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[en] Aim: To describe and evaluate anatomical characterizations of incidental left atrial (LA) diverticula in patients with suspected coronary artery disease using 64-channel multidetector computed tomography (MDCT). Materials and methods: From October 2008 to June 2009, 2059 patients with suspected coronary artery disease underwent electrocardiogram-gated 64-channel MDCT. Five hundred and thirty-two LA diverticula were identified in 377 patients (18.3%, male to female ratio: 216:161, mean age 59 ± 10.89 years, range from 20 to 91 years). Two radiologists retrospectively analysed the number (single or multiple), size (diameter and length), shape (cystiform or tubiform), surface (smooth or irregular), and location (right or mid or left/upper or lower/lateral or posterior). If the length/diameter was <1.5, the diverticular shape was considered to be cystiform. Results: Among 532 LA diverticula, single (270/532, 51.1%), cystiform (411/532, 77.3%), and smooth (332/532, 62.4%) diverticula were found. The right upper region (255/532, 47.9%) was the most common location, followed by the left lateral area (172/532, 32.3%). The average diameter was 4.7 ± 2 mm (range from 1-19 mm), and the average length was 4.7 ± 2.1 mm (range 1-13 mm). The average ratio of length to diameter was 1.15 (range 0.25-1.45). The average number of diverticula was 2 ± 1.06 (range 1-5). Conclusion: Incidental LA diverticulum is not an uncommon finding in patients with suspected coronary artery disease. MDCT can provide anatomical details of LA diverticula. However, further studies are needed to determine their clinical significance.
[en] During ECG-controlled cardio-computer tomography, only certain defined phases of the cardiac cycle are used for computing the image. Consequently several cycles are necessary in order to obtain the required projection. ECG-controlled cardio-computer tomography produces findings regarding dys- or akinetic portions of the myocardium which are in good agreement with the laevo-cardiogram. The septum, apex and antero-lateral wall are demonstrated most easily, since their movement lies within the appropriate plane. Demonstration of the anterior and posterior walls is more difficult, since their movement is angled to the computer tomographic plane. (orig.)
[de]Bei der EKG-gesteuerten Kardiocomputertomographie werden nur die einer bestimmten Herzphase zugehoerigen Messwerte fuer die Bildberechnung beruecksichtigt. Daher sind zur Erlangung der erforderlichen Anzahl von Projektionen mehrere Umlaeufe erforderlich. Mit der EKG-gesteuerten Kardiocomputertomographie ist der Nachweis dys- oder akinetischer Herzwandabschnitte in guter Uebereinstimmung mit den Befunden der Laevokardiographie moeglich. Am guenstigsten sind die Abbildungsbedingungen fuer das Septum, die Spitzenregion und die Anterolateralwand, deren Bewegungen innerhalb der computertomographischen Schichtebene stattfinden. Die Beurteilung der basisnahen Vorder- und Hinterwand ist schwieriger, da deren Bewegungen schraeg zur computertomographischen Schichtebene verlaufen. (orig.)
