Radial Function

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F Weidemann - One of the best experts on this subject based on the ideXlab platform.

  • 195 improvement of cardiac Function during enzyme replacement therapy in patients with fabry disease a prospective strain rate imaging studie
    European Journal of Echocardiography, 2003
    Co-Authors: F Weidemann, Frank Breunig, Meinrad Beer, A Knoll, Oliver Turschner, Christoph Wanner, Joern J W Sandstede, W Voelker, Georg Ertl, J Strotmann
    Abstract:

    Background—Enzyme replacement therapy (ERT) has been shown to enhance microvascular endothelial globotriaosylceramide clearance in the hearts of patients with Fabry disease. Whether these results can be translated into an improvement of myocardial Function has yet to be demonstrated. Methods and Results—Sixteen patients with Fabry disease who were treated in an open-label study with 1.0 mg/kg body weight of recombinant -Gal A (agalsidase , Fabrazyme) were followed up for 12 months. Myocardial Function was quantified by ultrasonic strain rate imaging to assess Radial and longitudinal myocardial deformation. End-diastolic thickness of the left ventricular posterior wall and myocardial mass (assessed by magnetic resonance imaging, n10) was measured at baseline and after 12 months of ERT. Data were compared with 16 age-matched healthy controls. At baseline, both peak systolic strain rate and systolic strain were significantly reduced in the Radial and longitudinal direction in patients compared with controls. Peak systolic strain rate increased significantly in the posterior wall (Radial Function) after one year of treatment (baseline, 2.80.2 s 1 ; 12 months, 3.70.3 s 1 ; P0.05). In addition, end-systolic strain of the posterior wall increased significantly (baseline, 343%; 12 months, 454%; P0.05). This enhancement in Radial Function was accompanied by an improvement in longitudinal Function. End-diastolic thickness of the posterior wall decreased significantly after 12 months of treatment (baseline, 13.80.6 mm; 12 months, 11.80.6 mm; P0.05). In parallel, myocardial mass decreased significantly from 20118 to 180 21 g( P0.05). Conclusions—These results suggest that ERT can decrease left ventricular hypertrophy and improve regional myocardial Function. (Circulation. 2003;108:1299-1301.)

  • the feasibility of ultrasonic regional strain and strain rate imaging in quantifying dobutamine stress echocardiography
    European Journal of Echocardiography, 2003
    Co-Authors: Miroslaw Kowalski, Piet Claus, Marie-christine Herregods, Lieven Herbots, F Weidemann, L Simmons, Jorg Strotmann, Christoph Dommke, Jan Dhooge, Bart Bijnens
    Abstract:

    Background: Ultrasonic strain rate and strain can characterize regional one-dimensional myocardial deformation at rest. In theory, these deformation indices could be used to quantify normal or abnormal regional Function during a dobutamine stress echo test. Aims: The aims of our pilot study were threefold: (1) to determine the percentage of segments in which interpretable strain rate/strain data could be obtained during routine dobutamine stress echo, (2) to establish whether either the increase in heart rate or artefacts induced by respiration during dobutamine stress echo would influence analysis by degrading the data and (3) to determine the optimal frame rate vs image sector angle settings for data acquisition. Furthermore, although the detection of ischaemia was not to be addressed specifically in this study, we would describe the findings on the potential clinical role of regional deformation vs velocity imaging in detecting ischaemia-induced changes. Methods: A standard dobutamine stress echo protocol was performed in 20 consecutive patients with a history of chest pain (16 with angiographic coronary artery disease and four with normal coronary angiograms). DMI velocities were acquired at baseline, low dose, peak dose, and recovery. To evaluate Radial Function (basal segment of the left ventricle posterior wall segment), parasternal LAX, SAX views were used. For long axis Function data were acquired (4-CH, 2-CH views) from the septum; lateral, inferior and anterior left ventricle walls. Data was acquired using both 15° (>150 frames per second (fps) and 45° (115 fps) sector angles. During post-processing each wall was divided into three segments: basal, mid and apical. Strain rate/strain values were averaged over three consecutive heart cycles. Results: Data was obtained from 1936 segments, of which only 54 had to be excluded from subsequent analysis (2.8%) because of suboptimal quality. An increase in heart rates (up to 150/min) was not associated with a significant reduction in the number of interpretable segments. There was a significant correlation between maximal systolic strain rate/strain values obtained at narrow and at wide sector angles (e.g. a correlation for the septal segments: r=0.73, P <0.001 for strain rate, and r=0.71; P <0.001 for strain). The correlation for the timing of events obtained from narrow and wide sector angles was weaker. This would indicate that there was the insufficient temporal resolution for the latter acquisition method. Normal and abnormal regional strain rate/strain responses to an incremental dobutamine infusion were defined. In normal segments, maximal systolic strain rate values increased continuously from baseline, reaching the highest values at the peak dose of dobutamine. The segmental strain response was different. For strain, there was an initial slight increase at low dose of dobutamine (5, 10 μg/kg/min), but no further increase with increasing dose. A pattern representing an ischaemic response was identified and described. Conclusions: The feasibility study would suggest that with appropriate data collection and post-processing methodologies, strain rate/strain imaging can be applied to the quantification of dobutamine stress echo. However, appropriate post-processing algorithms must be introduced to reduce data analysis time in order to make this a practical clinical technique. Copyright 2002 The European Society of Cardiology. Published by Elsevier Science Ltd. All rights reserved .

  • defining the transmurality of a chronic myocardial infarction by ultrasonic strain rate imaging implications for identifying intramural viability an experimental study
    Circulation, 2003
    Co-Authors: F Weidemann, Piet Claus, Christoph Dommke, Jan Dhooge, Bart Bijnens, Paul Mertens, Eric Verbeken, Alex Maes, Frans Van De Werf, Ivan De Scheerder
    Abstract:

    Background— In a correlative Functional/histopathologic study, we investigated the regional deformation characteristics of both chronic nontransmural and transmural infarctions before and after a dobutamine challenge. Methods and Results— After stenosing copper-coated stent implantation to produce circumflex artery endothelial proliferation, 18 pigs were followed up for 5 weeks. Posteuthanasia histology showed 10 to have a nontransmural and 8 a transmural infarction. Eight nonstented animals served as controls. Regional Radial Function was monitored by measuring ultrasound-derived peak systolic strain rates (SRSYS) and systolic strains (eSYS) (1) before stent implantation and (2) at 5 weeks, at baseline (bs) and during an incremental dobutamine infusion. In controls, dobutamine induced a linear increase in SRSYS (dobutamine: bs, 4.8±0.4 s−1; 20 μg · kg−1 · min−1, 9.9±0.7 s−1; P<0.0001) and an initial increase of eSYS at low dose (bs, 58±5%; at 5 μg · kg−1 · min−1, 78±6%; P<0.05) but a subsequent decrease ...

