Electrical activation and mechanical asynchronism in the cardiac cycle of the dog

1959 ◽  
Vol 14 (3) ◽  
pp. 417-420 ◽  
Author(s):  
Philip Samet ◽  
William H. Bernstein ◽  
Robert S. Litwak ◽  
William H. Meyer ◽  
Louis Lemberg
Keyword(s):  
Left Ventricle ◽  
Isometric Contraction ◽  
Cardiac Cycle ◽  
Left Ventricular Pressure ◽  
Left Ventricular ◽  
Electrical Activation ◽  
Qrs Complex ◽  
Simultaneous Registration ◽  
The Right ◽  
Premature Beats

Dissociation of electrical and mechanical asynchronism in the right and left ventricle of the dog has been studied by simultaneous registration of the precordial electrocardiogram and right and left ventricular pressure curves. Observations were made during sinus rhythm and during digitalis-induced ventricular premature beats with widened aberrant QRS complexes. Measurements were made of the time of onset of isometric contraction in the ventricles, relative to each other, and to the onset of the QRS complex. The results indicate that mechanical asynchronism in onset of isometric contraction is not a necessary consequence of the asynchronous electrical depolarization of ventricular premature systoles. Submitted on November 10, 1958

Porous medium finite element model of the beating left ventricle

1992 ◽  
Vol 262 (4) ◽  
pp. H1256-H1267 ◽  
Author(s):  
J. M. Huyghe ◽  
T. Arts ◽  
D. H. van Campen ◽  
R. S. Reneman
Keyword(s):  
Left Ventricle ◽  
Wall Thickness ◽  
Cardiac Cycle ◽  
Left Ventricular Pressure ◽  
Left Ventricular ◽  
Fiber Direction ◽  
Intraventricular Pressure ◽  
Angle Distribution ◽  
Fiber Angle ◽  
Intramyocardial Pressure

The axisymmetric model described represents myocardial tissue as a spongy anisotropic viscoelastic material. It includes torsion around the axis of symmetry of the ventricle, transmural variation of fiber angle, and redistribution of intracoronary blood in the myocardial wall. In simulations, end-systolic principal strains were equal to 0.45, -0.01, and -0.24 at two-thirds of the wall thickness from the epicardium and 0.26, 0.00, and -0.19 at one-third of the wall thickness from the epicardium. The direction of maximal shortening varied by less than 30 degrees from epicardium to endocardium, whereas fiber direction varied by greater than 100 degrees from epicardium to endocardium. During a normal cardiac cycle peak, equatorial intramyocardial pressure differed by less than 5% from peak intraventricular pressure. When redistribution of intracoronary blood in the ventricular wall was suppressed, peak equatorial intramyocardial pressure was found to exceed peak intraventricular pressure by greater than 30%. Simulated contraction of an unloaded left ventricle (left ventricular pressure = 0 kPa) produced similar magnitude for systolic intramyocardial pressures as the normal cardiac cycle. Transmural systolic fiber stress distribution was very sensitive to the chosen transmural fiber angle distribution.

Ventricular asynchronism in the dog

1962 ◽  
Vol 17 (3) ◽  
pp. 479-481 ◽  
Author(s):  
Philip Samet ◽  
William H. Bernstein ◽  
Robert S. Litwak
Keyword(s):  
Sinus Rhythm ◽  
Strain Gauge ◽  
Left Ventricular Pressure ◽  
Left Ventricular ◽  
Ventricular Pressure ◽  
Ventricular Premature Beats ◽  
Simultaneous Registration ◽  
Premature Beats

Dissociation of electrical and mechanical asynchronism in the canine right and left ventricles has been studied by simultaneous registration of right and left ventricular pressure and strain gauge arch curves and the electrocardiogram. Observations were made during sinus rhythm and during acetylstrophanthidin-induced ventricular premature beats with widened aberrant QRS complexes. The data demonstrate only limited mechanical asynchronism during the asynchronous electrical depolarization of ventricular premature systoles. Submitted on October 19, 1961

Analysis of QRS complex recorded through a semiorthogonal lead system in the horse

