Diastolic Intraventricular Pressure Research Articles

Time domain adaptation of left ventricular diastolic intraventricular pressure in elite female ice hockey athletes.

Ice hockey is a high-intensity dynamic sport for which competitive athletes train for longer than 20 hours each week for several years. The cumulative time of myocardial exposure to hemodynamic stress affects cardiac remodeling. However, the intracardiac pressure distribution of the elite ice hockey athletes' heart during adaptation to long-term training remains to be explored. This study aimed to compare the diastolic intraventricular pressure difference (IVPD) of the left ventricle (LV) between healthy volunteers and ice hockey athletes with different training times. Fifty-three female ice hockey athletes (27 elite and 26 casual) and 24 healthy controls were included. The diastolic IVPD of the LV during diastole was measured by vector flow mapping. The peak amplitude of the IVPD during isovolumic relaxation (P0), diastolic rapid filling (P1), and atrial systole (P4); the difference in the peak amplitude between adjacent phases (DiffP01, DiffP14); the time interval between the peak amplitude of adjacent phases (P0P1, P1P4); and the maximum decrease rate in diastolic IVPD were calculated. Differences between groups, as well as correlations between hemodynamic parameters and training time, were analyzed. Structural parameters of the LV were significantly higher in elite athletes than in casual players and controls. No significant difference in the peak amplitude of the IVPD during the diastolic phase was found among the three groups. The analysis of covariance with heart rate as a covariate showed that P1P4 in the elite athlete and casual player groups was significantly longer than that in the healthy control group (p < 0.001 for all). An increased P1P4 was significantly associated with an increased training year (β = 4.90, p < 0.001). The diastolic cardiac hemodynamics of the LV in elite female ice hockey athletes could be characterized by a prolonged diastolic IVPD, and P1P4 prolonged with an increase in the training years, reflecting a time-domain adaptation in diastolic hemodynamics after long-term training.

Assessment of Early Diastolic Intraventricular Pressure Difference in Children by Blood Speckle-Tracking Echocardiography

The lack of reliable echocardiographic techniques to assess diastolic function in children is a major clinical limitation. Our aim was to develop and validate the intraventricular pressure difference (IVPD) calculation using blood speckle-tracking (BST) and investigate the method's potential role in the assessment of diastolic function in children. Blood speckle-tracking allows two-dimensional angle-independent blood flow velocity estimation. Blood speckle-tracking images of left ventricular (LV) inflow from the apical 4-chamber view in 138 controls, 10 patients with dilated cardiomyopathies (DCMs), and 21 patients with hypertrophic cardiomyopathies (HCMs)<18years of age were analyzed to study LV IVPD during early diastole. Reproducibility of the IVPD analysis was assessed, IVPD estimates from BST and color M mode were compared, and the validity of the BST-based IVPD calculations was tested in a computer flow model. Mean IVPD was significantly higher in controls (-2.28±0.62mm Hg) compared with in DCM (-1.21±0.39mm Hg, P<.001) and HCM (-1.57±0.47mm Hg, P<.001) patients. Feasibility was 88.3% in controls, 80% in DCM patients, and 90.4% in HCM patients. The peak relative negative pressure occurred earlier at the apex than at the base and preceded the peak E-wave LV filling velocity, indicating that it represents diastolic suction. Intraclass correlation coefficients for intra- and interobserver variability were 0.908 and 0.702, respectively. There was a nonsignificant mean difference of 0.15mm Hg between IVPD from BST and color M mode. Estimation from two-dimensional velocities revealed a difference in peak IVPD of 0.12mm Hg (6.6%) when simulated in a three-dimensional fluid mechanics model. Intraventricular pressure difference calculation from BST is highly feasible and provides information on diastolic suction and early filling in children with heart disease. Intraventricular pressure difference was significantly reduced in children with DCM and HCM compared with controls, indicating reduced early diastolic suction in these patient groups.

