[Transluminal retrieval of intravasal foreign bodies. Incidence, clinical signs, diagnostics and interventional therapy of catheter embolization]. / Transluminale Bergung intravasaler Fremdkörper. Inzidenz, Klinik, Diagnostik und interventionelle Therapie der Katheterembolie.

Patients with central venous lines or implanted Hickman catheters and port systems, suffer catheter embolization in 0.1-2.8% of the cases due to material fatigue or medical malpractice. In a 58-year-old vascular surgery patient, a central venous line catheter fragment was successfully retrieved from the pulmonary artery using a snare catheter via a transfemoral approach. From this case, we discuss the incidence, clinical aspects, diagnosis and interventional therapy of catheter embolization.

[Differentiation between vital heart muscle tissue and infarct scar using magnetocardiography]. / Differenzierung zwischen vitalem Herzmuskelgewebe und Infarktnarbe mit Hilfe der Magnetokardiographie.

Magnetocardiography provides touchless information about myocardial excitation propagation and repolarization. This evolving diagnostic technique has been used so far to risk-stratify patients in terms of sudden cardiac death and to detect myocardial ischemia. We evaluated its potential to assess myocardial viability in patients with coronary artery disease. Magnetocardiography was performed using a shielded prototype 49-channel LTS SQUID system. A specific algorithm was developed to calculate automatically a set of magnetocardiographic parameters. Regional myocardial viability was determined using 18F-labeled fluoro-2-deoxyglucose positron emission tomography. We found that magnetocardiography may contribute essentially to discriminate between viable myocardium and infarct scar.

[Supporting primary stent implantation by angiographic length measurement]. / Unterstützung der primären Stentimplantation durch angiographische Längenmessung.

In this study a procedure for online measurement of a coronary segment length during primary stenting is presented. The spatial segmental axis is calculated from a biplane angiogram and the corresponding projection data by simple delineation of the proximal and distal segment sites in each image. In a clinical evaluation the length error, projectional foreshortening and time frame during measurement of 222 stents or carrier balloons were calculated. The overall percentage length error was 3.3(+)-2.4%. The device length imaged with a mean projectional foreshortening of 18(+)-20% was measured within 18(+)-4 s. The procedure yields the accurate length of coronary segments within a short computation time taking projectional foreshortening into account.

[3-D localization of cardiac structures in real time]. / 3-D-Lokalisation kardialer Strukturen in Echtzeit.

Radiographic 3-D localisation enables measurements to be made that facilitate the placement of the interventional device during cardiac intervention. To enable the reader to implement the method himself, we describe the computation of 3-D coordinates, acquisition of the imaging and projection data on-line, and the accuracy that can be expected with the method. The 3-D coordinates of a cardiac structure are calculated from the image point coordinates, the projection data and the system constants of a biplane isocentric X-ray unit. Technical imaging errors are corrected a priori. The biplane projection data of a run are acquired on-line and stored in a data base. The image pair of interest is identified automatically from the inscribed run number, and assigned to the projection data from the data base. The target image point is marked on the monitor for 3-D localisation. The accuracy of the method was determined by comparing the calculated and actual cross-sectional points of a centimetre grid imaged in biplane X-ray projections. 3-D localisation took an average of 9.8 +/- 1.2 seconds. Angles and distances were assessed with a standard error of 1.1 degrees and 0.8 mm. The run number is identified correctly in 98.5% of the cases. The mean absolute location error for all points and image pairs was 0.61 +/- 0.32 mm. The accuracy and precision was 0.03 +/- 0.40 mm. Radiographic 3-D localisation can be performed readily and accurately on-line. The results obtained with the method enable interventional decisions to be optimized.

[Development and validation of a graphic method for spatial interpretation and evaluation of biplanar coronary angiograms]. / Entwicklung und Validierung eines graphischen Verfahrens zur räumlichen Interpretation und Bewertung biplaner Koronarangiogramme.