  • doppler tissue velocity strain and strain rate imaging with transesophageal echocardiography in the operating room a feasibility study
    Journal of The American Society of Echocardiography, 2002
    Co-Authors: L Simmons, F Weidemann, Jan Dhooge, Bart Bijnens, George R. Sutherland, Paul Sergeant, Patrick Wouters
    Abstract:

    Abstract Objective: Transesophageal echocardiography (TEE) is increasingly used to monitor regional myocardial Function during cardiac operation. Doppler myocardial imaging (DMI) indices can potentially provide new information on regional Radial and longitudinal myocardial motion and local deformation. This study examined the feasibility of TEE acquisition of regional Radial and longitudinal velocity, displacement (D), strain, and strain rate data during cardiac operation and evaluated the effects of sternotomy and pericardial opening on these indices. Methods: After a baseline transthoracic echocardiographic study, TEE was performed in 22 patients (age 64 ± 7 years) before sternotomy, after sternotomy with intact pericardium, and after pericardial opening. Regional DMI velocity analysis was performed for the transgastric anterior and inferior walls midpapillary segment (Radial Function) and the 4-chamber septum and 2-chamber inferior walls basal, mid, and apical segments (longitudinal Function). For each segment, systolic and diastolic velocity were derived and D, strain, and strain rate calculated. Results: Transthoracic echocardiographic study and TEE provided similar data from an equivalent number of interpretable segments. In the basal and mid septum, maximum longitudinal systolic D decreased with pericardial opening (basal septum pericardium closed: 6.6 ± 1.5 mm, open: 4.6 ± 1.8 mm, P =.007; midseptum pericardium closed: 4.7 ± 2.5 mm, open: 2.7 ± 1.5 mm, P =.028). No changes were evident in systolic or diastolic DMI indices in all other segments. Conclusion: DMI with TEE is feasible during cardiac operation. During pericardial opening, longitudinal D decreases in the septum, but not in the inferior wall. DMI requires further evaluation in the assessment of ventricular Function and the detection of ischemia in the operating room. (J Am Soc Echocardiogr 2002;15:768-76.)

  • quantification of regional left and right ventricular Radial and longitudinal Function in healthy children using ultrasound based strain rate and strain imaging
    Journal of The American Society of Echocardiography, 2002
    Co-Authors: F Weidemann, Miroslaw Kowalski, Jan Dhooge, Bart Bijnens, Benedicte Eyskens, F Jamal, Luc Mertens, Marc Gewillig, Frank Rademakers, Liv Hatle
    Abstract:

    Background: Noninvasive assessment of left (LV) and right (RV) ventricular Function in children could benefit from a technique that would characterize local myocardial deformation. Color Doppler myocardial imaging (CDMI) allows the calculation of either local longitudinal or Radial Strain Rate (SR) and Strain (e). To determine the clinical feasibility and reproducibility of longitudinal and Radial SR and e, the following study was carried out. Methods: CDMI data were obtained from 33 healthy children (4-16 years). To quantify regional longitudinal and Radial Function SR and e data were obtained from apical and parasternal views respectively. From the extracted SR curves, peak values for systole, early diastole, and late diastole were calculated. From the extracted e curves the systolic, early and late diastolic e values were calculated. Results: LV longitudinal deformation were homogeneous for LV basal, mid and apical segments (peak systolic SR: –1.9 ± 0.7 s–1, systolic e –25% ± 7%). Longitudinal SR and e values were significantly higher and heterogeneous in the RV (compared with LV walls) and were maximal in the mid part of the RV free wall (peak systolic SR: –2.8 ± 0.7 s–1, systolic e –45% ± 13%). The RV inferior wall showed homogenous but lower longitudinal SR and e values. The LV systolic and diastolic SR and e values were higher for deformation in the Radial direction compared with the longitudinal direction (Radial peak systolic SR: 3.7 ± 0.9 s–1, Radial systolic e 57% ± 11%; P < .0001). The interobserver variability for Radial systolic e and SR was 10.3% and 13.1%, respectively. Conclusion: Ultrasound-based Strain SR/e imaging is a practical, reproducible clinical technique, which allows the calculation of regional longitudinal and Radial deformation from both LV and RV segments. The combination of regional SR/e indices and the timing of specific systolic or diastolic regional events may offer a new noninvasive approach to quantifying regional myocardial Function in congenital and acquired heart disease in children. (J Am

Bart Bijnens - One of the best experts on this subject based on the ideXlab platform.

  • the feasibility of ultrasonic regional strain and strain rate imaging in quantifying dobutamine stress echocardiography
    European Journal of Echocardiography, 2003
    Co-Authors: Miroslaw Kowalski, Piet Claus, Marie-christine Herregods, Lieven Herbots, F Weidemann, L Simmons, Jorg Strotmann, Christoph Dommke, Jan Dhooge, Bart Bijnens
    Abstract:

    Background: Ultrasonic strain rate and strain can characterize regional one-dimensional myocardial deformation at rest. In theory, these deformation indices could be used to quantify normal or abnormal regional Function during a dobutamine stress echo test. Aims: The aims of our pilot study were threefold: (1) to determine the percentage of segments in which interpretable strain rate/strain data could be obtained during routine dobutamine stress echo, (2) to establish whether either the increase in heart rate or artefacts induced by respiration during dobutamine stress echo would influence analysis by degrading the data and (3) to determine the optimal frame rate vs image sector angle settings for data acquisition. Furthermore, although the detection of ischaemia was not to be addressed specifically in this study, we would describe the findings on the potential clinical role of regional deformation vs velocity imaging in detecting ischaemia-induced changes. Methods: A standard dobutamine stress echo protocol was performed in 20 consecutive patients with a history of chest pain (16 with angiographic coronary artery disease and four with normal coronary angiograms). DMI velocities were acquired at baseline, low dose, peak dose, and recovery. To evaluate Radial Function (basal segment of the left ventricle posterior wall segment), parasternal LAX, SAX views were used. For long axis Function data were acquired (4-CH, 2-CH views) from the septum; lateral, inferior and anterior left ventricle walls. Data was acquired using both 15° (>150 frames per second (fps) and 45° (115 fps) sector angles. During post-processing each wall was divided into three segments: basal, mid and apical. Strain rate/strain values were averaged over three consecutive heart cycles. Results: Data was obtained from 1936 segments, of which only 54 had to be excluded from subsequent analysis (2.8%) because of suboptimal quality. An increase in heart rates (up to 150/min) was not associated with a significant reduction in the number of interpretable segments. There was a significant correlation between maximal systolic strain rate/strain values obtained at narrow and at wide sector angles (e.g. a correlation for the septal segments: r=0.73, P <0.001 for strain rate, and r=0.71; P <0.001 for strain). The correlation for the timing of events obtained from narrow and wide sector angles was weaker. This would indicate that there was the insufficient temporal resolution for the latter acquisition method. Normal and abnormal regional strain rate/strain responses to an incremental dobutamine infusion were defined. In normal segments, maximal systolic strain rate values increased continuously from baseline, reaching the highest values at the peak dose of dobutamine. The segmental strain response was different. For strain, there was an initial slight increase at low dose of dobutamine (5, 10 μg/kg/min), but no further increase with increasing dose. A pattern representing an ischaemic response was identified and described. Conclusions: The feasibility study would suggest that with appropriate data collection and post-processing methodologies, strain rate/strain imaging can be applied to the quantification of dobutamine stress echo. However, appropriate post-processing algorithms must be introduced to reduce data analysis time in order to make this a practical clinical technique. Copyright 2002 The European Society of Cardiology. Published by Elsevier Science Ltd. All rights reserved .

  • defining the transmurality of a chronic myocardial infarction by ultrasonic strain rate imaging implications for identifying intramural viability an experimental study
    Circulation, 2003
    Co-Authors: F Weidemann, Piet Claus, Christoph Dommke, Jan Dhooge, Bart Bijnens, Paul Mertens, Eric Verbeken, Alex Maes, Frans Van De Werf, Ivan De Scheerder
    Abstract:

    Background— In a correlative Functional/histopathologic study, we investigated the regional deformation characteristics of both chronic nontransmural and transmural infarctions before and after a dobutamine challenge. Methods and Results— After stenosing copper-coated stent implantation to produce circumflex artery endothelial proliferation, 18 pigs were followed up for 5 weeks. Posteuthanasia histology showed 10 to have a nontransmural and 8 a transmural infarction. Eight nonstented animals served as controls. Regional Radial Function was monitored by measuring ultrasound-derived peak systolic strain rates (SRSYS) and systolic strains (eSYS) (1) before stent implantation and (2) at 5 weeks, at baseline (bs) and during an incremental dobutamine infusion. In controls, dobutamine induced a linear increase in SRSYS (dobutamine: bs, 4.8±0.4 s−1; 20 μg · kg−1 · min−1, 9.9±0.7 s−1; P<0.0001) and an initial increase of eSYS at low dose (bs, 58±5%; at 5 μg · kg−1 · min−1, 78±6%; P<0.05) but a subsequent decrease ...

  • defining the transmurality of a chronic myocardial infarction by ultrasonic strain rate imaging implications for identifying intramural viability an experimental study
    Circulation, 2003
    Co-Authors: Frank Weidemann, Piet Claus, Christoph Dommke, Jan Dhooge, Bart Bijnens, Paul Mertens, Eric Verbeken, Alex Maes, Frans Van De Werf, Ivan De Scheerder
    Abstract:

    BACKGROUND: In a correlative Functional/histopathologic study, we investigated the regional deformation characteristics of both chronic nontransmural and transmural infarctions before and after a dobutamine challenge. METHODS AND RESULTS: After stenosing copper-coated stent implantation to produce circumflex artery endothelial proliferation, 18 pigs were followed up for 5 weeks. Posteuthanasia histology showed 10 to have a nontransmural and 8 a transmural infarction. Eight nonstented animals served as controls. Regional Radial Function was monitored by measuring ultrasound-derived peak systolic strain rates (SR(SYS)) and systolic strains (epsilon(SYS)) (1) before stent implantation and (2) at 5 weeks, at baseline (bs) and during an incremental dobutamine infusion. In controls, dobutamine induced a linear increase in SR(SYS) (dobutamine: bs, 4.8+/-0.4 s(-1); 20 microg x kg(-1) x min(-1), 9.9+/-0.7 s(-1); P<0.0001) and an initial increase of epsilon(SYS) at low dose (bs, 58+/-5%; at 5 microg x kg(-1) x min(-1), 78+/-6%; P<0.05) but a subsequent decrease during higher infusion rates. In the nontransmural group, bs SR(SYS) and epsilon(SYS) were significantly lower than prestent values (SR(SYS), 2.9+/-0.5 s(-1) and epsilon(SYS), 32+/-6%, P<0.05 versus prestent). During dobutamine infusion, SR(SYS) increased slightly at 5 microg x kg(-1) x min(-1) (4.7+/-0.6 s(-1), P<0.05) but fell during higher infusion rates, whereas epsilon(SYS) showed no change. For nontransmural infarctions, transmural scar extension correlated closely with epsilon(SYS) at bs (r=0.88). For transmural infarctions, SR(SYS) at bs was significantly reduced and epsilon(SYS) was almost not measurable (SR(SYS), 1.8+/-0.3 s(-1); epsilon(SYS), 3+/-4%). Both deformation parameters showed no further change during the incremental dobutamine infusion. CONCLUSIONS: Ultrasonic deformation values could clearly differentiate chronic nontransmural from transmural myocardial infarction. The transmural extension of the scar could be defined by the regional deformation response.

  • doppler tissue velocity strain and strain rate imaging with transesophageal echocardiography in the operating room a feasibility study
    Journal of The American Society of Echocardiography, 2002
    Co-Authors: L Simmons, F Weidemann, Jan Dhooge, Bart Bijnens, George R. Sutherland, Paul Sergeant, Patrick Wouters
    Abstract:

    Abstract Objective: Transesophageal echocardiography (TEE) is increasingly used to monitor regional myocardial Function during cardiac operation. Doppler myocardial imaging (DMI) indices can potentially provide new information on regional Radial and longitudinal myocardial motion and local deformation. This study examined the feasibility of TEE acquisition of regional Radial and longitudinal velocity, displacement (D), strain, and strain rate data during cardiac operation and evaluated the effects of sternotomy and pericardial opening on these indices. Methods: After a baseline transthoracic echocardiographic study, TEE was performed in 22 patients (age 64 ± 7 years) before sternotomy, after sternotomy with intact pericardium, and after pericardial opening. Regional DMI velocity analysis was performed for the transgastric anterior and inferior walls midpapillary segment (Radial Function) and the 4-chamber septum and 2-chamber inferior walls basal, mid, and apical segments (longitudinal Function). For each segment, systolic and diastolic velocity were derived and D, strain, and strain rate calculated. Results: Transthoracic echocardiographic study and TEE provided similar data from an equivalent number of interpretable segments. In the basal and mid septum, maximum longitudinal systolic D decreased with pericardial opening (basal septum pericardium closed: 6.6 ± 1.5 mm, open: 4.6 ± 1.8 mm, P =.007; midseptum pericardium closed: 4.7 ± 2.5 mm, open: 2.7 ± 1.5 mm, P =.028). No changes were evident in systolic or diastolic DMI indices in all other segments. Conclusion: DMI with TEE is feasible during cardiac operation. During pericardial opening, longitudinal D decreases in the septum, but not in the inferior wall. DMI requires further evaluation in the assessment of ventricular Function and the detection of ischemia in the operating room. (J Am Soc Echocardiogr 2002;15:768-76.)

  • quantification of regional left and right ventricular Radial and longitudinal Function in healthy children using ultrasound based strain rate and strain imaging
    Journal of The American Society of Echocardiography, 2002
    Co-Authors: F Weidemann, Miroslaw Kowalski, Jan Dhooge, Bart Bijnens, Benedicte Eyskens, F Jamal, Luc Mertens, Marc Gewillig, Frank Rademakers, Liv Hatle
    Abstract:

    Background: Noninvasive assessment of left (LV) and right (RV) ventricular Function in children could benefit from a technique that would characterize local myocardial deformation. Color Doppler myocardial imaging (CDMI) allows the calculation of either local longitudinal or Radial Strain Rate (SR) and Strain (e). To determine the clinical feasibility and reproducibility of longitudinal and Radial SR and e, the following study was carried out. Methods: CDMI data were obtained from 33 healthy children (4-16 years). To quantify regional longitudinal and Radial Function SR and e data were obtained from apical and parasternal views respectively. From the extracted SR curves, peak values for systole, early diastole, and late diastole were calculated. From the extracted e curves the systolic, early and late diastolic e values were calculated. Results: LV longitudinal deformation were homogeneous for LV basal, mid and apical segments (peak systolic SR: –1.9 ± 0.7 s–1, systolic e –25% ± 7%). Longitudinal SR and e values were significantly higher and heterogeneous in the RV (compared with LV walls) and were maximal in the mid part of the RV free wall (peak systolic SR: –2.8 ± 0.7 s–1, systolic e –45% ± 13%). The RV inferior wall showed homogenous but lower longitudinal SR and e values. The LV systolic and diastolic SR and e values were higher for deformation in the Radial direction compared with the longitudinal direction (Radial peak systolic SR: 3.7 ± 0.9 s–1, Radial systolic e 57% ± 11%; P < .0001). The interobserver variability for Radial systolic e and SR was 10.3% and 13.1%, respectively. Conclusion: Ultrasound-based Strain SR/e imaging is a practical, reproducible clinical technique, which allows the calculation of regional longitudinal and Radial deformation from both LV and RV segments. The combination of regional SR/e indices and the timing of specific systolic or diastolic regional events may offer a new noninvasive approach to quantifying regional myocardial Function in congenital and acquired heart disease in children. (J Am

Jan Dhooge - One of the best experts on this subject based on the ideXlab platform.

  • the feasibility of ultrasonic regional strain and strain rate imaging in quantifying dobutamine stress echocardiography
    European Journal of Echocardiography, 2003
    Co-Authors: Miroslaw Kowalski, Piet Claus, Marie-christine Herregods, Lieven Herbots, F Weidemann, L Simmons, Jorg Strotmann, Christoph Dommke, Jan Dhooge, Bart Bijnens
    Abstract:

    Background: Ultrasonic strain rate and strain can characterize regional one-dimensional myocardial deformation at rest. In theory, these deformation indices could be used to quantify normal or abnormal regional Function during a dobutamine stress echo test. Aims: The aims of our pilot study were threefold: (1) to determine the percentage of segments in which interpretable strain rate/strain data could be obtained during routine dobutamine stress echo, (2) to establish whether either the increase in heart rate or artefacts induced by respiration during dobutamine stress echo would influence analysis by degrading the data and (3) to determine the optimal frame rate vs image sector angle settings for data acquisition. Furthermore, although the detection of ischaemia was not to be addressed specifically in this study, we would describe the findings on the potential clinical role of regional deformation vs velocity imaging in detecting ischaemia-induced changes. Methods: A standard dobutamine stress echo protocol was performed in 20 consecutive patients with a history of chest pain (16 with angiographic coronary artery disease and four with normal coronary angiograms). DMI velocities were acquired at baseline, low dose, peak dose, and recovery. To evaluate Radial Function (basal segment of the left ventricle posterior wall segment), parasternal LAX, SAX views were used. For long axis Function data were acquired (4-CH, 2-CH views) from the septum; lateral, inferior and anterior left ventricle walls. Data was acquired using both 15° (>150 frames per second (fps) and 45° (115 fps) sector angles. During post-processing each wall was divided into three segments: basal, mid and apical. Strain rate/strain values were averaged over three consecutive heart cycles. Results: Data was obtained from 1936 segments, of which only 54 had to be excluded from subsequent analysis (2.8%) because of suboptimal quality. An increase in heart rates (up to 150/min) was not associated with a significant reduction in the number of interpretable segments. There was a significant correlation between maximal systolic strain rate/strain values obtained at narrow and at wide sector angles (e.g. a correlation for the septal segments: r=0.73, P <0.001 for strain rate, and r=0.71; P <0.001 for strain). The correlation for the timing of events obtained from narrow and wide sector angles was weaker. This would indicate that there was the insufficient temporal resolution for the latter acquisition method. Normal and abnormal regional strain rate/strain responses to an incremental dobutamine infusion were defined. In normal segments, maximal systolic strain rate values increased continuously from baseline, reaching the highest values at the peak dose of dobutamine. The segmental strain response was different. For strain, there was an initial slight increase at low dose of dobutamine (5, 10 μg/kg/min), but no further increase with increasing dose. A pattern representing an ischaemic response was identified and described. Conclusions: The feasibility study would suggest that with appropriate data collection and post-processing methodologies, strain rate/strain imaging can be applied to the quantification of dobutamine stress echo. However, appropriate post-processing algorithms must be introduced to reduce data analysis time in order to make this a practical clinical technique. Copyright 2002 The European Society of Cardiology. Published by Elsevier Science Ltd. All rights reserved .