1964 ◽  
Vol 207 (2) ◽  
pp. 325-333 ◽  
Author(s):  
Robert L. Hamlin ◽  
David L. Smetzer ◽  
C. Roger Smith
Keyword(s):  
Spinous Process ◽  
Interventricular Septum ◽  
Left Ventricular ◽  
The Body ◽  
Qrs Complex ◽  
Lead System ◽  
Ventricular Premature Beats ◽  
Unipolar Lead ◽  
The Right ◽  
Premature Beats

A semiorthogonal lead system for recording electrocardiograms from horses was designed. The X, Y, and Z axes of the body were monitored by leads I, aVF, and V10 (the unipolar lead taken from the dorsal spinous process of the seventh thoracic vertebra), respectively. Records were taken from 15 standing horses. Ventricular premature beats were elicited by pricking foci on the right and left ventricular epicardium. For normally conducted beats, two major vectors represented forces generating the QRS complex. Vector 1, probably representing excitation of the apical third of the interventricular septum from left to right, was relatively low in magnitude, and was oriented dextrad, ventrad, and craniad. Vector 2, probably representing depolarization of the basilar third of the interventricular septum from left to right and in an apicobasilar direction, was of greater magnitude and was oriented ventrad, sinistrad, and craniad. Occasionally a vector intermediate between vectors 1 and 2 was oriented caudad and dorsad. The origin of this vector is equivocal. Left ventricular premature beats generated vectors of great magnitude oriented dextrad and craniad. Right ventricular premature beats generated vectors of magnitude between those of sinus or left ventricular origin, and directed predominantly sinistrad.

scholarly journals Hemodynamic Support Using Percutaneous Transfemoral Impella 5.0 and Impella RP for Refractory Cardiogenic Shock

2019 ◽  
Vol 2019 ◽  
pp. 1-6 ◽  
Author(s):  
Pratik K. Dalal ◽  
Amy Mertens ◽  
Dinesh Shah ◽  
Ivan Hanson
Keyword(s):  
Left Ventricle ◽  
Pulmonary Artery ◽  
Cardiogenic Shock ◽  
Ventricular Function ◽  
Standard Of Care ◽  
Left Ventricular ◽  
Biventricular Failure ◽  
Ventricular Support ◽  
The Right ◽  
Flow Pump

Acute myocardial infarction (AMI) resulting in cardiogenic shock continues to be a substantial source of morbidity and mortality despite advances in recognition and treatment. Prior to the advent of percutaneous and more durable left ventricular support devices, prompt revascularization with the addition of vasopressors and inotropes were the standard of care in the management of this critical population. Recent published studies have shown that in addition to prompt revascularization, unloading of the left ventricle with the placement of the Impella percutaneous axillary flow pump can lead to improvement in mortality. Parameters such as the cardiac power output (CPO) and pulmonary artery pulsatility index (PAPi), obtained through pulmonary artery catheterization, can help ascertain the productivity of right and left ventricular function. Utilization of these parameters can provide the information necessary to escalate support to the right ventricle with the insertion of an Impella RP or the left ventricle with the insertion of larger devices, which provide more forward flow. Herein, we present a case of AMI complicated by cardiogenic shock resulting in biventricular failure treated with the percutaneous insertion of an Impella RP and Impella 5.0 utilizing invasive markers of left and right ventricular function to guide the management and escalation of care.

scholarly journals Left ventricular noncompaction—a rare cause of triad: heart failure, ventricular arrhythmias, and systemic embolic events: a case report 

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Despina Toader ◽  
Alina Paraschiv ◽  
Petrișor Tudorașcu ◽  
Diana Tudorașcu ◽  
Constantin Bataiosu ◽  
...  
Keyword(s):  
Heart Failure ◽  
Cardiac Magnetic Resonance ◽  
Magnetic Resonance ◽  
Left Ventricle ◽  
Ventricular Arrhythmias ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Left Ventricular Noncompaction ◽  
Ventricular Noncompaction ◽  
The Right

