P619Stress-strain loop area better represents regional myocardial work than pressure-strain loop area in the dyssynchronous and remodelled left ventricle

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
J Duchenne ◽  
M Cvijic ◽  
A Turco ◽  
S Unlu ◽  
E D Pagourelias ◽  
...  
Keyword(s):  
Glucose Uptake ◽  
Wall Thickness ◽  
Wall Stress ◽  
Lateral Wall ◽  
Right Atrial ◽  
Atrial Pacing ◽  
Right Ventricular Free Wall ◽  
Stress Strain ◽  
Loop Area ◽  
Regional Work

Abstract Background Pressure-strain-loops (PSL) have been suggested as surrogate parameter of regional myocardial work. However, in left ventricles (LV) with inhomogeneous remodelling, e.g. due to left bundle branch block (LBBB), wall stress may be unevenly distributed. Stress-strain loops (SSL) include information on both regional wall thickness and curvature, and may therefore provide a better surrogate. Study plan We therefore compared the correlation of segmental myocardial work estimated through both PSL and SSL to segmental myocardial glucose metabolism as a gold standard, in an animal model of pacing-induced LV remodelling. Methods Twelve sheep developed LV dilatation, thinned septum and thickened lateral wall, due to eight weeks of rapid right-atrial and right-ventricular free wall (DDD) pacing (at 180 bpm), causing a LBBB-like dyssynchrony. Invasive LV pressure and echocardiographic speckle tracking based circumferential strain were used to construct PSL. SSL were calculated by considering in addition dynamic changes in segmental myocardial wall thickness and curvature using the formula of Laplace. 18F-fluorodeoxyglucose (FDG)-uptake was measured by positron emission tomography (PET) in absolute values as standardised uptake ratio (SUR). Spatial resolution of PET was improved by ECG- and breathing-gating and using anatomical priors. All imaging was performed during dyssynchronous DDD-pacing and synchronous AAI-pacing (right-atrial pacing only), at baseline (n=3 animals), and after eight weeks of pacing induced remodelling (n=12 animals). Results Both at baseline (Fig. A+B) and after 8 weeks (Fig. D+E), switching between AAI and DDD-pacing caused an acute re-distribution of regional myocardial work as measured by both PSL and SSL. In contrast to PSL, however, SSL identified more regional differences among walls in remodelled hearts and showed clearer regional changes when switching between AAI and DDD-pacing. The correlation between regional work, assessed by PSL and SSL, and metabolism by PET, was comparable at baseline (r=0.65 and r=0.64, respectively) (Fig. C). In remodelled hearts after 8 weeks, however, the correlation of regional work assessed by SSL and glucose uptake by PET was significantly higher compared to PSL (r=0.73 vs. r=0.59, respectively; p<0.05) (Fig. F). Conclusions Regional myocardial work assessed by stress-strain loops correlates significantly better to regional metabolism as measured by PET glucose uptake, particularly after remodelling. Our findings therefore suggest that integrating information on wall thickness and curvature is essential for the reliable assessment of regional myocardial work, especially in dyssynchronous and remodelled left ventricles.

Changes in regional myocardial function and external work in exercising dogs with ischemia

1993 ◽  
Vol 264 (1) ◽  
pp. H110-H116 ◽  
Author(s):  
S. Miyazaki ◽  
Y. Goto ◽  
B. D. Guth ◽  
T. Miura ◽  
C. Indolfi ◽  
...  
Keyword(s):  
Wall Thickness ◽  
Left Ventricular ◽  
Time Difference ◽  
Wall Thickening ◽  
Stress Strain ◽  
External Work ◽  
Loop Area ◽  
Systolic Thickening ◽  
Exercise Induced ◽  
Systolic Wall Thickening

Changes in regional myocardial work of the nonischemic wall and left ventricular (LV) asynchrony of the nonischemic wall during exercise-induced ischemia were examined in seven conscious dogs instrumented with a micromanometer for LV pressure measurement and sonomicrometers for control and ischemic wall thickness and LV external short and long axes. Ischemia was produced during steady-state exercise by a pneumatic constrictor on the left circumflex coronary artery. Time difference between peak thickening of control (anterior) and ischemic (posterior) walls was measured as an index of LV asynchrony. LV pressure-wall thickness loop area of both the control wall (LVP-CW loop) and ischemic wall was calculated as an index of regional myocardial external work. With ischemia during exercise, peak LV pressure decreased by 11%, and time difference of peak thickening in the two walls increased, accompanied by marked deformation of the LVP-CW loop during early relaxation, which was related to protodiastolic thickening of the ischemic wall. Thus, despite a significant increase in percent systolic thickening during exercise, loop area of control wall was not enhanced. These changes of the LVP-CW loop were confirmed by calculation of stress-strain loop areas as an additional index of regional myocardial external work but having true dimensions of work. Stress-strain loop area in the control wall during ischemic exercise showed a similar value to that during control exercise, thereby confirming lack of compensatory increase. Thus, during exercise-induced ischemia, regional myocardial external work in the normal region does not increase despite an increase in systolic wall thickening.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of alterations in heart rate on left ventricular echocardiographic measurements in healthy cats

