Intraventricular Pressure Gradient Research Articles

Abstract 12899: CMR Derived Intraventricular Pressure Gradients Analysis Shows Impaired Left Ventricular Function in Precapillary Pulmonary Hypertension

Introduction: Precapillary pulmonary hypertension (pPH) predominantly harms the right ventricle. Still, due to ventricular interdependence, it also affects left ventricular (LV) function. Since LV ejection fraction (EF) is often preserved, more sensitive techniques may be better suited to detect LV dysfunction, such as LA strain or estimation of LV intraventricular pressure gradients (IVPG). However, the value of these techniques in pPH is still unknown. Hypothesis: Cardiovascular magnetic resonance (CMR) derived LA phasic function and LV-IVPG can detect LV dysfunction in pPH patients. Methods: pPH patients (n=31) and healthy controls (n=10), age- and sex-matched, underwent CMR imaging. LA phasic function and the LV-IVPG, calculating the pressure gradient between apex and base throughout the cardiac cycle, were analyzed using standard long-axis cines. Results: LV systolic function, both LVEF as well as the IVPG positive systolic ejection force, was preserved in pPH patients compared to healthy controls (p=0.90, p=0.08 resp.). However, diastolic function in pPH patients was impaired, depicted by 1. lower LA reservoir (patients vs. controls 26% ±9 vs. 37% ±7, p=0.001) and conduit strain (15% ±8 vs. 26% ±7, p=0.001), and 2. an impaired diastolic suction force, and decreased E-wave decelerative force, indicating a weaker passive filling in early to mid-diastole ( see Table ). Also, 11 pPH patients (35%) showed reversal of IVPG at systolic-diastolic transition, meaning that LV pressure temporarily exceeds LA pressure, whereas none of the healthy controls showed this pattern (p=0.04). Conclusions: pPH impacts LV function by altering diastolic function, demonstrated by an impairment of LA phasic function and LV-IVPG analysis. These parameters could therefore potentially be used as early markers for LV functional decline in pPH patients.

Effect of Loading Changes on the Intraventricular Pressure Measured by Color M-Mode Echocardiography in Rats.

Evaluation of diastolic function is a pivotal challenge due to limitations of the conventional echocardiography, especially when the heart rate is rapid as in rats. Currently, by using color M-mode echocardiography (CMME), intraventricular pressure difference (IVPD) and intraventricular pressure gradient (IVPG) in early diastole can be generated and are available as echocardiographic indices. These indices are expected to be useful for the early diagnosis of heart failure (HF), especially diastolic dysfunction. There have not been any studies demonstrating changes in IVPD and IVPG in response to changes in loading conditions in rats. Therefore, the present study aims to evaluate CMME-derived IVPD and IVPG changes in rats under various loading conditions. Twenty rats were included, divided into two groups for two different experiments, and underwent jugular vein catheterization under inhalational anesthetics. Conventional echocardiography, CMME, and 2D speckle tracking echocardiography were measured at the baseline (BL), after intravenous infusion of milrinone (MIL, n = 10), and after the infusion of hydroxyethyl starch (HES, n = 10). Left ventricular IVPD and IVPG were calculated from color M-mode images and categorized into total, basal, mid-to-apical, mid, and apical parts, and the percentage of the corresponding part was calculated. In comparison to the BL, the ejection fraction, mid-to-apical IVPG, mid IVPG, and apical IVPD were significantly increased after MIL administration (p < 0.05); meanwhile, the end-diastolic volume, E-wave velocity, total IVPD, and basal IVPD were significantly increased with the administration of HES (p < 0.05). The increase in mid-to-apical IVPD, mid IVPD, and apical IVPD indicated increased relaxation. A significant increase in basal IVPD reflected volume overloading by HES. CMME-derived IVPD and IVPG are useful tools for the evaluation of various loading conditions in rats. The approach used in this study provides a model for continuous data acquisition in chronic cardiac disease models without drug testing.