Abstract Background Left ventricular noncompaction is a rare cardiomyopathy characterized by a thin, compacted epicardial layer and a noncompacted endocardial layer, with trabeculations and recesses that communicate with the left ventricular cavity. In the advanced stage of the disease, the classical triad of heart failure, ventricular arrhythmia, and systemic embolization is common. Segments involved are the apex and mid inferior and lateral walls. The right ventricular apex may be affected as well. Case presentation A 29-year-old Caucasian male was hospitalized with dyspnea and fatigue at minimal exertion during the last months before admission. He also described a history of edema of the legs and abdominal pain in the last weeks. Physical examination revealed dyspnea, pulmonary rales, cardiomegaly, hepatomegaly, and splenomegaly. Electrocardiography showed sinus rhythm with nonspecific repolarization changes. Twenty-four-hour Holter monitoring identified ventricular tachycardia episodes with right bundle branch block morphology. Transthoracic echocardiography at admission revealed dilated left ventricle with trabeculations located predominantly at the apex but also in the apical and mid portion of lateral and inferior wall; end-systolic ratio of noncompacted to compacted layers > 2; moderate mitral regurgitation; and reduced left ventricular ejection fraction. Between apical trabeculations, multiple thrombi were found. The right ventricle had normal morphology and function. Speckle-tracking echocardiography also revealed systolic left ventricle dysfunction and solid body rotation. Abdominal echocardiography showed hepatomegaly and splenomegaly. Abdominal computed tomography was suggestive for hepatic and renal infarctions. Laboratory tests revealed high levels of N-terminal pro-brain natriuretic peptide and liver enzymes. Cardiac magnetic resonance evaluation at 1 month after discharge confirmed the diagnosis. The patient received anticoagulants, antiarrhythmics, and heart failure treatment. After 2 months, before device implantation, he presented clinical improvement, and echocardiographic evaluation did not detect thrombi in the left ventricle. Coronary angiography was within normal range. A cardioverter defibrillator was implanted for prevention of sudden cardiac death. Conclusions Left ventricular noncompaction is rare cardiomyopathy, but it should always be considered as a possible diagnosis in a patient hospitalized with heart failure, ventricular arrhythmias, and systemic embolic events. Echocardiography and cardiac magnetic resonance are essential imaging tools for diagnosis and follow-up.

Regulation of K+ and Ca2+ channels in experimental cardiac failure

1991 ◽  
Vol 261 (6) ◽  
pp. H1979-H1987 ◽  
Author(s):  
M. Gopalakrishnan ◽  
D. J. Triggle ◽  
A. Rutledge ◽  
Y. W. Kwon ◽  
J. A. Bauer ◽  
...  
Keyword(s):  
Heart Failure ◽  
Left Ventricle ◽  
Right Ventricle ◽  
Cardiac Failure ◽  
Radioligand Binding ◽  
Weight Ratio ◽  
Left Ventricular ◽  
Coronary Artery Ligation ◽  
Artery Ligation ◽  
The Right

To examine the status of ATP-sensitive K+ (K+ATP) channels and 1,4-dihydropyridine-sensitive Ca2+ (Ca2+DHP) channels during experimental cardiac failure, we have measured the radioligand binding properties of [3H]glyburide and [3H]PN 200 110, respectively, in tissue homogenates from the rat cardiac left ventricle, right ventricle, and brain 4 wk after myocardial infarction induced by left coronary artery ligation. The maximal values (Bmax) for [3H]glyburide and [3H]PN 200 110 binding were reduced by 39 and 40%, respectively, in the left ventricle, and these reductions showed a good correlation with the right ventricle-to-body weight ratio in heart-failure rats. The ligand binding affinities were not altered. In the hypertrophied right ventricle, Bmax values for both the ligands were not significantly different when data were normalized to DNA content or right ventricle weights but showed an apparent reduction when normalized to unit protein or tissue weight. Moderate reductions in channel densities were observed also in whole brain homogenates from heart failure rats. Assessment of muscarinic receptors, beta-adrenoceptors and alpha 1-adrenoceptors by [3H]quinuclidinyl benzilate, [3H]dihydroalprenolol, and [3H]prazosin showed reductions in left ventricular muscarinic and beta-adrenoceptor densities but not in alpha 1-adrenoceptor densities, consistent with earlier observations. It is suggested that these changes may in part contribute to the pathology of cardiac failure.

