10.10 HEMODYNAMIC CORRELATES OF THE LEFT VENTRICULAR MEAN EJECTION PRESSURE: A CAROTID TONOMETRY STUDY

2016 ◽  
Vol 16 (C) ◽  
pp. 74
Author(s):  
Mathieu Jozwiak ◽  
Sandrine Millasseau ◽  
Jean-Louis Teboul ◽  
Jean-Emmanuel Alphonsine ◽  
Francois Depret ◽  
...  
Keyword(s):  
Left Ventricular ◽  
Ejection Pressure

Left ventricular force-length relations of isovolumic and ejecting contractions

1976 ◽  
Vol 231 (2) ◽  
pp. 337-343 ◽  
Author(s):  
KT Weber ◽  
JS Janicki ◽  
LL Hefner
Keyword(s):  
Left Ventricle ◽  
Linear Function ◽  
Diastolic Pressure ◽  
Left Ventricular ◽  
Sectional Area ◽  
Active Force ◽  
Cross Sectional ◽  
Contractile State ◽  
State Dependent ◽  
Ejection Pressure

To determine the interrelationships between ejecting and isovolumic force-length relations and the extent to which the left ventricle will shorten, data obtained in 27 isolated, servo-regulated hearts were examined. For each heart a series of contractions, variably loaded (delta L) were derived for a thickwalled sphere and normalized by the cross-sectional area of muscle and length at zero end-diastolic pressure. It was found that within the physiological range examined total and active force were essentially a linear function of initial L with respective increments or reductions in slope produced by positive or negative shifts in contractile state. The force-L relations obtained isovolumically and at end ejection were virtually identical. For a given ejection pressure, end-systolic L was constant, despite variations in filling and therefore independent of initial L and deltaL; moreover, the L to which the ventricle shortened was determined by the course of the systolic force L-relation. Thus, irrespective of loading, delta L occurs within the confines of the contractile state-dependent isovolumic force-L relation and where the latter is equivalent to the end-systolic force-length relation.

Modification of force-interval relations during early adaptation to pressure overload in dogs

1987 ◽  
Vol 253 (6) ◽  
pp. H1506-H1513
Author(s):  
B. Crozatier ◽  
L. Hittinger ◽  
M. Chavance
Keyword(s):  
Ventricular Function ◽  
Systolic Pressure ◽  
Pressure Overload ◽  
Left Ventricular ◽  
Atrial Pacing ◽  
Force Frequency ◽  
Systolic Volume ◽  
Calculated Volume ◽  
End Systolic Volume ◽  
Ejection Pressure

Ventricular function was analyzed in the end-systolic and end-ejection pressure-volume diagrams in seven conscious dogs during acute aortic stenosis (AS) and sustained stenosis (SS) 24 h later. Dogs were previously instrumented with a left ventricular micromanometer and ultrasonic crystals measuring left ventricular major and minor axes and parietal wall thickness. The end-ejection pressure-calculated volume points were significantly shifted to the left during SS as compared with those obtained during AS both during a regular atrial pacing (150 beats/min) and during spontaneous heart rate. Postpacing beats were not different during AS and SS. During AS, end-systolic volume was larger after short intervals (SI) between beats (22.5 +/- 1.6 ml) than after long intervals (LI; 20.8 +/- 1.7 ml) for a smaller end-systolic pressure (P less than 0.001). This difference was minimal during SS. When SS was compared with AS, the end-systolic and end-ejection pressure-volume points were significantly shifted to the left after SI but not after LI. This suggests an acceleration of the restitution process during SS that modifies ventricular force-frequency relations and increases ventricular function as compared with AS, particularly for high heart rates.

Hysteresis of left ventricular end ejection pressure-dimension relations after acute pressure loading in the intact canine heart

1986 ◽  
Vol 20 (7) ◽  
pp. 490-497 ◽  
Author(s):  
B. WAY ◽  
J. VICTORY ◽  
M. M LEWINTER ◽  
W. Y LEW ◽  
R. DOYLE ◽  
...  
Keyword(s):  
Left Ventricular ◽  
Canine Heart ◽  
Pressure Loading ◽  
Ejection Pressure

Ejection pressure and the diastolic left ventricular pressure-volume relation

1977 ◽  
Vol 232 (6) ◽  
pp. H545-H552 ◽  
Author(s):  
J. S. Janicki ◽  
K. T. Weber
Keyword(s):  
Diastolic Pressure ◽  
Left Ventricular Pressure ◽  
Ventricular Volume ◽  
Left Ventricular ◽  
A Value ◽  
Total Magnitude ◽  
Level Method ◽  
Volume Relation ◽  
Response Method ◽  
Ejection Pressure

The influence of ejection pressure (EP) on the left ventricular end-diastolic pressure-volume (P-V) relation was examined in 24 paced, isolated canine hearts. A pressure servo system was used to control EP and monitor ventricular volume. For any given contractile state EP was varied: a) by 10- to 20-mmHg increments and the steady-state P-V response observed at each EP level (method A); or b) by instantaneously attaining the isovolumic condition (PO) from a given EDV and examining the immediate P-V response (method B). With either method it was possible to alter the P-V relation; the maximum variation occurred when, for a given EDV or EDP, EP was raised from a value less than 50% of its corresponding peak isovolumic pressure to PO. For the EDP range 2-25 mmHg, the direction and total magnitude of change were: 1) an increase in EDV 1.3-9 ml was required to maintain EDP constant; and 2) for a constant EDV, EDP decreased an average 16.5%+/-1.2 SE (6-23.9%; P less than .02). The EDP decline observed with method B was immediate and reversible within several beats upon returning to the ejecting mode. Thus, under the conditions of this experiment the diastolic pressure-volume relation is a physiological variable dependent on ejection pressure.

scholarly journals Effects of coronary artery stenosis on left ventricular end-ejection pressure-ejected volume relationships in isolated perfused canine hearts.

