Phasic Dimensional Changes in the Left Ventricle

Pf, Salisbury; Ce, Cross; Pa, Rieben

doi:10.3109/13813456509084247

Cited by 7 publications

(7 citation statements)

References 18 publications

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“…It was further suggested that LV isovolumic movements may only indicate vibrations produced by "isometric" tensing of the LV wall (27,38). However, our observations, like some earlier investigations (18,19,33,39,40), confirm that cardiac muscle behavior during IVC and IVR cannot be considered isometric. TDI waves, therefore, most likely capture an asynchronous myocardial wall movement that results from nonuniform deformations of different myocardial layers.…”

Section: Discussionsupporting

confidence: 72%

“…Rushmer (39) showed that LV geometric changes during the initial phases of systole were not isometric but were characterized by abrupt expansion of the external circumference such that the chamber assumed a more spherical configuration with a rise in LV pressure. Subsequent investigations showed that the external LV could assume a spherical (18,40) or an elliptical configuration (19,33) and that this change was a function of the LV volume (37). Advent of TDI facilitated quantification of LV function at the regional level, and positive and negative components of myocardial velocities during IVC and IVR were observed in both open-chest experimental animal models and human studies (11,12,26,31).…”

Section: Discussionmentioning

confidence: 99%

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Biphasic tissue Doppler waveforms during isovolumic phases are associated with asynchronous deformation of subendocardial and subepicardial layers

Sengupta

Khandheria

Kořínek

et al. 2005

Journal of Applied Physiology

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Subendocardial and subepicardial layers of the left ventricle (LV) are characterized with right- and left-handed helical orientations of myocardial fibers. We investigated the origin of biphasic deformations of the LV wall during isovolumic contraction (IVC) and relaxation (IVR). In eight open-chest adult pigs, strain rates were measured along the right- and left-handed helical directions in the LV anterior wall by implanting 16 sonomicrometry crystals. Sonomicrometry strain rates were compared with the longitudinal subendocardial strain rates obtained by tissue Doppler imaging. During ejection and diastolic filling, shortening and lengthening occurred synchronously along the right- and left-handed helical directions. However, during IVC and IVR, the deformations were dissimilar in the two directions. Transmural shortening during IVC occurred along the right-handed helical direction and was accompanied with transient lengthening in the left-handed helical direction. Conversely, during IVR, the LV lengthened along the left-handed helical direction and shortened in the right-handed helical direction. Peak subendocardial strain rates obtained by tissue Doppler imaging during IVC and IVR correlated with corresponding sonomicrometry strain rate values obtained along the right- and left-handed helical directions (r = 0.81, P < 0.001 and r = 0.70, P = 0.001, respectively). Our data suggest that brief counterdirectional movements occur within the LV wall during IVC and IVR. Shortening along the right-handed helical direction is accompanied with reciprocal lengthening in the left-handed helical direction during IVC and vice versa during IVR. The results support an association between asynchronous deformation of subendocardial and subepicardial muscle fibers and the biphasic isovolumic movements observed with high-resolution tissue Doppler imaging.

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Section: Discussionsupporting

confidence: 72%

Section: Discussionmentioning

confidence: 99%

Biphasic tissue Doppler waveforms during isovolumic phases are associated with asynchronous deformation of subendocardial and subepicardial layers

Sengupta

Khandheria

Kořínek

et al. 2005

Journal of Applied Physiology

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“…This sphericity of the external LV during IVC has also been described by several investigators (9,27), who, in most cases, used epicardial markers. Others demonstrated the opposite, i.e., an elliptical pattern due to shortening of the LV internal minor axis (10,19) and lengthening of its major axis diameters (27). This apparent discordance is probably due to the different behavior of the external (epicardial) and internal (endocardial) location of the markers.…”

supporting

confidence: 76%

“…Nevertheless, he concluded that the LV abruptly shortens during IVC and that this shortening is accompanied by an outward bulging of the LV main body (24,26). This sphericity of the external LV during IVC has also been described by several investigators (9,27), who, in most cases, used epicardial markers. Others demonstrated the opposite, i.e., an elliptical pattern due to shortening of the LV internal minor axis (10,19) and lengthening of its major axis diameters (27).…”

mentioning

confidence: 70%

Left ventricular endocardial longitudinal and transverse changes during isovolumic contraction and relaxation: a challenge

