Literatura académica sobre el tema "Maximal early diastolic relaxation velocity"
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Artículos de revistas sobre el tema "Maximal early diastolic relaxation velocity"
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Zdravkovic, Marija, Marina Deljanin-Ilic, Danijela Trifunovic-Zamaklar, Nikola Milinic, Darko Zdravkovic y Natasa Milic. "Pulsed doppler tissue imaging in the early diagnosis of coronary artery disease". Medical review 60, n.º 9-10 (2007): 444–48. http://dx.doi.org/10.2298/mpns0710444z.
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Introduction Cardiovascular diseases are the leading cause of death in the majority of well-developed countries. Importance of early diagnosis Early diagnosis of coronary artery disease is difficult due to blood vessels remodeling, late manifestations of reduced maximal and normal coronary blood flow, and negative correlation between stenosis and plaque burden. Pulsed Doppler tissue imaging Pulsed Doppler tissue imaging is used for assessment of myocardial velocity, whereas classical Doppler imaging is used for measurement of blood flow velocity. Systolic myocardial velocity profile During the systolic phase only a single myocardial motion is registered - S wave. Diastolic myocardial velocity profile There are early and late myocardial relaxation velocities. Impact of coronary artery disease on myocardial velocities Early to late myocardial relaxation velocity ratio is influenced by coronary artery disease. This paper provides practical guidelines for using pulsed doppler tissue imaging. Conclusion Pulsed Doppler tissue imaging is an excellent procedure for early diagnosis of coronary artery disease. .
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VINEREANU, Dragos, Nicolae FLORESCU, Nicholas SCULTHORPE, Ann C. TWEDDEL, Michael R. STEPHENS y Alan G. FRASER. "Left ventricular long-axis diastolic function is augmented in the hearts of endurance-trained compared with strength-trained athletes". Clinical Science 103, n.º 3 (8 de agosto de 2002): 249–57. http://dx.doi.org/10.1042/cs1030249.
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In order to determine left ventricular global and regional myocardial functional reserve in endurance-trained and strength-trained athletes, and to identify predictors of exercise capacity, we studied 18 endurance-trained and 11 strength-trained athletes with left ventricular hypertrophy (172±27 and 188±39g/m2 respectively), and compared them with 14 sedentary controls. Global systolic (ejection fraction) and diastolic (transmitral flow) function, and regional longitudinal and transverse myocardial velocities [tissue Doppler echocardiography (TDE)], were measured at rest and immediately after exercise. In endurance-trained compared with strength-trained athletes, resting heart rate was lower (59±11 and 76±9beats/min respectively; P<0.001), and the increase at peak exercise was greater (+211% and +139% respectively; P<0.001). In addition, exercise duration, workload, maximal oxygen consumption and global systolic functional reserve (but not peak ejection fraction) were higher in the endurance-trained athletes, and resting global diastolic function (E/A ratio 1.62±0.40 compared with 1.18±0.23; P<0.01) (where E-wave is peak velocity of early-diastolic mitral inflow and A-wave is peak velocity of mitral inflow during atrial contraction) and long-axis diastolic velocities (ETDE/ATDE ratio 2.2±1.2 compared with 1.1±0.3; P<0.01) (where ETDE and ATDE represent peak early- and late-diastolic myocardial or tissue velocity respectively) were augmented. Systolic velocities were similar. Exercise capacity was best predicted from end-diastolic diameter index and E/A ratio at rest, and end-diastolic volume index and diastolic longitudinal velocity during exercise (r = 0.74, n = 43, P<0.001). In conclusion, endurance-trained athletes had higher left ventricular long-axis diastolic velocities, augmented global early diastolic filling, and greater chronotropic and global systolic functional reserve. Maximal oxygen consumption was determined by diastolic loading and early relaxation rather than by systolic function, suggesting that dynamic exercise training improves cardiac performance by an effect on diastolic filling.
