unexpected, because we had assumed that the disinfection potential of ozone would have been interfered with by the presence of hydrogen peroxide. Escherichia coli and the three test viruses revealed a reduction of about 6-log. In contrast, spores of Bacillus subtilis showed after the total process a reduction of 0.4-log. These results matched the effect of the ozone treatment (a) with a residual of 0.4 mg/L after 4 min contact time (20 degrees C). The test condition (b) with a residual of 0.1 mg/L ozone after a contact time of 10 min at 20 degrees C gave a higher reduction of the B. subtilis spores (1.5-log). The presented study revealed a satisfying microbicidal efficacy of the ozone/hydrogen peroxide process with respect to vegetative bacteria and viruses (bacteriophages). However, it has to be emphasised that intense mixing and sufficient contact time have to be optimised and tested for each individual installation.

Bacillus subtilis↗

PubMed2002

[Differential thoracic pain diagnosis. An internal medicine challenge].

In the event of chest pain developing, the task of initial evaluation must be either to confirm and treat an acute life-threatening condition, or to exclude it. The diagnosis of a harmless functional disorder can be established only after the exclusion of a number of cardiovascular, pulmonary or gastrointestinal conditions, as also infection or malignancy. Such an approach often requires cooperation with orthopedic surgeons, general surgeons, psychiatrists and also pain specialists.

Cardiovascular Diseases↗

PubMed2002

[Rapid assessment of thoracic pain. Is it a myocardial infarct?].

The high mortality rate of acute myocardial infarction underline the importance of this entity in the differential diagnosis of acute chest pain. Medical history, clinical presentation, ECG, biochemical markers of myocardial injury and imaging techniques are used to establish a correct diagnosis. Myocardial infarction can be divided into ST-segment elevation myocardial infarction and non-ST-segment elevation myocardial infarction. In the case of ST-segment elevation myocardial infarction thrombolytic therapy or percutaneous transluminal coronary angioplasty should be instituted as soon as possible. In patients without persistent ST-segment elevation biochemical markers of myocardial damage, especially troponin T and troponin I, are of major importance for risk stratification. Patients with elevated troponin levels should be treated with GPIIb/IIIa antagonists and early intervention.

Chest Pain↗

PubMed2002

[Expansion of the Multilink-Tristar stent after direct implantation and predilatation: comparison of clinical, angiography and intravascular ultrasound parameters].

Coronary stenting has become the primary therapeutic option for many coronary lesions. As opposed to conventional stenting the advantages of direct stenting are a reduction of procedural time, radiation exposure and costs. However, data about the incidence of in-stent restenosis are so far not available. It was the aim of this prospective study to compare the expansion of the Multilink stent after direct stenting and predilatation by quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS). Between January 2000 and June 2001, 82 patients were assigned to direct stenting (46 lesions) or predilatation (40 lesions) in lesions of coronary arteries > 3 mm. The procedural success rate was 92% in patients undergoing direct stenting. The baseline clinical characteristics were similar in both groups. The comparison of the angiographic data shows that direct stenting was performed in lesions with a lower degree of stenosis (71 +/- 12% vs 79 +/- 11%, p = 0.01) and that significantly shorter stents were used (14.4 +/- 3.0 vs 17.8 +/- 4.1 mm, p = 0.0007). The mean stenosis length was not significantly different in either group (10.5 +/- 3.4 vs 11.7 +/- 4.3 mm, n.s.). The QCA data after stent implantation show no differences of either implantation technique. Stent expansion was assessed by IVUS estimation of the proximal, distal and minimal in stent area. The minimal in-stent area (9.53 +/- 3.23, mm2 vs 8.65 +/- 1.96 mm2, n.s.) and the stent symmetry index (0.88 vs 0.88 n.s.) were not different in either patient group. These results indicate that in this subset of selected coronary lesions > 3 mm, elective stent implantation with and without predilatation effectively can achieve comparable stent expansion as assessed by QCA and IVUS. In comparison to conventional stent implantation stents, which were implanted without predilatation, were significantly shorter to cover the same lesion length.

Adult↗

PubMed2001

Role of vessel size as a predictor for the occurrence of in-stent restenosis in patients with diabetes mellitus.

