Late Diastolic Phase Research Articles

Reproducibility of artificial intelligence-enabled plaque measurements between systolic and diastolic phases from coronary computed tomography angiography.

Current coronary CT angiography (CTA) guidelines suggest both end-systolic and mid-diastolic phases of the cardiac cycle can be used for CTA image acquisition. However, whether differences in the phase of the cardiac cycle influence coronary plaque measurements is not known. We aim to explore the potential impact of cardiac phases on quantitative plaque assessment. We enrolled 39 consecutive patients (23 male, age 66.2 ± 11.5 years) who underwent CTA with dual-source CT with visually evident coronary atherosclerosis and with good image quality. End-systolic and mid- to late-diastolic phase images were reconstructed from the same CTA scan. Quantitative plaque and stenosis were analyzed in both systolic and diastolic images using artificial intelligence (AI)-enabled plaque analysis software (Autoplaque). Overall, 186 lesions from 39 patients were analyzed. There were excellent agreement and correlation between systolic and diastolic images for all plaque volume measurements (Lin's concordance coefficient ranging from 0.97 to 0.99; R ranging from 0.96 to 0.98). There were no substantial intrascan differences per patient between systolic and diastolic phases (p > 0.05 for all) for total (1017.1 ± 712.9 mm3 vs. 1014.7 ± 696.2 mm3), non-calcified (861.5 ± 553.7 mm3 vs. 856.5 ± 528.7 mm3), calcified (155.7 ± 229.3 mm3 vs. 158.2 ± 232.4 mm3), and low-density non-calcified plaque volume (151.4 ± 106.1 mm3 vs. 151.5 ± 101.5 mm3) and diameter stenosis (42.5 ± 18.4% vs 41.3 ± 15.1%). Excellentagreement and no substantial differences were observed in AI-enabled quantitative plaque measurements on CTA in systolic and diastolic images. Following further validation, standardized plaque measurements can be performed from CTA in systolic or diastolic cardiac phase. Quantitative plaque assessment using artificial intelligence-enabled plaque analysis software can provide standardized plaque quantification, regardless of cardiac phase. • The impact of different cardiac phases on coronary plaque measurements is unknown. • Plaque analysis using artificial intelligence-enabled software on systolic and diastolic CT angiography images shows excellent agreement. • Quantitative coronary artery plaque assessment can be performed regardless of cardiac phase.

Reduction of left ventricular diastolic pressure as a key regulator of infarct coronary flow under mechanical left ventricular support.

Restoring ischaemic myocardial tissue perfusion is crucial for minimizing infarct size. Acute mechanical left ventricular (LV) support has been suggested to improve infarct tissue perfusion. However, its regulatory mechanism remains unclear. We investigated the physiological mechanisms in six Yorkshire pigs, which were subjected to 90-min balloon occlusion of the left anterior descending artery. During the acute reperfusion phase, LV support using an Impella heart pump was initiated. LV pressure, coronary flow and pressure of the infarct artery were simultaneously recorded to evaluate the impact of LV support on coronary physiology. Coronary wave intensity was calculated to understand the forces regulating coronary flow. Significant increases in coronary flow velocity and its area under the curve were found after mechanical LV support. Among the coronary flow-regulating factors, coronary pressure was increased mainly during the late diastolic phase with less pulsatility. Meanwhile, LV pressure was reduced throughout diastole resulting in significant and consistent elevation of coronary driving pressure. Interestingly, the duration of diastole was prolonged with LV support. In the wave intensity analysis, the duration between backward suction and pushing waves was extended, indicating that earlier myocardial relaxation and delayed contraction contributed to the extension of diastole. In conclusion, mechanical LV support increases infarct coronary flow by extending diastole and augmenting coronary driving pressure. These changes were mainly driven by reduced LV diastolic pressure, indicatingthat the key regulator of coronary flow under mechanical LV support is downstream of the coronary artery, rather than upstream. Our study highlights the importance of LV diastolic pressure in infarct coronary flow regulation. KEY POINTS: Restoring ischaemic myocardial tissue perfusion is crucial for minimizing infarct size. Although mechanical left ventricular (LV) support has been suggested to improve infarct coronary flow, its specific mechanism remains to be clarified. LV support reduced LV pressure, and elevated coronary pressure during the late diastolic phase, resulting in high coronary driving pressure. This study demonstrated for the first time that mechanical LV support extends diastolic phase, leading to increased infarct coronary flow. Future studies should evaluate the correlation between improved infarct coronary flow and resulting infarct size.