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Samuel, T. Jake, Rhys Beaudry, Mark J. Haykowsky, Satyam Sarma y Michael D. Nelson. "Diastolic stress testing: similarities and differences between isometric handgrip and cycle echocardiography". Journal of Applied Physiology 125, n.º 2 (1 de agosto de 2018): 529–35. http://dx.doi.org/10.1152/japplphysiol.00304.2018.
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Cycle echocardiography (CE) is recommended for noninvasive diagnosis of diastolic dysfunction but can be limited by respiratory and movement artifact. Isometric handgrip echocardiography (IHE) is also a robust diastolic discriminator, while avoiding the limitations associated with dynamic exercise. This study sought to compare these two diastolic stress testing approaches. Twelve elderly individuals were recruited from the community (age 71 ± 6 yr). Heart rate, arterial blood pressure, and left ventricular (LV) diastolic function (via echocardiography) were assessed at rest and in response to 3 min of IHE at 40% of their maximal voluntary contraction, followed by 3 min of CE at 20 W. Both IHE and CE caused a significant increase in heart rate and blood pressure, leading to similar increases in myocardial oxygen demand. Both stressors also evoked a similar rise in the ratio between early LV mitral inflow velocity to early lateral annular velocity, a surrogate measure of LV filling pressure. The underlying mechanisms leading to these changes, however, were inherently different. IHE increased mean arterial pressure, and impaired myocardial relaxation, to a greater extent than CE. In contrast, CE augmented cardiac index, and increased early mitral filling velocity, to a great extent than IHE. In conclusion, for the first time, these data highlight several important similarities and differences between IHE and CE. That IHE avoids respiratory and movement artifact, while still serving as a robust diastolic discriminator, supports IHE as a strong alternative to CE for diastolic stress testing. NEW & NOTEWORTHY This is the first study to compare the diastolic stress response between isometric handgrip exercise and conventional cycle exercise. The data suggest that isometric handgrip echocardiography is comparable to conventional cycle echocardiography, both in terms of its hemodynamic challenge and global diastolic stress response. That isometric handgrip echocardiography eliminates both respiratory and movement artifact and is low cost and incredibly portable supports its integration into routine echocardiography exams.
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Lalande, Sophie, Robert J. Petrella y J. Kevin Shoemaker. "Effect of exercise training on diastolic function in metabolic syndrome". Applied Physiology, Nutrition, and Metabolism 38, n.º 5 (mayo de 2013): 545–50. http://dx.doi.org/10.1139/apnm-2012-0383.
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It has been reported that metabolic syndrome (MetS) impairs left ventricular (LV) diastolic function. The objective of this study was to determine whether exercise training can improve LV diastolic function in individuals with MetS. Twenty-eight individuals with MetS (9 males, aged 60 ± 5 years) underwent a 1-year combined endurance and resistance exercise training program; maximal aerobic capacity (V̇O2max), blood pressure, blood markers, and LV diastolic function were measured at weeks 0, 12, 24, and 52 throughout the training. Pulsed wave Doppler echocardiography across the mitral valve was used to assess peak early flow velocity (E) and peak atrial flow velocity (A) to determine the E/A ratio. Individuals with MetS had a reversed E/A ratio, suggesting impaired LV relaxation, the first stage of LV diastolic dysfunction. Exercise training reduced systolic blood pressure (SBP) (129 ± 14 to 120 ± 12 mm Hg; p < 0.01) and increased V̇O2max (29.2 ± 6.3 to 33.4 ± 6.5 mL·kg−1·min−1; p < 0.01) and high-density lipoprotein cholesterol (1.04 ± 0.21 to 1.12 ± 0.25 mmol·L−1; p = 0.02), but did not improve LV diastolic function. Individuals with an E/A ratio <1 at the start of training had a tendency toward an increased E/A ratio (p = 0.12) accompanied by significant decreases in SBP and increases in V̇O2max with exercise training. Combined resistance and aerobic exercise training improved cardiometabolic health but did not improve the impaired LV diastolic function of individuals with MetS.