VALIDATION OF A NONINVASIVE METHOD TO ESTIMATE SUBENDOCARDIAL OXYGEN SUPPLY AND DEMAND BALANCE

Objective: Evaluation of balance between subendocardial oxygen supply and demand is useful in order to assess the risk of myocardial ischemia. The subendocardial viability ratio (SEVR, also known as Buckberg index) evaluated by invasive recordings of left ventricular and aortic pressure curves represents a valid method to estimate the degree of myocardial perfusion relative to left ventricular workload. However, routine clinical use of this parameter requires a noninvasive estimation and the demonstration of its reliability. Design and method: Arterial applanation tonometry allows a noninvasive estimation of SEVR as the ratio of the areas directly beneath the central aortic pressure curves obtained during diastole (myocardial oxygen supply) and during systole (myocardial oxygen demand). However, this traditional method does not account for the intraventricular diastolic pressure and proper allocation to systole and diastole of left ventricular isometric contraction and relaxation, respectively, resulting in an overestimation of the SEVR values. These issues are considered in a novel method for SEVR assessment tested in this study. SEVR values were estimated with carotid tonometry by traditional and new method and compared with those evaluated invasively in 51 undergoing an cardiac catheterization for coronary angiography. Results: The traditional method provided significantly higher SEVR values than the reference invasive SEVR: average of differences ± SD = 44 ± 11%. The noninvasive new method showed a much better agreement with the invasive determination of SEVR: average of differences ± SD = 0 ± 8%. The new method for SEVR estimation showed a good repeatability between consecutive assessments (coefficient of variation 7.8%). Conclusions: A noninvasive estimation of SEVR by carotid applanation tonometry is feasible. All the main factors determining myocardial supply and demand flow should be considered in order to provide a valid estimate, in particular intraventricular diastolic pressure, left ventricular isometric contraction and relaxation.

Non-invasive assessment of left ventricular relaxation property using color M-mode-derived intraventricular pressure gradients in cats

IntroductionDiastolic dysfunction is an early clinical feature of feline hypertrophic cardiomyopathy (HCM). The left ventricular filling in early diastole is facilitated by the diastolic intraventricular pressure gradient (IVPG). The study objectives were to evaluate color Doppler M-mode-derived IVPG calculation in cats as a non-invasive assessment of the left ventricular relaxation property to determine the normal ranges of peak IVPG in cats and investigate the influence of left ventricular function and heart rate (HR). AnimalsOne hundred and six client-owned apparently healthy cats. MethodsProspective cross-sectional study. Quantitative analysis of color Doppler M-mode images was used to estimate total and segmental IVPGs non-invasively. ResultsThe total IVPG was 0.76 mmHg (95% reference interval (RI): 0.28–1.29 mmHg), the basal IVPG 0.34 mmHg (95% RI: 0.07–0.63 mmHg), and the mid-apical IVPG 0.42 mmHg (95% RI: 0.15–0.71 mmHg). Total and segmental IVPG increased with HR (P < 0.003), while segmental percent IVPG was HR independent. A short isovolumic relaxation time (IVRT) and a high mitral annular velocity in early diastole were associated with an increase in total IVPG (P = 0.008 and P = 0.009, respectively) adjusted for HR. An increase in IVPG was associated with an increase in mitral inflow velocity (P < 0.001). ConclusionsFeline IVPGs increase with HR and a short IVRT, which was believed to be a normal physiologic adrenergic response associated with an increased sympathetic tone. Future studies of segmental IVPG changes in feline HCM are needed to evaluate the clinical applicability of color Doppler M-mode estimated IVPGs in feline cardiology.

S- and P-type cobra venom cardiotoxins differ in their action on isolated rat heart.

Background: The cardiovascular system is one of the first systems to be affected by snake toxins; but not many toxins exert a direct effect on the heart. Cobra venom cardiotoxins are among those few toxins that attack the heart. Although the two cardiotoxin types (S and P) differ in their central-loop structure, it is not known whether they differ in their effect on the mammalian heart. We compared the effects of S- and P-type cardiotoxins, CTХ-1 and CTХ-2, respectively, from the cobra Naja oxiana, on the isolated rat heart. Methods: An isolated rat heart perfused according to the Langendorff technique was used in this study to investigate the activity of cardiotoxins CTX-1 and CTX-2. The following parameters were registered: the left ventricular developed pressure, calculated as the difference between systolic and diastolic pressure in the left ventricle, the end-diastolic pressure, the heart rate, time to maximal end-diastolic pressure (heart contracture), and time to depression of the heart contraction.Results: Both cardiotoxins at the concentration of 5 μg/mL initially produce a slight increase in systolic intraventricular pressure, followed by its rapid decrease with a simultaneous increase in diastolic intraventricular pressure until reaching contracture. CTX-2 blocks cardiac contractions faster than CTX-1; in its presence the maximum diastolic pressure is reached faster and the magnitude of the developed contracture is higher.Conclusion: The P-type cardiotoxin CTX-2 more strongly impairs rat heart functional activity than the S-type cardiotoxin CTX-1, as expressed in its faster blockage of cardiac contractions as well as in more rapid development and greater magnitude of contracture in its presence.