Dynamic Left Intraventricular Obstruction Phenotype in Takotsubo Syndrome.

Takotsubo syndrome (TTS) is characterized by acute, generally transient left ventricular (LV) dysfunction. Although TTS has been long regarded as a benign condition, recent evidence showed that rate of acute complications and in-hospital mortality is comparable to that of patients with acute coronary syndrome. In particular, the prevalence of cardiogenic shock ranges between 6% and 20%. In this setting, detection of mechanisms leading to cardiogenic shock can be challenging. Besides a severely impaired systolic function, onset of LV outflow tract obstruction (LVOTO) together with mitral regurgitation related to systolic anterior motion of mitral valve leaflets can lead to hemodynamic instability. Early identification of LVOTO with echocardiography is crucial and has important implications on selection of the appropriate therapy. Application of short-acting b1-selective betablockers and prudent administration of fluids might help to resolve LVOTO. Conversely, inotrope agents may increase basal hypercontractility and worsen the intraventricular pressure gradient. To date, outcomes and management of patients with TTS complicated by LVOTO as yet has not been comprehensively investigated.

Left ventricular diastolic pressure gradient and outcome in advanced chronic kidney disease patients with preserved ejection fraction.

Assessment of left ventricular (LV) diastolic dysfunction is important in patients with chronic kidney disease (CKD). The early diastolic peak intraventricular pressure gradient (IVPG) has a vital role in diastolic function. Relative pressure imaging (RPI) is a new echocardiographic method to quantify IVPG. The purpose of this study was to analyze RPI-derived IVPG in advanced CKD patients with preserved LV ejection fraction. The study population consisted of 51 advanced CKD patients and 39 healthy controls. Patients were stratified by the evidence of heart failure with preserved ejection fraction (HFpEF) into HFpEF group (32 patients) and non-HFpEF group (19 patients). RPI analysis was used to determine the early diastolic LV relative pressure and pressure distribution. The total IVPG and segmental IVPGs corresponding to basal, mid, and apical part of the LV were calculated. Total IVPG, along with apical and mid IVPGs were all significantly reduced in HFpEF Group compared with non-HFpEF Group and controls (all P < 0.05). But no significant difference of total or segmental IVPGs was found between non-HFpEF Group and the controls. Additionally, apical IVPG < 0.02 mmHg/cm (Hazard ratio 9.82, 95 % confidence interval 2.01-48.01, P = 0.005) was the independent risk factor for the composite outcome (mortality and cardiovascular hospitalization) during a median follow-up of 24 months. Advanced CKD patients with HFpEF exhibited decreased apical and mid IVPG of the LV, and the severity of apical IVPG reduction correlated with poor outcome.