Intracoronary stents have been shown to reduce the rate of restenosis when compared with balloon angioplasty, but in-stent restenosis continues to be an important clinical problem. It was therefore the aim of this registry to identify procedural and angiographic predictors for the occurrence of in-stent restenosis. We analyzed 368 patients with 421 lesions who underwent coronary stent implantation between January 1998 and February 2000. Indications for the placement of a coronary stent were severe dissections (37%), suboptimal angiographic results (38%), restenotic lesions (20%), and graft lesions (4%). Angiographic follow-up was obtained in 270 patients (73%) with 293 lesions after 6 months. Clinical and angiographic variables were analyzed by univariate and multivariate models for the ability to predict the occurrence of in-stent restenosis, defined as a diameter stenosis >50%. In-stent restenosis was angiographically documented in 67 patients and 68 lesions (23%). Under all tested variables the reference luminal diameter before stent implantation (p = 0.006) and diabetes mellitus (p = 0.023) were identified as independent predictors for the occurrence of in-stent restenosis. The comparison of diabetic and nondiabetic patients according to vessel size revealed a 2 times higher rate of in-stent restenosis in small vessels (44% vs 23%, p = 0.002), whereas in vessels >3.0 mm the rate of in-stent restenosis was not significantly different between the 2 groups. In this registry, the clinical variable diabetes and the procedural variable reference vessel size were independent predictors for the occurrence of in-stent restenosis. In these patients, the rate of in-stent restenosis was as high as 45%.

Analysis of Variance↗

PubMed2001

Haemodynamic quantification of different provocation manoeuvres by simultaneous measurement of right and left atrial pressure: implications for the echocardiographic detection of persistent foramen ovale.

AIMS: Persistent foramen ovale (PFO) is found in 9.2--32% of echocardiographic examinations. The gold standard for the detection of a PFO is transoesophageal echocardiography (TEE) and the mostly used provocation test is the Valsalva manoeuvre. The aim of our study was to evaluate the effectiveness of the Valsalva manoeuvre compared to other provocation tests by simultaneous haemodynamic measurements of the right and left atrial pressure. METHODS: Fifty patients underwent Swan-Ganz catheterization. Right atrial pressure and pulmonary capillary wedge pressure, which corresponds to the left atrial pressure, were measured simultaneously. The following manoeuvres were compared: the Valsalva manoeuvre, coughing, deep inspiration and expiration pressures of 20 mmHg, 40 mmHg and 60 mmHg. The main objective of our study was to compare the occurrence of pressure gradients (right atrial pressure> left atrial pressure). For further quantification mean gradients, time duration of pressure overlap, as well as products of mean gradients and overlap time were analysed. RESULTS: During the Valsalva manoeuvre a significant pressure gradient could be observed in 84% of the patients, followed by an expiration pressure of 60 mmHg (82%), inspiration (78%), expiration pressure of 40 mmHg (76%), coughing (75%) and an expiration pressure of 20 mmHg (62%). Comparing the mean gradients and the products of mean gradients and overlap time duration during the different manoeuvres, we could detect the significantly best results with the Valsalva manoeuvre. CONCLUSIONS: The Valsalva manoeuvre might be the most effective test to provoke a right-to-left atrial shunt for the detection of a PFO during echocardiographic examinations.

Adult↗

PubMed1999

Evaluation of systolic performance by automated impedance cardiography.

Impedance cardiography (ICG) is a noninvasive method for evaluating cardiac function. Left ventricular stroke volume (SV) is the basic hemodynamic parameter derived from thoracic bioimpedance curves. Issues of our study were to investigate the diagnostic value of other indices of left ventricular systolic performance, such as ejection fraction (EF), index of contractility (IC), peak flow index (PFI), and acceleration index (ACI), which can also be calculated by ICG. Forty patients (PTS) with suspected coronary artery disease (CAD) were monitored by automated ICG during pharmacologic stress testing with dobutamine. All PTS underwent subsequent cardiac catheterization. In PTS with single vessel disease, the dobutamine-induced changes of SV, EF, IC, PFI, and ACI were comparable to those of PTS without CAD. In PTS with multivessel disease, the impaired systolic performance during dobutamine stimulation could be clearly demonstrated. We conclude that automated ICG is a useful method for monitoring SV and other indices of left ventricular systolic performance for detecting PTS with ischemic left ventricular dysfunction during cardiovascular stress.

Aged↗

PubMed1999

BOLD-MRI in ten patients with coronary artery disease: evidence for imaging of capillary recruitment in myocardium supplied by the stenotic artery.