Loss of apical suction assessed by noninvasive pressure differences and twist in acute heart failure: a novel method using vector flow mapping

Abstract Background Early diastolic intraventricular pressure difference (IVPD) reflects left ventricular (LV) apical suction, and IVPD is closely related to cardiac function, especially LV twist. Vector Flow Mapping (VFM) allows visualization of regional pressure distribution and noninvasive quantification of IVPD. The purpose of the present study was to investigate if and how IVPDs are related to LV twist in a model of acute heart failure (HF). Methods In 15 open-chest dogs, HF was induced by intracoronary injection of microspheres. The HF model was classified into two groups based on the LV end-diastolic pressure (LVEDP) (group1: LVEDP&amp;lt;18 mmHg (n=10), group2: LVEDP≥18 mmHg (n=8)). Color Doppler images from apical long-axis views were acquired at baseline and during HF. From these images, pressure differences (ΔP) were calculated along the LV inflow tract throughout the cardiac cycle. For the purpose of this study, the differences between apex and base during isovolumic relaxation time (ΔPIRT) and rapid early inflow period (ΔPE) were used for analyses. Furthermore, apical and basal short axis high frame rate 2D images were acquired, and peak rotation and peak twist were analyzed. Results LVEDP was 7±9, 14±2, 21±3 mmHg for baseline, group1 HF, and group2 HF, respectively. Pressure differences (both ΔPIRT and ΔPE) were visibly changed by the increase of LVEDP (Figure), and the magnitude of ΔPIRT, ΔPE and peak twist decreased significantly with the severity of heart failure. There were significant relationships between pressure differences (ΔPIRT and ΔPE) and dP/dtmin, tau, EF and peak twist (Table). In multivariate analyses, tau and peak twist were independent predictors for ΔPIRT and peak twist was independent predictor for ΔPE. Conclusion VFM analysis is feasible to noninvasively assess the IVPDs in acute heart failure. The IVPDs are closely related to the twisting motion of the LV, and reflect loss of apical suction during severe HF. Funding Acknowledgement Type of funding sources: None. VFM images of pressure differencesCorrelations of pressure differences

Noninvasive estimation of impaired left ventricular untwisting velocity by peak early diastolic intra-ventricular pressure gradients using vector flow mapping.

Introduction of vector flow mapping (VFM) based on the combination of color Doppler and speckle-tracking echocardiography provides noninvasive assessment of early diastolic intra-ventricular pressure gradient (ED-IVPG). The purpose of this study was to evaluate the value of peak ED-IVPG measurement just after aortic valve closure using VFM for noninvasive estimation of impaired LV untwisting velocity as the index of LV relaxation in the clinical setting. The study included 65 consecutive patients in whom echocardiography was performed for the assessment of LV function. We assessed peak ED-IVPG between LV apex and base by VFM analysis software. We also measured peak LV untwisting velocity and LV twisting by speckle-tracking strain analysis. Peak ED-IVPG was successfully and quickly assessed in all the study patients. Peak ED-IVPG was significantly reduced in patients with impaired peak LV untwisting velocity (< 70 degrees/s) compared with patients without impaired peak LV untwisting velocity. The receiver operating characteristic analysis showed the best cut-off value of peak ED-IVPG for determining impaired peak LV untwisting velocity was 0.40mmHg (sensitivity 81%, specificity 74%, and area under the curve 0.81). There was a well correlation between peak ED-IVPG and peak LV untwisting velocity (r = 0.64, p < 0.0001). The present results suggest that peak ED-IVPG just after aortic valve closure measured by VFM may be used as noninvasive index for estimation of impaired LV untwisting velocity in the clinical setting.

Effects of Individual and Coexisting Diabetes and Cardiomyopathy on Diastolic Function in Rats (Rattus norvegicus domestica).