Impact of ejection on magnitude and time course of ventricular pressure-generating capacity

1993 ◽  
Vol 265 (3) ◽  
pp. H899-H909 ◽  
Author(s):  
D. Burkhoff ◽  
P. P. De Tombe ◽  
W. C. Hunter
Keyword(s):  
Time Course ◽  
Cardiac Cycle ◽  
Left Ventricular Pressure ◽  
Left Ventricular ◽  
Ventricular Pressure ◽  
Time Varying ◽  
Generating Capacity ◽  
Ejection Phase ◽  
Time Point ◽  
Ventricular Dynamics

This study focuses on elucidating how ventricular afterloading conditions affect the time course of change of left ventricular pressure (LVP) throughout the cardiac cycle, with particular emphasis on revealing specific limitations in the time-varying elastance model of ventricular dynamics. Studies were performed in eight isolated canine hearts ejecting into a simulated windkessel afterload. LVP waves measured (LVPm) during ejection were compared with those predicted (LVPpred) according to the elastance theory. LVPm exceeded LVPpred from a time point shortly after the onset of ejection to the end of the beat. The instantaneous difference between LVPm and LVPpred increased steadily as ejection proceeded and reached between 45 and 65 mmHg near end ejection. This was in large part due to an average 35-ms prolongation of the time to end systole (tes) in ejecting compared with isovolumic beats. The time constant of relaxation was decreased on ejecting beats so that, despite the marked prolongation of tes, the overall duration of ejecting contractions was not greater than that of isovolumic beats. The results demonstrate a marked ejection-mediated enhancement and prolongation of ventricular pressure-generating capacity during the ejection phase of the cardiac cycle with concomitant acceleration of relaxation. None of these factors are accounted for by the time-varying elastance theory.

Ventricular systolic interdependence: volume elastance model in isolated canine hearts

1987 ◽  
Vol 253 (6) ◽  
pp. H1381-H1390 ◽  
Author(s):  
W. L. Maughan ◽  
K. Sunagawa ◽  
K. Sagawa
Keyword(s):  
Left Ventricle ◽  
Right Ventricle ◽  
Cross Talk ◽  
Systolic Pressure ◽  
Left Ventricular ◽  
Ventricular Free Wall ◽  
Free Wall ◽  
Right Ventricular Free Wall ◽  
Systolic Volume ◽  
The Right

To analyze the interaction between the right and left ventricle, we developed a model that consists of three functional elastic compartments (left ventricular free wall, septal, and right ventricular free wall compartments). Using 10 isolated blood-perfused canine hearts, we determined the end-systolic volume elastance of each of these three compartments. The functional septum was by far stiffer for either direction [47.2 +/- 7.2 (SE) mmHg/ml when pushed from left ventricle and 44.6 +/- 6.8 when pushed from right ventricle] than ventricular free walls [6.8 +/- 0.9 mmHg/ml for left ventricle and 2.9 +/- 0.2 for right ventricle]. The model prediction that right-to-left ventricular interaction (GRL) would be about twice as large as left-to-right interaction (GLR) was tested by direct measurement of changes in isovolumic peak pressure in one ventricle while the systolic pressure of the contralateral ventricle was varied. GRL thus measured was about twice GLR (0.146 +/- 0.003 vs. 0.08 +/- 0.001). In a separate protocol the end-systolic pressure-volume relationship (ESPVR) of each ventricle was measured while the contralateral ventricle was alternatively empty and while systolic pressure was maintained at a fixed value. The cross-talk gain was derived by dividing the amount of upward shift of the ESPVR by the systolic pressure difference in the other ventricle. Again GRL measured about twice GLR (0.126 +/- 0.002 vs. 0.065 +/- 0.008). There was no statistical difference between the gains determined by each of the three methods (predicted from the compartment elastances, measured directly, or calculated from shifts in the ESPVR). We conclude that systolic cross-talk gain was twice as large from right to left as from left to right and that the three-compartment volume elastance model is a powerful concept in interpreting ventricular cross talk.

scholarly journals Age-associated Decline in Phosphorylated Connexin 43 Protein Expression in the Left Ventricular Tissue of Wister Rats