Assessment of right ventricular diastolic function in pediatric patients with repaired tetralogy of Fallot by cardiovascular magnetic resonance and echocardiography.

Cardiovascular magnetic resonance (CMR) imaging is routinely performed for assessing right ventricular (RV) systolic but not diastolic function. We aimed to investigate CMR-based assessment of RV diastolic function in pediatric patients with repaired tetralogy of Fallot (rTOF), compared to transthoracic echocardiography (TTE) measurements. A total of 130 consecutive pediatric patients with rTOF who underwent clinically indicated CMR and same-day TTE were included. Forty-three controls were recruited. Phase-contrast images were used to measure trans-tricuspid valve flow velocities during early (E) and late diastolic (A) phases (measured in cm/s). Feature tracking of the tricuspid annulus was performed to derive early (e') and late diastolic (a') myocardial velocities (measured in cm/s). RV diastolic function was evaluated by E/A ratio, E/e' ratio, and E-wave deceleration time (measured in milliseconds). Regression analyses were utilized to identify potential variables associated with RV diastolic dysfunction (DD). The performance of CMR-derived parameters in diagnosing RV DD was assessed using receiver-operating characteristic analyses. Good agreement was found between CMR and TTE measurements (ICC 0.70-0.89). Patients with RV DD (n = 67) showed significantly different CMR-derived parameters including E and e' velocities, and E/A and E/e' ratio, compared to patients without DD (n = 63) (all p < 0.05). CMR-derived E and e' velocities and E/e' ratio were independent predictors of RV DD. E/e' of 5.8 demonstrated the highest discrimination of RV DD (AUC 0.76, sensitivity 70%, specificity 86%). CMR-derived parameters showed good agreement with TTE parameters in determining RV DD. CMR-derived E/e' was proved to be the most effective in identifying RV DD. This study demonstrated the feasibility and efficacy of CMR in assessing diastolic function in pediatric patients. RV DD was presented in over half of patients according to current TTE guidelines, highlighting the need for assessing RV diastolic function during follow-up. • Routinely acquired cine and phase-contrast cardiovascular magnetic resonance (CMR) images yielded right ventricular (RV) diastolic parameters which demonstrated good agreement with transthoracic echocardiography (TTE) measurements. • There was a high prevalence of RV diastolic function impairment in pediatric patients with repaired tetralogy of Fallot (rTOF). • CMR is a reliable complementary modality of TTE for RV diastolic function evaluation.

Biventricular intraventricular mechanical and electrical dyssynchrony in pulmonary arterial hypertension

BackgroundPulmonary arterial hypertension (PAH) leads to myocardial remodeling, manifesting as mechanical dyssynchrony (M-dys) and electrical dyssynchrony (E-dys), in both right (RV) and left ventricles (LV). However, the impacts of layer-specific intraventricular M-dys on biventricular functions and its association with E-dys in PAH remain unclear. MethodsSeventy-nine newly diagnosed patients with PAH undergoing cardiac magnetic resonance scanning were consecutively recruited between January 2011 and December 2017. The biventricular volumetric and layer-specific intraventricular M-dys were analyzed. The QRS duration z-scores were calculated after adjusting for age and sex. Results77.22 % of patients were female (mean age 30.30 ± 9.79 years; median follow-up 5.53 years). Further, 29 (36.71 %) patients succumbed to all-cause mortality by the end of the study. At the baseline, LV layer–specific intraventricular M-dys had apparent transmural gradients compared with RV in the radial and circumferential directions. However, deceased patients lost the transmural gradients. The LV longitudinal strain rate time to late diastolic peak in the myocardial region (LVmyoLSRTTLDPintra) predicted long-term survival. The Kaplan–Meier curve revealed that patients with PAH with LVmyoLSRTTLDPintra <20.01 milliseconds had a worse prognosis. Larger right ventricle (RV) intraventricular M-dys resulted in worse RV ejection fraction. However, larger LV intraventricular M-dys in the late diastolic phase indicated remarkable exercise capacity and higher LV stroke volume index. E-dys and intraventricular M-dys had no direct correlations. ConclusionsThe layer-specific intraventricular M-dys had varying impacts on biventricular functions in PAH. PAH patients with LVmyoLSRTTLDPintra <20.01 milliseconds had a worse prognosis. LV intraventricular M-dys in the late diastolic phase needs more attention to precisely evaluate LV function.