The goal of this study was to evaluate diastolic intraventricular pressure gradients (IVPG) and 2-dimensional tissue tracking (2DTT) patterns during diabetes and cardiomyopathy. Rats (n = 60) were induced to become diabetic (DM group, n = 15) by using streptozotocin, to become cardiomyopathic (CM group, n = 15) by using isoproterenol, and to become both diabetic and cardiomyopathic (DMCM group, n = 15); control rats (CT group, n = 15) were injected with saline. Two months after induction, all rats underwent conventional echocardiography, IVPG, and 2DTT and then were euthanized for microscopic examination of cardiac fibrosis. Compared with the controls, all 3 treated groups showed diastolic dysfunction and delayed cardiac relaxation. DMCM rats showed the most pronounced cardiac abnormalities. In addition, CM and DMCM groups had showed decreased middle IVPG, whereas DMCM rats had decreased midapical IVPG. Although the overall IVPG of the CM group was normal, the middle segment was significantly decreased. 2DTT results showed that the DMCM group had a delay in relaxation compared with other groups. IVPG and 2DTT can be used to overcome the limitation of conventional echocardiographic methods and reveal diastolic dysfunction. DM worsened diastolic function during cardiac disease.

Noninvasive assessment of intraventricular pressure difference in left ventricular dyssynchrony using vector flow mapping.

Diastolic intraventricular pressure difference (IVPD) reflects left ventricular (LV) diastolic function. The relative pressure imaging (RPI) enables the noninvasive quantification of IVPD based on vector flow mapping (VFM) and visualization of regional pressure distribution. LV dyssynchrony causes deterioration of cardiac performance. However, it remains unclear how IVPD is modulated by LV dyssynchrony. LV dyssynchrony was created in ten open-chest dogs by right ventricular (RV) pacing. The other ten dogs undergoing right atrial (RA) pacing set at the similar heart rate with RV pacing were used as controls. Echocardiographic images were acquired at baseline and during pacing simultaneously with LV pressure measurement by a micromanometer. Pressure difference (ΔP) was computed between the apex and the base of the LV inflow tract during a cardiac cycle by RPI and ΔP during isovolumic relaxation time (ΔPIRT), a parameter of diastolic suction, and that during early filling phase (ΔPE) were measured. During RV pacing, stroke volume (SV) and ΔPIRT decreased significantly, while ΔPE did not change compared to the baseline. During RA pacing, SV, ΔPIRT and ΔPE did not change significantly. ΔPIRT tended to correlate with -dP/dtmin and end-systolic volume, and significantly correlated with ejection fraction. IVPD during isovolumic relaxation time was decreased by LV dyssynchrony, while IVPD during early filling phase was not. A reduction of diastolic suction is observed in LV dyssynchrony and is significantly related to a decrease in SV.

Analysis of inter-system variability of systolic and diastolic intraventricular pressure gradients derived from color Doppler M-mode echocardiography

Assessment of intraventricular pressure gradients (IVPG) using color Doppler M-mode echocardiography has gained increasing interest in the evaluation of cardiac function. However, standardized analysis tools for IVPG quantification are missing. We aimed to evaluate the feasibility, the test-retest observer reproducibility, and the inter-system variability of a semi-automated IVPG quantification algorithm. The study included forty healthy volunteers (50% were men). All volunteers were examined using two ultrasound systems, the Philips Epiq 7 and the General Electric Vivid 6. Left ventricular diastolic (DIVPG) and systolic (SIVPG) intraventricular pressure gradients were measured from the spatiotemporal distribution of intraventricular propagation flow velocities using color Doppler M-mode in standard apical views. There was good feasibility for both systolic and diastolic IVPG measurements (82.5% and 85%, respectively). Intra and inter-observer test-retest variability measured with the intraclass correlation coefficient were 0.98 and 0.93 for DIVPG respectively, and 0.95 and 0.89 for SIVPG respectively. The inter-system concordance was weak to moderate with Lin’s concordance correlation coefficient of 0.59 for DIVPG and 0.25 for SIVPG. In conclusion, it is feasible and reproducible to assess systolic and diastolic IVPG using color Doppler M-mode in healthy volunteers. However, the inter-system variability in IVPG analysis needs to be taken into account, especially when using displayed data.