  • defining the transmurality of a chronic myocardial infarction by ultrasonic strain rate imaging implications for identifying intramural viability an experimental study
    Circulation, 2003
    Co-Authors: F Weidemann, Piet Claus, Christoph Dommke, Jan Dhooge, Bart Bijnens, Paul Mertens, Eric Verbeken, Alex Maes, Frans Van De Werf, Ivan De Scheerder
    Abstract:

    Background— In a correlative Functional/histopathologic study, we investigated the regional deformation characteristics of both chronic nontransmural and transmural infarctions before and after a dobutamine challenge. Methods and Results— After stenosing copper-coated stent implantation to produce circumflex artery endothelial proliferation, 18 pigs were followed up for 5 weeks. Posteuthanasia histology showed 10 to have a nontransmural and 8 a transmural infarction. Eight nonstented animals served as controls. Regional Radial Function was monitored by measuring ultrasound-derived peak systolic strain rates (SRSYS) and systolic strains (eSYS) (1) before stent implantation and (2) at 5 weeks, at baseline (bs) and during an incremental dobutamine infusion. In controls, dobutamine induced a linear increase in SRSYS (dobutamine: bs, 4.8±0.4 s−1; 20 μg · kg−1 · min−1, 9.9±0.7 s−1; P<0.0001) and an initial increase of eSYS at low dose (bs, 58±5%; at 5 μg · kg−1 · min−1, 78±6%; P<0.05) but a subsequent decrease ...

  • defining the transmurality of a chronic myocardial infarction by ultrasonic strain rate imaging implications for identifying intramural viability an experimental study
    Circulation, 2003
    Co-Authors: Frank Weidemann, Piet Claus, Christoph Dommke, Jan Dhooge, Bart Bijnens, Paul Mertens, Eric Verbeken, Alex Maes, Frans Van De Werf, Ivan De Scheerder
    Abstract:

    BACKGROUND: In a correlative Functional/histopathologic study, we investigated the regional deformation characteristics of both chronic nontransmural and transmural infarctions before and after a dobutamine challenge. METHODS AND RESULTS: After stenosing copper-coated stent implantation to produce circumflex artery endothelial proliferation, 18 pigs were followed up for 5 weeks. Posteuthanasia histology showed 10 to have a nontransmural and 8 a transmural infarction. Eight nonstented animals served as controls. Regional Radial Function was monitored by measuring ultrasound-derived peak systolic strain rates (SR(SYS)) and systolic strains (epsilon(SYS)) (1) before stent implantation and (2) at 5 weeks, at baseline (bs) and during an incremental dobutamine infusion. In controls, dobutamine induced a linear increase in SR(SYS) (dobutamine: bs, 4.8+/-0.4 s(-1); 20 microg x kg(-1) x min(-1), 9.9+/-0.7 s(-1); P<0.0001) and an initial increase of epsilon(SYS) at low dose (bs, 58+/-5%; at 5 microg x kg(-1) x min(-1), 78+/-6%; P<0.05) but a subsequent decrease during higher infusion rates. In the nontransmural group, bs SR(SYS) and epsilon(SYS) were significantly lower than prestent values (SR(SYS), 2.9+/-0.5 s(-1) and epsilon(SYS), 32+/-6%, P<0.05 versus prestent). During dobutamine infusion, SR(SYS) increased slightly at 5 microg x kg(-1) x min(-1) (4.7+/-0.6 s(-1), P<0.05) but fell during higher infusion rates, whereas epsilon(SYS) showed no change. For nontransmural infarctions, transmural scar extension correlated closely with epsilon(SYS) at bs (r=0.88). For transmural infarctions, SR(SYS) at bs was significantly reduced and epsilon(SYS) was almost not measurable (SR(SYS), 1.8+/-0.3 s(-1); epsilon(SYS), 3+/-4%). Both deformation parameters showed no further change during the incremental dobutamine infusion. CONCLUSIONS: Ultrasonic deformation values could clearly differentiate chronic nontransmural from transmural myocardial infarction. The transmural extension of the scar could be defined by the regional deformation response.

  • doppler tissue velocity strain and strain rate imaging with transesophageal echocardiography in the operating room a feasibility study
    Journal of The American Society of Echocardiography, 2002
    Co-Authors: L Simmons, F Weidemann, Jan Dhooge, Bart Bijnens, George R. Sutherland, Paul Sergeant, Patrick Wouters
    Abstract:

    Abstract Objective: Transesophageal echocardiography (TEE) is increasingly used to monitor regional myocardial Function during cardiac operation. Doppler myocardial imaging (DMI) indices can potentially provide new information on regional Radial and longitudinal myocardial motion and local deformation. This study examined the feasibility of TEE acquisition of regional Radial and longitudinal velocity, displacement (D), strain, and strain rate data during cardiac operation and evaluated the effects of sternotomy and pericardial opening on these indices. Methods: After a baseline transthoracic echocardiographic study, TEE was performed in 22 patients (age 64 ± 7 years) before sternotomy, after sternotomy with intact pericardium, and after pericardial opening. Regional DMI velocity analysis was performed for the transgastric anterior and inferior walls midpapillary segment (Radial Function) and the 4-chamber septum and 2-chamber inferior walls basal, mid, and apical segments (longitudinal Function). For each segment, systolic and diastolic velocity were derived and D, strain, and strain rate calculated. Results: Transthoracic echocardiographic study and TEE provided similar data from an equivalent number of interpretable segments. In the basal and mid septum, maximum longitudinal systolic D decreased with pericardial opening (basal septum pericardium closed: 6.6 ± 1.5 mm, open: 4.6 ± 1.8 mm, P =.007; midseptum pericardium closed: 4.7 ± 2.5 mm, open: 2.7 ± 1.5 mm, P =.028). No changes were evident in systolic or diastolic DMI indices in all other segments. Conclusion: DMI with TEE is feasible during cardiac operation. During pericardial opening, longitudinal D decreases in the septum, but not in the inferior wall. DMI requires further evaluation in the assessment of ventricular Function and the detection of ischemia in the operating room. (J Am Soc Echocardiogr 2002;15:768-76.)

