The Experts below are selected from a list of 8073 Experts worldwide ranked by ideXlab platform
Julio E. Pérez - One of the best experts on this subject based on the ideXlab platform.
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myocardial Contractile State in dogs with chronic mitral regurgitation echocardiographic approach to the peak systolic pressure end systolic area relationship
American Heart Journal, 1993Co-Authors: Victor G Davilaroman, Lawrence L. Creswell, Michael Rosenbloom, Julio E. PérezAbstract:Analysis of the pressure-dimension relationship provides a sensitive index of myocardial contractility, but widespread application of this method is limited because it requires invasive measurement techniques. The recent development of two-dimensional echocardiographic automatic boundary detection permits accurate and reproducible on-line measurement of ventricular cavity areas that can be combined with ventricular pressure measurements to derive instantaneous pressure-area relationships. In anesthetized closed-chest dogs with chronic mitral regurgitation, the slope of the ventricular pressure-area relationship was determined by obtaining baseline measurements (at baseline and after infusion of methoxamine or nitroglycerin) and measurements after infusion of a positive inotropic drug (dobutamine) alone and concurrently with methoxamine or nitroglycerin. The slope of the ventricular pressure-area relationship was altered significantly ( p = 0.0002) and in the expected direction (steeper slope) from baseline to the enhanced myocardial inotropic State after dobutamine infusion. Thus on-line echocardiographic measurements of ventricular cavity area facilitate the implementation of elastance determinations to serially evaluate the myocardial Contractile State under conditions of alterations in preload, afterload, and the inotropic State. This method is promising for the noninvasive evaluation of left ventricular function modified by diverse pathologic conditions.
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Myocardial Contractile State in dogs with chronic mitral regurgitation: Echocardiographic approach to the peak systolic pressure/end-systolic area relationship*
American heart journal, 1993Co-Authors: Victor G. Davila-roman, Lawrence L. Creswell, Michael Rosenbloom, Julio E. PérezAbstract:Analysis of the pressure-dimension relationship provides a sensitive index of myocardial contractility, but widespread application of this method is limited because it requires invasive measurement techniques. The recent development of two-dimensional echocardiographic automatic boundary detection permits accurate and reproducible on-line measurement of ventricular cavity areas that can be combined with ventricular pressure measurements to derive instantaneous pressure-area relationships. In anesthetized closed-chest dogs with chronic mitral regurgitation, the slope of the ventricular pressure-area relationship was determined by obtaining baseline measurements (at baseline and after infusion of methoxamine or nitroglycerin) and measurements after infusion of a positive inotropic drug (dobutamine) alone and concurrently with methoxamine or nitroglycerin. The slope of the ventricular pressure-area relationship was altered significantly ( p = 0.0002) and in the expected direction (steeper slope) from baseline to the enhanced myocardial inotropic State after dobutamine infusion. Thus on-line echocardiographic measurements of ventricular cavity area facilitate the implementation of elastance determinations to serially evaluate the myocardial Contractile State under conditions of alterations in preload, afterload, and the inotropic State. This method is promising for the noninvasive evaluation of left ventricular function modified by diverse pathologic conditions.
Masayoshi Yanagisawa - One of the best experts on this subject based on the ideXlab platform.
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left ventricular Contractile State in preterm infants relation between wall stress and velocity of circumferential fiber shortening
American Heart Journal, 1994Co-Authors: Hiroshi Igarashi, Hirohiko Shiraishi, Hideki Endoh, Masayoshi YanagisawaAbstract:Abstract Fetal and newborn lambs' hearts have limited capacity to adapt to increased afterload. In human preterm infants, however, this limited left ventricular pump function has not been investigated. To determine the normal left ventricular resting Contractile State in preterm infants, we studied the relation of end-systolic wall stress to the rate-corrected velocity of circumferential fiber shortening (VCF) in 11 preterm infants of gestational ages 28 to 36 weeks. We performed the first (7 to 14 days of postnatal age) and the second (29 to 39 days of postnatal age) examinations. There was a significant inverse linear correlation between wall stress and VCF in the first and the second examinations ( r = −0.616 and r = −0.715, respectively). Both regression lines had slopes that were steeper than those previously reported for older age groups. The preterm infants had high VCF values (mean 1.05 and 1.09 circ/sec, respectively) and low-wall stress values (mean 36.0 and 36.9 gm/cm 2 , respectively) in the first and the second examinations. We therefore suggest that the preterm infants have a high resting Contractile State, but left ventricular performance may deteriorate in the face of increased afterload.
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Noninvasive estimation of left ventricular Contractile State and afterload in normal newborn infants.