Echocardiographic evidence of left ventricular untwisting-filling interplay

BackgroundLeft ventricular untwisting generates an early diastolic intraventricular pressure gradient (DIVPG) than can be quantified by echocardiography. We sought to confirm the quantitative relationship between peak untwisting rate and peak DIVPG in a large adult population.MethodsFrom our echocardiographic database, we retrieved all the echocardiograms with a normal left ventricular ejection fraction, for whom color Doppler M-Mode interrogation of mitral inflow was available, and left ventricular untwisting rate was measurable using speckle tracking. Standard indices of left ventricular early diastolic function were assessed by Doppler (peaks E, e’ and Vp) and speckle tracking (peak strain rate Esr). Load dependency of DIVPG and untwisting rate was evaluated using a passive leg raising maneuver.ResultsWe included 154 subjects, aged between 18 to 77 years old, 63% were male. Test-retest reliability for color Doppler-derived DIVPG measurements was good, the intraclass correlation coefficients were 0.97 [0.91–0.99] and 0.97 [0.67–0.99] for intra- and inter-observer reproducibility, respectively. Peak DIVPG was positively correlated with peak untwisting rate (r = 0.73, P < 0.001). On multivariate analysis, peak DIVPG was the only diastolic parameter that was independently associated with untwisting rate. Age and gender were the clinical predictive factors for peak untwisting rate, whereas only age was independently associated with peak DIVPG. Untwisting rate and DIVPG were both load-dependent, without affecting their relationship.ConclusionsColor Doppler-derived peak DIVPG was quantitatively and independently associated with peak untwisting rate. It thus provides a reliable flow-based index of early left ventricular diastolic function.

P3365Relationship between early diastolic intra-ventricular pressure gradient shortly after aortic valve closure estimated by vector flow mapping and left ventricular diastolic untwisting rate in humans

Abstract Background Early diastolic suction is an important determinant of early diastolic function. Previous studies using color Doppler M-mode and speckle-tracking echocardiography have shown left ventricular (LV) early diastolic LV untwisting rate is directly related to LV intra-ventricular pressure gradient (IVPG) between LV base and apex during early diastole. Recent introduction of vector flow mapping (VFM) using combination of color Doppler and speckle-tracking echocardiography provides noninvasive and feasible assessment of early diastolic IVPG shortly after aortic valve closure including isovolmic relaxation period (ED-IVPG) in humans. However, relationship between VFM–derived ED-IVPG and early diastolic LV untwisting rate has not been well investigated. Purpose The purpose of this study was to examine relationship between ED-IVPG estimated by VFM and LV untwisting rate by speckle-tracking echocardiography. Methods The study population consists of 66 patients without segmental wall motion abnormality, significant valvular diseases, and atrial fibrillation who underwent echocardiography for evaluation of LV function (age: 60±15 years, LVEF: 49±16%). From the apical long-axis views by color Doppler echocardiography, we analyzed peak ED-IVPG between LV base and apex just after aortic valve closure (figure) using commercially available VFM analysis software (DAS-RS1, Hitachi). We assessed peak early diastolic LV untwisting rate and LV torsion from LV basal and apical short-axis view by speckle-tracking echocardiography. We evaluated correlation between ED-IVPG and LV untwisting rate. We also evaluated correlation between ED-IVPG and peak systolic LV torsion, LV end-diastolic (EDV) and end-systolic volumes (ESV), ejection fraction (EF), early diastolic velocity (E) of LV inflow, average early diastolic velocity (e') of mitral annulus, and average E/e'. Results In all the study patients, ED-IVPG was successfully and quickly evaluated. 1) ED-IVPG correlated well with peak LV untwisting rate (r=0.64, p&lt;0.0001). 2) ED-IVPG significantly correlated with LV torsion, LVEDV, LVESV, and LVEF (r=0.47, r=−0.48, r=−0.46, and r=0.48, respectively, p&lt;0.001). 3) There were no significant correlations between ED-IVPG and other indexes including E, average e', and average E/e'. According to receiver operating characteristic analysis, the best cut-off value of ED-IVPG for determining impaired LV untwisting rate (&lt;80 degrees/s) was found at 0.42 mmHg (sensitivity 81%, specificity 76%, and area under the curve 0.86) ED-IVPG measurement by VFM Conclusions The present results showed that noninvasive VFM-derived peak ED-IVPG shortly after aortic valve closure is related to early diastolic peak LV untwisting rate. ED-IVPG easily and quickly estimated by VFM may be used as an additional index for LV diastolic function.

Cardiac Function in Infants Born to Mothers With Gestational Diabetes - Estimation of Early Diastolic Intraventricular Pressure Differences.