Goetz¹,

Lansac²,

Lim³

et al. 2005

American Journal of Physiology-Heart and Circulatory Physiology

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. Left ventricular endocardial longitudinal and transverse changes during isovolumic contraction and relaxation: a challenge. Am J Physiol Heart Circ Physiol 289: H196-H201, 2005. First published February 11, 2005 doi:10.1152/ajpheart.00867.2004 longitudinal and transverse geometric changes during isovolumic contraction and relaxation are still controversial. This confusion is compounded by traditional definitions of these phases of the cardiac cycle. High-resolution sonomicrometry studies might clarify these issues. Crystals were implanted in six sheep at the LV apex, fibrous trigones, lateral and posterior mitral annulus, base of the aortic right coronary sinus, anterior and septal endocardial wall, papillary muscle tips, and edge of the anterior and posterior mitral leaflets. Changes in distances were time related to LV and aortic pressures and to mitral valve opening. At the beginning of isovolumic contraction, while the mitral valve was still open, the LV endocardial transverse diameter started to shorten while the endocardial longitudinal diameter increased. During isovolumic relaxation, while the mitral valve was closed, LV transverse diameter started to increase while the longitudinal diameter continued to decrease. These findings are inconsistent with the classic definitions of the phases of the cardiac cycle. mitral valve; ventricles; hemodynamics; isovolumic contraction; isovolumic relaxation; mitral valve closure; cardiac cycle phases; left ventricle diameters THE CARDIAC CYCLE IS TRADITIONALLY divided into isovolumic contraction (IVC), ejection, isovolumic relaxation (IVR), and diastole (7). The concept of an initial isometric contraction during ventricular systole was originated by Wiggers (32), who stated that the first elevation in intraventricular pressure closes the atrioventricular valves while the ventricles contract in an isometric fashion. During the interval between the beginning of the rise in intraventricular pressure and the opening of the semilunar valves, the ventricular cavities are completely enclosed with a rising tension without change in ventricular volume. Later, Rushmer (23) showed that the initial phase of contraction was not an isometric contraction of all myocardial fibers of the left ventricle (LV). During IVC, he observed a rapid increase in LV pressure, a fast expansion of LV external circumference, and a rapid shortening of LV internal length. His conclusions were drawn from two experiments where he could successfully place internal distance gauges. In all other experiments, he failed to demonstrate the initial shortening of internal longitudinal dimension during IVC. Nevertheless, he concluded that the LV abruptly shortens during IVC and that this shortening is accompanied by an outward bulging of the LV main body (24,26). This sphericity of the external LV during IVC has also been described by several investigators (9, 27), who, in most cases, used epicardial markers. Others demonstrated the opposite, i.e., an elliptical pattern due to shortening of the LV internal mi...

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“…The ratio of 55% was based upon measurements made in our laboratory on six postmortem hearts and is similar to the values published by Streeter and*<Hanna. 10 The dynamic internal volume (V[) of the shell was computed using the formula for a prolate ellipsoid:…”

Section: Discussionmentioning

confidence: 99%

The three-dimensional dynamic geometry of the left ventricle in the conscious dog.

Rankin¹,

Modesti²,

Arentzen³

et al. 1976

Circulation Research

357

107

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Phasic Dimensional Changes in the Left Ventricle

Cited by 7 publications

References 18 publications

Biphasic tissue Doppler waveforms during isovolumic phases are associated with asynchronous deformation of subendocardial and subepicardial layers

Biphasic tissue Doppler waveforms during isovolumic phases are associated with asynchronous deformation of subendocardial and subepicardial layers

Left ventricular endocardial longitudinal and transverse changes during isovolumic contraction and relaxation: a challenge

The three-dimensional dynamic geometry of the left ventricle in the conscious dog.

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