Visual evaluation and measurement of the lesion geometry is impaired by the foreshortening of the radiographically displayed target coronary segment. For this reason, we developed and validated a simple graphic procedure that facilitates the spatial interpretation and allows an objectifiable assessment of the view of the target coronary segment. The method computes a spatial axis of the coronary segment imaged in two planes and determines its inclination in the radiation path of each projection view. A triangle made up of the axis of the imaged segment, the unforeshortened axis of the imaged segment and the foreshortening height is displayed in each projection plane. The shape of the triangle indicates the degree of foreshortening while its position in the angiogram indicates the orientation of the spatial axis relative to the observer. The method was validated by comparing calculated and true foreshortening in the radiographic views of a centimetre grid obtained in the usual angiographic projections. The method has an accuracy and precision of 0.05 +/- 0.62%. It is applied clinically to evaluate biplane segmental visualization during coronary interventions and to select valid segmental views for measurements during quantitative biplane coronary angiography. This application may considerably facilitate the interpretation and assessment of biplane angiograms.

The impact of vessel and catheter position on the measurement accuracy in catheter-based quantitative coronary angiography.

BACKGROUND: The calculation of absolute artery dimensions in quantitative coronary angiography is usually carried out by catheter calibration. It is based on the proportional comparison of the dimension of the imaged artery segment to the dimension of the imaged angiographic catheter of known size. This calibration method presumes an identical radiographic magnification between angiographic catheter and artery segment of interest. However, due to the different intrathoracic location of both objects the radiographic magnification or calibration factor is often not identical for a given angiographic projection. The aim of this study was to quantify the magnification error (out-of-plane magnification error) for the major coronary artery segments imaged in frequently used angiographic projections. METHODS: The intrathoracic spatial location of 468 coronary segments (RCA 196, LAD 156, LCX 116) and their respective coronary catheters were established with biplane angiography and known imaging geometry data. The error in the radiographic magnification or calibration factor was then calculated for all 936 monoplane projections using the spatial coordinates and imaging geometry data. RESULTS: The mean magnitude of magnification error was 4% within all 936 measurements. The magnitude and direction of error varied with the lesion localization and the angiographic projection angle (range -12.6% to +10.6%). The error characteristics could be described with six typical error groups by stratifying the data according to the three main coronaries and two angiographic planes. In 24% of measurements, the magnification error exceeded the 5.2% error limit acceptable for reference vessel sizing. Measurements of left coronary arteries were mainly affected by it. CONCLUSION: The magnification error contributes to the calibration error in measuring arterial dimensions by quantitative angiography. This error may affect the reliability of clinical studies and the proper sizing of interventional devices. These findings could be used to improve current error correction algorithms in order to reduce the effect of the magnification error in measuring arterial dimensions.

[Development and evaluation of a spectroscopy system for classification of laser-induced arterial fluorescence spectra]. / Entwicklung und Erprobung eines Spektroskopiesystems zur Klassifizierung laserinduzierter arterieller Fluoreszenzspektren.

The present study evaluated the potential of fluorescence guidance of laser angioplasty without using a second laser for fluorescence excitation. A prototype spectroscopy system with a grating spectrograph, microchannel plate, CCD array and digital image processor on a personal computer was developed and coupled to a clinical XeCl excimer laser. Using multifibre catheters, specimens of human aorta were ablated in physiological saline and blood. The spectra thus generated were recorded and validated histologically. Five types of spectra could be differentiated. Based on a training set, classification algorithms were developed using multiple linear regression and linear discriminant analysis with intensity ratios as predictor variables. Discriminant analysis yielded prospective classification of the remaining validation spectra with high sensitivity and specificity for each type. These data demonstrate that fluorescence spectroscopy during excimer laser ablation at 308 nm does not require a diagnostic laser. Principal types of atherosclerotic lesions and the media can be differentiated spectroscopically in physiological saline and blood.

Giant cell myocarditis due to coxsackie B2 virus infection.

Giant cell myocarditis is a rare disorder characterized by the histologic hallmark of diffuse inflammatory infiltrates with the appearance of multinucleated giant cells. We report on a 52-year-old man who died of rapidly progressive cardiogenic shock due to giant cell myocarditis. Serological and immunoblotting techniques revealed a myocardial infection with coxsackie B2 virus, suggesting a viral etiology of this disease. Here we present evidence for the involvement of autoimmune responses to the myocardium as numerous cardiomyocytes exhibited deposits of cell-adherent immunoglobulins. Although other causative factors may initiate giant cell myocarditis as well, our case suggests coxsackie B2 virus as one etiologic agent capable of triggering autoimmune reactions to altered heart tissue.

