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Biomedical subjects

R Zotz

Publications and source records attributed to R Zotz.

At least 19 recordsLinked to original sources
PubMed2006

Freehand three-dimensional assessment of left ventricular volumes and ejection fraction with ultrasound contrast agent LK565.

AIMS: Accurate assessment of left ventricular function by determining left ventricular volumes and ejection fraction is important in evaluating the prognoses of patients with heart failure. Two-dimensional (2D) echocardiography suffers from low correlation with reference methods like ventriculography. Three-dimensionally (3D) assessed data have been proved to have better conformity. Endocardial border delineation remains a problem, however, especially in patients with suboptimal recordings. Few data exist on 3D-echocardiographic volumetry with ultrasound contrast agents (UCAs). We evaluated the second-generation UCA LK565 for its boundary-tracing capacities in freehand 3D echocardiography in a phase II clinical trial. Safety and efficacy of the novel contrast agent were also evaluated. METHODS AND RESULTS: Forty patients between the age of 42 and 77 were included in this trial. Left ventricular end-systolic and -diastolic volume (LVESV, LVEDV) and ejection fraction (EF) were determined by either 2D or 3D freehand second harmonic echocardiography with and without use of LK565. Parameters were compared statistically with ventriculography performed in 35 patients. Immune response to LK565 was evaluated by analysing phagocytosis capacity and kinetics of inflammatory cytokines (TNF-alpha, IL-4, IL-10, IFN-gamma). Patients were monitored for adverse events up to 72 h after application of the UCA. Calculated values for left ventricular volumes and ejection fraction correlated best for freehand 3D echocardiography in combination with LK565 (r=0.92 for LVEDV; r=0.96 for LVESV; r=0.94 for EF). Excellent left ventricular contrast enhancement was achieved for approximately 8 min. A reversible saturation of phagocytosis capacity for monocytes and neutrophils set in with a maximum peak at 6h. No significant increase in cytokine expression was observed. CONCLUSION: LK565 improves feasibility of endocardial border delineation in 3D echocardiography, leading to better correlation of left ventricular volumetry with reference methods. Efficacy and safety of LK565 are equivalent to those of conventional UCAs.

Adult↗
PubMed2001

[A testing device for quality assurance of 3D-ultrasound equipment].

A test object for 3D-ultrasound (US) imaging equipment was constructed, that could be used for various purposes: For training of the correct technical setup procedures and practical handling of a 3D-US equipment, as well as for various quality assurance procedures. The size and volume of these structures were known precisely (+/- 0.1 mm resp. +/- 0.06 mL, respectively; smallest volume: 0.1 mL). The stability of the structures was in agreement with guideline IEC 854 and allowed to quantify exactly the imaging and measurement errors of size and volume measurements performed with commercial 3D-equipment. The test object is well suited to validate measured volume data, as well as to perform procedures of technical quality assurance in a reproducible manner.

Guidelines as Topic↗
PubMed2001

Rationale and design of the LURIC study--a resource for functional genomics, pharmacogenomics and long-term prognosis of cardiovascular disease.

