Left ventricular end-systolic pressure-dimension and stress-length relations in normal human subjects

To determine whether histamine alters human left ventricular contractility we measured heart rate, calibrated carotid arterial pressure, and left ventricular dimensions (echocardiogram) in nine healthy volunteers. We assessed baseline contractility using the end-systolic pressure-dimension relationship and the end-systolic meridional wall stress-rate-corrected velocity of circumferential fiber shortening relationship determined over a wide range of afterloads using phenylephrine and nitroprusside infusions. We then infused histamine for 3–5 min at a dose predetermined to decrease mean arterial pressure by 20%, both before and after H1 receptor antagonist pretreatment (diphenhydramine 50 mg i.v.). Histamine decreased end-systolic pressure but, unlike an equally hypotensive infusion of nitroprusside, did not decrease end-systolic dimension or increase fractional shortening. Histamine also decreased velocity of circumferential fiber shortening at the same end-systolic meridional wall stress as controls (P < 0.05). These effects of histamine were inhibited by H1 antagonist pretreatment. We conclude that the dominant effect of histamine on the human heart is to decrease left ventricular contractility and that this decrease in contractility is dependent, at least partially, on H1-receptor activation.

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The Effect of the Administration of Nitroglycerin and Atropine on the Pattern of Left Ventricular Diastolic Filling as Assessed by Doppler Echocardiography in Normal Human Subjects

Korean Circulation Journal ◽

10.4070/kcj.1994.24.3.412 ◽

1994 ◽

Vol 24 (3) ◽

pp. 412

Author(s):

Kyeong A Oh ◽

Jong Cheol Park ◽

Nam Jin Yoo ◽

Soo Yeon Won ◽

Jin Won Jeong ◽

...

Keyword(s):

Doppler Echocardiography ◽

Human Subjects ◽

Left Ventricular ◽

Diastolic Filling ◽

Normal Human ◽

Left Ventricular Diastolic Filling

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Slope of human left ventricular end-systolic force-length relation is independent of myocardial length

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1991.261.4.h1060 ◽

1991 ◽

Vol 261 (4) ◽

pp. H1060-H1066

Author(s):

K. Takeda ◽

K. Tamano ◽

A. Okamura ◽

N. Kobayashi ◽

T. Shimizu ◽

...

Keyword(s):

Human Heart ◽

Human Subjects ◽

Posterior Wall ◽

Left Ventricular ◽

Dobutamine Infusion ◽

Arterial Cannulation ◽

Hyperbolic Relation ◽

Average Variation ◽

Normal Human

We have introduced a new contractility index (Ec), i.e., the slope of the left ventricular (LV) end-systolic force-length (Fes-Les) relation. To examine whether Ec was dependent on the LV wall myocardial length, 16 normal hearts of human subjects were evaluated to determine the LV end-systolic force-dimension (Fes-Des) and pressure-dimension (Pes-Des) relations (dimension denotes the distance between the LV septum and posterior wall). LV end-systolic pressures and dimensions were estimated simultaneously by intra-arterial cannulation and LV echocardiography. In seven subjects, the effect of a dobutamine infusion was also assessed. The Fes-Des relation was found to be nearly linear. Slopes and extrapolated dimension intercepts were obtained for the LV Fes-Des and Pes-Des relations [Ec, slope of LV Pes-Des relation (Es), and extrapolated dimension intercept of LV Fes-Des (Do), and of Pes-Des relation (D'o), respectively]. Es showed a hyperbolic relation to the baseline LV Des, whereas Ec was unrelated to it. The average variation for Ec (9.5%) was smaller than that for Es (22.5%). Dobutamine infusion increased Ec, Es, and D'o, whereas Do was not changed. Thus the assumption of linearity of the LV Fes-Les relation was found to be reasonable in normal human hearts. Do appears to provide a more accurate parameter than D'o for estimating the actual unstressed myocardial length, whereas Ec could possibly serve as an index of LV wall performance in the normal human heart that is independent of myocardial length and nearly constant between individuals.

