scholarly journals DIASTOLIC FUNCTION: MEASURING LEFT VENTRICULAR UNTWISTING AS A DAMPED HARMONIC OSCILLATOR

2021 ◽  
Vol 77 (18) ◽  
pp. 583
Author(s):  
Forrest Gamble ◽  
Rifqi Aufan ◽  
Oleg F. Sharifov ◽  
Lamario J. Williams ◽  
Shane Reighard ◽  
...  
1987 ◽  
Vol 252 (1) ◽  
pp. H178-H187 ◽  
Author(s):  
S. J. Kovacs ◽  
B. Barzilai ◽  
J. E. Perez

A new parametrized diastolic filling (PDF) formalism for evaluation of holodiastolic (left and right) ventricular function via Doppler echocardiography is presented. It is motivated by the empiric observation that during diastole the heart behaves as a suction pump whose dynamics, in certain respects, are those of a damped harmonic oscillator. An expression for elastic recoil (suction) initiated ventricular diastolic fluid inflow velocity v(t) is obtained by differentiation from the solution x(t) of the linear differential equation that describes the motion of a forced, damped harmonic oscillator. It is solved for “over-damped” motion, for zero initial velocity and initial displacement = xo cm. An explicit forcing term F(t) = Fosin(omega t) is included to account for late diastolic (atrial) filling. The quantitative parameters of the model include inertia (mass; m), viscosity (damping constant; c), source of stored energy for suction (spring constant; k), and its initial displacement xo, the amplitude and frequency of the (atrial) forcing term Fo, omega. The mathematical behavior of the solution v(t) and its dependence on the parameters xo, c, and k, which characterize the contour of the Doppler velocity profile (DVP), is discussed. When clinical examples of normal and abnormal transmitral DVPs are compared with v(t) calculated using the harmonic oscillator model, excellent agreement [DVP-v(t)]/v(t) approximately 0.05 is obtained throughout diastole. Thus the model allows accurate qualitative and quantitative characterization of global ventricular diastolic behavior by noninvasive means in a variety of normal and abnormal stiffness-compliance states. In addition, it may serve as a prototype for a class of mathematical models that can encompass the essential dynamic elements of ventricular diastolic function that couple to flow and further enhance the role of the heart as a suction pump.


2014 ◽  
Vol 4 (1) ◽  
pp. 404-426
Author(s):  
Vincze Gy. Szasz A.

Phenomena of damped harmonic oscillator is important in the description of the elementary dissipative processes of linear responses in our physical world. Its classical description is clear and understood, however it is not so in the quantum physics, where it also has a basic role. Starting from the Rosen-Chambers restricted variation principle a Hamilton like variation approach to the damped harmonic oscillator will be given. The usual formalisms of classical mechanics, as Lagrangian, Hamiltonian, Poisson brackets, will be covered too. We shall introduce two Poisson brackets. The first one has only mathematical meaning and for the second, the so-called constitutive Poisson brackets, a physical interpretation will be presented. We shall show that only the fundamental constitutive Poisson brackets are not invariant throughout the motion of the damped oscillator, but these show a kind of universal time dependence in the universal time scale of the damped oscillator. The quantum mechanical Poisson brackets and commutation relations belonging to these fundamental time dependent classical brackets will be described. Our objective in this work is giving clearer view to the challenge of the dissipative quantum oscillator.


2012 ◽  
Vol 35 (4) ◽  
pp. 229 ◽  
Author(s):  
Fatih Poyraz ◽  
Murat Turfan ◽  
Sinan A. Kocaman ◽  
Huseyin U. Yazici ◽  
Nihat Sen ◽  
...  

Purpose: The purpose of this study was to evaluate whether a association exits among overweight and obesity and left ventricular systolic and diastolic functions in patients admitted with first ST-elevation myocardial infarction (STEMI). Methods: The present study was performed on 451 consecutive patients diagnosed with first STEMI (376 men, 75 women; mean age 56.1±10.8 years). The patients were classified into three groups based on their body mass index (BMI) as normal weight (BMI < 25 kg/m2), overweight (BMI: 25-29.9 kg/m2) and obese (BMI > 30 kg/m2). Echocardiographic features were evaluated and compared among the three groups. Results: Mitral annulus E velocities were higher in obese individuals than normal weight group (p < 0.01). In contrast, mitral A velocities were lower (p =0.03); consequently, E\A and E'\A' ratios were lower (both p =0.01) in the obese group with respect to normal weight group. When the correction of entire variations existing among the groups were performed using multivariate linear regressions analyses, it turned out that BMI was independently associated with E/A (β= -0.19, p =0.044) and with E'/A' (β= -0.016, p=0.021). Ejection fraction, wall motion score index and myocardial S velocities were comparable among the study groups (p > 0.05). Conclusion: These results suggest that while obesity has no adverse effect on the left ventricular systolic function, it has unfavorable consequences on the left ventricular diastolic function in the patients with first STEMI. In contrast, no unfavorable effects of overweight on the left ventricular systolic and diastolic function were detected.


2011 ◽  
pp. 137-144
Author(s):  
Thi Ngoc Ha Hoang ◽  
Anh Vu Nguyen ◽  
Minh Loi Hoang ◽  
Cuu Long Nguyen ◽  
Thi Thuy Hang Nguyen

Purposes: Describe the morphological and diastolic function of left ventricular changes in the patients with dilated cardiomyopathy (DCM) on US, X-ray findings, and Evaluate the correlation between morphology and diastolic function of left ventricular. Materials and method: Cross sectional study from Dec 2009 to Aug 2010, on 39 patients with dilated cardiomyopathy were evaluated at the University Hospital of Hue College of Medical and Pharmaceutical. Results: 1. X-ray and US findings characteristics of DCM is significantly increased in diameter of L, H and mG; LVM, LVMI, LVDd and LAD. 2. The pression of pulmonary artery has been significantly increased with redistribution pulmonary arteries in 61.5% cases and 23.1% have reversed pulmonary artery distribution. 3. DCM have diastolic dysfunction in 100% patients, including severe disorders to 61.5%; the restrictive dysfunction has ratio E/A>2 and E/Em average was 23.89± 17.23. 4.The correlation between the morphology and function in DCM: the diameter of H and L on the X-ray, LAD and ratio LA/AO on US correlated with the level of diastolic dysfunction (p< 0.05). All three radiographic parameters on the radio standard (H, L, the index Cardio/Thoracic) and LVDd on US have negative correlated with EF and FS with p <0.05. Key words: dilated cardiomyopathy, diastolic dysfunction, cardiac tissue Doppler, reversed pulmonary artery distribution


2019 ◽  
Vol 3 (11) ◽  
pp. 1725-1728 ◽  
Author(s):  
Yoshiaki Abe ◽  
Tetsuya Kobayashi ◽  
Kentaro Narita ◽  
Hiroki Kobayashi ◽  
Akihiro Kitadate ◽  
...  

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