Regional variations in calculated diastolic wall stress in rat left ventricle

1978 ◽  
Vol 235 (2) ◽  
pp. H247-H250 ◽  
Author(s):  
L. Role ◽  
D. Bogen ◽  
T. A. McMahon ◽  
W. H. Abelmann
Keyword(s):  
Heart Disease ◽  
Left Ventricle ◽  
Significant Variation ◽  
Diastolic Pressure ◽  
Wall Stress ◽  
Free Wall ◽  
Predisposing Factor ◽  
Rat Hearts ◽  
The Mean ◽  
Apical Aneurysm

Principal radii of curvature and wall thickness were measured at the apex and three other loci on the free wall of the left ventricle in 16 rat hearts that had been fixed at end-diastolic pressure. The law of Laplace was applied to calculate the mean tensile stress at each locus. No significant variation was found among the nonapical loci, but apical stress was approximately twice the stress calculated for any nonapical locus. The higher stresses that must be borne by the apex may be a predisposing factor for apical aneurysm in certain cardiomyopathies such as Chagas' disease. These higher stresses may also help to promote apical aneurysms in patients with ischemic heart disease.

SURGICAL TREATMENT OF PSEUDOANEURYSM OF THE FREE LEFT VENTRICLE WALL: A CLINICAL CASE

2021 ◽  
Vol 5 (1) ◽  
pp. 1195-1201
Author(s):  
O. Kiziukevich ◽  
◽  
S. Spiridonov ◽  
A. Zhyhalkovich ◽  
D. Isachkin ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Heart Disease ◽  
Surgical Treatment ◽  
Left Ventricle ◽  
Ischemic Heart Disease ◽  
Clinical Case ◽  
Ischemic Heart ◽  
Free Wall ◽  
Heart Rupture ◽  
Myocardial Rupture

Today diseases of the cardiovascular system are the leading cause of death in many countries. The key role in this pathology is played by ischemic heart disease. An extreme manifestation of ischemic heart disease - myocardial infarction is one of the main causes of complications and mortality in patients with ischemic heart disease. One of the most formidable complications of acute myocardial infarction is heart rupture, which most often leads to death, more than 60% of cases occurring in the prehospital stage. Many studies of similar groups of patients show a wide spread in assessing the incidence and mortality of this pathology. The development of myocardial ruptures has two frequency peaks: the first day and 5-7 days from the onset of AMI. The most common case is acute rupture of the free wall of the left ventricle with extensive hemorrhage in the pericardium leading to a fulminant death. The development of a pseudoaneurysm of the left ventricle is a very rare outcome of the myocardial rupture. There are no convincing data on the incidence of pseudoaneurysms as a result of myocardial infarction (according to many authors, it is less than 0.5% of all cases of myocardial infarction). This type of rupture is most favorable in terms of the possibility of providing assistance. The complexity of providing care to patients with pseudoaneurysms of the left ventricle lies in their low frequency of occurrence and often asymptomatic nature of the course, which complicates the diagnosis of this pathology. Timely diagnosis plays a key role in avoiding a fatal outcome, since the vast majority of pseudoaneurysms are extremely unstable and, except occasional cases, require urgent surgical intervention. This article describes a clinical case of a patient who underwent surgical treatment for pseudoaneurysm of the free wall of the left ventricle as a result of myocardial infarction. The article also presents a brief literature review of the available isolated data on risk factors for myocardial rupture, methods of diagnosis and treatment of this pathology.

scholarly journals Method for Calibration of Left Ventricle Material Properties Using Three-Dimensional Echocardiography Endocardial Strains

2019 ◽  
Vol 141 (9) ◽  
Author(s):  
Yaghoub Dabiri ◽  
Kevin L. Sack ◽  
Nuno Rebelo ◽  
Peter Wang ◽  
Yunjie Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Left Ventricle ◽  
Diffusion Tensor ◽  
Diastolic Pressure ◽  
Three Dimensional ◽  
Heart Association ◽  
Mean Difference ◽  
Imaging Data ◽  
The Mean

We sought to calibrate mechanical properties of left ventricle (LV) based on three-dimensional (3D) speckle tracking echocardiographic imaging data recorded from 16 segments defined by American Heart Association (AHA). The in vivo data were used to create finite element (FE) LV and biventricular (BV) models. The orientation of the fibers in the LV model was rule based, but diffusion tensor magnetic resonance imaging (MRI) data were used for the fiber directions in the BV model. A nonlinear fiber-reinforced constitutive equation was used to describe the passive behavior of the myocardium, whereas the active tension was described by a model based on tissue contraction (Tmax). isight was used for optimization, which used abaqus as the forward solver (Simulia, Providence, RI). The calibration of passive properties based on the end diastolic pressure volume relation (EDPVR) curve resulted in relatively good agreement (mean error = −0.04 ml). The difference between the experimental and computational strains decreased after segmental strain metrics, rather than global metrics, were used for calibration: for the LV model, the mean difference reduced from 0.129 to 0.046 (circumferential) and from 0.076 to 0.059 (longitudinal); for the BV model, the mean difference nearly did not change in the circumferential direction (0.061) but reduced in the longitudinal direction from 0.076 to 0.055. The calibration of mechanical properties for myocardium can be improved using segmental strain metrics. The importance of realistic fiber orientation and geometry for modeling of the LV was shown.