2016 ◽  
Vol 19 (8) ◽  
pp. 841-845 ◽  
Author(s):  
Keisuke Sugimoto ◽  
Yoko Fujii ◽  
Yuto Ogura ◽  
Hiroshi Sunahara ◽  
Takuma Aoki
Keyword(s):  
Heart Rate ◽  
Wall Thickness ◽  
Interventricular Septum ◽  
Left Ventricular ◽  
Right Atrial ◽  
Atrial Pacing ◽  
Free Wall ◽  
Left Ventricular Free Wall ◽  
Linear Fashion ◽  
Significant Relationships

Objectives The purpose of this study was to evaluate the effect of sudden alterations in heart rate (HR) on left ventricular (LV) wall thickness and dimensions determined by echocardiography in healthy cats. Methods Six experimental cats were used. All cats were anaesthetised and HR was controlled with right atrial pacing. The interventricular septum and left ventricular free wall thickness at end diastole (IVSd and LVFWd, respectively), left ventricular end-diastolic and end-systolic diameter (LVIDd and LVIDs, respectively) and shortening fraction (FS) of each cat were assessed using echocardiography at pacing rates of 120, 130, 140, 150, 160, 170 and 180 ppm. Results There were significant relationships between HR and IVSd, LVFWd, LVIDd, LVIDs and FS. As the HR increased, LV wall thickness increased and chamber dimensions got smaller in a linear fashion. The maximum and minimum differences in wall thickness between 120 ppm and 180 ppm were 2.0 mm and 0.7 mm in single measurements, respectively. Conclusions and relevance LV wall thickness and dimensions were significantly influenced by alterations in HR.

scholarly journals Regional work of the human left ventricle calculated by wall stress and the natural logarithm of reciprocal of wall thickness

1988 ◽  
Vol 12 (6) ◽  
pp. 1442-1448 ◽  
Author(s):  
Kiyoharu Nakano ◽  
Motoaki Sugawara ◽  
Tatsuya Kato ◽  
Shigetake Sasayama ◽  
Blase A. Carabello ◽  
...  
Keyword(s):  
Left Ventricle ◽  
Wall Thickness ◽  
Wall Stress ◽  
Natural Logarithm ◽  
Human Left Ventricle ◽  
Regional Work

scholarly journals Elevated septal wall stress - a driver of left ventricular dysfunction in left bundle branch block?

2021 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
OJ Sletten ◽  
JM Aalen ◽  
EW Remme ◽  
H Izci ◽  
J Duchenne ◽  
...  
Keyword(s):  
Heart Failure ◽  
Wall Thickness ◽  
Left Bundle Branch Block ◽  
Wall Stress ◽  
Lateral Wall ◽  
Left Ventricular ◽  
Public Institution ◽  
Wall Thickening ◽  
Bundle Branch Block ◽  
Septal Wall

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): The Norwegian Health Association Background Septal dysfunction is a main feature of left bundle branch block (LBBB), and increasing wall stress is a proposed mechanism of heart failure development in LBBB patients. To try to reveal the pathophysiologic pathway from dyssynchrony to heart failure, we investigated the relationship between septal and left ventricular (LV) lateral wall stress in patients with LBBB. Hypothesis Increased septal wall stress causes septal dysfunction in LBBB. Methods We included 24 LBBB-patients (65 ± 11 years, 11 males) with LV ejection fraction (EF) ranging from 18 to 67%, and 8 healthy controls (58 ± 10 years, 4 males). Wall stress was calculated at peak LV pressure (LVP) according to the law of La Place ([LVP x radius]/[wall thickness]). Wall thickness was measured using M-mode, and regional curvature was measured in mid-ventricular shortaxis from 2D echocardiographic images. We used a previously validated non-invasive method to estimate LVP from brachial blood pressure and adjusted for valvular events. Myocardial scar was ruled out by late gadolinium enhancement cardiac magnetic resonance imaging. Results Wall stress was significantly higher in septum than LV lateral wall at peak LVP (48 ± 12 vs 37 ± 11 kPa, p &lt; 0.01) in LBBB patients, while no difference was seen in the controls (Figure A). In patients, septal wall thickening showed a strong correlation with LVEF (r = 0.77, p &lt; 0.01) (Figure B). Similar correlation was not significant for the LV lateral wall (r = 0.13, NS). Attenuation of septal wall thickening in LBBB-patients correlated well with increasing septal wall stress (r=-0.60, p &lt; 0.01). Wall thickening and stress did not correlate in the LV lateral wall (r=-0.14, NS). Conclusion Increased septal wall stress is associated with reduced systolic thickening in patients with LBBB. Septal wall thickening, in contrast to LV lateral wall thickening, was correlated to global LV function. These findings suggest that septal remodeling which could have normalized septal wall stress, was not achieved and heart failure may develop. Abstract Figure.