The American journal of cardiology, 1991Co-Authors: Hiroshi Igarashi, Hirohiko Shiraishi, Hideki Endoh, Masayoshi YanagisawaAbstract:Abstract Cardiac performance is altered by loading conditions and by heart rate, especially in newborn infants. Ejection phase indexes such as ejection fraction and fractional shortening might be useful in evaluating their cardiac function. The clinical use of these indexes is limited by the inability to distinguish between the effects of altered loading conditions and of abnormalities in left ventricular contractility. The relation between end-systolic endocardial meridional stress and the rate-corrected velocity of circumferential fiber shortening is a sensitive echocardiographic method for evaluating left ventricular contractility, which is relatively independent of loading. 1–5 There have been no reports on the relation between endocardial meridional stress and rate-corrected velocity of circumferential fiber shortening in newborns. We studied the relation between endocardial meridional stress and the rate-corrected velocity of circumferential fiber shortening in normal newborn infants to determine the normal values and to estimate the Contractile State.
Michael Rosenbloom - One of the best experts on this subject based on the ideXlab platform.
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myocardial Contractile State in dogs with chronic mitral regurgitation echocardiographic approach to the peak systolic pressure end systolic area relationship
American Heart Journal, 1993Co-Authors: Victor G Davilaroman, Lawrence L. Creswell, Michael Rosenbloom, Julio E. PérezAbstract:Analysis of the pressure-dimension relationship provides a sensitive index of myocardial contractility, but widespread application of this method is limited because it requires invasive measurement techniques. The recent development of two-dimensional echocardiographic automatic boundary detection permits accurate and reproducible on-line measurement of ventricular cavity areas that can be combined with ventricular pressure measurements to derive instantaneous pressure-area relationships. In anesthetized closed-chest dogs with chronic mitral regurgitation, the slope of the ventricular pressure-area relationship was determined by obtaining baseline measurements (at baseline and after infusion of methoxamine or nitroglycerin) and measurements after infusion of a positive inotropic drug (dobutamine) alone and concurrently with methoxamine or nitroglycerin. The slope of the ventricular pressure-area relationship was altered significantly ( p = 0.0002) and in the expected direction (steeper slope) from baseline to the enhanced myocardial inotropic State after dobutamine infusion. Thus on-line echocardiographic measurements of ventricular cavity area facilitate the implementation of elastance determinations to serially evaluate the myocardial Contractile State under conditions of alterations in preload, afterload, and the inotropic State. This method is promising for the noninvasive evaluation of left ventricular function modified by diverse pathologic conditions.
-
Myocardial Contractile State in dogs with chronic mitral regurgitation: Echocardiographic approach to the peak systolic pressure/end-systolic area relationship*
American heart journal, 1993Co-Authors: Victor G. Davila-roman, Lawrence L. Creswell, Michael Rosenbloom, Julio E. PérezAbstract:Analysis of the pressure-dimension relationship provides a sensitive index of myocardial contractility, but widespread application of this method is limited because it requires invasive measurement techniques. The recent development of two-dimensional echocardiographic automatic boundary detection permits accurate and reproducible on-line measurement of ventricular cavity areas that can be combined with ventricular pressure measurements to derive instantaneous pressure-area relationships. In anesthetized closed-chest dogs with chronic mitral regurgitation, the slope of the ventricular pressure-area relationship was determined by obtaining baseline measurements (at baseline and after infusion of methoxamine or nitroglycerin) and measurements after infusion of a positive inotropic drug (dobutamine) alone and concurrently with methoxamine or nitroglycerin. The slope of the ventricular pressure-area relationship was altered significantly ( p = 0.0002) and in the expected direction (steeper slope) from baseline to the enhanced myocardial inotropic State after dobutamine infusion. Thus on-line echocardiographic measurements of ventricular cavity area facilitate the implementation of elastance determinations to serially evaluate the myocardial Contractile State under conditions of alterations in preload, afterload, and the inotropic State. This method is promising for the noninvasive evaluation of left ventricular function modified by diverse pathologic conditions.
Lawrence L. Creswell - One of the best experts on this subject based on the ideXlab platform.