Mechanical LV support lowers diastolic LV pressure and prolongs diastolic coronary flow in the infarcted artery

Abstract Background Percutaneous left ventricular (LV) assist device provides not only circulatory support but also LV unloading. However, impact of LV unloading on coronary flow and mechanisms by which it is regulated remain unclear. We aimed to elucidate potential effects of LV unloading on coronary physiology in a pig model of myocardial infarction (MI). Methods First, six Yorkshire pigs underwent mechanical LV unloading using Impella two weeks after percutaneous MI induction. Regional blood flow (RBF) in infarct, border and remote myocardium were measured by fluorescent microsphere injections before and 120 min after LV unloading (Study 1). Next, we investigated coronary flow patterns with detailed temporal information. Six Yorkshire pigs were subjected to 90-minute balloon occlusion of the middle left anterior descending artery followed by reperfusion. At 60 minutes after reperfusion, LV unloading was initiated and maintained at maximal support. LV pressure, coronary flow and pressure in the infarcted artery were simultaneously recorded. Measurements were repeated with and without LV mechanical support. Coronary wave intensity was calculated from the flow/pressure data (Study 2). Results In Study 1, RBF calculated using microsphere was significantly increased only in the infarct area, but not in the border or remote areas. In Study 2, LV unloading resulted in lower LV pressure during the whole diastolic phase and higher coronary pressure during the late diastolic phase in all animals. Coronary flow velocity was higher throughout the diastole under LV unloading. In addition, the proportion of diastole to the whole cardiac cycle was significantly prolonged with LV unloading. Accordingly, area under the curve of coronary flow was increased during diastole and also for the whole cardiac cycle. In the wave intensity analysis, the magnitude of forward wave intensity was reduced by LV unloading, suggesting that the impact of forces from the aortic side was less significant under continuous device support. The duration between backward suction and pushing waves was extended, implicating earlier relaxation and delayed contraction, further supporting prolonged diastole from the myocardial force perspective. Conclusions Mechanical LV unloading increases coronary flow by prolonging diastolic phase in the infarcted artery.

Subclinical dysfunction in left atrial compliance after successful cryoballoon versus radiofrequency ablation for paroxysmal atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): The Medical Centre of Postgraduate Education. Purpose It has been suggested that cryoballoon ablation (CB) for paroxysmal atrial fibrillation (PAF) may lead to more extensive left atrial (LA) injury than radiofrequency ablation (RF), however, results are conflicting. The aim of our study was to estimate the LA function after successful CB and RF for PAF using transthoracic echocardiography (TTE). Methods 90 pts (66% males, mean age 57±10 years) successfully treated (no AF recurrences confirmed in serial 4–7 day ECG Holter monitoring) with RF (51%) or CB (49%) for PAF were prospectively studied. TTE with speckle tracking (STE) and tissue doppler was performed before and 12 months after the procedure in sinus rhythm. The peak longitudinal LA strain (LAS) during the reservoir (r), conduit (cd) and contraction (ct) phases were measured. The global LAS for each LA phase was calculated by averaging the values observed in all LA segments in the 4- and 2-Chamber views. We set the zero strain point as the time from the beginning of the QRS wave. The velocities of the early (e') and late (a') diastolic phases at the mitral annular septal and lateral corners were measured. Analysis of covariance was applied to compare changes over time with the baseline measurement as covariance and the type of ablation as the factor. The parallelism of the slopes of the covariance was tested. Results Parameters of LA function regarding the mode of ablation at 12 months after the procedure are shown in the table. Significant decrease in LAScd and e’ was observed in the CB subgroup with better preserved baseline values (≥16% and ≥12cm/s respectively). Conclusion Worsening of parameters reflecting LA compliance was observed 12 months after successful CB vs RF ablation for PAF. This might suggest subclinical dysfunction of LA after CB procedure. Clinical significance of this finding warrant further long-term observation.