BACKGROUND AND AIM: Coronary artery disease (CAD), arterial hypertension and Type 2 diabetes mellitus are common polygenetic disorders which have a major impact on public health. Disease prevalence and progression to cardiovascular complications, such as myocardial infarction (MI), stroke or heart failure, are the product of environment and gene interaction. The LUdwigshafen RIsk and Cardiovascular Health (LURIC) study aims to provide a well-defined resource for the study of environmental and genetic risk factors, and their interactions, and the study of functional relationships between gene variation and biochemical phenotype (functional genomics) or response to medication (pharmacogenomics). Long-term follow-up on clinical events will allow us to study the prognostic importance of common genetic variants (polymorphisms) and plasma biomarkers. SETTING: Cardiology unit in tertiary care medical centre in south-west Germany. STUDY DESIGN: Prospective cohort study of individuals with and without cardiovascular disease at baseline. PATIENTS AND METHODS: LURIC is an ongoing prospective study of currently > 3300 individuals in whom the cardiovascular and metabolic phenotypes CAD, MI, dyslipidaemia, hypertension, metabolic syndrome and diabetes mellitus have been defined or ruled out using standardised methodologies in all study participants. Inclusion criteria for LURIC were: German ancestry (limitation of genetic heterogeneity) clinical stability (except for acute coronary syndromes [ACSs]) availability of a coronary angiogram (this inclusion criterium was waived for family members provided that they met all other inclusion and exclusion criteria) Exclusion criteria were: any acute illness other than ACSs any chronic disease where non-cardiac disease predominated a history of malignancy within the past five years. Exclusion criteria were pre-specified in order to minimise the impact of concomitant non-cardiovascular disease on intermediate biochemical phenotypes or on clinical prognosis (limitation of clinical heterogeneity). A standardised personal and family history questionnaire and an extensive laboratory work-up (including glucose tolerance testing in non-diabetics and objective assessment of smoking exposure by determination of cotinine plasma levels) was obtained from all individuals after informed consent. A total of 115 ml of fasting venous blood was sampled for the determination of a pre-specified wide range of intermediate biochemical phenotypes in serum, plasma or whole blood, for leukocyte DNA extraction and immortalisation of B-lymphocytes. Biochemical phenotypes measured included markers of endothelial dysfunction, inflammation, oxidative status, coagulation, lipid metabolism and flow cytometric surface receptor expression of lympho-, mono- and thrombocytes. In addition, multiple aliquots of blood samples were stored for future analyses. RESULTS: A total of 3500 LURIC baseline measurements were performed in 3316 individuals between July 1997 and January 2000. The baseline examination was repeated within a median of 35 days in 5% of study participants (n = 166, including a third examination in 18 after a median of 69 days) for pharmacogenomic assessment of lipid-lowering therapy and for quality control purposes. A five-year follow-up on major clinical events (death, any cardiovascular event including MI, stroke and revascularisation, malignancy and any hospitalisation) is ongoing. The clinical phenotypes prevalent at baseline in the cohort of 2309 men (70%) with a mean age of 62 +/- 11 years and 1007 women (30%), mean age 65 +/- 10 years, were angiographically-documented CAD in 2567 (79%), MI in 1368 (41%), dyslipidaemia in 2050 (62%) with hypercholesterolaemia > or = 240 mg/dl (27%), hypertriglyceridaemia > or = 150 mg/dl (44%) and HDL-cholesterol < or = 35 mg/dl (38%) in individuals not treated with lipid-lowering agents, systemic hypertension in 1921 (58%), metabolic syndrome in 1591 (48%), Type 2 diabetes in 1063 (32%) and obesity defined by body mass index > or = 30 kg/m2 in 770 (23%). Control patients in whom CAD had been ruled out angiographically were five years younger than those with CAD (59 +/- 12 and 64 +/- 10 years, respectively; p < 0.001), twice as often females (48% compared to 25% females in the CAD group, p < 0.001) and had significantly less cardiovascular risk factors than individuals with CAD. The prevalence of specific cardiovascular risk subsets in LURIC, such as the elderly (> or = 75 years), was 375 (11%), while 213 (6%) were young adults (< 45 years) and 904 (27%) were postmenopausal women (90% of all females). A low risk status (< or = 1 out of the four traditional risk factors: dyslipidaemia, smoking, hypertension and diabetes mellitus) was identified in 314 (9%) individuals of the entire cohort (5% in CAD and 26% in controls, p < 0.001) and 97 (3%) carried none of the four risk factors (1% in CAD and 9% in controls, p < 0.001). (ABSTRACT TRUNCATED)

Cardiovascular Diseases↗
PubMed2000

[Secondary splenic rupture after thrombolysis for acute myocardial infarction]