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myocardial Contractile State in dogs with chronic mitral regurgitation echocardiographic approach to the peak systolic pressure end systolic area relationship
American Heart Journal, 1993Co-Authors: Victor G Davilaroman, Lawrence L. Creswell, Michael Rosenbloom, Julio E. PérezAbstract:Analysis of the pressure-dimension relationship provides a sensitive index of myocardial contractility, but widespread application of this method is limited because it requires invasive measurement techniques. The recent development of two-dimensional echocardiographic automatic boundary detection permits accurate and reproducible on-line measurement of ventricular cavity areas that can be combined with ventricular pressure measurements to derive instantaneous pressure-area relationships. In anesthetized closed-chest dogs with chronic mitral regurgitation, the slope of the ventricular pressure-area relationship was determined by obtaining baseline measurements (at baseline and after infusion of methoxamine or nitroglycerin) and measurements after infusion of a positive inotropic drug (dobutamine) alone and concurrently with methoxamine or nitroglycerin. The slope of the ventricular pressure-area relationship was altered significantly ( p = 0.0002) and in the expected direction (steeper slope) from baseline to the enhanced myocardial inotropic State after dobutamine infusion. Thus on-line echocardiographic measurements of ventricular cavity area facilitate the implementation of elastance determinations to serially evaluate the myocardial Contractile State under conditions of alterations in preload, afterload, and the inotropic State. This method is promising for the noninvasive evaluation of left ventricular function modified by diverse pathologic conditions.
-
Myocardial Contractile State in dogs with chronic mitral regurgitation: Echocardiographic approach to the peak systolic pressure/end-systolic area relationship*
American heart journal, 1993Co-Authors: Victor G. Davila-roman, Lawrence L. Creswell, Michael Rosenbloom, Julio E. PérezAbstract:Analysis of the pressure-dimension relationship provides a sensitive index of myocardial contractility, but widespread application of this method is limited because it requires invasive measurement techniques. The recent development of two-dimensional echocardiographic automatic boundary detection permits accurate and reproducible on-line measurement of ventricular cavity areas that can be combined with ventricular pressure measurements to derive instantaneous pressure-area relationships. In anesthetized closed-chest dogs with chronic mitral regurgitation, the slope of the ventricular pressure-area relationship was determined by obtaining baseline measurements (at baseline and after infusion of methoxamine or nitroglycerin) and measurements after infusion of a positive inotropic drug (dobutamine) alone and concurrently with methoxamine or nitroglycerin. The slope of the ventricular pressure-area relationship was altered significantly ( p = 0.0002) and in the expected direction (steeper slope) from baseline to the enhanced myocardial inotropic State after dobutamine infusion. Thus on-line echocardiographic measurements of ventricular cavity area facilitate the implementation of elastance determinations to serially evaluate the myocardial Contractile State under conditions of alterations in preload, afterload, and the inotropic State. This method is promising for the noninvasive evaluation of left ventricular function modified by diverse pathologic conditions.
Hiroshi Igarashi - One of the best experts on this subject based on the ideXlab platform.
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left ventricular Contractile State in preterm infants relation between wall stress and velocity of circumferential fiber shortening
American Heart Journal, 1994Co-Authors: Hiroshi Igarashi, Hirohiko Shiraishi, Hideki Endoh, Masayoshi YanagisawaAbstract:Abstract Fetal and newborn lambs' hearts have limited capacity to adapt to increased afterload. In human preterm infants, however, this limited left ventricular pump function has not been investigated. To determine the normal left ventricular resting Contractile State in preterm infants, we studied the relation of end-systolic wall stress to the rate-corrected velocity of circumferential fiber shortening (VCF) in 11 preterm infants of gestational ages 28 to 36 weeks. We performed the first (7 to 14 days of postnatal age) and the second (29 to 39 days of postnatal age) examinations. There was a significant inverse linear correlation between wall stress and VCF in the first and the second examinations ( r = −0.616 and r = −0.715, respectively). Both regression lines had slopes that were steeper than those previously reported for older age groups. The preterm infants had high VCF values (mean 1.05 and 1.09 circ/sec, respectively) and low-wall stress values (mean 36.0 and 36.9 gm/cm 2 , respectively) in the first and the second examinations. We therefore suggest that the preterm infants have a high resting Contractile State, but left ventricular performance may deteriorate in the face of increased afterload.
-
Noninvasive estimation of left ventricular Contractile State and afterload in normal newborn infants.
The American journal of cardiology, 1991Co-Authors: Hiroshi Igarashi, Hirohiko Shiraishi, Hideki Endoh, Masayoshi YanagisawaAbstract:Abstract Cardiac performance is altered by loading conditions and by heart rate, especially in newborn infants. Ejection phase indexes such as ejection fraction and fractional shortening might be useful in evaluating their cardiac function. The clinical use of these indexes is limited by the inability to distinguish between the effects of altered loading conditions and of abnormalities in left ventricular contractility. The relation between end-systolic endocardial meridional stress and the rate-corrected velocity of circumferential fiber shortening is a sensitive echocardiographic method for evaluating left ventricular contractility, which is relatively independent of loading. 1–5 There have been no reports on the relation between endocardial meridional stress and rate-corrected velocity of circumferential fiber shortening in newborns. We studied the relation between endocardial meridional stress and the rate-corrected velocity of circumferential fiber shortening in normal newborn infants to determine the normal values and to estimate the Contractile State.