Single-laser approach for fluorescence guidance of excimer laser angioplasty at 308 nm: evaluation in vitro and during coronary angioplasty.

BACKGROUND AND OBJECTIVE: Spectroscopic guidance of laser angioplasty has been attempted using a diagnostic He-Cd laser in addition to the therapeutic laser system. This study evaluated a single-laser approach for simultaneous ablation and fluorescence excitation. STUDY DESIGN/MATERIALS AND METHODS: A spectroscopy system was coupled to a clinical XeCl excimer laser. Ablation of 162 human aortic samples in saline and blood with 45 mJ/mm2 per pulse yielded 676 fluorescence spectra validated histologically. The same equipment was used in 16 patients for angioplasty of 18 coronary stenoses applying 500 to 1,725 pulses with 45 to 60 mJ/mm2 under saline flushing. A total of 783 spectra were recorded and validated by intracoronary ultrasound (categories: atheroma, fibrous plaque, calcified lesion). RESULTS: In vitro, 5 types of spectra could be differentiated: (1) atheroma, (2) fibrous plaque, (3) calcified lesion in saline, (4) media, and (5) calcified lesion in blood. Discriminant analysis prospectively classified 576 validation spectra with the following sensitivity and specificity for each type: (1) 83.5 and 97.1%, (2) 85.7 and 96.8% (3) 100 and 98.5%, (4) 98.1 and 99.3%, (5) 98.9 and 100%, respectively. In vivo type 1, 2, 3, and 5 spectra were also observed, but not the media spectrum. The predominant sonographic category also prevailed in spectroscopy. Calcified lesions yielded type 3 and 5 as well as mixed spectra. CONCLUSIONS: Using an excimer laser for angioplasty allows combining ablation and fluorescence excitation without a diagnostic laser. Principal types of atherosclerotic lesions and the media can be differentiated spectroscopically with this approach.

Morphology of chronic coronary occlusions and response to interventional therapy--a study by intracoronary ultrasound.

OBJECTIVES: Balloon angioplasty of chronic coronary occlusions has a low procedural success and a high recurrence rate. Better tomographic insights into the lesion morphology may improve the interventional strategy and results. METHODS: Intracoronary ultrasound was used during the recanalizaton procedure of 45 chronic coronary occlusions (2 weeks to 14 months; average 3.4 months) to determine the lesion morphology and to assess the angioplasty result. The luminal area and the plaque burden were measured proximal and distal to the occlusion, and within the occlusion. The ultrasonographic characteristics of the occlusive lesions were compared to 45 nonocclusive lesions of age-matched patients with stable angina pectoris. RESULTS: Occlusive lesions were more often echodense as compared to nonocclusive lesions (35% vs. 20%; p = 0.10). In chronic occlusions a multi-layered plaque morphology was observed in 22%, and this morphology was not found in nonocclusive lesions. Angiographic characteristics were not related to the ultrasonographic morphology of the lesion. Despite similar vessel areas in occlusive and nonocclusive lesions, the balloon size selected according to the angiographic image was underestimated in occlusive lesions. Based on the quantitative ultrasound measurement the balloon size was increased from 2.6 +/- 0.3 mm to 3.3 +/- 0.5 mm in 53% of the lesions. This resulted in an increase of the luminal area from 3.51 +/- 0.92 to 5.08 +/- 1.43 mm2 (p < 0.001). The acute recoil after balloon angioplasty was similar (34 +/- 18%) in hypodense and echodense plaques, but was significantly higher in lesions with a multi-layered plaque morphology (49 +/- 22%; p < 0.05). In 19 patients with severe dissections or extreme acute recoil (residual stenosis > 50%) the use of a stent increased the luminal area from 3.94 +/- 0.81 to 7.51 +/- 1.71 mm2 (p < 0.001). CONCLUSIONS: Intracoronary ultrasound demonstrated a multi-layered plaque morphology in one fourth of the chronic occlusions. This type of plaque was associated with a significant acute recoil. The presence of diffuse atherosclerosis in neighbouring segments of chronic coronary occlusions leads to underestimation of the balloon size. Quantitative assessment by intracoronary ultrasound helped to optimize the balloon size leading to a significant luminal area gain. The detection of excessive acute recoil should be considered an indication for stent deployment.