Influence of a single hemodialysis on left ventricular energy loss and wall shear stress in patients with uremic cardiomyopathy assessed with vector flow mapping.

BackgroundThe influence of hemodialysis (HD) on hydromechanics of the left ventricle has not been reported. This study evaluated the left ventricular summation of energy loss (EL-SUM), average energy loss (EL-AVE), and wall shear stress (WSS) before and after HD using vector flow mapping (VFM) in patients with end-stage renal disease (ESRD).MethodsWe prospectively recruited 40 patients receiving long-term HD and excluded those with structural cardiac disease. Echocardiography was performed before and within 24 hours after HD. Conventional echocardiographic parameters, summation, and average energy loss (EL-SUM, EL-AVE, EL-base, EL-mid and EL-apex), and WSS in each segment were compared.ResultsA total of 40 patients with uremia were recruited. After HD, left ventricular EL-AVE-total, and EL-SUM-total decreased significantly in the early diastolic [29.43 (18.76 to 46.28) vs. 17.70 (10.76 to 95.60) N/(m2·s) and 12 (6 to 17) vs. 5 (3 to 11) e−2 J; P<0.001, respectively], mid-diastolic [17.07 (10.38 to 24.35) vs. 10.29 (5.86 to 16.30) N/(m2·s) and 7 (3 to 10) vs. 4 (2 to 6) e−2 J; P<0.001, respectively], and early systolic [17.82 (12.79 to 24.77) vs.14.90 (10.23 to 19.05) N/(m2·s) P=0.011 and 8 (5 to 11) vs. 5 (4 to 8) e−2 J, P=0.002, respectively] phases. It was revealed that HD did not change EL-AVE-total and EL-SUM-total in the late diastolic and late systolic phases. The EL-AVE decreased after HD in the left ventricular (LV) basal [50.70 (24.19 to 77.92) vs. 26.00 (11.50 to 47.68) N/(m2·s); P<0.001] and mid [15.52 (8.88 to 20.90) vs. 9.47 (6.41 to 14.21) N/(m2·s); P=0.001] segments during the early diastolic phase; in the LV basal [18.64 (10.33 to 29.80) vs. 10.25 (6.98 to 19.43) N/(m2·s); P<0.001), mid (15.70 (9.93 to 23.08) vs. 9.99 (6.03 to 16.25) N/(m2·s); P<0.001), and apical [9.78 (4.06 to 15.77) vs. 4.52 (3.14 to 10.36) N/(m2·s); P=0.001) segments during the mid-diastolic phase; in the LV mid [14.34 (8.34 to 23.88) vs. 9.36 (6.48 to 17.05) N/(m2·s); P=0.013] and apex [11.25 (6.37 to 21.88) vs. 6.60 (5.33 to 12.17) N/(m2·s); P=0.016] segments during the late diastolic phase; and in the apical [10.28 (6.05 to 17.01) vs. 7.59 (3.73 to 13.20) N/(m2·s) P=0.025] segment during the early systolic phase. After HD, WSS significantly reduced in the mid-diastolic [0.51 (0.32 to 0.69) vs. 0.38 (0.30 to 0.46) Pa, P=0.001] and early systolic [0.60 (0.45 to 0.81) vs. 0.57 (0.42 to 0.68) Pa, P=0.029] phases. There was no change in WSS during the early diastolic, late diastolic, and late systolic phases.ConclusionsAfter HD, EL and WSS of LV decrease during the systolic and diastolic phases. The VFM can reflect the LV hemodynamics in patients undergoing HD under different fluid loads.

Association of Non-Alcoholic Fatty Liver Disease and Hepatic Fibrosis with Epicardial Adipose Tissue Volume and Atrial Deformation Mechanics in a Large Asian Population Free from Clinical Heart Failure.