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Petrella, Robert J., Donald A. Cunningham y David H. Paterson. "Effects of 5-Day Exercise Training in Elderly Subjects on Resting Left Ventricular Diastolic Function and VO2max". Canadian Journal of Applied Physiology 22, n.º 1 (1 de febrero de 1997): 37–47. http://dx.doi.org/10.1139/h97-004.
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We evaluated the effects of short-term, high-intensity exercise training and detraining on resting left ventricular diastolic function (LVDF) and maximal aerobic power (VO2max) in 7 sedentary older (age = 68 ± 4 years) men (n = 5) and women (n = 2). Training consisted of cycling for 60 min with power output set at 70% (Day 1), 80% (Day 2), and 90% (Days 3-5) of the pretraining peak work rate. Detraining consisted of a return to regular exercise habits. LVDF increased 10% in the early (E) flow velocity, decreased 18% in the late (A) flow velocity wave, and decreased 31% in the isovolumic relaxation time. VO2max was increased 12% while plasma volume (PV) increased 10% following, training and returned to baseline after detraining. The exercise-induced change in VO2max was directly related to the change in E/A (r =.52) and indirectly related to the change in IVRT (r = −.62). It was concluded that short-term, high-intensity exercise training improves LVDF and is tolerated well in older subjects, and that the calculated changes in PV and aerobic power are similar to those observed previously in a younger population. Key words: aging, training, cardiac filling
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Varagic, Jasmina, Edward D. Frohlich, Dinko Susic, Jwari Ahn, Luis Matavelli, Begoña López y Javier Díez. "AT1receptor antagonism attenuates target organ effects of salt excess in SHRs without affecting pressure". American Journal of Physiology-Heart and Circulatory Physiology 294, n.º 2 (febrero de 2008): H853—H858. http://dx.doi.org/10.1152/ajpheart.00737.2007.
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Our recent studies have demonstrated that salt excess in the spontaneously hypertensive rat (SHR) produces a modestly increased arterial pressure while promoting marked myocardial fibrosis and structural damage associated with altered coronary hemodynamics and ventricular function. The present study was designed to determine the efficacy of an angiotensin II type 1 (AT1) receptor blocker (ARB) in the prevention of pressure increase and development of target organ damage from high dietary salt intake. Eight-week-old SHRs were given an 8% salt diet for 8 wk; their age- and gender-matched controls received standard chow. Some of the salt-loaded rats were treated concomitantly with ARB (candesartan; 10 mg·kg−1·day−1). The ARB failed to reduce the salt-induced rise in pressure, whereas it significantly attenuated left ventricular (LV) remodeling (mass and wall thicknesses), myocardial fibrosis (hydroxyproline concentration and collagen volume fraction), and the development of LV diastolic dysfunction, as shown by longer isovolumic relaxation time, decreased ratio of peak velocity of early to late diastolic waves, and slower LV relaxation (minimum first derivative of pressure over time/maximal LV pressure). Without affecting the increased pulse pressure by high salt intake, the ARB prevented the salt-induced deterioration of coronary and renal hemodynamics but not the arterial stiffening or hypertrophy (pulse wave velocity and aortic mass index). Additionally, candesartan prevented the salt-induced increase in kidney mass index and proteinuria. In conclusion, the ARB given concomitantly with dietary salt excess ameliorated salt-related structural and functional cardiac and renal abnormalities in SHRs without reducing arterial pressure. These data clearly demonstrated that angiotensin II (via AT1receptors), at least in part, participated importantly in the pressure-independent effects of salt excess on target organ damage of hypertension.
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O’Driscoll, Jamie M., Steven M. Wright, Katrina A. Taylor, Damian A. Coleman, Rajan Sharma y Jonathan D. Wiles. "Cardiac autonomic and left ventricular mechanics following high intensity interval training: a randomized crossover controlled study". Journal of Applied Physiology 125, n.º 4 (1 de octubre de 2018): 1030–40. http://dx.doi.org/10.1152/japplphysiol.00056.2018.