Trabecular cutting: a novel surgical therapy to increase diastolic compliance

2019 ◽  
Vol 127 (2) ◽  
pp. 457-463
Author(s):  
Meagan Oglesby ◽  
Danny Escobedo ◽  
Gladys Patricia Escobar ◽  
Fatemeh Fatemifar ◽  
Edward Y. Sako ◽  
...  
Keyword(s):  
Heart Failure ◽  
Left Ventricle ◽  
Diastolic Pressure ◽  
Ex Vivo ◽  
Systolic Function ◽  
Wall Stress ◽  
Rabbit Heart ◽  
Left Ventricular ◽  
Before And After ◽  
Diastolic Compliance

Heart failure with preserved ejection fraction (HFpEF) is a common cause of hospital admission in patients over 65 yr old and has high mortality. HFpEF is characterized by left ventricular (LV) hypertrophy that reduces compliance. Current HFpEF therapies control symptoms, but no existing medications or therapies can sustainably increase LV compliance. LV trabeculae develop hypertrophy and fibrosis that contribute to reduced LV compliance. This study expands our previous results in ex vivo human hearts to show that severing LV trabeculae increases diastolic compliance in an ex vivo working rabbit heart model. Trabecular cutting was performed in ex vivo rabbit hearts set up in a working heart perfusion system perfused with oxygenated Krebs-Henseleit buffer. A hook was inserted in the LV to cut trabeculae. End-systolic and end-diastolic pressure-volume relationships during transient preload reduction were recorded using an admittance catheter in the following three groups: control (no cutting; n = 9), mild cutting (15 cuts; n = 5), and aggressive cutting (30 cuts; n = 5). In a second experiment, each heart served as its own control. Hemodynamic data were recorded before and after trabecular cutting ( n = 10) or sham cutting ( n = 5) within the same heart. In the first experiments, trabecular cutting did not affect systolic function ( P > 0.05) but significantly increased overall diastolic compliance ( P = 0.009). Greater compliance was seen as trabecular cutting increased ( P = 0.002, r2 = 0.435). In the second experiment, significant increases in systolic function ( P = 0.048) and diastolic compliance ( P = 0.002) were seen after trabecular cutting compared with baseline. In conclusion, trabecular cutting significantly increases diastolic compliance without reducing systolic function. NEW & NOTEWORTHY We postulate that, in mammalian hearts, free-running trabeculae carneae exist to provide tensile support to the left ventricle and minimize diastolic wall stress. Because of hypertrophy and fibrosis of trabeculae in patients with left ventricular hypertrophy, this supportive role can become pathologic, worsening diastolic compliance. We demonstrate a novel operation involving cutting trabeculae as a method to acutely increase diastolic compliance in patients presenting with heart failure and diastolic dysfunction to improve their left ventricle compliance.

Left ventricular dysfunction induced by chronic alcohol ingestion in rats

1991 ◽  
Vol 261 (1) ◽  
pp. H212-H219 ◽  
Author(s):  
J. M. Capasso ◽  
P. Li ◽  
G. Guideri ◽  
P. Anversa
Keyword(s):  
Left Ventricle ◽  
Diastolic Pressure ◽  
Systolic Pressure ◽  
Wall Stress ◽  
Longitudinal Axis ◽  
Left Ventricular ◽  
Experimental Animals ◽  
Chamber Volume ◽  
The Right ◽  
Myocyte Damage

To determine whether moderate ingestion of alcohol for protracted periods of time affects normal cardiac performance and produces myocyte damage, male Fischer 344 rats at 4 mo of age were given 30% ethanol in their drinking water every day for a period of 8 mo. Experimental animals and age-matched controls were examined hemodynamically and morphometrically at 12 mo of age. Body and cardiac growth were depressed in alcoholic animals by 15 and 12%, respectively. Although left ventricular (LV) weight was reduced by 14% in alcoholic rats, no difference in right ventricular (RV) weight was noted, and consequently the ratio of RV weight to body weight increased by 12%. Systemic arterial pressures as well as LV peak systolic pressure decreased in alcoholic rats despite an unchanged heart rate. Myocardial contractility in alcoholic rats was further depressed as revealed by a significant decrease in the peak rate of ventricular pressure decay. Importantly, end-diastolic pressure was elevated 5.2-fold in the left ventricle and 2.9-fold in the right ventricle after 8 mo of ethanol consumption. LV diastolic chamber volume increased through myocardial remodeling as the longitudinal axis and transverse diameters from the base to the apex increased in experimental animals while the thickness of the LV diminished. Structural and hemodynamic alterations resulted in a 571% increase in the volume of diastolic circumferential wall stress on the left ventricle. Damage to the myocardium was increased in alcoholic animals with the volume percent of myocardial lesions increasing 342% in the wall of the left ventricle.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of sympathomimetic amines on intramyocardial pressure in the rabbit