A sneak peek on Takotsubo Syndrome

Abstract Funding Acknowledgements Type of funding sources: None. INTRODUCTION Takotsubo syndrome (TS) is characterized by transient wall motion abnormality of the left ventricle, which may happen in response to different triggers. AIM To characterize the population with confirmed diagnosis of TS. METHODS We analysed retrospectively 129 patients (pts) admitted in our center from 2010 to 2018 with this presumptive diagnosis. 29pts were excluded because TS wasn´t confirmed. For each pt we evaluate clinical characteristics, exams results, inhospital complications and long-term outcomes (minimum FUP of 1 year). RESULTS The average age was 66 years and 89% were females. Regarding the cardiovascular (Cv) risk factors, 78% had hypertension, 53% dyslipidemia and 19% Diabetes mellitus. In relation to noncardiovascular comorbidities it’s important to point out that 32% had psychiatric disorders. The trigger was emotional in 37%, physical in 18%, and unidentifiable in 45%. Concerning the clinical presentation 72% had Killip(K) 1 and 13% K≥3 at admission. The initial electrocardiogram had ST-elevation in 37%, T wave inversion in 64% and a mean QTc interval of 470ms. The mean ejection fraction (EF) by echocardiogram was 37%, with apical ballooning in 83% and at least moderate mitral regurgitation (MR) in 11%. Only 16% had intraventricular pressure gradient. Coronarography revealed absence of obstructive coronary disease in 71% of pts. In addition, 51% of pts underwent cardiac magnetic resonance (CMR), which had an increase usage since 2013. The mean time until the CMR was 14 days, which may explain why only 14% had segmental kinetic changes. It’s noteworthy that the mean peak NTproBNP/troponin I ratio was 1,4 ± 2,9. We compared the ratio in TS with EF &amp;lt; 40% with the one obtained in a cohort of ST-elevation myocardial infarction (MI) with EF &amp;lt; 40% and found statistically difference (1,7 ± 3,8vs0,01 ± 0,03; p &amp;lt; 0,001). Considering inhospital complications, 6% had intracardiac thrombus, 2% acute severe MR, 2% ventricular dysrhythmia and 2% died. During the FUP, 2% had recurrence, 4% had acute heart failure hospitalizations an 17% died. CONCLUSION Despite increased awareness TS is still poorly recognized. Lack of non-invasive tools for reliable diagnosis obliged the use of coronarography. It’s noteworthy that the peak NTproBNP/troponin I ratio may help to differentiate TS from MI and the use of CMR should be encouraged to exclude other causes. Although considered a benign condition, significant in-hospital mobility and 2% mortality was observed.

The Utility of Intraventricular Pressure Gradient for Early Detection of Chemotherapy-Induced Subclinical Cardiac Dysfunction in Dogs.

Simple SummaryCardiotoxicity is a serious side effect of doxorubicin in cancer patients due to the risk of development of heart failure. Early detection of doxorubicin-induced cardiomyopa-thy (DXR-ICM) has become a major objective to reduce heart failure in cancer patients. Echocar-diography is the gold standard method to diagnose cardiac diseases when cardiac dysfunction is prominent; however, it still cannot predict or early diagnose heart failure before functional de-cline. The intraventricular blood flow is characterized by intraventricular pressure gradients (IVPG) that created due to the suction of blood by the ventricles. Currently, advanced imaging techniques allow non-invasive assessment of IVPG from color M-mode echocardiography (CMME) after image processing for the clinical setting. Studies revealed that IVPG indices are promising for the early diagnosis of cardiac dysfunction. In this study, we aimed to investigate the usefulness of IVPG to detect cardiac function changes after DXR administration in dogs. Early detection of doxorubicin (DXR)-induced cardiomyopathy (DXR-ICM) is crucial to improve cancer patient outcomes and survival. In recent years, the intraventricular pressure gradient (IVPG) has been a breakthrough as a sensitive index to assess cardiac function. This study aimed to evaluate the usefulness of IVPG for the early detection of chemotherapy-related cardiac dysfunction. For this purpose, six dogs underwent conventional, speckle tracking, and color M-mode echocardiography concomitantly with pressure-and-volume analysis by conductance catheter. The cardiac function measurements were assessed before DXR administration (baseline, Pre), at the end of treatment protocol (Post), and at 1.5 years follow-up (Post2). The result showed a significant reduction in the left ventricular end-systolic pressure-volume (Emax: 4.4 ± 0.7, 6.1 ± 1.6 vs. 8.4 ± 0.8 mmHg/mL), total-IVPG (0.59 ± 0.12, 0.62 ± 0.15 vs. 0.86 ± 0.12 mmHg), and mid-IVPG (0.28 ± 0.12, 0.31 ± 0.11 vs. 0.48 ± 0.08 mmHg), respectively in Post2 and Post compared with the baseline (p < 0.05). Mid-to-apical IVPG was also reduced in Post2 compared with the baseline (0.29 ± 0.13 vs. 0.51 ± 0.11). Meanwhile, the fraction shortening, ejection fraction, and longitudinal strain revealed no change between groups. Total and mid-IVPG were significantly correlated with Emax (R = 0.49; p < 0.05, both) but only mid-IVPG was a predictor for Emax (R2 = 0.238, p = 0.040). In conclusion, this study revealed that impairment of contractility was the initial changes observed with DXR-ICM in dogs and only IVPG could noninvasively detect subclinical alterations in cardiac function. Color M-mode echocardiography-derived IVPG could be a potential marker for the early detection of doxorubicin cardiomyopathy.