Changes of myocardial oxygenation can be studied by measurements of the apparent transverse relaxation time T2*, which is correlated with the oxygenation state of hemoglobin. In this study, ten patients with coronary artery disease (CAD) underwent blood oxygenation level dependent (BOLD) T2* measurements using a segmented gradient echo pulse sequence with ten echoes. T2* measurements were performed in a single short-axis slice of the heart at rest and under pharmacological stress with dipyridamole (DIP), which increases myocardial blood flow. For comparison, all patients underwent X-ray angiography and stress-echocardiography within 4 days after the MR exam. In one patient, MR examination was repeated 10 weeks after percutaneous transluminal coronary angioplasty (PTA). In the differential T2* maps, expected ischemic areas of myocardium were identified in six patients. In these regions, T2+ values (30 +/- 8 ms) were significantly reduced when compared to the remaining myocardium (48 +/- 9 ms, P < 0.01). In four patients, the myocardial region of interest could not be assessed owing to severe susceptibility artifacts in the ischemic region. The success of the PTA treatment could be visualized from a more homogeneous DIP induced increase in T2* within the ischemic myocardium (from 26 +/- 1 to 29 +/- 1 ms before PTA versus 26 +/- 1 to 31 +/- 4 ms after PTA, P < 0.001).

Adult↗

PubMed1998

[Neurologic symptoms in acute thoracic aortic dissection--a case report].

Acute thoracic aortic dissection is a life-threatening illness. It is often difficult to diagnose preclinically due to its many possible symptoms. One out of three patients has neurological deficits. The prognosis depends on rapid diagnosis and immediate adequate therapy. Therefore, every emergency physician should know the signs and risk factors of this disease. The most important goals of prehospital therapy are management of pain and anxiety and pharmacological control of the systolic blood pressure and heart rate. We report on a 46-year-old female patient who developed neurological deficits caused by an acute thoracic aortic dissection.

Acute Disease↗

PubMed1997

Evaluation of signal-averaged cardiokymography for the detection of ischaemic left ventricular dysfunction.

UNLABELLED: Cardiokymography (CKG) is a non-invasive method for the detection of patients with coronary artery disease (CAD). Issues of the present study were to evaluate the feasibility, sensitivity and specificity of a recently developed signal-averaged CKG system for detecting patients with pharmacologically induced ischaemic left ventricular wall motion abnormalities (WMA) during pharmacologic stress echocardiography (SE). Precordial CKG curves were recorded in 100 consecutive patients who underwent dobutamine-SE for suspected CAD. For interpretation, CKG curves were classified into three different types, depending on the degree of systolic outward motion. CKG test results were regarded as positive (indicating myocardial ischaemia) if there was a change of the baseline CKG type at peak pharmacologic stress. The CKG test results were positive in 18 of 27 patients with a pathologic dobutamine-SE (sensitivity 67%), but did not show any change of the prior CKG type in 57 of 69 patients with a normal SE (specificity 83%). Patients with a true positive CKG test had significantly (P<0.05) more echocardiographic segments with WMA than patients with a false negative CKG test. CONCLUSIONS: Signal-averaged CKG can detect patients with ischaemic ventricular dysfunction. Sensitivity of CKG in detecting patients with WMA depends on the extent of left ventricular ischaemia. Further studies are needed to define the diagnostic value of signal-averaged CKG in the non-invasive detection of patients with suspected CAD.

Adult↗

PubMed1997

Detection of patients with restenosis after PTCA by dipyridamole-atropine-stress-echocardiography.

Stress-echocardiography (SE) has been proven to be a valuable method for the diagnosis of coronary artery disease. For patients who cannot exercise, pharmacological stress-echocardiography represents an alternative method for the induction of cardiovascular stress. Few studies exist concerning the value of dipyridamole-SE for the detection of restenosis in patients after primary successful PTCA. It has been demonstrated that the addition of atropine can significantly increase the diagnostic potential of dipyridamole-SE, especially in patients with 1- or 2-vessel disease. The purpose of our study was to investigate the diagnostic value of high-dose dipyridamole-SE plus atropine (DASE) for the detection of restenosis after primary successful PTCA. We investigated 65 patients 3-6 months after PTCA before a control angiography was performed. Restenosis was defined as > 70% lumen narrowing, determined by quantitative coronary angiography. In 20/27 patients with restenosis, the DASE was pathological (sensitivity 74%); in 34/38 patients without restenosis the DASE was normal or showed no induced WMA (specificity 89%). Patients with tight restenosis (> 90%) were always correctly detected by DASE. Concerning the different vessels, restenosis of the LAD was correctly predicted by DASE in 11/12 patients, restenosis of the LCX in 6/9 patients and restenosis of the RCA in 8/11 patients. From the results of our study we conclude that DASE is a reliable diagnostic method for the non-invasive evaluation of patients after PTCA. DASE can identify patients with relevant restenosis after PTCA and help to select those patients who will probably benefit from further coronary interventions, for repeat angiography.