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Physical inactivity and sedentary behavior is associated with increased cardiovascular disease risk. Short duration high-intensity interval training (HIIT) has been shown to improve important health parameters. The aim of the present study was to assess the combined adaptations of the cardiac autonomic nervous system and myocardial functional and mechanical parameters to HIIT. Forty physically inactive and highly sedentary men completed two weeks of HIIT and control period. The HIIT protocol consisted of 3 × 30-s maximal cycle ergometer sprints against a resistance of 7.5% body weight, interspersed with 2 min of active recovery. Total power spectral density (PSD) and associated low-frequency (LF) and high-frequency (HF) power spectral components of heart rate variability were recorded. Conventional and speckle tracking echocardiography recorded left ventricular (LV) structural, functional, and mechanical parameters. HIIT produced a significant increase in total log-transformed (ln) PSD and ln HF and a significant decrease in LF/HF ratio (all P < 0.05) compared with the control period. HIIT produced significant improvements in LV diastolic function, including lateral E′, estimated filling pressure (E/E′ ratio), E deceleration time, and isovolumetric relaxation time ( P < 0.05 for all). Fractional shortening was the only conventional marker of LV systolic function to significantly improve ( P < 0.05). In this setting, there were significant improvements in global peak systolic strain rate, early and late diastolic strain rate, and early to late diastolic strain rate ratio, as well as apical rotation, apical systolic and diastolic rotation velocity, apical radial and circumferential strain and strain rate, LV torsion, and LV systolic and diastolic torsion velocity (all P < 0.05). A short-term program of HIIT was associated with a significant increase in cardiac autonomic modulation, demonstrated by a residual increase in cardiac vagal activity as well as significantly improved cardiac function and mechanics. This study demonstrates that HIIT may be an important stimulus to reduce the health implications associated with physical inactivity and sedentary behavior. NEW & NOTEWORTHY This is the first study to measure the combined adaptations of the cardiac autonomic nervous system and myocardial function and mechanics following high-intensity interval training (HIIT). This study demonstrates that a 2-wk HIIT intervention provides significant improvements in cardiac autonomic modulation and myocardial function and mechanics in a large cohort of young physically inactive and highly sedentary individuals. HIIT may be a powerful stimulus to reduce the health implications associated with physical inactivity and sedentary behavior.
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PASHCHENKO, E. V., A. I. CHESNIKOVA, V. P. TERENTYEV, V. I. KUDINOV y E. A. DEVETYAROVA. "STRUCTURAL AND FUNCTIONAL FEATURES OF LEFT VENTRICLE IN PATIENTS WITH HEART FAILURE, CORONARY HEART DISEASE AND THYROTOXICOSIS". Kuban Scientific Medical Bulletin 25, n.º 4 (3 de octubre de 2018): 68–74. http://dx.doi.org/10.25207/1608-6228-2018-25-4-68-74.
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Aim. This study was designed to determine the structural and functional features of left ventricle in patients with heart failure, coronary heart disease and thyrotoxicosis.Materials and methods. 85 patients aged 58.3±5.6 years were divided into 3 groups: the main one – 25 patients with coronary heart disease (CHD), chronic heart failure (CHF) II-III functional classes (FC) and thyrotoxicosis, average age –59.23±3.81; the 1st comparison group – 30 patients with CHD and CHF FC II-III without thyroid dysfunction, the average age – 57.6±2.73; the 2nd comparison group – 30 patients with thyrotoxicosis without concomitant cardiovascular diseases (CVD), the average age – 45.4±3.51. The structure and function of the thyroid gland were examined in all patients. The echocardiographic (EchoCG) examination was performed to evaluate the structural and functional indicators of the left ventricle (LV).Results. The LV pathologic remodeling in patients of the main group is represented by two types: concentric left ventricle hypertrophy (CLVH) and eccentric left ventricle hypertrophy (ELVH), CLVH was more common than in patients without thyroid dysfunction but with CHF and CHD (84.0%, р=0.01). The LV myocardium contractility was reduced in patients of both groups with CHF, the values of the ejection fraction corresponded with the intermediate type of HF, there was no significant difference between the indices (p = 0.1). The main group had significantly more pronounced decrease in the ratio of the blood flow velocity of early diastolic filling of the LV and the maximal atrial systolic velocity (E / A) − 0.63 and the increase in the isovolumic relaxation time (IVRT) – 84.69 ms in comparison with the indicators of the CHD and CHF patients without thyroid dysfunction (p = 0.021, p = 0.034).Conclusion. For patients with CHF, CHD and thyrotoxicosis, predominance of LV remodeling according to the type of CLVH (84.0% of cases) is typical as well as a moderate decrease in the contractility of the LV and a more pronounced diastolic dysfunction. It determines the structural and functional features of the left ventricle in patients with CHF with this comorbidity.