Secondary splenic rupture after thrombolysis for acute myocardial infarction. HISTORY AND ADMISSION FINDINGS: A 67-year-old male patient was admitted with acute chest pain and signs of an acute anterior myocardial infarction in the ECG. The usual contraindications were excluded and after a systemic lysis with rt-PA the ECG-alterations as well as the symptoms of angina resolved completely. 2 hours later the patient developed an acute abdomen with a severe circulatory shock. INVESTIGATIONS: On ultrasound and CT a massive intraabdominal bleeding was found. TREATMENT AND COURSE: Emergency laparotomy revealed a splenic rupture. Retrospectively, 6 weeks before admission, the patient had fallen from a ladder to his left side. This is a rare case of a secondary splenic rupture during thrombolysis for acute myocardial infarction. 2 weeks later the patient developed rein-farction with angiographically shown two vessel disease. After angioplasty of the ramus interventricularis anterior (RIVA) he was stable. CONCLUSIONS: Intravenous thrombolysis in case of acute myocardial infarction is the method of choice. In the past a great number of patients were excluded from thrombolysis because of an extensive interpretation of contraindications. The aim to reach an alteration in this use may not risk health of patients by insufficient history.

Journal Article↗
PubMed1999

Angiotensinogen M235T polymorphism is associated with plasma angiotensinogen and cardiovascular disease.

BACKGROUND: Genes encoding components of the renin-angiotensin system have been associated with elevated blood pressure (BP) and an increased risk of coronary artery disease. To explore the role of the angiotensinogen (AGT) gene in coronary atherosclerosis and thrombosis, we studied the effect of the AGT M235T gene variant on plasma AGT levels and BP in patients with coronary artery disease and in the subgroup of survivors of myocardial infarction as compared with angiographically defined control subjects. METHODS AND RESULTS: This was a case-control study of 301 white male subjects examined at Frankfurt University medical center. Plasma AGT levels increased stepwise according to the number of T235 alleles present (no T235 allele, 14.8 +/- 3.9 nmol/L; 1 allele, 15.7 +/- 5.1 nmol/L; 2 alleles, 17.3 +/- 4.7 nmol/L; P =.006). In a multivariate model, circulating AGT emerged as the most important predictor of diastolic pressure (P =.001). In addition, AGT M235T gene polymorphism remained a significant predictor of diastolic BP in a multivariate model adjusted for age, body mass index, fasting glucose, apolipoprotein B, presence of coronary artery disease, and treatment with antihypertensive agents ( P <.05). Finally, homozygosity for T235 was associated with increased univariate risk of coronary artery disease and myocardial infarction (odds ratio estimates 1.5; 95% confidence intervals 1.1 to 2.1, P =.03, and 1.0 to 2.1, P =.05, respectively). CONCLUSIONS: The significant relations observed between the AGT M235T variant, its protein product, and the cardiovascular disease phenotypes provide evidence for a possible role of elevated circulating AGT in the pathogenesis of coronary artery disease.

Alleles↗
PubMed1997

[Comparative studies of the rate of restenosis after implantation of Palmaz-Schatz and AVE-Micro stents].

Late results of interventional procedures utilizing coronary stents are largely determined by the rate of restenosis. So far few data are available addressing the effect of stent design, implantation pressure and morphologic factors on this crucial variable. Therefore we analyzed the coronary angiograms obtained in 259 patients before, immediately after and at 3 to 6 months following stent implantation for obstructive coronary disease. A total of 196 AVE-Micro-Stents and 142 Palmaz-Schatz-Stents were implanted into 307 stenoses. In 126 stenoses there were implanted only Palmaz-Schatz-Stents, in 170 only AVE-Micro-Stents and in 11 stenoses there were implanted Palmaz-Schatz- as well as Micro-Stents. Restenosis was defined as an over 50% stenosis at follow up. No significant difference was detected with regard to global restenosis rate at an average of 4 months following implantation (Palmaz-Schatz 33%, Micro-Stent 27%). If results were analyzed according to implantation pressure however, there was a significantly lower restenosis rate for AVE-Micro-Stents implanted with > 10 atm (17%) as compared to < or = 10 atm (35%, p < 0.02) and as compared to Palmaz-Schatz-Stents (34%, p < 0.02), which were also implanted with high pressure over 10 atm. In addition to implantation pressure, vessel segment and morphology of stenosis proved to be important determinants of late results. In this series of patients the AVE-Micro-Stent compared favourably to the Palmaz-Schatz-Stent not only with respect to a significantly lower restenosis rate, when implanted with pressures > 10 atm, but also with regard to its superior flexibility and handling characteristics.