2019 ◽  
pp. 1-8
Author(s):  
Donatus Onukwufor Onwuli ◽  
Sandra A. Jones
Keyword(s):  
Left Ventricle ◽  
Western Blot ◽  
Cardiac Arrhythmia ◽  
Connexin 43 ◽  
The Elderly ◽  
Left Ventricular ◽  
Cardiac Impulse ◽  
Ventricular Tissue ◽  
Connexin Proteins ◽  
The Right

Cardiac arrhythmia affects ~ 6% in those over 65 years of age (old), but with 0.2% occurrence in those of 45 years and below (young). Arrhythmia can result from dysregulation of the cardiac impulse generation and its conduction. Connexin proteins are responsible for cardiac impulse conduction, and phosphorylation of connexin 43 determines its functional ability. In this study, Phosphorylated connexin 43, density and expression were assessed in ventricular tissues from young (6 months old) and old (24 months old) Wister rats, using the techniques of western blot and immunohistochemistry. Results show that phosphorylated Cx43 in the left ventricle of 24 months old rats significantly declined (P=0.04 & 0.01) by method of western blot and immunohistochemistry respectively, but did not differ in the right ventricle. The left ventricle is known to be responsible for cardiac output. This data suggest an age-associated decline in the expression of phosphorylated connexin 43 in the left ventricle, which may play a significant role in the development of cardiac arrhythmia in the elderly.

Levels of brain natriuretic peptide in children with right ventricular overload due to congenital cardiac disease

2005 ◽  
Vol 15 (4) ◽  
pp. 396-401 ◽  
Author(s):  
Thomas S. Mir ◽  
Jan Falkenberg ◽  
Bernd Friedrich ◽  
Urda Gottschalk ◽  
Throng Phi Lê ◽  
...  
Keyword(s):  
Right Ventricle ◽  
Brain Natriuretic Peptide ◽  
Right Ventricular ◽  
Natriuretic Peptide ◽  
Cardiac Disease ◽  
Left Ventricular Pressure ◽  
Left Ventricular ◽  
Ventricular Pressure ◽  
Congenital Cardiac Disease ◽  
The Right

Objective:To evaluate the role of the concentration of brain natriuretic peptide in the plasma, and its correlation with haemodynamic right ventricular parameters, in children with overload of the right ventricle due to congenital cardiac disease.Methods:We studied 31 children, with a mean age of 4.8 years, with volume or pressure overload of the right ventricle caused by congenital cardiac disease. Of the patients, 19 had undergone surgical biventricular correction of tetralogy of Fallot, 11 with pulmonary stenosis and 8 with pulmonary atresia, and 12 patients were studied prior to operations, 7 with atrial septal defects and 5 with anomalous pulmonary venous connections. We measured brain natriuretic peptide using Triage®, from Biosite, United States of America. We determined end-diastolic pressures of the right ventricle, and the peak ratio of right to left ventricular pressures, by cardiac catheterization and correlated them with concentrations of brain natriuretic peptide in the plasma.Results:The mean concentrations of brain natriuretic peptide were 87.7, with a range from 5 to 316, picograms per millilitre. Mean end-diastolic pressure in the right ventricle was 5.6, with a range from 2 to 10, millimetres of mercury, and the mean ratio of right to left ventricular pressure was 0.56, with a range from 0.24 to 1.03. There was a positive correlation between the concentrations of brain natriuretic peptide and the ratio of right to left ventricular pressure (r equal to 0.7844, p less than 0.0001) in all patients. These positive correlations remained when the children with tetralogy of Fallot, and those with atrial septal defects or anomalous pulmonary venous connection, were analysed as separate groups. We also found a weak correlation was shown between end-diastolic right ventricular pressure and concentrations of brain natriuretic peptide in the plasma (r equal to 0.5947, p equal to 0.0004).Conclusion:There is a significant correlation between right ventricular haemodynamic parameters and concentrations of brain natriuretic peptide in the plasma of children with right ventricular overload due to different types of congenital cardiac disease. The monitoring of brain natriuretic peptide may provide a non-invasive and safe quantitative follow up of the right ventricular pressure and volume overload in these patients.

Sign in / Sign up

Export Citation Format

Share Document