Assessment of myocardial viability in persistent defects on thallium-201 SPECT after reinjection using gradient-echo MRI.

This prospective study assessed myocardial viability in 30 patients with coronary heart disease and persistent defects despite reinjection on TI-201 single-photon computed tomography (SPECT). In each patient, three observers graded TI-201 uptake in 7 left ventricular wall segments. Gradient-echo magnetic resonance imaging in the region of the persistent defect generated 12 to 16 short axis views representing a cardiac cycle. A total of 120 segments were analyzed. Mean end-diastolic wall thickness and systolic wall thickening (+/-SD) was 11.5 +/- 2.7 mm and 5.8 +/- 3.9 mm in 48 segments with normal TI-201 uptake, 10.1 +/- 3.4 mm and 3.7 +/- 3.1 mm in 31 with reversible lesions, 11.3 +/- 2.8 mm and 3.3 +/- 1.9 mm in 10 with mild persistent defects, 9.2 +/- 2.9 mm and 3.2 +/- 2.2 mm in 15 with moderate persistent defects, 5.8 +/- 1.7 mm and 1.3 +/- 1.4 mm in 16 with severe persistent defects, respectively. Significant differences in mean end-diastolic wall thickness (p < 0.0005) and systolic wall thickening (p < 0.005) were found only between segments with severe persistent defects and all other groups, but not among the other groups. On follow-up in 11 patients after revascularization, 6 segments with mild-to-moderate persistent defects showed improvement in mean systolic wall thickening that was not seen in 6 other segments with severe persistent defects. These data indicate that most myocardial segments with mild and moderate persistent TI-201 defects after reinjection still contain viable tissue. Segments with severe persistent defects, however, represent predominantly nonviable myocardium without contractile function.

[Simultaneous double nucleotide scintigraphy with indium 111 antimyosin Fab and technetium sestamibi for evaluation of myocardial viability after experimental and clinical infarct]. / Simultane Doppelnuklid-Szintigraphie mit Indium-111-Antimyosin-Fab und Technetium-99m-Sestamibi zur Beurteilung der Myokardvitalität nach experimentellem und klinischem Infarkt.

This study combined In-111 antimyosin Fab (AM) with Tc-99m sestamibi (MIBI) to assess myocardial viability in the subacute stage of infarction. In 9 pigs, the LAD was occluded for 45 min. Seventy-four MBq of AM were injected after 48 h of reperfusion and 740 MBq of MIBI 24 h later. In myocardial specimens, activity relative to normal myocardium (n = 35) in the region of necrosis (n = 35) was found to be 3.96 +/- 2.48 for AM and 0.30 +/- 0.20 for MIBI, in the intermediate zone of macrohistochemically reversibly damaged myocardium (n = 35) 2.79 +/- 1.29 and 0.83 +/- 0.28, respectively. Discriminant analysis classified all 105 specimens with a sensitivity of 83% and specificity of 96%. On the scans, the intermediate zone presented as overlap between both tracers. Twelve patients aged 40 to 76 years with invasively documented acute myocardial infarction (4 x anterior, 8 x inferior) were injected also with 74 MBq of AM 27 to 110 h after the onset of chest pain and with 740 MBq of MIBI 21 to 26 h later. In 8 patients, the infarct vessel was open not later than 5 h after the onset of chest pain. MIBI markedly supported reconstruction of the sections and localization of the lesions with AM on simultaneous double-nuclide single-photon emission computed tomography (SPECT). In 7 patients both tracers overlapped. Four patients showed only faint AM uptake. This demonstrates that in experimental infarction AM overestimates the region of necrosis while the combination with MIBI allows the delineation towards the intermediate zone and normal myocardium. In patients, SPECT shows similar patterns of tracer distribution. MIBI facilitates AM SPECT.

Ventilatory response to exercise and to carbon dioxide in patients with heart failure.