Non-alcoholic fatty liver disease (NAFLD) and cardiovascular disease share several cardiometabolic risk factors. Excessive visceral fat can manifest as ectopic fat depots over vital organs, such as the heart and liver. This study assessed the associations of NAFLD and liver fibrosis with cardiac structural and functional disturbances. We assessed 2161 participants using ultrasound, and categorized them as per the NAFLD Fibrosis Score into three groups: (1) non-fatty liver; (2) fatty liver with low fibrosis score; and (3) fatty liver with high fibrosis score. Epicardial fat volume (EFV) was measured through multidetector computed tomography. All participants underwent echocardiographic study, including tissue Doppler-based E/e’ ratio and speckle tracking-based left ventricular global longitudinal strain, peak atrial longitudinal strain (PALS), and atrial longitudinal strain rates during systolic, early and late-diastolic phases (ALSRsyst, ALSRearly. ALSRlate). Larger EFV, decreased e’ velocity, PALS, ALSRsyst, and ALSRearly, along with elevated E/e’ ratio, were seen in all groups, especially in those with high fibrosis scores. After multivariate adjustment for traditional risk factors and EFV, fibrosis scores remained significantly associated with elevated E/e’ ratio, LA stiffness, and decreased PALS (β: 0.06, 1.4, −0.01, all p < 0.05). Thus, NAFLD is associated with LV diastolic dysfunction and subclinical changes in LA contractile mechanics.

Application and clinical significance of tissue ultrasound for assessment of right ventricular diastolic function in patients with coronary slow flow.

Objectives:To evaluate right ventricular diastolic function in patients with coronary slow flow phenomenon (CSFP) by using Doppler tissue imaging (DTI).Methods:CSFP patients diagnosed using coronary angiography from June 2019 to December 2020 at the third Hospital of Quzhou were retrospectively investigated, with a similar number of patients with normal coronary blood flow during the same period taken as the control group. Right ventricular systolic and diastolic function index was measured via DTI.Results:No differences were found between CSFP and control groups in terms of baseline data, RV end systolic diameter, RV end diastolic diameter, or RV ejection fraction. The peak velocity E in the early diastolic phase of the right ventricle was decreased in CSFP patients, while the peak velocity a in the late diastolic phase of the right ventricle was increased, resulting in a lower E / a ratio.Conclusions:Right ventricular diastolic function in patients with CSFP is decreased, and this can be identified using DTI. DTI has important applicative value for evaluating right ventricular diastolic function in patients with CSFP.

Computational Fluid Dynamics Simulations to Predict False Lumen Enlargement After Surgical Repair of Type-A Aortic Dissection

We aim to use computational fluid dynamics to investigate the hemodynamic conditions that may predispose to false lumen enlargement in this patient population. Nine patients who received surgical repairs of their type-A aortic dissections between 2017-2018 were retrospectively identified. Multiple contrast-enhanced post-operative CT scans were used to construct 3D models of aortic geometries. Computational fluid dynamics simulations of the models were run on a high-performance computing cluster using SimVascular - an open-source simulation package. Physiological pulsatile flow conditions (4.9 L/min) were used at the aortic true lumen inlet, and physiological vascular resistances were applied at the distal vascular ends. Exploratory analyses showed no correlation between rate of false lumen growth and blood pressure, immediate post-op aortic diameter, or the number of fenestrations (p=0.2). 1-year post-operative CT scans showed a median false lumen growth rate of 4.31 (3.66, 14.67) mm/year Median (Interquartile range) peak systolic, mid-diastolic, and late diastolic velocity magnitudes were 0.90 (1.40); 0.10 (0.16); and 0.06 (0.06) cm/s respectively. Spearman's ranked correlations between fenestration velocity and 1-year false lumen growth rates were found to be statistically significant: Velocity magnitude at peak systolic (p=0.025; rho=0.75), mid diastolic (p=0.025; rho=0.75) and late diastolic phases of the cardiac cycle (p=0.006; rho=0.85). We have shown that false lumen growth is strongly correlated to fenestration flow velocity, which has potential implications for post-operative surveillance and risk stratification.

Serum NT-proBNP and TUG1 as novel biomarkers for elderly hypertensive patients with heart failure with preserved ejection fraction.