RENOVASCULAR HYPERTENSION-INDUCED CARDIAC CHANGES IN A RAT MODEL: FEASIBILITY OF CONVENTIONAL AND RECENT ECHOCARDIOGRAPHY

Objective: Renovascular hypertension (RH) is a major cause of secondary hypertension, and hypertension eventually led to cardiac remodeling in patients. Hypertension leads to concentric left ventricle hypertrophy, while hypervolemia originated from renal failure leads to eccentric hypertrophy. Both mechanisms occur in RH which results in complex cardiac remodeling. Uraemic cardiomyopathy results from RH is characterized by diastolic dysfunction, but traditional echocardiography was limited in evaluating the diastolic function due to unknown hemodynamic and morphologic status. Recently, non-invasive intraventricular pressure gradient (IVPG), a preload-independent diastolic function parameter, was established and showed higher sensitivity to evaluate diastolic dysfunctions, particularly during cardiomyopathy. However, no previous studies highlighted the feasibility of the IVPG in the diagnosis of RH. Design and method: Twelve rats were received subtotal nephrectomy in 1 week to produce progressive renal failure as the RH group. The other twelve rats were sham-operated as a control group. Conventional and color M-mode echocardiography was performed for isoflurane-anesthetized rats at 2nd, 4th, 6th, and 8th weeks post-operation. IVPG was evaluated based on the Euler equation. Results: Hypertension, polyuria and hypervolemia were observed in RH group from the 2nd, 4th, and 8th week, respectively. Marked left ventricle hypertrophy was evidenced at 6th (1.32 ± 0.28 vs 1.09 ± 0.09, p = 0.016) and 8th-week post-operation (1.34 ± 0.28 vs 1.16 ± 0.09, p = 0.014) that was more prominent in the posterior papillary muscle. Peak mitral E velocity in RH rats was higher than control at the 8th week (106.35 ± 16.04 vs 91.23 ± 10.82, p = 0.031). In contrast, tissue Doppler index, total IVPG, basal IVPG, and mid-to-apical IVPG showed no difference between groups throughout the experiment. Conclusions: Hypervolemia and RH lead to unclassified geometry in RH-associated cardiac remodeling. Blood pressure change precedes the change of preload during the development of RH cardiac remodeling.

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.

Left intraventricular pressure gradient in hypertrophic cardiomyopathy patients receiving implantable cardioverter-defibrillators for primary prevention