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Heterogeneity of left ventricular regional wall thickening following dobutamine infusion in normal human subjects

European Heart Journal ◽

10.1093/oxfordjournals.eurheartj.a060802 ◽

1995 ◽

Vol 16 (11) ◽

pp. 1726-1730 ◽

Cited By ~ 25

Author(s):

A. C. BORGES ◽

A. PlNGITORE ◽

A. CORDOVIL ◽

R. SlCARI ◽

G. BAUMANN ◽

...

Keyword(s):

Human Subjects ◽

Left Ventricular ◽

Dobutamine Infusion ◽

Wall Thickening ◽

Regional Wall ◽

Normal Human

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Influence of acute alterations in heart rate and systemic arterial pressure on echocardiographic measures of left ventricular perfornmance in normal human subjects.

Circulation ◽

10.1161/01.cir.52.5.835 ◽

1975 ◽

Vol 52 (5) ◽

pp. 835-841 ◽

Cited By ~ 106

Author(s):

J Hirshleifer ◽

M Crawford ◽

R A O'Rourke ◽

J S Karliner

Keyword(s):

Heart Rate ◽

Arterial Pressure ◽

Human Subjects ◽

Systemic Arterial Pressure ◽

Left Ventricular ◽

Normal Human

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Accelerating whole-heart 3D T2 mapping: Impact of undersampling strategies and reconstruction techniques

PLoS ONE ◽

10.1371/journal.pone.0252777 ◽

2021 ◽

Vol 16 (9) ◽

pp. e0252777

Author(s):

Dan Zhu ◽

Haiyan Ding ◽

M. Muz Zviman ◽

Henry Halperin ◽

Michael Schär ◽

...

Keyword(s):

Human Subjects ◽

T2 Mapping ◽

Left Ventricular ◽

Jaccard Index ◽

Limiting Factor ◽

Joint Sparsity ◽

Model Based ◽

Reconstruction Methods ◽

Normal Human ◽

Whole Heart

Purpose We aim to determine an advantageous approach for the acceleration of high spatial resolution 3D cardiac T2 relaxometry data by comparing the performance of different undersampling patterns and reconstruction methods over a range of acceleration rates. Methods Multi-volume 3D high-resolution cardiac images were acquired fully and undersampled retrospectively using 1) optimal CAIPIRINHA and 2) a variable density random (VDR) sampling. Data were reconstructed using 1) multi-volume sensitivity encoding (SENSE), 2) joint-sparsity SENSE and 3) model-based SENSE. Four metrics were calculated on 3 naïve swine and 8 normal human subjects over a whole left-ventricular region of interest: root-mean-square error (RMSE) of image signal intensity, RMSE of T2, the bias of mean T2, and standard deviation (SD) of T2. Fully sampled data and volume-by-volume SENSE with standard equally spaced undersampling were used as references. The Jaccard index calculated from one swine with acute myocardial infarction (MI) was used to demonstrate preservation of segmentation of edematous tissues with elevated T2. Results In naïve swine and normal human subjects, all methods had similar performance when the net reduction factor (Rnet) <2.5. VDR sampling with model-based SENSE showed the lowest RMSEs (10.5%-14.2%) and SDs (+1.7–2.4 ms) of T2 when Rnet>2.5, while VDR sampling with the joint-sparsity SENSE had the lowest bias of mean T2 (0.0–1.1ms) when Rnet>3. The RMSEs of parametric T2 values (9.2%-24.6%) were larger than for image signal intensities (5.2%-18.4%). In the swine with MI, VDR sampling with either joint-sparsity or model-based SENSE showed consistently higher Jaccard index for all Rnet (0.71–0.50) than volume-by-volume SENSE (0.68–0.30). Conclusions Retrospective exploration of undersampling and reconstruction in 3D whole-heart T2 parametric mapping revealed that maps were more sensitive to undersampling than images, presenting a more stringent limiting factor on Rnet. The combination of VDR sampling patterns with model-based or joint-sparsity SENSE reconstructions were more robust for Rnet>3.

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