1963 ◽  
Vol 205 (1) ◽  
pp. 10-16 ◽  
Author(s):  
J. L. D'Silva ◽  
D. Mendel ◽  
M. C. Winterton
Keyword(s):  
Left Ventricle ◽  
Linear Relationship ◽  
Diastolic Pressure ◽  
Systolic Pressure ◽  
Differential Pressure ◽  
Sympathomimetic Amines ◽  
Intramyocardial Pressure ◽  
The Mean

Intramyocardial pressure has been measured in rabbits by means of a small inflatable latex balloon inserted into the myocardium of the left ventricle. The mean maximum intramyocardial pressure was found to be of the order of the aortic diastolic pressure. Adrenaline and isoprenaline infusion increased the maximum intramyocardial pressure; noradrenaline was without effect. Differential pressure plots of aortic and intramyocardial pressure against time showed that the increase in intramyocardial pressure produced by adrenaline and isoprenaline was matched by at least an equal increase in aortic systolic pressure. The same linear relationship was found when the total area under the curves (i.e., a function of flow) was plotted against the aortic diastolic pressure in controls and during infusion with sympathomimetic amines.

Extended Myectomy for Hypertrophic Obstructive Cardiomyopathy

2012 ◽  
Vol 15 (5) ◽  
pp. 251
Author(s):  
Changqing Gao ◽  
Chonglei Ren ◽  
Cangsong Xiao ◽  
Yang Wu ◽  
Gang Wang ◽  
...  
Keyword(s):  
Mitral Valve ◽  
Left Ventricle ◽  
Mitral Regurgitation ◽  
Surgical Procedures ◽  
Hypertrophic Obstructive Cardiomyopathy ◽  
Systolic Anterior Motion ◽  
Anterior Leaflet ◽  
Septal Myectomy ◽  
The Mean

<p><b>Background:</b> The purpose of this study was to summarize our experience of extended ventricular septal myectomy in patients with hypertrophic obstructive cardiomyopathy (HOCM).</p><p><b>Methods:</b> Thirty-eight patients (26 men, 12 women) with HOCM underwent extended ventricular septal myectomy. The mean age was 36.3 years (range, 18-64 years). Diagnosis was made by echocardiography. The mean (mean � SE) systolic gradient between the left ventricle (LV) and the aorta was 89.3 � 31.1 mm Hg (range, 50-184 mm Hg) according to echocardiographic assessments before the operations. Moderate or severe systolic anterior motion (SAM) of the anterior leaflet of the mitral valve was found in 38 cases, and mitral regurgitation was present in 29 cases. Extended ventricular septal myectomy was performed in all 38 cases. The results of the surgical procedures were evaluated intraoperatively with transesophageal echocardiography (TEE) and with transthoracic echocardiography (TTE) at 1 to 2 weeks after the operation. All patients were followed up with TTE after their operation.</p><p><b>Results:</b> All patients were discharged without complications. The TEE evaluations showed that the mean systolic gradient between the LV and the aorta decreased from 94.8 � 35.6 mm Hg preoperatively to 13.6 � 10.8 mm Hg postoperatively (<i>P</i> = .0000) and that the mean thickness of the ventricular septum decreased from 28.3 � 7.9 mm to 11.8 � 3.2 mm (<i>P</i> = .0000). Mitral regurgitation and SAM were significantly reduced or eliminated. During the follow-up, all patients promptly became completely asymptomatic or complained of mild effort dyspnea only, and syncope was abolished. TTE examinations showed that the postoperative pressure gradient either remained the same or diminished.</p><p><b>Conclusions:</b> Extended ventricular septal myectomy is mostly an effective method for patients with HOCM, and good surgical exposure and thorough excision of the hypertrophic septum are of paramount importance for a successful surgery.</p>

Double-chambered left ventricle with complex congenital heart disease in an infant: an extremely rare pathology

2019 ◽  
Vol 16 (3) ◽  
pp. 187-191
Author(s):  
T.V. Rogova ◽  
A.I. Kim ◽  
A.V. Sobolev ◽  
S.A. Aleksandrova ◽  
E.V. Kholmanskaya ◽  
...  
Keyword(s):  
Congenital Heart Disease ◽  
Heart Disease ◽  
Left Ventricle ◽  
Congenital Heart ◽  
Complex Congenital Heart Disease

scholarly journals Progress Report in Neuroscience and Education: Experiment of Four Neuropedagogical Methods

2021 ◽  
Vol 11 (8) ◽  
pp. 373
Author(s):  
Leila Elouafi ◽  
Lotfi Said ◽  
Mohammed Talbi
Keyword(s):  
Significant Variation ◽  
Progress Report ◽  
The Mean

We endeavor through this work to demonstrate the effects of the introduction of neuroeducation data in schools and their application, via an experiment of neuropedagogical methods, to respond to the hypothesis that the contribution of neuroeducation may be beneficial for learning. During this study we designed four neuropedagogical methods and to measure their effect on the learning of students in the classroom we used an evaluation grid comprising six psychopedagogical parameters. The results show that no statistically significant variation of these psychoeducational parameters is observed between sexes. However, a variation is recorded for the four neuropedagogical methods between the groups in pre-test and post at the levels of the mean scores ranging from 5.15% to 440%.

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