BackgroundConventional risk factors for sudden cardiac death (SCD) justify primary prevention through implantable cardioverter-defibrillator (ICD) implantation in hypertrophic cardiomyopathy (HCM) patients. However, the positive predictive values for these conventional SCD risk factors are low. Left ventricular outflow tract obstruction (LVOTO) and midventricular obstruction (MVO) are potential risk modifiers for SCD. The aims of this study were to evaluate whether an elevated intraventricular pressure gradient (IVPG), including LVOTO or MVO, is a potential risk modifier for SCD and ventricular arrhythmias requiring ICD interventions in addition to the conventional risk factors among HCM patients receiving ICDs for primary prevention.MethodsWe retrospectively studied 60 HCM patients who received ICDs for primary prevention. An elevated IVPG was defined as a peak instantaneous gradient ≥ 30 mmHg at rest, as detected by continuous-wave Doppler echocardiography. The main outcome was a composite of SCD and appropriate ICD interventions, which were defined as an antitachycardia pacing or shock therapy for ventricular tachycardia or fibrillation. The Cox proportional hazards model was used to assess the relationships between risk factors and the occurrence of SCD and appropriate ICD interventions.ResultsThirty patients met the criteria of elevated IVPG (50%). During the median follow-up period of 66 months, 2 patients experienced SCD, and 10 patients received appropriate ICD interventions. Kaplan–Meier curves showed that the incidence of the main outcome was higher in patients with an IVPG ≥ 30 mmHg than in those without an IVPG ≥ 30 mmHg (log-rank P = 0.03). There were no differences in the main outcome between patients with LVOTO and patients with MVO. The combination of nonsustained ventricular tachycardia (NSVT) and IVPG ≥ 30 mmHg was found to significantly increase the risk of the main outcome (HR 6.31, 95% CI 1.36–29.25, P = 0.02). Five patients experienced ICD implant-related complications.ConclusionsOur findings showed that a baseline IVPG ≥ 30 mmHg was associated with an increased risk of experiencing SCD or appropriate ICD interventions among HCM patients who received ICDs for primary prevention. Combined with NSVT, which is a conventional risk factor, a baseline IVPG ≥ 30 mmHg may be a potential modifier of SCD risk in HCM patients.

The hemodynamic power of the heart differentiates normal from diseased right ventricles

Cardiac mechanics is primarily described by the pressure-volume relationship. The ventricular pressure-volume loop displays the instantaneous relationship between intraventricular pressure and volume throughout the cardiac cycle; however, it does not consider the shape of the ventricles, their spatiotemporal deformation patterns, and how these balance with the flowing blood.Our study demonstrates that the pressure-volume relationship represents a first level of approximation for the mechanical power of the ventricles, while, at a further level of approximation, the importance of hemodynamic power emerges through the balance between deformation patterns and fluid dynamics. The analysis is preliminarily tested in a healthy subject’s right ventricle and two patients. Moreover, patients’ geometry was then rescaled to present a normal volumetric profile to verify whether results were affected by volume size or by the spatiotemporal pattern of how that volume profile was achieved.Results show that alterations of hemodynamic power were found in the abnormal ventricles and that they were not directly caused by the ventricular size but by changes in the ability of intraventricular pressure gradient to generate blood flow. Therefore, hemodynamic power represents a physics-based measure that takes into account the dynamics of the space-time shape changes in combination with blood flow.Hemodynamic power is assessed non-invasively using cardiac imaging techniques and can be an early indicator of cardiac dysfunction before changes occur in volumetric measurements. These preliminary results provide a physical ground to evaluate its diagnostic or prognostic significance in future clinical studies.

Intraventricular pressure gradients change during the development of left ventricular hypertrophy: Effect of salvianolic acid B and beta-blocker.

Intraventricular pressure gradient is regarded as a non-invasive indicator of diastolic function. Salvianolic acid B (Sal-B), a traditional Asian medicine, revealed its usefulness in myocardial infarction models; however, the hemodynamic effect of salvianolic acid B is still unknown. The present study aimed to investigate the intraventricular pressure gradient changes during the development of left ventricular hypertrophy with or without salvianolic acid B and a beta-blocker. In total, 48 rats were divided into four groups; Sham, Non-treatment, salvianolic acid B, and Carvedilol. Aortic coarctation-induced left ventricular hypertrophy was done in three groups and the treatment was started from the third to the sixth week. Blood pressure, conventional echocardiography, and color M-mode echocardiography for measurement of intraventricular pressure gradient were carried out for six consecutive weeks. At 4.5 weeks, the LV mass was elevated in the coarctation groups but the blood pressure was significantly lower in salvianolic acid B and Carvedilol groups (P < 0.05). In the Non-treatment group, the total intraventricular pressure gradient was increased at 4.5 and 6 weeks (2.60 and 2.65, respectively). Meanwhile, the basal intraventricular pressure gradient was elevated at 3 and 6 weeks (1.67 and 1.75) compared with the Sham group. Salvianolic acid B and Carvedilol significantly reduced the basal intraventricular pressure gradient at six weeks compared with the Non-treatment group (1.52 and 1.51 vs 1.75, respectively). Salvianolic acid B and Carvedilol promote cardiac function by decreasing the elevated basal intraventricular pressure gradient. The current preclinical results revealed the efficacy of salvianolic acid B as a potential therapy for left ventricular hypertrophy because of the non-blood pressure lowering effect.