Patients with heart failure with preserved ejection fraction (HFPEF) account for ~50% of all cases of heart failure and their clinical prognosis is poor. The present study attempted to investigate the diagnostic value of circulating long non-coding RNA taurine upregulated gene 1 (TUG1) for HFPEF in subjects with hypertension. Between January 2017 and January 2019, 80 aged/elderly hypertensive patients with or without HFPEF were recruited for the present study. The concentration of N-terminal pro-brain natriuretic peptide (NT-proBNP) in the serum was measured using ELISA and TUG1 expression levels were determined using reverse transcription-quantitative PCR. Echocardiography was used for the determination of cardiac function. The results indicated that the levels of NT-proBNP and TUG1 were increased in the serum of hypertensive patients with HFPEF. Pearson analysis demonstrated that NT-proBNP and TUG1 were positively correlated with the left atrial diameter and negatively correlated with the ratio of the peak flow velocity in the early diastolic phase to the peak flow velocity in the late diastolic phase. In addition, a positive correlation was confirmed between TUG1 and NT-proBNP levels. Receiver operating characteristic curve analysis demonstrated that TUG1 and NT-proBNP were useful biomarkers for the diagnosis of HFPEF. In conclusion, it was observed that NT-proBNP and TUG1 were increased in the serum of hypertensive patients with HFPEF. Furthermore, TUG1 and NT-proBNP were indicated to be useful plasma biomarkers for the diagnosis of HFPEF.

Physiological compensatory mechanisms of improved left heart function in response to simulated acute weightlessness: A human echocardiographic study by speckle tracking strain imaging

<p indent="0mm">The gravity-induced hydrostatic pressure gradient in the cardiovascular system is altered under the aerospace condition of weightlessness, leading to the increase of returned blood volume, and thus changes in cardiac structure and function. However, the characteristics and compensatory mechanisms are still unclear. The present study was to investigate the characteristics and compensatory mechanisms of cardiac preload and function in simulated acute aviation negative gravity and space microgravity using two-dimensional echocardiographic speckle-tracking strain imaging, and to provide theoretical evidence for aerospace heart protection. A total of 27 healthy young male volunteers were recruited. The tilting table was used to simulate acute microgravity (0.87~0 G) and negative gravity (0~−0.87 G). The left heart volumes, strain and functional parameters were collected and analyzed by both conventional and speckle tracking echocardiography. The systemic vascular resistance, compliance and ventricular-arterial coupling were calculated. The results showed that, the left heart volume and strain, left atrial emptying fraction and left ventricular ejecting fraction were all increased as gravity decreased. The arterial compliance was increased and the ventricular-arterial coupling index was decreased within the normal range. Of note, the reservoir, conduit and contraction function of left atrial strain were elevated proportionally; the flow velocity of left ventricular filling during early and late diastolic phases were both increased at the constant ratio. That is, the compensatory pattern was characterized by proportional improvement of cardiac motion in different phases and directions, which is different from that in aging and diseases. The present study demonstrated that the heart of healthy young men can effectively compensate the increase of preload caused by simulated acute microgravity and negative gravity. The major compensatory mechanism is the proportional improvement of myocardial motion of left atrium and ventricle during different phases (early and late diastole, systole) and along different directions (longitudinal and circumferential). The findings suggest that the aviators or astronauts generally have enough cardiac systolic/diastolic reserve to counter the acute change of cardiac preload induced by weightlessness (−0.87~1 G).

Factors contributing to energy loss in left ventricle during diastolic and systolic phases in elderly patients.