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Kawano, Yoko, K. Ohmori, Yoshihiro Wada, Isao Kondo, Katsufumi Mizushige, Shoichi Senda, Shiro Nozaki y Masakazu Kohno. "A novel color M-mode Doppler echocardiographic index for left ventricular relaxation: depth of the maximal velocity point of left ventricular inflow in early diastole". Heart and Vessels 15, n.º 5 (septiembre de 2000): 205–13. http://dx.doi.org/10.1007/s003800070009.
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Carrick-Ranson, Graeme, Jeffrey L. Hastings, Paul S. Bhella, Shigeki Shibata, Naoki Fujimoto, M. Dean Palmer, Kara Boyd y Benjamin D. Levine. "Effect of healthy aging on left ventricular relaxation and diastolic suction". American Journal of Physiology-Heart and Circulatory Physiology 303, n.º 3 (1 de agosto de 2012): H315—H322. http://dx.doi.org/10.1152/ajpheart.00142.2012.
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Doppler ultrasound measures of left ventricular (LV) active relaxation and diastolic suction are slowed with healthy aging. It is unclear to what extent these changes are related to alterations in intrinsic LV properties and/or cardiovascular loading conditions. Seventy carefully screened individuals (38 female, 32 male) aged 21–77 were recruited into four age groups (young: <35; early middle age: 35–49; late middle age: 50–64 and seniors: ≥65 yr). Pulmonary capillary wedge pressure (PCWP), stroke volume, LV end-diastolic volume, and Doppler measures of LV diastolic filling were collected at multiple loading conditions, including supine baseline, lower body negative pressure to reduce LV filling, and saline infusion to increase LV filling. LV mass, supine PCWP, and heart rate were not affected significantly by aging. Measures of LV relaxation, including isovolumic relaxation time and the time constant of isovolumic pressure decay increased progressively, whereas peak early mitral annular longitudinal velocity decreased with advancing age ( P < 0.001). The propagation velocity of early mitral inflow, a noninvasive measure of LV suction, decreased with aging with the greatest reduction in seniors ( P < 0.001). Age-related differences in LV relaxation and diastolic suction were not attenuated significantly when PCWP was increased in older subjects or reduced in the younger subjects. There is an early slowing of LV relaxation and diastolic suction beginning in early middle age, with the greatest reduction observed in seniors. Because age-related differences in LV dynamic diastolic filling parameters were not diminished significantly with significant changes in LV loading conditions, a decline in ventricular relaxation is likely responsible for the alterations in LV diastolic filling with senescence.
Tesis sobre el tema "Maximal early diastolic relaxation velocity"
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Loiske, Karin. "Echocardiographic measurements of the heart : with focus on the right ventricle". Doctoral thesis, Örebro universitet, Hälsoakademin, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-14528.