  • quantification of regional left and right ventricular Radial and longitudinal Function in healthy children using ultrasound based strain rate and strain imaging
    Journal of The American Society of Echocardiography, 2002
    Co-Authors: F Weidemann, Miroslaw Kowalski, Jan Dhooge, Bart Bijnens, Benedicte Eyskens, F Jamal, Luc Mertens, Marc Gewillig, Frank Rademakers, Liv Hatle
    Abstract:

    Background: Noninvasive assessment of left (LV) and right (RV) ventricular Function in children could benefit from a technique that would characterize local myocardial deformation. Color Doppler myocardial imaging (CDMI) allows the calculation of either local longitudinal or Radial Strain Rate (SR) and Strain (e). To determine the clinical feasibility and reproducibility of longitudinal and Radial SR and e, the following study was carried out. Methods: CDMI data were obtained from 33 healthy children (4-16 years). To quantify regional longitudinal and Radial Function SR and e data were obtained from apical and parasternal views respectively. From the extracted SR curves, peak values for systole, early diastole, and late diastole were calculated. From the extracted e curves the systolic, early and late diastolic e values were calculated. Results: LV longitudinal deformation were homogeneous for LV basal, mid and apical segments (peak systolic SR: –1.9 ± 0.7 s–1, systolic e –25% ± 7%). Longitudinal SR and e values were significantly higher and heterogeneous in the RV (compared with LV walls) and were maximal in the mid part of the RV free wall (peak systolic SR: –2.8 ± 0.7 s–1, systolic e –45% ± 13%). The RV inferior wall showed homogenous but lower longitudinal SR and e values. The LV systolic and diastolic SR and e values were higher for deformation in the Radial direction compared with the longitudinal direction (Radial peak systolic SR: 3.7 ± 0.9 s–1, Radial systolic e 57% ± 11%; P < .0001). The interobserver variability for Radial systolic e and SR was 10.3% and 13.1%, respectively. Conclusion: Ultrasound-based Strain SR/e imaging is a practical, reproducible clinical technique, which allows the calculation of regional longitudinal and Radial deformation from both LV and RV segments. The combination of regional SR/e indices and the timing of specific systolic or diastolic regional events may offer a new noninvasive approach to quantifying regional myocardial Function in congenital and acquired heart disease in children. (J Am

Ivan De Scheerder - One of the best experts on this subject based on the ideXlab platform.

  • defining the transmurality of a chronic myocardial infarction by ultrasonic strain rate imaging implications for identifying intramural viability an experimental study
    Circulation, 2003
    Co-Authors: F Weidemann, Piet Claus, Christoph Dommke, Jan Dhooge, Bart Bijnens, Paul Mertens, Eric Verbeken, Alex Maes, Frans Van De Werf, Ivan De Scheerder
    Abstract:

    Background— In a correlative Functional/histopathologic study, we investigated the regional deformation characteristics of both chronic nontransmural and transmural infarctions before and after a dobutamine challenge. Methods and Results— After stenosing copper-coated stent implantation to produce circumflex artery endothelial proliferation, 18 pigs were followed up for 5 weeks. Posteuthanasia histology showed 10 to have a nontransmural and 8 a transmural infarction. Eight nonstented animals served as controls. Regional Radial Function was monitored by measuring ultrasound-derived peak systolic strain rates (SRSYS) and systolic strains (eSYS) (1) before stent implantation and (2) at 5 weeks, at baseline (bs) and during an incremental dobutamine infusion. In controls, dobutamine induced a linear increase in SRSYS (dobutamine: bs, 4.8±0.4 s−1; 20 μg · kg−1 · min−1, 9.9±0.7 s−1; P<0.0001) and an initial increase of eSYS at low dose (bs, 58±5%; at 5 μg · kg−1 · min−1, 78±6%; P<0.05) but a subsequent decrease ...

  • defining the transmurality of a chronic myocardial infarction by ultrasonic strain rate imaging implications for identifying intramural viability an experimental study
    Circulation, 2003
    Co-Authors: Frank Weidemann, Piet Claus, Christoph Dommke, Jan Dhooge, Bart Bijnens, Paul Mertens, Eric Verbeken, Alex Maes, Frans Van De Werf, Ivan De Scheerder
    Abstract:

    BACKGROUND: In a correlative Functional/histopathologic study, we investigated the regional deformation characteristics of both chronic nontransmural and transmural infarctions before and after a dobutamine challenge. METHODS AND RESULTS: After stenosing copper-coated stent implantation to produce circumflex artery endothelial proliferation, 18 pigs were followed up for 5 weeks. Posteuthanasia histology showed 10 to have a nontransmural and 8 a transmural infarction. Eight nonstented animals served as controls. Regional Radial Function was monitored by measuring ultrasound-derived peak systolic strain rates (SR(SYS)) and systolic strains (epsilon(SYS)) (1) before stent implantation and (2) at 5 weeks, at baseline (bs) and during an incremental dobutamine infusion. In controls, dobutamine induced a linear increase in SR(SYS) (dobutamine: bs, 4.8+/-0.4 s(-1); 20 microg x kg(-1) x min(-1), 9.9+/-0.7 s(-1); P<0.0001) and an initial increase of epsilon(SYS) at low dose (bs, 58+/-5%; at 5 microg x kg(-1) x min(-1), 78+/-6%; P<0.05) but a subsequent decrease during higher infusion rates. In the nontransmural group, bs SR(SYS) and epsilon(SYS) were significantly lower than prestent values (SR(SYS), 2.9+/-0.5 s(-1) and epsilon(SYS), 32+/-6%, P<0.05 versus prestent). During dobutamine infusion, SR(SYS) increased slightly at 5 microg x kg(-1) x min(-1) (4.7+/-0.6 s(-1), P<0.05) but fell during higher infusion rates, whereas epsilon(SYS) showed no change. For nontransmural infarctions, transmural scar extension correlated closely with epsilon(SYS) at bs (r=0.88). For transmural infarctions, SR(SYS) at bs was significantly reduced and epsilon(SYS) was almost not measurable (SR(SYS), 1.8+/-0.3 s(-1); epsilon(SYS), 3+/-4%). Both deformation parameters showed no further change during the incremental dobutamine infusion. CONCLUSIONS: Ultrasonic deformation values could clearly differentiate chronic nontransmural from transmural myocardial infarction. The transmural extension of the scar could be defined by the regional deformation response.

Piet Claus - One of the best experts on this subject based on the ideXlab platform.