Aged↗
PubMed1996

Liver function in patients with pulmonary emphysema due to severe alpha-1-antitrypsin deficiency (Pi ZZ).

Alpha 1-Antitrypsin deficiency predisposes to pulmonary emphysema, liver cirrhosis and hepatocellular carcinoma. Anecdotal evidence and a large autopsy study suggest that severe lung and liver disease rarely coexist in the same subject, but this has not been studied in patients. Therefore we investigated 27 patients with severe alpha 1-deficiency (Pi ZZ) and pulmonary emphysema for signs of liver disease and impaired hepatic function. A subgroup of 7 patients underwent quantitative liver function tests. On physical examination or ultrasonography, cirrhosis or tumor was not suspected in any patient. Conventional liver function tests were completely normal in 17 patients. Elevated serum activities of gamma-glutamyltranspeptidase and/or aminotransferases were seen in 10 patients. In some, the elevation was only marginal and in none more than twice normal. The serum bilirubin concentration and activity of alkaline phosphatase were increased in 1 patient. Serum protein, albumin, fibrinogen, antithrombin III, alpha 1-fetoprotein concentrations, serum activities of cholinesterase and glutamate dehydrogenase, activated partial thromboplastin time and prothrombin time were normal in all patients. The indocyanine green half-life was abnormal only in 1 of 6 patients, suggesting that hepatic blood flow was not impaired in the study group. However, the lidocaine half-life and galactose elimination capacity, parameters of hepatic metabolization, were impaired in 4 and 6 of 7 patients, respectively. We conclude that liver disease or impaired liver function is not a clinically relevant problem in most patients with pulmonary emphysema due to alpha 1-antitrypsin deficiency. But results of quantitative liver function tests, although performed in only a small group of patients, suggest that hepatic metabolization might be impaired even in those patients who present with pulmonary disease.

Adult↗
PubMed1996

[Primary sclerosing cholangitis: conventional and quantitative liver function tests during long-term therapy with ursodeoxycholic acid].

Primary sclerosing cholangitis, a chronic cholestatic liver disease, frequently leads to an impairment of liver function. In nine men and two women, aged 23 to 57 years, we prospectively studied for three to six years the effect of treatment with ursodeoxycholic acid (UDCA) on liver function. 10 mg UDCA/kg bw significantly reduced serum activities of AP, gamma GT, AST and ALT for several years. After three years of treatment, however, serum concentration of bilirubin was higher than before therapy in eight out of eleven patients (1.8 +/- 0.8 versus 0.9 +/- 0.1 mg/dl; p = 0.01). Likewise, serum concentration of bilirubin was higher in eight out of nine patients after four years of treatment (1.3 +/- 0.3 versus 0.9 +/- 0.1 mg/dl; p = 0.03). In most cases, however, the increase was discrete. Parameters of synthetic liver function (coagulation, serum protein concentration, serum activity of cholinesterase) remained constant in the observation time. Quantitative liver function tests (galactose elimination capacity and indocyanine green half-life) also showed little variation in the observation time. We conclude that UDCA treatment significantly improves serum activities of liver enzymes for several years. Nevertheless, serum bilirubin concentration, believed to be of prognostic value in patients with PSC, seems to rise slowly over time. Serial determinations of galactose elimination capacity and indocyanine green halflife are not superior to conventional liver function tests in the timing of liver transplantation in the individual patient.

Adult↗
PubMed1996

[Comparison of NYHA classification with cardiopulmonary function in patients with chronic heart failure].