The change of left ventricular function deteriorated with age because of gradual increases of blood pressure may result in increased energy loss (EL) in left ventricle (LV). The present study investigated EL in LV among hypertensive elderly patients and examined factors contributing to EL. A single-center retrospective study was performed on elderly hypertensive outpatients (≥65 years) who underwent echocardiography (N = 105). EL in the LV was measured using a vector flow mapping system, and factors affecting peak EL during the early-diastolic phase (ED-EL), late-diastolic phase (LD-EL), and systolic phase (Sys-EL) were evaluated. Mean age was 79.9 ± 6.4 years (male 43%). Mean ED-EL, LD-EL, and Sys-EL were 42.1 ± 46.7, 75.6 ± 60.2, and 40.4 ± 40.2 mJ/N/s. In a stepwise regression analysis, the E/e'(lateral) (unstandardized B = 0.005, 95%CI -0.03 to 0.007, standardized β = 0.434, P < .001) was identified as factors affecting ED-EL. The factors affecting LD-EL were E/A ratio (B = -0.122, 95%CI -0.176 to -0.068, β = -0.470, P < .001) and time velocity integral (TVI) in LVOT (unstandardized B = 0.002, 95%CI 0.000 to 0.004, β = 0.247, P = .021). The factors influencing Sys-EL were TVI in LVOT (B = 0.002, 95%CI 0.001 to 0.004, β = 0.390, P < .001), E/A ratio (B = -0.054, 95%CI -0.093 to -0.015, β = -0.258, P = .008), left ventricular outflow tract (LVOT) diameter (B = -0.006, 95%CI -0.010 to -0.002, β = -0.307, P = .006), and left ventricular mass index (B = 0.000, 95%CI 0.000 to 0.001, β = 0.208, P = .039). Peak EL in the LV was higher during diastolic phase than systolic phase among elderly hypertensive patients. Peak EL both during late-diastolic phase and systolic phase was affected by systolic blood flow in LVOT and LV transmitral flow pattern.

Quantitative imaging of coronary flows using 3D ultrafast Doppler coronary angiography

Coronary flow rate remains complex to assess in clinical practice using non-invasive, non-ionizing imaging tools. In this study, we introduce 3D ultrafast Doppler coronary angiography (3D UDCA), an ultrasound-based method to assess coronary blood flows in three-dimensions at high volume-rate and in one single heartbeat. We demonstrate that 3D UDCA can visualize the coronary vasculature with high temporal and spatial resolution and quantify the absolute flow. The feasibility of the technique was demonstrated in an open-chest swine model. The flow rate of the left-anterior descending artery (LAD) assessed by 3D UDCA was reconstructed successfully at the early diastolic and late diastolic phases and was in good agreement with an invasive gold-standard flowmeter during baseline, reactive hyperemia and coronary stenosis (r2 = 0.84). Finally, we demonstrate that a coronary stenosis on the LAD can be visualized as well as its associated flow acceleration.

Assessment of right atrium dysfunction in patients with obstructive sleep apnea syndrome using velocity vector imaging

Background and ObjectivesThis study aimed to assess the changes of RA function in patients with obstructive sleep apnea syndrome (OSAS) using velocity vector imaging (VVI) and to evaluate the application of VVI technology.MethodsAccording to the apnea–hypopnea index (AHI), 71 patients with OSAS were divided into three groups: mild, moderate, and severe. A total of 30 cases of healthy subjects were enrolled as the control group. Digital images of apex four-chamber views were acquired to measure the right atrium (RA) linear dimensions and volume parameters including RA longitudinal diameter (RAL), transverse diameter (RAT), RA maximum volume (Vmax), RA minimum volume (Vmin), right atrial volume before contraction (Vpre). Right atrial volume parameters were corrected by body surface area (VImax, VImin, VIpre). The total right atrial emptying fraction (RATEF), right atrial passive emptying fraction (RAPEF), right atrial active contraction emptying fraction (RAAEF) were calculated. The VVI data measuring right atrial global strain (RA-GLS), right atrial strain rate in ventricular systolic phase (RA-SRs), right atrial strain rate in ventricular early diastolic phase (RA-SRe), right atrial strain rate in ventricular late diastolic phase (RA-SRa).ResultsRA linear dimensions and volume parameters in severe OSAS were higher than those of control group. RAPEF in severe group was lower than control group and mild OSAS group (t = 2.681, P = 0.021; t = 2.985, P = 0.011; respectively). RAAEF in OSAS moderate group was higher than that of control group (t = 3.006, P = 0.02), and without statistical difference (P > 0.05) in the severe OSAS group and the control group.RA-GLS in moderate OSAS group was significantly lower than that of control group (t = 2.333, P = 0.040) and reduced more obvious in the severe OSAS group (vs control, t = 3.25, P = 0.008, vs mild; t = 3.011, P = 0.012; respectively). RA-SRe in moderate and severe OSAS groups were lower than control group (t = 2.466, P = 0.031; t = 3.547, P = 0.005; respectively). RA-SRs of OSAS in severe group was lower than that of control and mild groups (t = 3.665, P = 0.004; t = 3.204, P = 0.008; respectively). RA-SRa in severe OSAS group was lower than that of control group (t = 2.425, P = 0.034).Multivariate regression analysis showed that RA-GLS and RA-SRe were independently correlated with AHI (t = − 2.738, P = 0.010; t = − 2.191, P = 0.036; respectively).ConclusionRA function was impaired in patients with OSAS. On hemodynamics, the change of RA function performed increased of reserve function, reduced pipeline function and increased of contraction function. However, the strain and strain rate reduced in different degree. RA-GLS and RA-SRe decreased the earliest, which suggested that strain and strain rate were the parameters which can reflect myocardial function damage earliest. VVI can more earlier and accurately detect myocardial dysfunction of right atrium in patients with OSAS, which is expected to be a worthy technique for early clinical therapy in patients with OSAS.

