Biomedical subjects

F Flachskampf

Publications and source records attributed to F Flachskampf.

7 recordsLinked to original sources

PubMed2002

Is Doppler tissue velocity during early left ventricular filling preload independent?

BACKGROUND: Transmitral Doppler flow indices are used to evaluate diastolic function. Recently, velocities measured by Doppler tissue imaging have been used as an index of left ventricular relaxation. OBJECTIVE: To determine whether Doppler tissue velocities are influenced by alterations in preload. METHODS: Left ventricular preload was altered in 17 patients (all men, mean (SD) age, 49 (8) years) during echocardiographic measurements of left ventricular end diastolic volume, maximum left atrial area, peak early Doppler filling velocity, and left ventricular myocardial velocities during early filling. Preload altering manoeuvres included Trendelenberg (stage 1), reverse Trendelenberg (stage 2), and amyl nitrate (stage 3). Systolic blood pressure was measured at each stage. RESULTS: In comparison with baseline, left ventricular end diastolic volume (p = 0.001), left atrial area (p = 0.003), peak early mitral Doppler filling velocity (p = 0.01), and systolic blood pressures (p = 0.001) were all changed by preload altering manoeuvres. Only left ventricular myocardial velocity during early filling remained unchanged by these manoeuvres. CONCLUSIONS: In contrast to standard transmitral Doppler filling indices, Doppler tissue early diastolic velocities are not significantly affected by physiological manoeuvres that alter preload. Thus Doppler tissue velocities during early left ventricular diastole may provide a better index of diastolic function in cardiac patients by providing a preload independent assessment of left ventricular filling.

Blood Flow Velocity↗

PubMed2000

[A standardized documentation structure for data documentation in echocardiography. Work Team on Standards and LV Function of the Work Group on Cardiovascular Ultrasound of the German Society of Cardiology, Heart and Circulation Research].

Presently, there are no well-defined standards for documentation of echocardiographic studies. Nevertheless, standards are essential to provide comparability of data and to realize electronic communication, both essential for quality management in echocardiography. Therefore, the working group "Standards and LV function" of the German Society of Cardiology developed a consensus for documentation of echocardiographic studies. In the present paper this consensus is presented and illustrated by typical clinical examples. Additionally, a prototype of a user-oriented software based on this data set is presented. The complete data set for transesophageal and transthoracic echocardiography and the software prototype can be downloaded at http:@echo.ma.uni-heidelberg.de.

Aortic Valve Stenosis↗

PubMed1999

NC100100, a new echo contrast agent for the assessment of myocardial perfusion--safety and comparison with technetium-99m sestamibi single-photon emission computed tomography in a randomized multicenter study.

BACKGROUND AND HYPOTHESIS: Myocardial contrast echocardiography using second-generation agents has been proposed to study myocardial perfusion. A placebo-controlled, multicenter trial was conducted to evaluate the safety, optimal dose, and imaging mode for NC100100, a novel intravenous second-generation echo contrast agent, and to compare this technique with technetium-99m sestamibi (MIBI) single-photon emission computed tomography (SPECT). METHODS: In a placebo-controlled, multicenter trial, 203 patients with myocardial infarction > 5 days and < 1 year previously underwent rest SPECT and MCE. Fundamental and harmonic imaging modes combined with continuous and electrocardiogram-- (ECG) triggered intermittent imaging were used. Six dose groups (0.030, 0.100, and 0.300 microliter particles/kg body weight for fundamental imaging; and 0.006, 0.030, and 0.150 microliter particles/kg body weight for harmonic imaging) were tested. A saline group was also included. Safety was followed for 72 h after contrast injection. Myocardial perfusion by MCE was compared with myocardial rest perfusion imaging using MIBI as a tracer. RESULTS: NC100100 was well tolerated. No serious adverse events or deaths occurred. No clinically relevant changes in vital signs, laboratory parameters, and ECG recordings were noted. There was no significant difference between adverse events in the NC100100 (25.7%) and in the placebo group (17.9%, p = 0.3). Intermittent harmonic imaging using the intermediate dose was superior to all other modalities, allowing the assessment of perfusion in 76% of all segments. Eighty segments (96%) with normal perfusion by SPECT imaging also showed myocardial perfusion with MCE. However, a substantial percentage of segments (61-80%) with perfusion defects by SPECT imaging also showed opacification by MCE. This resulted in an overall agreement of 66-81% and a high specificity (80-96%), but in low sensitivity (20-39%) of MCE for the detection of perfusion defects. CONCLUSION: NC100100 is safe in patients with myocardial infarction. Intermittent harmonic imaging with a dose of 0.03 microliter particles/kg body weight can be proposed as the best imaging protocol. Myocardial contrast echocardiography with NC 100100 provides perfusion information in approximately 76% of segments and results in myocardial opacification in the vast majority of segments with normal perfusion as assessed by SPECT. Although the discrepancies between MCE and SPECT with regard to the definition of perfusion defects requires further investigation, MCE with NC 100100 is a promising technique for the noninvasive assessment of myocardial perfusion.