In this study a correlation was sought between the NYHA class, the results of cardiopulmonary exercise testing (CPX) and the ejection fraction (EF) measured by echocardiography and scintigraphy. Of 36 patients enrolled, CHF in 20 patients was due to CAD and in 16 patients due to DCM. The NYHA class was determined independently by two cardiologists who were blinded to the CPX, echocardiography or scintigraphy results. Sixteen patients were classified as class II and 20 as class III. As a control, 23 patients without cardiopulmonary disease were examined. The CPX was done according to a ramp protocol with continuous measurement of respiratory gases, maximal oxygen consumption (VO2-max) and oxygen consumption at the anaerobic threshold (VO2-AT). A correlation (p = 0.0425) between the NYHA classification and the Weber classification for VO2-AT was found. There was no correlation for VO2-max. VO2-AT was significantly higher in NYHA II patients as compared to NYHA III patients. No significant difference was seen in relation to the VO2-max. In comparison to the normal group, the VO2-AT and VO2-max were significantly lower in NYHA II and III patients. There was no significant correlation between VO2-AT and EF, VO2-max and EF, or between NYHA class and EF. During a 16-month follow-up period lethality was 8/14 patients with VO2-AT < 10 ml/kg/min. Although the NYHA classification provides a valid method for determining the prognosis of CHF patients, if feasible, the CPX examinations should be used to provide updates of the disease progress.

Adult↗
PubMed1996

[Polymer microparticles for right and left heart echocardiography and imaging myocardial perfusion after peripheral vein injection].

It is conceivable that a stable ultrasound contrast agent could be used for reproducible right and left heart echocardiography and myocardial visualization after intravenous injection. Microparticles from different polymers and preparation procedures were screened in six dogs leading to one superior agent with reproducible high quality echo contrast in doses of 1 mg/kg. This special agent is based on condensates of aspartic acid, ethanolamine and decanoic acid. Out of this material particles were formed with an average diameter of 2 micrometers. The easily suspendable particles were used for the following studies in a dose of 1 mg/kg intravenously in eight pigs. Maximal video intensity averaged 116 +/- 42 relative intensity units (IU) in the right, 137 +/- 42 IU in the left ventricle, 42 +/- 7 in the normally perfused and 11 +/- 2 in the hypoperfused myocardium after circumflex ligature. The area under the intensity curve was 1942 +/- 100 IUxs in the right, 2452 +/- 1291 IUxs in the left ventricle, 518 +/- 124 in the normally perfused and 202 +/- 94 in the hypoperfused myocardium after circumflex ligature. There was no change of heart rate, central arterial or pulmonary artery pressure during and after the injections. There was also no loss of echo intensity during the passage of contrast material through the heart due to systolic pressure. The described agent can be used for the opacification and ultrasonic visualization of the right and left heart as well as normally and hypoperfused myocardium without visible side-effects in animal studies.

Animals↗
PubMed1994

[Transthoracic and transesophageal follow-up in patients with left atrial thrombosis].

The embolic risk and changes of thrombus location and size were investigated in 29 consecutive patients with echocardiographically proven thrombi in the left atrium. Inclusion criteria were the visualization of a left atrial thrombus using transesophageal echocardiography. Transesophageal follow-up echocardiograms were performed at a mean period of 18 months. In this period 6 cases of embolism were observed at an interval of 20 days to 26 months after the detection of thrombus. Thus, the embolic rate was 14% per patient year. All patients received phenprocoumon (n = 4) or aspirin at the time of embolism. Furthermore, in two patients after cardiac thrombectomy left atrial thrombi were seen again although patients were treated with anticoagulants. On the other hand, in 12 patients (5 received oral anticoagulation, 2 received aspirin) thrombi completely resolved. It can be concluded from these data, that the majority of patients receiving anticoagulation profit from this therapy, however, a complete protection against arterial embolism or reoccurrence of thrombi cannot be reached. Left atrial spontaneous echo contrast was the only risk factor significantly associated with thromboembolism in patients with left atrial thrombi.

Aged↗
PubMed1993

Influence of blood sampling from venipunctures and catheter systems on serial determinations of prothrombin activation fragment 1 + 2 and thrombin-antithrombin III complex.