Patients with heart failure exhibit an increased ventilatory response to exercise; their slope of the overall ventilation/carbon dioxide production ratio (VE/VCO2) is elevated. This elevation is related to impaired exercise performance and is commonly explained by an increased ventilation-perfusion mismatch. However, the concept of afferents to the respiratory centre modulating ventilation during exercise has been raised. In healthy subjects, ventilation during exercise is related to the hypercapnic ventilatory response during rebreathing. This is explained by a similar response of the respiratory centre to different stimuli. The aim of this study was to analyse the relationship between the ventilatory response to exercise and to carbon dioxide in patients with chronic heart failure. The hypercapnic ventilatory response was measured at rest using the rebreathing method in 31 patients with chronic heart failure and a left ventricular ejection fraction < 40% and 25 controls. Thereafter a maximal bicycle exercise test with evaluation of VE/VCO2 was performed. The maximal oxygen uptake during exercise was 13.1 +/- 5.2 ml. min-1.kg-1. The slope of the hypercapnic ventilatory response was normal (1.1 +/- 0.81. min-1. mmHg-1) but minute ventilation breathing room air was increased in the patients as compared to the controls. VE/VCO2 during exercise was positively correlated to the hypercapnic ventilatory response (r = 0.70; P < 0.00001). This relationship supports the concept that in patients with heart failure, ventilation during exercise is not only influenced by an increased ventilation-perfusion mismatch but is in part mediated by the responsiveness of the respiratory centre. Different afferents to the respiratory centre, such as central command or muscle ergoreflex may play a role in modulating ventilation during exercise.

Diagnostic value of transesophageal compared with transthoracic echocardiography in suspected prosthetic valve endocarditis.

To compare transthoracic (TTE) and transesophageal (TEE) echocardiography specifically in prosthetic valve endocarditis, 73 consecutive patients (age, 7 to 80 years) with 86 prostheses who had TTE and TEE for suspected endocarditis were analyzed retrospectively. Thirty-four patients proved to have endocarditis according to clinical criteria (pathoanatomical confirmation in 16), the remaining 39 served as controls. In the endocarditis group, a total of 38 (25 mitral, 13 aortic) prostheses were investigated. Vegetations were detected by TTE in 5 (all aortic) and TEE in 28 (20 mitral, 8 aortic) prostheses (13 vs 74%, p < 0.0001). An annular abscess was found on TEE in 1 mitral implant (3%). New perivalvular regurgitation was demonstrated on TTE in 7 (2 mitral, 5 aortic) and on TEE in 16 (10 mitral, 6 aortic) prostheses (18 vs 42%, p = 0.025). All in all, abnormalities suggestive of endocarditis were revealed on TTE in 10 (2 mitral, 8 aortic) and on TEE in 35 (23 mitral, 12 aortic) prostheses (sensitivity 26 and 92%, p < 0.0001). In the control group, TEE was false positive in 1 mitral prosthesis (specificity for TTE and TEE 100 and 97%, respectively; p = NS). These results indicate that TEE is markedly superior to TTE in prosthetic valve endocarditis. The diagnostic advantage is most evident in mitral prostheses. This holds for the detection of both morphologic changes and prosthetic malfunction.

[Infectious endocarditis of native and prosthetic valves. A comparative analysis based on 155 cases]. / Infektiöse Endokarditis nativer und prothetischer Klappen. Eine vergleichende Analyse anhand von 155 Fällen.

OBJECTIVE: In a retrospective study, we compared the characteristics of native valve and prosthetic valve endocarditis. PATIENTS AND METHODS: All 155 cases of left-sided infective endocarditis in 142 patients admitted at our institution between 1986 and 1992 were analyzed based on their medical records. Native valve endocarditis was found in 119 cases (74 men, 45 women; median age 55, range 29 to 80 years), prosthetic valve endocarditis in 36 cases (11 men, 25 women; median age 63, range 38 to 80 years; 29 cases of late infection). RESULTS: There were more older (P < 0.0005) and more female (P = 0.001) patients with prosthetic valve endocarditis. Most frequently, native aortic valves (53.8%) or mitral prostheses (55.6%) were solely involved. In both groups, Staphylococcus epidermidis was the most frequent isolate followed by Staphylococcus aureus and Enterococci. Symptoms and clinical findings were similar in both groups. In all cases since July 1989, transthoracic echocardiography was suggestive of endocarditis in native valves in 63.9% and in prostheses in 29.2% (P = 0.004), combined with the transesophageal approach in 91.7 and 91.8%, respectively (not significant). Embolism and surgical intervention were about equally frequent in both groups. The in-hospital mortality was 19.3% in native valves and 22.2% in prostheses (not significant). CONCLUSION: Native valve and late prosthetic valve endocarditis are now similar in the spectrum of causative microorganisms, echocardiographic diagnostics, clinical course and prognosis.