Background: This study compared the myocardial performance of infants born to mothers with gestational diabetes mellitus (IGDM) and without GDM (controls) under the new GDM definitions.Methods and Results: The subjects consisted of 36 IGDM and 39 control infants. GDM diagnosis was based on oral glucose tolerance test during pregnancy or the presence of diabetes prior to the current pregnancy. Between-group infant cardiac function was determined and compared using 2-D speckle tracking analysis, intraventricular pressure difference (IVPD) and IVP gradient (IVPG), using color M-mode Doppler imaging. IVPD and IVPG were higher in IGDM than in the controls, particularly the mid–apical IVPG. The global circumferential strain (GCS) and endocardial GCS were higher in IGDM than in controls. Increased maternal glycated hemoglobin was correlated with reduced transmural and epicardial GCS in the IGDM. Maternal maximum fasting blood sugar had a mild, positive correlation with IVPD and IVPG.Conclusions: Ventricular sucking force, measured as the IVPD, IVPG, and endocardial GCS, were higher in IGDM than in the controls. A hyperglycemic environment during pregnancy leads to impaired cardiac performance in IGDM, compared with control infants. IGDM might have favorable systolic and diastolic cardiac performance due to cardiac metabolic adaptations occurring before poor glucose control causes impaired cardiac performance.

Intracardiac hemodynamics, infarct-limiting effects and myocardial expression of microRNA 223 after necroptosis inhibition in a rat model of heterotopic allogeneic heart transplantation

Objective.To investigate the effect of necroptosis inhibition on the morphofunctional state of the myocardium and the expression of microRNA 223 after heterotopic allogeneic heart transplantation in rat.Design and methods. Twenty Wistar rats were examined in the study. Animals were divided into the following groups: 1) control (n = 7), 2) dimethyl sulfoxide (DMSO) (n = 6), 3) necrostatin-1s (n = 7). Necrostatin-1s was used as an inhibitor of necroptosis, which was administered intraperitoneally in DMSO solution 1 hour before the start of the experiment at a dose of 1,65 mg/kg. HTK solution cooled to 4 °C was used as a preservation solution. Two hours after heart arrest, the heart was heterotopically transplanted in the abdominal cavity of recipient rat using the scheme “aorta-aorta, pulmonary trunc-posterior vena cava”. Three hours later, intracardiac hemodynamics was assessed by recording the pressure in the left ventricle, heart rate and coronary flow rate in Langendorff-perfused heart. The expression level of microRNA 223–5p and –3p in left ventricular myocardium was assessed using real-time polymerase chain reaction. The plasma levels of troponin I were assessed by enzyme immunoassay. Myocardial infarct size was measured planimetrically at the end of the experiment by staining myocardium with triphenyltetrazolium chloride.Results. Inhibition of necroptosis significantly improved the morphofunctional state of the myocardium, which manifested in a decrease of myocardial infarct size in the necrostatin-1s group compared with the control group and DMSO group. Thus, in the necrostatin-1s group, myocardial infarct size was 25 ± 8,7 %, which was smaller than in the control and DMSO groups (56 ± 9,5 and 57 ± 8,7 %, respectively; p &lt; 0,05). Also in the necrostatin-1s group, lower diastolic intraventricular pressure was recorded, as well as higher values of pulse intraventricular pressure and coronary flow rate than in control group and DMSO group (p &lt; 0,05). Left ventricular myocardium in the necrostatin-1s group demonstrated higher expression of the antinecroptotic miRNA 223–5p and –3p as compared with the control and DMSO groups, as well as lower plasma levels of troponin I (p &lt; 0,05).Conclusions.Pharmacological inhibition of necroptosis in heterotopically transplanted donor heart is accompanied by marked cardioprotective effects and increases the expression of antinecroptotic microRNA 223–5p and –3p.

Direct comparison of the infarct-limiting and hemodynamic effects of various necroptosis inhibitors in the model of prolonged static cold storage of the donor rat heart