  • Young Investigator Award session - Basic Science74Regional differences in Radial Function in a closed chest, closed pericardium model of acute left ventricular afterload increase75Cardiac-specific over-expression of epidermal growth factor receptor 2
    European Heart Journal - Cardiovascular Imaging, 2013
    Co-Authors: Maja Cikes, Piet Claus, George R. Sutherland, Nina Jakuš, P. Haemers, Jan D'hooge, L. L. Sorensen, D. Bedja, P. Shah, Theodore P. Abraham
    Abstract:

    # 74 Regional differences in Radial Function in a closed chest, closed pericardium model of acute left ventricular afterload increase {#article-title-2} Purpose: Chronic pressure overload as in hypertension leads to regional LV remodelling, primarily affecting the basal iv. septum (IVS) which hypertrophies and shows reduced longitudinal Function. This can be compensated by increased Radial Function, particularly in early disease. Measurement of systolic upstroke and diastolic downstroke of LV wall motion by M-mode might provide similar Radial data. We have tested these easily obtainable measurements on our closed chest/closed pericardium pig model, pertaining as close to physiology as possible. In this model, we aimed to study LV wall systolic thickening and diastolic thinning velocities in acute pressure overload. Methods: 7 anesthetised, closed chest/closed pericardium pigs were instrumented with a descending aorta balloon, partially inflated during 5-10 heartbeats creating an 30% LV pressure increase. Echocardiographic LV LAX B-mode cine-loops were acquired (5 pre-, 5-10 inflation, 10 postinflation beats). The velocity of systolic thickening upstroke and diastolic thinning downstroke of the IVS and the LV posterior wall (LVPW) were measured from anatomic M-mode images of the LV base, mid and apex. Results: During balloon inflation, a reduction in the upstroke and downstroke velocities occurred in the basal LVPW, mid and apical IVS and LVPW, recovering after balloon deflation. However, the basal IVS showed the opposite-increased thickening and thinning velocities in response to afterload (Table 1). Conclusions: The basal LV septum differs from the remaining LV as the segment with the highest wall stress. In this model, we have demonstrated the increase in Radial thickening and relaxation of the basal IVS with acute afterload, as opposed to the other LV segments where these parameters acutely decrease. These findings provide better insight into LV Functional remodelling in acute afterload and, due to the selected animal model, might provide better translational data for the clinical setting.[⇓][1] View this table: Table. # 75 Cardiac-specific over-expression of epidermal growth factor receptor 2 (ErbB2); A novel small animal model of hypertrophic obstructive cardiomyopathy {#article-title-3} Background: Several small animal models of HCM exist with mutations in the troponin- or myosin heavy chain genes. Even though these animal models have metabolic, energetic and cellular abnormalities, the echocardiographic phenotype is usually mild with marginal or no hypertrophy and in some cases mild diastolic dysFunction expressed as impaired relaxation. Methods/Results: Our group has investigated the phenotypic consequences of a cardiac-restricted over-expression of ErbB2 in two novel lines of transgenic mice. Our previously published data on the ErbB2 animals showed pathological features compatible with HCM with myocyte disarray, fibrosis and myocyte hypertrophy. We performed a detailed echocardiography examination on 16 transgenic ErbB2 animals and 17 littermate controls using a high frequency ultrasound machine (32-56 MHz transducer). The ErbB2 animals show severe hypertrophy of both anterior and posterior walls. The hypertrophy is accompanied by severe diastolic dysFunction expressed by reduced E/A-ratio, prolonged deceleration time and severely elevated E/e’. Likewise the LVOT gradients were severely elevated in the ErbB2 animals. The systolic Function evaluated both with ejection fraction and systolic strain by speckle tracking was preserved in the ErbB2 animals. Conclusion: The ErbB2 mice model display a phenotype compatible with human HCM in many important aspects as massive LV-hypertrophy, diastolic dysFunction, systolic strain pattern and LVOT-obstruction, especially the presences of LVOT-obstruction is unique for a small animal model, making this model well suited for research in LVOT-gradient lowering drugs and interventions.[⇓][2] View this table: Table. Echocardiography comparison # 76 Impact of the nyquist limit on mitral regurgitant flow rate as measured by 3-dimensional proximal isovelocity surface area {#article-title-4} Introduction: Using 2-D echocardiography, the proximal isovelocity surface area (PISA) is assumed to be a hemisphere. The calculated flow rate across the leaking mitral valve (Qmr) varies with the selected aliasing velocity. In addition, the optimal range of velocities is shifted upward with increasing Qmr. Conceptually, Qmr derived from 3-D PISA is independent of the Nyquist limit, because PISA surface is directly measured. Methods: In patients suffering from mitral regurgitation (MR) referred for TEE, color Doppler pyramidal volumes focused on MR-PISA were recorded during 6 heart beats in apnea using ECG triggered multiple-beat 3-D echocardiography. PISA with clear aliasing boundaries were extracted as slices. After 3-D reconstruction using customized software, PISA was measured in cm2 and the Qmr was calculated (Nyquist velocity x PISA). Results: Loops were acquired in 9 patients, 60 volumes were chosen and, using 4 different Nyquist limits per volume (10.3, 20.5, 30.8 and 41.1cm/s), 240 PISA were 3-D-modeled. Calculated Qmr ranged from 10 to 157 ml/s. The correlations between the calculated Qmr at different Nyquist limits were excellent (R2>0.8, fig. 1). There was no difference between Qmr calculated with Nyquist limits of 30.8 and 41.1cm/s; at lower Nyquist velocities, the computed Qmr were significantly lower (fig. 2). Conclusions: Using Nyquist limits of 30.8 and 41.1cm/s, Qmr as measured by 3-D PISA are stable; this stability is not influenced by the amount of Qmr. At lower aliasing velocity, i.e. increasing distance from the orifice, the MR jet confinement by solid boundaries and its disturbance by the ventricular outflow field is known to result in increasingly paraboloid PISA. This seems to cause a reduction of the measured 3-D PISA and a fall in the calculated Qmr.[⇓][3] ![Figure][4] Figure [1]: #T1 [2]: #T2 [3]: #F1 [4]: pending:yes

  • the feasibility of ultrasonic regional strain and strain rate imaging in quantifying dobutamine stress echocardiography
    European Journal of Echocardiography, 2003
    Co-Authors: Miroslaw Kowalski, Piet Claus, Marie-christine Herregods, Lieven Herbots, F Weidemann, L Simmons, Jorg Strotmann, Christoph Dommke, Jan Dhooge, Bart Bijnens
    Abstract:

    Background: Ultrasonic strain rate and strain can characterize regional one-dimensional myocardial deformation at rest. In theory, these deformation indices could be used to quantify normal or abnormal regional Function during a dobutamine stress echo test. Aims: The aims of our pilot study were threefold: (1) to determine the percentage of segments in which interpretable strain rate/strain data could be obtained during routine dobutamine stress echo, (2) to establish whether either the increase in heart rate or artefacts induced by respiration during dobutamine stress echo would influence analysis by degrading the data and (3) to determine the optimal frame rate vs image sector angle settings for data acquisition. Furthermore, although the detection of ischaemia was not to be addressed specifically in this study, we would describe the findings on the potential clinical role of regional deformation vs velocity imaging in detecting ischaemia-induced changes. Methods: A standard dobutamine stress echo protocol was performed in 20 consecutive patients with a history of chest pain (16 with angiographic coronary artery disease and four with normal coronary angiograms). DMI velocities were acquired at baseline, low dose, peak dose, and recovery. To evaluate Radial Function (basal segment of the left ventricle posterior wall segment), parasternal LAX, SAX views were used. For long axis Function data were acquired (4-CH, 2-CH views) from the septum; lateral, inferior and anterior left ventricle walls. Data was acquired using both 15° (>150 frames per second (fps) and 45° (115 fps) sector angles. During post-processing each wall was divided into three segments: basal, mid and apical. Strain rate/strain values were averaged over three consecutive heart cycles. Results: Data was obtained from 1936 segments, of which only 54 had to be excluded from subsequent analysis (2.8%) because of suboptimal quality. An increase in heart rates (up to 150/min) was not associated with a significant reduction in the number of interpretable segments. There was a significant correlation between maximal systolic strain rate/strain values obtained at narrow and at wide sector angles (e.g. a correlation for the septal segments: r=0.73, P <0.001 for strain rate, and r=0.71; P <0.001 for strain). The correlation for the timing of events obtained from narrow and wide sector angles was weaker. This would indicate that there was the insufficient temporal resolution for the latter acquisition method. Normal and abnormal regional strain rate/strain responses to an incremental dobutamine infusion were defined. In normal segments, maximal systolic strain rate values increased continuously from baseline, reaching the highest values at the peak dose of dobutamine. The segmental strain response was different. For strain, there was an initial slight increase at low dose of dobutamine (5, 10 μg/kg/min), but no further increase with increasing dose. A pattern representing an ischaemic response was identified and described. Conclusions: The feasibility study would suggest that with appropriate data collection and post-processing methodologies, strain rate/strain imaging can be applied to the quantification of dobutamine stress echo. However, appropriate post-processing algorithms must be introduced to reduce data analysis time in order to make this a practical clinical technique. Copyright 2002 The European Society of Cardiology. Published by Elsevier Science Ltd. All rights reserved .

  • defining the transmurality of a chronic myocardial infarction by ultrasonic strain rate imaging implications for identifying intramural viability an experimental study
    Circulation, 2003
    Co-Authors: F Weidemann, Piet Claus, Christoph Dommke, Jan Dhooge, Bart Bijnens, Paul Mertens, Eric Verbeken, Alex Maes, Frans Van De Werf, Ivan De Scheerder
    Abstract:

    Background— In a correlative Functional/histopathologic study, we investigated the regional deformation characteristics of both chronic nontransmural and transmural infarctions before and after a dobutamine challenge. Methods and Results— After stenosing copper-coated stent implantation to produce circumflex artery endothelial proliferation, 18 pigs were followed up for 5 weeks. Posteuthanasia histology showed 10 to have a nontransmural and 8 a transmural infarction. Eight nonstented animals served as controls. Regional Radial Function was monitored by measuring ultrasound-derived peak systolic strain rates (SRSYS) and systolic strains (eSYS) (1) before stent implantation and (2) at 5 weeks, at baseline (bs) and during an incremental dobutamine infusion. In controls, dobutamine induced a linear increase in SRSYS (dobutamine: bs, 4.8±0.4 s−1; 20 μg · kg−1 · min−1, 9.9±0.7 s−1; P<0.0001) and an initial increase of eSYS at low dose (bs, 58±5%; at 5 μg · kg−1 · min−1, 78±6%; P<0.05) but a subsequent decrease ...

  • defining the transmurality of a chronic myocardial infarction by ultrasonic strain rate imaging implications for identifying intramural viability an experimental study
    Circulation, 2003
    Co-Authors: Frank Weidemann, Piet Claus, Christoph Dommke, Jan Dhooge, Bart Bijnens, Paul Mertens, Eric Verbeken, Alex Maes, Frans Van De Werf, Ivan De Scheerder
    Abstract:

    BACKGROUND: In a correlative Functional/histopathologic study, we investigated the regional deformation characteristics of both chronic nontransmural and transmural infarctions before and after a dobutamine challenge. METHODS AND RESULTS: After stenosing copper-coated stent implantation to produce circumflex artery endothelial proliferation, 18 pigs were followed up for 5 weeks. Posteuthanasia histology showed 10 to have a nontransmural and 8 a transmural infarction. Eight nonstented animals served as controls. Regional Radial Function was monitored by measuring ultrasound-derived peak systolic strain rates (SR(SYS)) and systolic strains (epsilon(SYS)) (1) before stent implantation and (2) at 5 weeks, at baseline (bs) and during an incremental dobutamine infusion. In controls, dobutamine induced a linear increase in SR(SYS) (dobutamine: bs, 4.8+/-0.4 s(-1); 20 microg x kg(-1) x min(-1), 9.9+/-0.7 s(-1); P<0.0001) and an initial increase of epsilon(SYS) at low dose (bs, 58+/-5%; at 5 microg x kg(-1) x min(-1), 78+/-6%; P<0.05) but a subsequent decrease during higher infusion rates. In the nontransmural group, bs SR(SYS) and epsilon(SYS) were significantly lower than prestent values (SR(SYS), 2.9+/-0.5 s(-1) and epsilon(SYS), 32+/-6%, P<0.05 versus prestent). During dobutamine infusion, SR(SYS) increased slightly at 5 microg x kg(-1) x min(-1) (4.7+/-0.6 s(-1), P<0.05) but fell during higher infusion rates, whereas epsilon(SYS) showed no change. For nontransmural infarctions, transmural scar extension correlated closely with epsilon(SYS) at bs (r=0.88). For transmural infarctions, SR(SYS) at bs was significantly reduced and epsilon(SYS) was almost not measurable (SR(SYS), 1.8+/-0.3 s(-1); epsilon(SYS), 3+/-4%). Both deformation parameters showed no further change during the incremental dobutamine infusion. CONCLUSIONS: Ultrasonic deformation values could clearly differentiate chronic nontransmural from transmural myocardial infarction. The transmural extension of the scar could be defined by the regional deformation response.