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Echocardiography is a well established technique when evaluating the size and function of the heart. One of the most common ways to measure the size of the right ventricle (RV) is to measure the RV outflow tract 1(RVOT1). Several ways to measure RVOT1 are described in the literature.These ways were compared with echocardiography on 27 healthy subjects.The result showed significant differences in RVOT1, depending on the way it was measured, concluding that the same site, method and body positionshould be used when comparing RVOT1 in the same subject over time.One parameter to evaluate the RV diastolic function (RVDF) is to measure the RV isovolumetric relaxation time (RV-IVRT), a sensitive marker ofRV dysfunction. There are different ways to measure this. In this thesis two ways of measuring RV-IVRT and their time intervals were compared in 20 patients examined with echocardiography. There was a significant difference between the two methods indicating that they are not measuring the same interval.Another way to assess the RVDF is to measure the maximal early diastolicvelocity (MDV) in the long-axis direction. MDV can be measured bydifferent methods, hence 29 patients were examined and MDV was measured according to two methods. There was a good correlation but a poor agreement between the two methods meaning that reference values cannot be used interchangeably.Takotsubo cardiomyopathy is characterized by apical wall motion abnormalities without coronary stenosis. The pathology of this condition remains unclear. To evaluate biventricular changes in systolic long-axisfunction and diastolic parameters in the acute phase and after recovery, 13 patients were included and examined with echocardiography at admission and after recovery. The results showed significant biventricular improvementof systolic long-axis function while most diastolic parameters remainedunchanged.
Libros sobre el tema "Maximal early diastolic relaxation velocity"
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Smiseth, Otto A., Maurizio Galderisi y Jae K. Oh. Left ventricle: diastolic function. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780198726012.003.0021.
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Evaluation of diastolic function by echocardiography is useful to diagnose heart failure with preserved ejection fraction by showing signs of diastolic dysfunction, and regardless of ejection fraction, echocardiography can be used to estimate left ventricular (LV) filling pressure. Diastolic dysfunction occurs in a number of cardiac diseases other than heart failure and mild diastolic dysfunction is part of the normal ageing process. The fundamental disturbances in diastolic dysfunction are slowing of myocardial relaxation, loss of restoring forces, and reduced LV chamber compliance. As a compensatory response there is elevated LV filling pressure. Slowing of relaxation and loss of restoring forces are reflected in reduction in LV early diastolic lengthening velocity (e?) by tissue Doppler. The reduced diastolic compliance is reflected in faster deceleration of early diastolic transmitral velocity by pulsed wave Doppler. Elevated LV filling pressure is reflected in a number of Doppler indices and in enlarged left atrium. This chapter reviews the physiology of diastolic function, the clinical methods and indices which are available, and how these should be applied.
Actas de conferencias sobre el tema "Maximal early diastolic relaxation velocity"
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Zheng, Xudong, Rajat Mittal y Qian Xue. "Computational Modeling and Analysis of Hemodynamic Effects of Diastolic Heart Dysfunction During the Whole Cardiac Cycle". En ASME 2013 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/sbc2013-14050.
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Diastolic heart dysfunction (DHD) is a common finding in a variety of cardiac diseases including hypertension, coronary disease and cardiomyopathy. Its prevalence increases with age and it manifests as incomplete or/and delayed ventricular relaxation and a compensatory stronger atrial contraction. DHD is often associated with heart failure and contributes greatly to morbidity and hospitalizations especially in the elderly[3]. DHD is a very rich problem in fluid mechanics and it involves complex hemodynamic interactions among all of major cardiac phases during the whole cardiac cycle including ventricular filling, diastatsis, atrial filling, and systole[1]. Most studies to-date have, however, employed simple time varying volume-change profiles to model and examine the dynamics of ventricular filling[2]. Intercardiac flow effects i.e. interaction between filling and ejection have, however, not been investigated in detail. Also not studied in detail is the role of multiphasic filling which consists of early (E) filling, diastasis, and atrial (A) filling. In the current study, we will utilize three dimensional simulations to study the hemodynamics of DHD during the whole cardiac cycle. The vortex structure, filling velocity, intraventricular pressure gradient and energy budget will be analyzed to uncover the biomechanical effects and genesis of DHD.