To evaluate the influence of different blood sampling techniques on test results of thrombin-antithrombin III complex (TAT) and prothrombin fragment 1 + 2 (F1 + 2) serial determinations were performed. In six groups of nonrandomized patients (ten patients each) the concentrations of the coagulation markers of blood samples from central catheters (internal jugular, caval, Shaldon, pulmonary artery) and peripheral cannulas (17G and 18G) were compared with those of blood samples obtained simultaneously from direct venipunctures of the contralateral arm. Medians and 25th-75th percentiles of TAT and F1 + 2 concentrations of plasmas obtained from central catheters were not different from those taken from venipunctures. When delta mean values (catheter - venipuncture) were calculated negative results were obtained, indicating lower concentrations measured from blood sampled through central catheters with the exception of blood that taken from Shaldon catheters. Only for TAT concentrations significantly were lower values measured in blood samples taken from internal jugular catheters when compared with blood samples obtained from direct venipunctures. Significantly higher TAT concentrations were determined in blood samples obtained from Shaldon catheters. For both coagulation markers correlations were found between concentrations in blood samples from central catheters and venipunctures. In blood samples taken from peripheral venous cannulas only F1 + 2 concentrations correlated with the concentrations found in samples from direct venipuncture. In contrast to F1 + 2, TAT concentrations measured from blood samples via peripheral cannulas were determined significantly higher than those taken from direct venipunctures.(ABSTRACT TRUNCATED AT 250 WORDS)

Antithrombin III↗
PubMed1993

[Diastolic flow analysis of the left ventricle after myocardial infarct].

The diastolic function of the left ventricle was investigated in 12 normal young volunteers, 10 older volunteers, 10 patients without evidence of coronary artery disease, 26 patients with inferior wall and 19 patients with anterior wall infarction at eight locations of the total circumference of the left ventricle using pulsed wave Doppler. The ratio of early diastolic inflow (Vmax E) to the maximal velocity of atrial contraction (Vmax A) was determined. Furthermore, the delay between the end of electrical diastole until the end of the A-wave of the pulsed Doppler was measured. The results were compared with a clinically used marker of myocardial ischemia, treadmill exercise testing. The E/A ratio was 2.03 +/- 0.51 in normal volunteers, 1.16 +/- 0.41 in older volunteers, 1.41 +/- 0.59 in patients without evidence for coronary artery disease, 1.28 +/- 1.13 in patients with inferior and 1.08 +/- 0.41 in patients with anterior wall infarction (p = 0.020 ANOVA). The diastolic delay at the apex was 47.3 +/- 8.9 ms in normal volunteers, 78.3 +/- 8.3 ms in older volunteers, 79.1 +/- 13.7 ms in patients without coronary artery disease, 109.1 +/- 12 ms in patients with inferior and 169.5 +/- 18.8 ms in patients with anterior wall infarction (p = 0.000 ANOVA). There was a correlation between the latter parameter of delay and the amount of pathological wall segments at wall motion analysis (r = 0.61, p = 0.007). In two patients with anterior myocardial infarction (11%) with significant diastolic delay intraventricular thrombi developed consecutively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[Heart involvement in mixed connective tissue disease (MCTD)].

The incidence of cardial involvement in mixed connective tissue disease (MCTD) was investigated by two-dimensional echocardiography. Pericardial manifestation was found in two patients. Mitral valve prolapse was detected in 61% of the patients, which may indicate a specific cardial involvement in MCTD. Myocardial changes were rare.

Adult↗
PubMed1991

Analysis of high-frequency rotational angioplasty-induced echo contrast.