Echocardiography in the Assessment of Intraventricular Flows and Pressure Gradients in Obstructive Hypertrophic Cardiomyopathy

Aim To evaluate results of myomectomy by intraventricular pressure gradients (IVPG) and blood flows in patients with obstructive hypertrophic cardiomyopathy (OHCMP).Material and methods The study included a total of 76 subjects, 42 patients with OHCMP (mean age, 39±7 years) and 34 healthy volunteers (mean age, 41±3 years). Prior to and after myomectomy, transthoracic echocardiography was performed and followed by digital image processing and calculation of IVPG and left ventricular (LV) vortex flows. Vector analysis was used to estimate the myocardial displacement rate (V), vortex flows, and LV apex-to-base pressure gradients.Results The study showed a dynamic decrease in the LV apex-to-outflow IVPG by more than 50% and recovery of myocardial contraction velocity in the septal area (р&lt;0.001). The decrease in LV cavity pressure gradient serves as an index for evaluating the effectiveness of OHCMP correction. Myomectomy reduces the load on the myocardium and abolishes mitral valve regurgitation with improvement of LV blood flows as also evidenced by the dynamics of long axis velocity change during the cardiac cycle (dL / dt) and the myocardial contraction velocity (V).Conclusion Effectiveness of the surgical correction of OHCMP is based on the dynamics of myocardial contraction velocities, vortex blood flows, and a decrease in LV apex-to-base IVPG.

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.

In the Eye of the Storm: Echocardiographic Particle Image Velocimetry Analysis in a Patient with Takotsubo Syndrome.

Echo particle imaging velocimetry (Echo PIV) is a contrast-echo-based technique, used to evaluate the instantaneous vortical blood motion into the left ventricle (LV). Here, we report, for the first time, echo-PIV findings in a patient with Takotsubo syndrome (TTS). Vortex behavior suggested that TTS might present with peculiar PIV characteristics, including relatively preserved intra-ventricular pressure gradient and energy dissipation. Further studies are needed to elucidate whether the preservation of a more physiological vortex behavior could be related to the structural and functional recovery observed in TTS.

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.

Changes in left ventricular blood flow during diastole due to differences in chamber size in healthy dogs

Vorticity is a novel index that reflects diastolic function of left ventricle. The size of the ventricle can influence the ventricular diastolic blood flow. We evaluated effect of ventricular size on diastolic function and diastolic intracardiac blood flow using a particular species of dogs, which has a wide range of body size. Vector flow mapping was used for evaluation of intracardiac blood flow, and intraventricular pressure gradient (IVPG) was used for evaluation of diastolic function. 58 dogs weighing 1.3–42.3 kg were included in this study. Vorticity was found to be inversely proportional to the length of the ventricular chamber. Intraventricular pressure difference was positively correlated with the length of the left ventricle, whereas IVPG was not. This study showed that the vorticity is influenced by the size of the left ventricle independently of other factors. To evaluate the hemodynamic state of each individual appropriately by using vorticity and IVPD, ventricular size should be taken into account especially in the field of veterinary medicine and human pediatric and adolescent cardiology.