1985 ◽  
Vol 147 (4) ◽  
pp. 389-402
Author(s):  
YUKIO MARUYAMA ◽  
YOSHIO SHIMIZU ◽  
JUN WATANABE ◽  
KOICHI ASHIKAWA ◽  
SHOGEN ISOYAMA ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Coronary Artery Stenosis ◽  
Left Ventricular ◽  
Artery Stenosis ◽  
Ejection Pressure

scholarly journals Nonobstructive left ventricular ejection pressure gradients in man.

1987 ◽  
Vol 61 (2) ◽  
pp. 220-227 ◽  
Author(s):  
A Pasipoularides ◽  
J P Murgo ◽  
J W Miller ◽  
W E Craig
Keyword(s):  
Left Ventricular ◽  
Ventricular Ejection ◽  
Left Ventricular Ejection ◽  
Pressure Gradients ◽  
Ejection Pressure

Left ventricular systolic dynamics in terms of its chamber mechanical properties

1983 ◽  
Vol 245 (1) ◽  
pp. H110-H124 ◽  
Author(s):  
S. G. Shroff ◽  
J. S. Janicki ◽  
K. T. Weber
Keyword(s):  
Mechanical Properties ◽  
Left Ventricular ◽  
Canine Heart ◽  
Third Order ◽  
End Diastolic Volume ◽  
Linear Resistance ◽  
Inertial Component ◽  
Single Cardiac Cycle ◽  
Functional Forms ◽  
Ejection Pressure

To determine the mechanical properties of the left ventricle (LV) as a pump, a mathematical model of its systolic dynamics was developed. Initially the model consisted of three elements, i.e., elastance, resistance, and inertance. Results from three experiments, however, indicated that the inertial component was negligible compared with the other two components. The functional forms of elastance and resistance were determined by applying the flow-pulse response technique to an isovolumetrically beating, isolated canine heart. Results from three experiments indicated that the systolic elastance and resistance can be represented by a third-order polynomial in time and a linear function of instantaneous ventricular pressure (LVP), respectively. The simplified model was then tested by calculating the systolic elastance and resistance from LVP, volume, and flow data of an ejecting LV obtained over a single cardiac cycle. A total of 225 combinations (10 expts) of end-diastolic volume (EDV), ejection pressure (EP), heart rate (HR), and contractile state (CS) were evaluated. The results indicated that 1) the elastance function was insensitive to variations in EDV and EP but was a function of CS and HR; 2) the linear resistance-pressure relationship was insensitive to variations in EDV, EP, HR, and CS; and 3) the model could "prospectively" predict the LV isovolumetric pressure from the data of an ejecting beat. Thus a model of LV systolic dynamics has been established that can be used to calculate the intrinsic chamber mechanical properties, i.e., elastance and resistance, of an ejecting LV.

Mitochondria in Cardiomyopathy: Alterations in Size, Number and Internal Structures

1968 ◽  
Vol 26 ◽  
pp. 126-127
Author(s):  
George Hug ◽  
William K. Schubert
Keyword(s):  
Heart Failure ◽  
Biochemical Analysis ◽  
Left Ventricular ◽  
Size Number ◽  
Internal Structures ◽  
Left Ventricular Outflow ◽  
Chest X Ray ◽  
Myocardial Fibers ◽  
Muscle Biopsies ◽  
Needle Liver Biopsy

A white boy six months of age was hospitalized with respiratory distress and congestive heart failure. Control of the heart failure was achieved but marked cardiomegaly, moderate hepatomegaly, and minimal muscular weakness persisted.At birth a chest x-ray had been taken because of rapid breathing and jaundice and showed the heart to be of normal size. Clinical studies included: EKG which showed biventricular hypertrophy, needle liver biopsy which showed toxic hepatitis, and cardiac catheterization which showed no obstruction to left ventricular outflow. Liver and muscle biopsies revealed no biochemical or histological evidence of type II glycogexiosis (Pompe's disease). At thoracotomy, 14 milligrams of left ventricular muscle were removed. Total phosphorylase activity in the biopsy specimen was normal by biochemical analysis as was the degree of phosphorylase activation. By light microscopy, vacuoles and fine granules were seen in practically all myocardial fibers. The fibers were not hypertrophic. The endocardium was not thickened excluding endocardial fibroelastosis. Based on these findings, the diagnosis of idiopathic non-obstructive cardiomyopathy was made.

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