[en] Regulatory concern about potential QT-interval prolongation by serotonin-receptor antagonist antiemetics prompted product-label changes. The first-generation serotonin-receptor antagonist granisetron is available in oral (PO), intravenous (IV), and transdermal formulations. APF530 is a formulation that provides sustained release of granisetron when administered as a single subcutaneous (SC) injection. The Phase I study reported here evaluated effects of APF530 on electrocardiographic intervals. This single-site, double-blind, placebo-controlled, four-period crossover trial randomized healthy men and women to receive varying sequences of APF530 1 g SC, granisetron 50 μg/kg IV, moxifloxacin 400 mg PO, and placebo. Subjects were assessed for 49 hours after each treatment. The primary objective was to evaluate differences between baseline-adjusted, heart rate-corrected QT-interval change using the Fridericia rate correction (dQTcF) for APF530 1 g SC and placebo. Electrocardiograms were performed at various times throughout the assessment period. Pharmacokinetics and safety were evaluated. The upper one-sided 95% confidence interval (CI) for mean baseline-adjusted dQTcF at each post-dose time point between APF530 and placebo excluded 10 ms, indicating that APF530 1 g SC had no clinically significant effect on QTcF. Maximum observed QTcF change was 4.15 ms (90% CI, 0.94 to 7.36) at Hour 3. No clinically significant changes in other electrocardiogram intervals were observed. APF530 SC pharmacokinetics were as expected, with slow absorption (maximum plasma concentration 35.8 ng/mL, median time to maximum plasma concentration 11.1 hours) and slow elimination (mean half-life 18.6 hours; systemic clearance 20.2 L/hour) of granisetron versus the expected early peak concentration and elimination of granisetron IV. APF530 SC was well tolerated. Adverse events, most commonly constipation and SC injection-site reactions, were generally mild and quickly resolved. APF530 1 g SC did not induce clinically significant QTcF interval prolongation or changes in the other electrocardiogram intervals, and was well tolerated at twice the recommended dose
[en] Electrocardiogram (ECG) and magnetocardiogram (MCG) signals are among the most considerable sources of noise for other biomedical signals. In some recent works, a Bayesian filtering framework has been proposed for denoising the ECG signals. In this paper, it is shown that this framework may be effectively used for removing cardiac contaminants such as the ECG, MCG and ballistocardiographic artifacts from different biomedical recordings such as the electroencephalogram, electromyogram and also for canceling maternal cardiac signals from fetal ECG/MCG. The proposed method is evaluated on simulated and real signals
[en] The electrocardiographic (ECG) inverse problem is ill-posed and usually solved by regularization schemes. These regularization methods, such as the Tikhonov method, are often based on the L2-norm data and constraint terms. However, L2-norm-based methods inherently provide smoothed inverse solutions that are sensitive to measurement errors, and also lack the capability of localizing and distinguishing multiple proximal cardiac electrical sources. This paper presents alternative regularization schemes employing the L1-norm data term for the reconstruction of epicardial potentials (EPs) from measured body surface potentials (BSPs). During numerical implementation, the iteratively reweighted norm algorithm was applied to solve the L1-norm-related schemes, and measurement noises were considered in the BSP data. The proposed L1-norm data term-based regularization schemes (with L1 and L2 penalty terms of the normal derivative constraint (labelled as L1TV and L1L2)) were compared with the L2-norm data terms (Tikhonov with zero-order and normal derivative constraints, labelled as ZOT and FOT, and the total variation method labelled as L2TV). The studies demonstrated that, with averaged measurement noise, the inverse solutions provided by the L1L2 and FOT algorithms have less relative error values. However, when larger noise occurred in some electrodes (for example, signal lost during measurement), the L1TV and L1L2 methods can obtain more accurate EPs in a robust manner. Therefore the L1-norm data term-based solutions are generally less perturbed by measurement noises, suggesting that the new regularization scheme is promising for providing practical ECG inverse solutions.
[en] Materials and methods: In ten patients after CABG surgery, ECG-triggered CT with thin (2 mm), contiguous slices was performed in the region of the proximal bypass anastomoses in the ascending aorta. The data evaluation was done on axial images and on reconstructed 2D and 3D data sets. Results: The applied technique demonstrated good imaging quality, which allowed evaluation of the CABG anastomoses in all cases. Overall 18 CABG anastomoses could be visualized; 17 anastomoses could be assessed as normal, non-stenotic and patent. Discussion: ECG-triggered thin-slice CT permits reliable assessment of proximal CABG anastomoses and expands the usage of CT in the evaluation of CABG. (orig.)