Indium-111-antimyosin Fab imaging to demonstrate myocardial involvement in systemic lupus erythematosus.

Indium-111-antimyosin Fab imaging has been used to indicate myocardial injury. This report describes antimyosin accumulation in two patients with myocardial involvement in systemic lupus erythematosus. Both patients complained of chest pain, and significant stenoses of extramural coronary arteries were ruled out by angiography. The first patient, a 64-yr-old woman, had immunopathologic findings suggestive of systemic lupus. Indium-111-antimyosin Fab imaging showed myocardial tracer uptake. This prompted endomyocardial biopsy providing evidence of systemic lupus. The patient improved under immunosuppressive therapy. The second patient, a 47-yr-old man, had systemic lupus diagnosed by immunopathologic findings and skin biopsy. He had evidence of pericarditis on electrocardiography and echocardiography. Indium-111-antimyosin Fab imaging demonstrated additional myocardial involvement, which supported the initiation of immunosuppressive therapy. Our results suggest that 111In-antimyosin Fab imaging may provide valuable diagnostic information and influence patient management in systemic lupus erythematosus with suspected myocardial involvement.

[The clinical importance of scintigraphy with the murine monoclonal antigranulocyte antibody BW 250/183 for the diagnosis of prosthesis-related endocarditis]. / Klinische Bedeutung der Szintigraphie mit dem murinen monoklonalen Antigranulozyten-Antikörper BW 250/183 für die Diagnose der Prothesenendokarditis.

Thirty-eight patients (16 men, 22 women; median age 62.5, range 7 to 80 years) were enrolled in a prospective study to assess the clinical utility of radioimaging using the antigranulocyte antibody BW 250/183 in suspected valve endocarditis. Eighteen patients had prosthetic valve endocarditis according to clinical criteria (surgical confirmation in 8 patients), the remaining 20 patients served as controls. All patients underwent transthoracic and transesophageal echocardiography. Eight to 10 MBq of technetium-99m-labeled antibody were intravenously injected and single-photon emission computed tomography (SPECT) of the thorax was performed after 20 to 24 h. Echocardiography revealed pathological findings in 16 of 18 patients with endocarditis (sensitivity 89%) and was false positive in one of 20 control subjects (specificity 95%). Scintigraphy was true positive in 14 of 18 patients with endocarditis (sensitivity 78%) and false positive in three of 20 control subjects (specificity 85%). Scintigraphy was true positive in the patients with false negative echocardiography and vice versa (sensitivity for both methods combined 100%, specificity 80%). In all five follow-up patients, scintigraphy became negative parallel to clinical improvement. This suggests that scintigraphy indicates the floridity of the inflammatory process. In clinically suspected prosthetic valve endocarditis with equivocal echocardiographic findings, SPECT using the antigranulocyte antibody BW 250/183 may provide valuable additional diagnostic information.

Scintigraphic detection of inflammatory heart disease.

Inflammatory diseases of the heart encompass myocarditis, endocarditis and pericarditis. This paper discusses the diagnostic potential of scintigraphy in these entities. In myocarditis, indium-111 antimyosin Fab imaging can visualize active myocyte damage and thus contribute substantially to the diagnosis. Antimyosin uptake is also seen in a large subset of patients with dilated cardiomyopathy, indicating ongoing myocyte injury in these cases. In endocarditis, immunoscintigraphy using monoclonal technetium-99m-labelled antigranulocyte antibodies provides useful diagnostic information in patients with equivocal echocardiographic findings. Immunoscintigraphy seems to indicate the floridity of the inflammatory process in endocarditis and may be used to monitor antibiotic therapy. In pericarditis, the clinical value of scintigraphy has not been convincingly demonstrated.