During high-frequency rotational angioplasty (HFRA), myocardial contrast enhancement (echo contrast) was observed by means of two-dimensional echocardiography. In order to evaluate the echo contrast produced by HFRA, an in vitro experimental model was built using a cylinder with the HFRA catheter scanned in a water bath. The cylinder was filled with blood, mineral water, and distilled water. With a 2.5-MHz transducer, echograms were recorded and analyzed by video intensitometer, and the maximum intensity IUmax and persistence time P were calculated. Rotation frequencies of 20,000-200,000 rpm with 2.0--mm burrs and times of 10 s were tested. In another model, hyperbaric conditions for the same media were produced. The influence of debris from arterioscleroic plaque and of hematocrit on echo contrast intensity were also analyzed. The effect of HFRA on hemolysis (LDH, free hemoglobin) within 10 s and temperature were also measured. The contrast effect was transient, depending on the rotation frequency. In blood, it appeared at 20,000 rpm (IUmax at 200,000 rpm: 237 IU), in mineral water at 40,000 rpm (IUmax 165 IU), and in distilled water at 80,000 rpm (IUmax 72 IU). Persistence time was measured up to about a half-minute. Echo contrast production was reduced at 0.5 bar and fully suppressed at 2.5 bar. Debris increased contrast intensity from about 219 IU to 225 IU (at 160,000 rpm). In blood IUmax decreased from 227 IU to 97 IU by lowering the hematocrit from 44.2% to 3.6%.(ABSTRACT TRUNCATED AT 250 WORDS)

Echocardiography↗
PubMed1990

New mechanical devices for treatment of coronary artery disease.

Percutaneous high-speed coronary rotablation allows to remove arterio-sclerotic material from the vessel wall. A diamond-coated (15-30 microns) brass burr drill fastened to a flexible drive shaft rotating and tracking along a drill coaxial guide wire is used. The turbine rotates the drive shaft at 150,000-190,000 rpm. High-frequency rotational angioplasty was successful in 27 of 28 patients, but in about 34% additional PTCA was necessary. Only one patient went to bypass surgery, and myocardial infarction (CK less than 150 u/l) occurred in only one of 28 patients. No vessel perforation was observed. All vessels were open at 24 h control. The restenosis rate was not increased. The main indication for high-speed rotational angioplasty seems to be rigid sclerotic lesions that cannot be passed by a conventional balloon catheter. Whether restenosis rate can be reduced by this method will be judged in future studies. In order to avoid acute complications of PTCA and to reduce restenosis rate, coronary stents were developed. Self-expandable and balloon-expandable stents are available. It could be demonstrated that these stents can be used as a bail-out system and can block elastic recoil of coronary arteries. The major remaining problem is that of subacute closure of coronary vessels. In order to prevent this, treatment with coumarine, acetylsalicylic acid, and dipyridamol is necessary. Coronary stents can be successfully delivered in more than 90% of the patients, as demonstrated by a cooperative study. In a highly selective patient group using single stents, restenosis rate measured 15%, but was higher in patients with multiple stents.

Angioplasty, Balloon, Coronary↗
PubMed1989

[Possibilities and limits of 2-dimensional echocardiography in quantitative image analysis].

By two-dimensional echocardiography left ventricular volumes can be measured and ejection fraction can be calculated. But volume and ejection fraction determination are combined with a systematic underestimation despite high correlation in comparison to "true volume", whereas cineventriculography systematically overestimates true volume. This echocardiographic methodological problem is related not only to tangential scanning but also to low lateral resolution yielding a reduced endocardial border delineation. Meanwhile, advanced transducer technology and digital imaging techniques with zoom and cineloop possibilities have improved endocardial border detection. In comparison to cineventriculography, volume determination by two-dimensional echocardiography has improved significantly in comparison to results in 1983; this improvement was mainly due to a better determination of endsystolic volume. Similarly, left ventricular contrast echocardiography using color coding with statistical analysis of digitized images enhanced the accuracy of analysis of global and regional left ventricular function. Transesophageal echocardiography will be used when there is reduced image quality of transthoracic echocardiography, for example, in obese patients or those with pulmonary emphysema or mechanical ventilation. Transthoracic echocardiography has become a routine method for assessing global and regional left ventricular function. Echoventriculography can be used in patients with renal insufficiency, anaphylactic reaction to contrast medium, and poor left ventricular function.

Algorithms↗