[de]Methode: Bei 10 Patienten wurde nach Bypassoperation eine EKG-getriggerte CT mit duennen (2 mm), kontinuierlichen Schichten von den proximalen Bypassanastomosen im Bereich der Aorta ascendens durchgefuehrt. Die Datenauswertung erfolgte an axialen Einzelschichten und nachverarbeiteten 2D- und 3D-Datensaetzen. Ergebnisse: Die Untersuchungstechnik ergab in allen Faellen eine gute Bildqualitaet und Beurteilungsmoeglichkeit der Anastomosenverhaeltnisse. Insgesamt wurden 18 Bypassanastomosen dargestellt. Von diesen Anastomosen konnten 17 als unauffaellig, durchgaengig und ohne Stenosierung gewertet werden. Schlussfolgerung: Die EGK-getriggerte CT in duennen Schichten erlaubt eine Beurteilung der proximalen Anastomosenverhaeltnisse aortokoronarer Bypaesse und erweitert somit das Einsatzspektrum der CT. (orig.)
[en] A series of experiments are conducted to confirm whether the vectors calculated for an early section of a continuous non-invasive fetal electrocardiogram (fECG) recording can be directly applied to subsequent sections in order to reduce the computation required for real-time monitoring. Our results suggest that it is generally feasible to apply the initial optimal maternal and fetal ECG combination vectors to extract the fECG and maternal ECG in subsequent recorded sections. (interdisciplinary physics and related areas of science and technology)
[en] Magnetic resonance is the ideal imaging technique for the study of congenital or acquired disease of the thoracic aorta since it combines the advantages of arteriography, echocardiography and Ct in a single examination. However, this techniques has to be adjusted to each individual situation. The first part of this article deals with the different pulse sequences applicable to MR assessment of the thoracic aorta,which ranges from spin echo images synchronizes with electrograms to three-dimensional angio-MR with gadolinium enhancement. The technical aspects are described and the clinical applications of MR in different congenital and acquired thoracic disorders is assessed. (Author) 67 refs
[en] This new multiprocessor system, is designed to automate an intensive care unit in cardiology. It contains intelligent modules including microprocessors, developped by the CEA, according to the rules of the international standard IEC 66.22 (GP-IB). These modules analyse the ECG from two different channels and detect a total of twenty arrhythmias. Up to eight of those modules can be connected to a controlling unit, linked to a matrix oriented plasma display and a function touch panel. This controller, developped by HMI, analyses the data files recorded from the arrhythmias analyser and monitors up to 10 different histograms. This technique of subdivision into independent modules with their own alarms, guarantees the safety of the system. Furthermore, by this method, maintenance is highly simplified. The basic system has been under clinical evaluation for 1 year. Percentages of true positive detection for three typical arrhythmias are: ventricular extrasystole 95%; auricular extra systole 98%; supra ventricular tachycardia 100%; and the results for other arrhythmias are likewise very good
[fr]Ce nouveau systeme multiprocesseur est concu pour automatiser une unite de soins intensifs coronariens. Il comporte des modules 'intelligents' a microprocesseurs developpes par le CEN-SACLAY et geres selon les normes du standard international CEI 66.22 (GP.IB). Ces modules analysent les ECG a partir de deux derivations distinctes electrocardiographiques et detectent une vingtaine d'arythmies. L'ensemble des 8 modules (1 module par malade) peut etre connecte a l'unite de controle, elle meme associee a une visualisation a plasma et a un clavier de fonctions. Ce controleur developpe par le HMI de Berlin, analyse les blocs de donnees fournis par les modules analyseurs d'arythmies et elabore entre autre une dizaine d'histogrammes par malade. Cette technique de subdivision entre des modules independants d'analyse de signal engendrant leurs propres alarmes, garantit une bonne securite de fonctionnement du systeme. De plus, par cette methode, la maintenance est grandement simplifiee. Un prototype de definition est en validation clinique depuis 1 an. Les pourcentages de bonne detection pour 3 types d'arythmie sont: ESV: 95%; ESA: 98%; TSV: 100%. Les resultats pour les autres types d'arythmies detectees sont egalement tres satisfaisants