Abstract 16018: Impaired Intrinsic Myocardial Shortening in Both Two Directions and Compensatory Mechanism to Maintain Left Ventricular Ejection Fraction in Patients With Hypertensive Heart Disease

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Satoshi Yamada ◽  
Kazunori Okada ◽  
Hisao Nishino ◽  
Hiroyuki Iwano ◽  
Daisuke Murai ◽  
...  
Keyword(s):  
Heart Disease ◽  
Ejection Fraction ◽  
Wall Thickness ◽  
Circumferential Strain ◽  
Hypertensive Heart Disease ◽  
Wall Stress ◽  
Left Ventricular ◽  
Relative Wall Thickness ◽  
Left Ventricular Ejection ◽  
Compensatory Mechanism

Background: Longitudinal myocardial shortening is known to be reduced even if left ventricular (LV) ejection fraction (EF) is preserved in patients with hypertensive heart disease (HHD). However, the compensatory mechanism remains to be elucidated. Thus layer-specific longitudinal and circumferential strain as well as stress-strain relationship was observed in HHD patients. Methods: In 46 HHD patients with preserved EF (>50%) and 29 age-matched control subjects, global longitudinal strain (LS) and layer-specific circumferential strain (CS) were measured from the apical 4-chamber view and mid-ventricular short-axis view, respectively, by using speckle tracking echocardiography. LS was measured at innermost LV wall layer, and CS at innermost, midwall, and outermost layers. Layer-specific end-systolic circumferential wall stress (CWS) according to Mirsky’s formula and endocardial meridional wall stress (MWS) were calculated. Results: Systolic blood pressure (147±20 mm Hg), interventricular septal thickness (13±2 mm), and LV dimension (48±4 mm) were greater in HHD than controls, whereas EF was comparable (66±8 vs 66±5%). LS was smaller in HHD than controls (-13±3 vs -17±3%, p<0.001) in spite of reduced MWS (520±141 vs 637±164 dyn·mm -2 , p<0.01), suggesting impaired longitudinal myocardial function in HHD. Similarly, CS was smaller in HHD than controls at outer layer (-6.8±2.2 vs -8.8±2.2%, p<0.01) and at midwall (-11.3±3.4 vs -13.9±3.2%, p<0.01) in spite of reduced CWS (outer: 238±82 vs 336±110 dyn·mm -2 , p<0.001; mid: 360±107 vs 473±131 dyn·mm -2 , p<0.001). In contrast, at the innermost layer, both CS (-26±5 vs -25±5%, p=0.41) and CWS (979±153 vs 992±139 dyn·mm -2 , p=0.72) were comparable between groups. Furthermore, the difference of CS between inner and outer layers significantly correlated with relative wall thickness (r=-0.33, p<0.01). Finally, CS at inner layer significantly correlated with EF (r=-0.43, p<0.001), whereas LS did not. Conclusions: In patients with HHD, intrinsic myocardial shortening was impaired both longitudinally and circumferentially. Some compensatory mechanism associated with increased relative wall thickness might work to maintain subendocardial CS, resulting in preserved EF.

scholarly journals Infarcted Left Ventricles Have Stiffer Material Properties and Lower Stiffness Variation: Three-Dimensional Echo-Based Modeling to Quantify In Vivo Ventricle Material Properties

2015 ◽  
Vol 137 (8) ◽  
Author(s):  
Longling Fan ◽  
Jing Yao ◽  
Chun Yang ◽  
Dalin Tang ◽  
Di Xu
Keyword(s):  
Wall Thickness ◽  
Material Properties ◽  
Strain Curve ◽  
Stress And Strain ◽  
Stress Strain ◽  
Material Stiffness ◽  
The Mean ◽  
Lv Volume ◽  
Parameter Values