Objective . To investigate the effects of various necroptosis inhibitors on the morphological and functional characteristics of the myocardium in the model of prolonged cold preservation of the donor rat heart. Design and methods. Thirty eight Wistar rats were divided into the following groups: 1) control (n = 7), 2) dimethylsulfoxide (DMSO) (n = 7), 3) necrostatin-1s (n = 6), 4) necrosulfonamide (n = 6), 5) necrostatin-5 (n = 6), 6) necrostatin-1 (n = 6). Necroptosis inhibitors were administered by intraperitoneal injection 1 hour prior to the start of the experiment, previously dissolved in DMSO. HTK solution cooled to 4 °C was used as a preservative solution. The functional state of the myocardium was assessed by continuous recording of intraventricular pressure, heart rate and coronary flow velocity. Morphological changes in the myocardium were assessed by the size of myocardial necrosis, measured planimetrically after the end of 8-hour ischemia and 2-hour reperfusion. Results. All investigated necroptosis inhibitors significantly improved the morphological and functional state of the myocardium, which manifested itself in a significantly smaller amount of myocardial necrosis in the groups of necroptotic inhibitors in comparison with control groups and DMSO. Thus, in the groups of necrosulfonamide and necrostatin-1s, myocardial necrosis size was 31 ± 8,7 % and 27 ± 8,2 %, respectively; in necrostatin-5 and necrostatin-1 groups — 37 ± 9,2 % and 34 ± 7,8, respectively, which is lower than in control groups and DMSO (58 ± 8,6 % and 60 ± 7,6 %, respectively, p < 0,05). Also, diastolic intraventricular pressure was lower and pulse intraventricular pressure and coronary flow velocity were higher during the reperfusion period in the groups of necroptosis inhibitors compared to control group and DMSO group (p < 0,05). We did not find any significant differences between necroptosis inhibitors regarding cardioprotective activity in the model of prolonged cold preservation of the donor heart. Conclusions. All inhibitors of necroptosis equally improved the morphological and functional state of the myocardium in the model of prolonged static cold storage of the donor heart.

Evaluation of Myocardial Function According to Early Diastolic Intraventricular Pressure Difference in Fetuses

Intraventricular pressure difference (IVPD), the diastolic suction during early diastole, is known as a useful marker of myocardial diastolic function in adults with different heart diseases, but there are no studies of fetal IVPD. The aim of this study was to determine whether IVPD exists and changes prenatally and whether IVPD correlates with preexisting parameters to evaluate fetal cardiac diastolic function and ventricular dominance. Cross-sectional study data (stroke volume, fetal cardiac output, E/A ratio, and myocardial performance index) from 117 healthy fetuses at 17 to 36weeks of gestation were retrospectively evaluated. The total IVPD was calculated using Euler's equation with color M-mode data. Segmental IVPD was evaluated as apical, mid, and basal IVPDs. The total IVPD in the right ventricle and left ventricle significantly increased in late gestation compared with that in different fetuses studied at midgestation (right and left ventricles, ρ=0.813 and ρ=0.895, respectively; P<.001). In both ventricles, the apical IVPD percentage, but not basal or mid IVPD, significantly increased at late gestation compared with that in different fetuses studied at midgestation. Both stroke volumes were correlated with IVPD (right and left ventricles, ρ=0.796 and ρ=0.784, respectively; P<.001). Although myocardial performance index in the left ventricle did not show a significant correlation with IVPD, the E/A ratio had a very weak correlation with IVPD (right ventricle, ρ=0.576, P<.001; left ventricle, ρ=0.338, P<.01). IVPD has been proved to exist in both ventricles during the fetal stage. The total IVPD increased in late gestation, and the ventricular length increased because of increased apical IVPD in both ventricles. Furthermore, the increase of IVPD in both ventricles was correlated with stroke volume and, accordingly, cardiac output. Left ventricular dominance in IVPD from the fetal stage may offer interesting insight into fetal cardiac development.

Assessment of early diastolic intraventricular pressure gradient in the left ventricle among patients with repaired tetralogy of Fallot

Assessment of left ventricular (LV) dysfunction is vital in patients with repaired tetralogy of Fallot (rTOF). The early diastolic intraventricular pressure gradient (IVPG) in the LV plays an important role in diastolic function. IVPG is calculated as the intraventricular pressure difference divided by the LV length, which allows to account for differences in LV size and therefore calculate IVPG in children. We aimed to investigate the mechanisms of LV diastolic dysfunction by measuring mid-to-apical IVPG as an indicator of the active suction force sucking blood from the left atrium into the LV. We included 38 rTOF patients and 101 healthy controls. The study population was stratified based on age group into children (4-9years), adolescents (10-15years), and adults (16-40years). IVPGs were calculated based on mitral inflow measurements obtained using color M-mode Doppler echocardiography. Although total IVPGs did not differ between rTOF patients and controls, mid-to-apical IVPGs in adolescents and adults were smaller among rTOF patients than among controls (0.15±0.05 vs. 0.21±0.06mmHg/cm, p<0.05; 0.09±0.07 vs. 0.17±0.05mmHg/cm, p<0.001; respectively). Additionally, only mid-to-apical IVPG correlated linearly with peak circumferential strain (ρ=0.217, p=0.011), longitudinal strain (ρ=-0.231, p=0.006), torsion (ρ=-0.200, p=0.018), and untwisting rate in early diastole (ρ=-0.233, p=0.006). In rTOF, the mechanisms underlying diastolic dysfunction involve reduced active suction force, which correlates with reduced LV deformation in all directions.