P795 Intraventricular fluid patterns during dobutamine stress echo in patients with significant coronary stenosis

Abstract Background Dobutamine stress echo (DSE) is a useful tool for the evaluation of patients with suspected stable coronary artery disease (CAD). There has been no detailed investigation about the effects of exercise or pharmacological stress on intraventricular fluid dynamics. The possible association between significant CAD and abnormal fluid patterns has not been studied yet. Purpose Aim of the study was to evaluate the intraventricular vortices during dobutamine stress and to find fluid-dynamic patterns associated with the presence of significant CAD. Methods 36 patients scheduled for coronary angiography (CA) and with clinical indication for DSE for suspected CAD were enrolled. Each patient underwent 2D, 3D and contrast echocardiography for Echo-PIV analysis and vortex quantification, both at rest and at peak stress. Vortex geometric and energetic parameters were evaluated using a post- processional software. Intraventricular pressure gradients were evaluated as well. Positive CA for significant CAD was defined as the presence of at least one epicardial coronary stenosis with ≥70% luminal narrowing. Result CA was positive in 58% of patients while DSE in 33%. In the whole population, at peak stress a reduction in vortex area (from 0.36 ± 0.01 to 0.21 ± 0.02; p= 0.001) and in absolute value of vortex intensity (from 0.36 ± 0.1 to 0.26 ± 0.12; p= 0.001) were detected. Vorticity fluctuation and kinetic energy (KE) fluctuation showed a significant increment at peak stress (respectively 0.84 ± 0.17 to 0.93 ± 0.07; p= 0.005; from 1.76 ± 0.37 to 2.47 ± 0.82; p= 0.001), as well as a deviation of flow force momentum angle (φ: from 36 ± 8 to 44 ±9; p= 0.001). Patients with positive CA showed during DSE an higher decrease of the absolute value of vortex intensity (Δ% |vortex intensity| -1.7 ± 0.39 vs -1.3 ± 0.56 vs; p= 0.021), and higher increase of flow force angle (Δ% φ 0.48 ± 0.6 vs 0.1 ± 0.27; p= 0.042). A reversal in the main direction of the vortical flow occurred in 9 patients (25%) at peak stress and 7 of them (64%) were found to have significant right coronary stenosis. This unexpected change in the vortical flow and the presence of right coronary artery stenosis were found significantly associated (X2 p= 0,02). Moreover, patients with circumflex artery stenosis were less likely to have a decrease of vortex length at peak stress (Δ% Vortex length - 0,06 ± 0, 36 vs - 0,34 ± 0,28, p= 0,034). Conclusion Significant changes in intraventricular vortices occur during DSE. The presence of significant CAD evaluated with CA was associated with different behavior of fluid dynamics during DSE. Further studies are needed to assess normal and pathological intraventricular flow patterns evaluated during DSE. Abstract P795 Figure. Vortex reversal at peak stress

P228 Mitral valve aneurysm in the context of post-infective endocarditis in hypertrophic cardiomyopathy: an issue of inflammation or pressure gradients?