Methods to quantify ventricle material properties noninvasively using in vivo data are of great important in clinical applications. An ultrasound echo-based computational modeling approach was proposed to quantify left ventricle (LV) material properties, curvature, and stress/strain conditions and find differences between normal LV and LV with infarct. Echo image data were acquired from five patients with myocardial infarction (I-Group) and five healthy volunteers as control (H-Group). Finite element models were constructed to obtain ventricle stress and strain conditions. Material stiffening and softening were used to model ventricle active contraction and relaxation. Systolic and diastolic material parameter values were obtained by adjusting the models to match echo volume data. Young's modulus (YM) value was obtained for each material stress–strain curve for easy comparison. LV wall thickness, circumferential and longitudinal curvatures (C- and L-curvature), material parameter values, and stress/strain values were recorded for analysis. Using the mean value of H-Group as the base value, at end-diastole, I-Group mean YM value for the fiber direction stress–strain curve was 54% stiffer than that of H-Group (136.24 kPa versus 88.68 kPa). At end-systole, the mean YM values from the two groups were similar (175.84 kPa versus 200.2 kPa). More interestingly, H-Group end-systole mean YM was 126% higher that its end-diastole value, while I-Group end-systole mean YM was only 29% higher that its end-diastole value. This indicated that H-Group had much greater systole–diastole material stiffness variations. At beginning-of-ejection (BE), LV ejection fraction (LVEF) showed positive correlation with C-curvature, stress, and strain, and negative correlation with LV volume, respectively. At beginning-of-filling (BF), LVEF showed positive correlation with C-curvature and strain, but negative correlation with stress and LV volume, respectively. Using averaged values of two groups at BE, I-Group stress, strain, and wall thickness were 32%, 29%, and 18% lower (thinner), respectively, compared to those of H-Group. L-curvature from I-Group was 61% higher than that from H-Group. Difference in C-curvature between the two groups was not statistically significant. Our results indicated that our modeling approach has the potential to determine in vivo ventricle material properties, which in turn could lead to methods to infer presence of infarct from LV contractibility and material stiffness variations. Quantitative differences in LV volume, curvatures, stress, strain, and wall thickness between the two groups were provided.

Elevated plasma endothelin-1 levels in coronary sinus during rapid right atrial pacing in patients with slow coronary flow

2004 ◽  
Vol 97 (1) ◽  
pp. 35-41 ◽  
Author(s):  
Hasan Pekdemir ◽  
Gurbuz Polat ◽  
V.Gökhan Cin ◽  
Ahmet Çamsari ◽  
Dilek Cicek ◽  
...  
Keyword(s):  
Coronary Sinus ◽  
Coronary Flow ◽  
Right Atrial ◽  
Atrial Pacing ◽  
Elevated Plasma ◽  
Slow Coronary Flow ◽  
Endothelin 1

scholarly journals Recurrent cardiac hydatid cyst located near the root of the superior vena cava and the interatrial septum: a case report

2022 ◽  
pp. 1-4
Author(s):  
Redha Lakehal ◽  
Farid Aymer ◽  
Soumaya Bendjaballah ◽  
Rabah Daoud ◽  
Khaled Khacha ◽  
...  
Keyword(s):  
Hydatid Cyst ◽  
Facial Paralysis ◽  
Superior Vena Cava ◽  
Superior Vena ◽  
Vena Cava ◽  
Lower Lobe ◽  
Lateral Wall ◽  
Right Atrial ◽  
Risk Of Rupture ◽  
The Right

Introduction: Cardiac localization of hydatid disease is rare (<3%) even in endemic countries. Affection characterized by a long functional tolerance and a large clinical and paraclinical polymorphism. Serious cardiac hydatitosis because of the risk of rupture requiring urgent surgery. The diagnosis is based on serology and echocardiography. The aim of this work is to show a case of recurrent cardiac hydatid cyst discovered incidentally during a facial paralysis assessment. Methods: We report the observation of a 26-year-old woman operated on in 2012 for pericardial hydatid cyst presenting a cardiac hydatid cyst located near the abutment of the SCV discovered incidentally during an exploration for left facial paralysis: NYHA stage II dyspnea. Chest x-ray: CTI at 0.48. ECG: RSR. Echocardiography: Image of cystic appearance at the level of the abutment of the SVC. SAPP: 38 mmhg, EF: 65%. Thoracic scan: 30/27 mm cardiac hydatid cyst bulging the lateral wall of the right atrium and the trunk of the right pulmonary artery with fissured cardiac hydatid cyst of the apical segment of the right lung of the right lower lobe with multiple bilateral intra parenchymal and sub pleural nodules. The patient was operated on under CPB. Intraoperative exploration: Presence of a hard and whitish mass, about 03 / 03cm developed in the full right atrial wall opposite the entrance to the superior vena cava. Procedure: Resection of the mass removing the roof of the LA, the AIS and the wall of the RA with reconstruction of the roof of the RA by patch in Dacron and reconstruction of the IAS and the wall of the RA by a single patch in Dacron. Results: The postoperative suites were simple. Conclusion: The hydatid cyst is still a real endemic in Algeria, the cardiac location is rare but serious and can constitute a real surgical emergency, hence the importance of prevention. Keywords: Hydatid cyst of the heart; Recurrence; Surgery; Cardiopulmonary Bypass; Prevention

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