Angioplasty, Balloon, Coronary↗

PubMed1997

Continuous measurement of hemodynamic alterations during pharmacologic cardiovascular stress using automated impedance cardiography.

The contribution of computerized impedance cardiography in monitoring and differentiating cardiovascular responses to pharmacologic stress after the administration of dipyridamole (group 1, n = 24) or dobutamine (group 2, n = 26) was investigated during stress echocardiography. Heart rate, stroke volume index, cardiac index and systemic vascular resistance index were evaluated continuously with an automated, computerized, signal-averaged impedance cardiography system. Dipyridamole had little average effect on heart rate, stroke volume index, and cardiac index. The responses were similar in patients with positive (n = 9) or negative (n = 15) stress echocardiography test results (as characterized by echocardiographic wall-motion abnormalities). Dobutamine induced a similar mean increase in heart rate in patients with negative (n = 13) or positive (n = 13) results on stress echocardiography. The mean increase in stroke volume index induced by dobutamine was greater in patients with negative stress echocardiography test results than in patients with stress-induced wall-motion abnormalities. This distinction was also seen in the cardiac index; the mean change in patients with negative stress echocardiography test results was larger than in patients with positive results. It is concluded that automated computerized impedance cardiography not only allows surveying and monitoring hemodynamic changes during pharmacologic stress echocardiography but also contributes to differentiation of pathologic stress responses.

Adult↗

PubMed1996

[Value of dipyridamole-atropine stress echocardiography for detection of patients with restenosis after PTCA].

UNLABELLED: Stress-Echocardiography has been proven to be a valuable method in the diagnosis of patients with suspected coronary artery disease. It has been demonstrated that the addition of atropine can increase the sensitivity of pharmacological stress-echocardiography-tests. The aim of our study was to evaluate the diagnostic potential of dipyridamole-atropine-echocardiography for the detection of restenosis after coronary angioplasty. We investigated 50 patients 3-6 months after primary successful coronary angioplasty. Restenosis was defined as recurrence of stenosis of > or = 70% at the site of dilatation determined by quantitative coronary angiography. All patients were investigated on antianginal medication and underwent control-coronary angiography within 1-3 days after the echocardiographic study. In 17/23 patients with restenosis, the dipyridamole-atropine-stress-test was pathologic (sensitivity 74%), in 25/27 patients without significant restenosis the echocardiography stress-test was normal (specificity 93%). In 6 patients with restenosis and an unsuspicious stress-test, the percent diameter of restenosis did not exceed > or = 90% lumen narrowing, restenosis of the LAD was correctly identified in all patients (n = 11). The diagnostic accuracy of the dipyridamole-atropine-stress-test for the detection of patients with restenosis after PTCA in our study was 84%, the positive predictive value of a pathologic echocardiography stress-test for the detection of significant restenosis was 89%, the negative predictive value was 81%. CONCLUSIONS: Dipyridamole-atropine-echocardiography has diagnostic potential for non-invasive assessment of patients after coronary angioplasty. In patients with a normal echocardiographic stress-test, the probability of significant restenosis is considerably low, even if restenosis cannot be definitely excluded.

Aged↗

PubMed1992

Antibacterial activity of sparfloxacin against experimental renal infections in mice.

In a murine model of renal infection (Staphylococcus aureus and Escherichia coli), sparfloxacin was compared with ciprofloxacin and fleroxacin. After intrarenal inoculation, mice were treated orally for 5 days. The drugs were administered at five different dosages, ranging from 3.125 to 50 mg/kg of body weight per day for S. aureus and from 0.78 to 12.5 mg/kg/day for E. coli. Evaluation of efficacy was based on the proportional reduction of bacterial counts in the kidney tissues of treated animals compared with those of untreated control animals. For S. aureus, the doses required to clear the infection in 50% of mice were as follows: sparfloxacin, 10 mg/kg/day; ciprofloxacin, 33 mg/kg/day; and fleroxacin, 16 mg/kg/day. For E. coli renal infection, the corresponding dosages were as follows: sparfloxacin, 1.5 mg/kg/day; ciprofloxacin, 2.45 mg/kg/day; and fleroxacin, 1.8 mg/kg/day. Sparfloxacin and fleroxacin have a lower effective dose than ciprofloxacin in these models, probably because ciprofloxacin has a shorter serum half-life than the other two compounds.

Abscess↗