CARDIOPROTECTIVE EFFECTS OF NECROSTATIN‑1S AND NECROSULFONAMIDE IN THE MODEL OF PROLONGED STATIC COLD STORAGE OF THE DONOR RAT HEART

Objective . To investigate the effects of necroptosis inhibitors — necrosulfonamide and necrostatin‑1s — on morphofunctional characteristics of the myocardium in the model of prolonged cold preservation of the donor rat heart. Design and methods . The study was performed on 27 Wistar rats. The animals were divided into the following groups: 1) control (n = 7), 2) dimethylsulfoxide (DMSO, n = 6), 3) necrostatin‑1s (n = 8), 4) necrosulfonamide (n = 6). All test compounds were administered intraperitoneally 1 hour before the start of the experiment. Histidine-tryptophan-ketoglutarate (HTK) solution cooled to 4 °C was used as a preservative agent. DMSO was used as a solvent for necrostatin‑1s and necrosulfonamide. During the experiment, left ventricular pressure, heart rate and coronary flow were recorded. At the end of 8‑hour of ischemia and 2‑hour of reperfusion, myocardial infarct size was planimetrically evaluated. Results . Necrostatin-1s and necrosulfonamide show cardioprotective effects, as evidenced by the significantly lower levels of myocardial necrosis in these groups, as well as the best indices of intracardiac hemodynamics during reperfusion. In the groups of necrosulfonamide and necrostatin‑1s, myocardial infarct size was 32,2 ± 9,6 and 29,0 ± 9,2 %, respectively, which is significantly lower than in control groups and DMSO (54,4 ± 6,6 and 59,2 ± 5,6 %, respectively, p < 0,05). During reperfusion in necrosulfonamide and necrostatin‑1s groups, higher values of pulse intraventricular pressure and coronary flow rates were recorded, as well as lower diastolic intraventricular pressure, compared to control group and DMSO (p < 0,05). Conclusions . Necroptosis inhibitors necrostatin‑1s and necrosulfonamide improve morphofunctional characteristics of the myocardium state during prolonged cold preservation of the donor heart.

EP03.09: The change of early diastolic intraventricular pressure difference in fetuses at mid to late gestation

EP03.09: The change of early diastolic intraventricular pressure difference in fetuses at mid to late gestation

0157: Echo-based diastolic intraventricular pressure difference as a surrogate of left ventricular untwisting

Left ventricular (LV) early diastolic filling is related to an active process of LV relaxation, caused by its rapid untwisting. The untwisting rate (UR) has been reported to be a robust marker of diastolic function but is technically hard to assess in practice. The untwisting phenomenon generates a diastolic intraventricular pressure gradient (IVPGd), which can be assessed by colour Doppler M-Mode. Previous studies showed a close temporal relation between the UR and the IVPGd peaks, but the relation between their magnitudes as well as their load dependency remain unclear. We developed our own Matlab software for IVPGd assessment by colour Doppler M-Mode based on Bernoulli equation. From our research database, we retrieved all echocardiograms where ejection fraction was normal, the colour M-Mode tracing was available and UR was measurable using speckle tracking. Passive leg raising was used in 19 healthy volunteers to study the impact of preload on the IVPGd measurement. We included 104 echocardiograms (83% males, median age 23y [19-69]). The median peak IVPGd was 3.1mmHg [1.6-7.8] and correlated to the peak UR (r=0.57, P<0.0001, figure). There was also a significant correlation between the IVGPd peak and E’ (r=0.62, P<0.0001). For peak IVPGd, correlations between inter- and intra-observer measures were calculated on 10 randomly selected subjects and were 0.83 and 0.99 (P<0.05). Compared to UR and E’, IVPGd was also significantly increased with leg lifting (2.7±0.8mmHg vs 3.3±0.8mmHg, P<0.001). Peak IVPGd based on colour Doppler M mode echocardiography is positively correlated to the LV UR. Despite the observation that IVPGd is not less load-dependent than other parameters, it requires only an echo loop easily obtained during routine clinical studies and is highly reproducible using a semi-automatic software algorithm. This new tool could easily become a new practical echo index for diastolic function assessment. Abstract 0157 - Figure