Aged↗

PubMed1998

Accuracy and feasibility of contrast echocardiography for detection of perfusion defects in routine practice: comparison with wall motion and technetium-99m sestamibi single-photon emission computed tomography. The Nycomed NC100100 Investigators.

OBJECTIVES: We sought to assess the feasibility and accuracy of myocardial contrast echocardiography (MCE) using standard imaging approaches for the detection of perfusion defects in patients who had a myocardial infarction (MI). BACKGROUND: Myocardial contrast echocardiography may be more versatile than perfusion scintigraphy for identifying the presence and extent of perfusion defects after MI. However, its reliability in routine practice is unclear. METHODS: Fundamental or harmonic MCE was performed with continuous or triggered imaging in 203 patients with a previous MI using bolus doses of a perfluorocarbon-filled contrast agent (NC100100). All patients underwent single-photon emission computed tomography (SPECT) after the injection of technetium-99m (Tc-99m) sestamibi at rest. Quantitative and semiquantitative SPECT, wall motion and digitized echocardiographic data were interpreted independently. The accuracy of MCE was assessed for detection of segments and patients with moderate and severe sestamibi-SPECT defects, as well as for detection of patients with extensive perfusion defects (>12% of left ventricle). RESULTS: In segments with diagnostic MCE, the segmental sensitivity ranged from 14% to 65%, and the specificity varied from 78% to 95%, depending on the dose of contrast agent. Using both segment- and patient-based analysis, the greatest accuracy and proportion of interpretable images were obtained using harmonic imaging in the triggered mode. For the detection of extensive defects, the sensitivity varied from 13% to 48%, with specificity from 63% to 100%. Harmonic imaging remained the most accurate approach. Time since MI and SPECT defect location and intensity were all determinants of the MCE response. The extent of defects on MCE was less than the extent of either abnormal wall motion or SPECT abnormalities. The combination of wall motion and MCE assessment gave the best balance of sensitivity (46% to 55%) and specificity (82% to 83%). CONCLUSIONS: Although MCE is specific, it has limited sensitivity for detection of moderate or severe perfusion defects, and it underestimates the extent of SPECT defects. The best results are obtained by integration with wall motion. More sophisticated methods of acquisition and interpretation are needed to enhance the feasibility of this technique in routine practice.

Contrast Media↗

PubMed1996

Stenotic lesions.

Explore the source record for details and available documents.

Aortic Valve Stenosis↗

PubMed1995

Recent progress in quantitative echocardiography.

Substantial progress has been made recently in quantitating a variety of functional or morphologic parameters with echocardiography. Doppler techniques for measuring regurgitant flow rate and regurgitant orifice area in mitral and tricuspid regurgitation have become well established, along with other Doppler measures of regurgitation severity, such as proximal jet width. Doppler measurement of diastolic flow propagation in the left ventricle is emerging as a promising, albeit fascinatingly complex way of looking at diastolic function. Doppler velocimetry has been extended to wall motion, yielding color maps of tissue, an entirely new tool for assessing myocardial function and its timing. In the field of two-dimensional data processing, automatic on-line boundary detection based on integrated ultrasound backscatter has been used for volume and cardiac output calculations. Finally, three-dimensional reconstruction of cross-sectional images now has been well validated for in vivo measurements of heart cavity volumes and masses.

Blood Flow Velocity↗

PubMed1994

[Quality assurance in echocardiography].

Echocardiography is the most important noninvasive diagnostic tool for the cardiologist. More than 617.000 two-dimensional echo examinations and 425.000 color coded Doppler analyses were performed in 1992 in the Federal Republic of Germany in private practice. Based on a questionnaire, more than 60% of the departments of cardiology perform echocardiograms in more than 3000 pts per year, and the amount of TEE examinations is in the range 5-15% of the total annual echo performance rate. In more than 80% of all examinations color coded Doppler is used. With regard to the guidelines for performing the different echo modalities the German recommendations are stringent in comparison with the international standard. Due to the fact that an echocardiographic examination is strongly investigator dependent, the primary goal of quality management should be focused on training.

Cardiology↗