Abstract Mitral valve aneurysms (MVA) are uncommon and usually develop acutely in the setting of infective endocarditis (IE). We present a case report of a patient with a ruptured aneurysm of the mitral valve (MV) leaflet and obstructive hypertrophic cardiomyopathy (HCM), previously treated for IE. Echocardiography is essential for diagnosis, highlighting the importance of imaging for early identification and timely intervention. CASE REPORT 68-year-old male patient with type 2 diabetes mellitus and dyslipidemia was admitted to hospital with a 3-week history of malaise, fever and recent left-sided abdominal pain. No past relevant history. Physical examination revealed a grade II/VI systolic heart murmur at the cardiac apex, fever, abdominal tenderness in the left upper quadrant and purpuric lesions in the inferior limbs. Neutrophilia, CPR 211mg/L. Positive blood cultures for Staphylococcus aureus methicillin-sensitive. Spleen embolization, with no abcess on abdominal CT. Transthoracic (TTE) and transesophageal echocardiography (TEE) disclosed a highly mobile polypoid mass in the atrial side of the anterior MV leaflet, septal left ventricular hypertrophy and systolic anterior motion (SAM) of the MV. Mild mitral regurgitation (MR). No evidence of abcess, aneurysm or valve perforation. The diagnosis of IE was established and the patient completed 42 days of Flucloxaciline. Favorable clinical evolution, residual lesions on the MV. TTE and TEE were repeated on follow-up. Besides HCM and SAM of the MV, an aneurysm of the anterior leaflet of the MV was identified and two regurgitant jets: one due to incomplete coaptation of the leaflets; other through the perforated aneurysm. Mild global MR. A strategy of close follow-up was adopted. Beta blocker dose was increased. Maintenance of the characteristics of the aneurysm. DISCUSSION MVA are rare, with perforation and significant MR development as the most serious complications. They mostly develop in the acute setting of IE of the aortic valve (AV), due to the "jet lesion" from the regurgitant jet or direct extension of the infection. In this case, MVA developed as a late complication of IE of the MV. Previous infection and inflammation lead to increased susceptibility of the valve leaflet, with possible persistent chronic inflammation. In the setting of obstructive HCM, the lesioned endothelium is exposed to significant intraventricular pressure gradients, which have probably raised its propensity to bulge towards the atrium, resulting in aneurysm formation and perforation. Optimal approach to MVA has not been defined. If the setting of perforation with severe MR, surgery must be performed in order to avoid a fatal outcome. In small aneurysms with mild MR, a conservative approach seems reasonable. The purpose of this case is to highlight potential complications of IE, which should be actively investigated, with echocardiography playing a central role in the diagnosis and follow-up.

Application of vector flow mapping technique in the assessment of left intraventricular pressure gradients in heart failure patients

Objective To evaluate the changes of intraventricular pressure differences (IVPDs) and intraventricular pressure gradients (IVPGs) in different phases of cardiac cycle in patients with heart failure(HF) patients by relative pressure imaging based on vector flow imaging(VFM). Methods Forty-nine HF patients with left ventricular ejection fraction (LVEF) lower than 0.50 hospitalized in Qilu Hospital of Shandong University from November 2018 to January 2019, including thirty-three patients with HF with reduced ejection fraction (HFrEF group) and fifteen patients with midrange ejection fraction (HFmrEF group), and forty-three controls were enrolled in this study. Clinical data and echocardiographic images were collected and the conventional left ventricular diameter, mass, volume, and systolic and diastolic function parameters were measured. IVPDs and IVPGs during isovolemic systole (IC), rapid ejection (RE), isovolemic diastole (IR), rapid filling (RF) and atrial systole (AC) phases were obtained by the VFM technique. The changes of IVPDs and IVPGs in different phases between the HF and control groups, and their correlations with conventional ultrasound parameters were analyzed. Results IVPDs and IVPGs in heart failure group were significantly reduced compared with the control group especially in isovolumic relaxation phase(all P<0.001). IVPDs and IVPGs showed a decreasing trend in the control group, HFmrEF group and the HFrEF group(P<0.001). IVPDs and IVPGs were correlated with LVID, LVMI, ESV, LVEF, GLS and E/e′ (all P<0.01), among which IVPD-IR and IVPG-IR were best correlated. IVPD-IR and IVPG-IR had excellent diagnostic efficacy for HF patients with LVEF<0.5, with cut-off values of <0.73 mmHg (AUC=0.915, P<0.001) and <0.103 mmHg/cm (AUC=0.932, P<0.001), respectively. Conclusions Early diastolic hemodynamics are severely impaired when systolic function declines.IVPG-IR, as a marker of left ventricular diastolic function, significantly correlates with left ventricular systolic function, and can be used as a potential indicator for assessing left ventricular systolic and diastolic function in patients with heart failure and identifying patients with heart failure. Key words: Vector flow imaging; Relative pressure imaging; Intraventricular pressure gradients; Heart failure