Subclinical Impairment of Left Ventricular Longitudinal Function in Patients With Prolactinomas

Hyperprolactinemia has been associated with endothelial dysfunction and a wide range of cardiovascular risk factors, thus it can potentially lead to cardiac dysfunction. The present study was designed to interrogate our hypothesis that hyperprolactinemia can contribute to preclinical impaired left ventricular function. Thirty-one prolactinoma patients and 60 healthy volunteers were prospectively recruited. Left ventricular function was evaluated using conventional two dimensions and M-mode echocardiography, as well as Doppler tissue imaging (DTI). The Tei index (0.45 ± 0.06 vs. 0.41 ± 0.03, P = .005) and ratio of transmitral and myocardial early diastolic velocities (E/Em; 6.30 ± 1.45 vs. 5.64 ± 0.69, P = .045) were significantly higher, and septal systolic velocity (Sm; 9.88 ± 1.45 vs. 11.58 ± 1.28 cm/s, P<.001) was significantly lower in prolactinoma patients. Furthermore, significant motional abnormalities were detected in regional segments of prolactinoma patients. Pearson's correlation analysis revealed that prolactin level was inversely associated with Sm (r = -0.373, P = .009) and late diastolic phase (Am; r = -0.293, P = .043). Moreover, inverse correlations between prolactin and partial left ventricular segment wall motion were found, including the basal (r = -0.363, P = .014), middle (r = -0.418, P = .004), and apical segment (r = -0.574, P<.001) of the posterior ventricular septum. Multivariate linear regression analysis revealed that prolactin (β = -0.28, 95% confidence interval -0.011 to 0, P = .035), as a single factor, can significantly predict decreased Sm, independent of traditional vascular risk factors. Our results suggest that subclinical cardiac dysfunction occurs in untreated prolactinoma patients and is characterized by impaired systolic and diastolic function of the left ventricle, as well as regional segment motional abnormality. A = transmitral late diastolic velocity Am = late diastolic phase Apo = apolipoprotein DTI = Doppler tissue imaging E = transmitral early diastolic velocity Em = myocardial early diastolic velocity FMD = flow-mediated dilation HOMA-IR = homeostasis model assessment of insulin resistance hsCRP = high-sensitivity C-reactive protein IMT = intima media thickness LDL-C = low-density lipoprotein cholesterol LV = left ventricular PPCM = postpartum cardiomyopathy Sm = septal systolic velocity.

Age, Sex, and Blood Pressure-Related Influences on Reference Values of Left Atrial Deformation and Mechanics From a Large-Scale Asian Population.

Left atrial (LA) function is tightly linked to several cardiovascular diseases and confers key prognostic information. Speckle tracking-based deformation as a feasible and sensitive LA mechanical assessment has proven its clinical significance beyond volume measures; however, the reference values remain largely unknown. We studied 4042 participants undergoing annual cardiovascular survey. Among them, 2812 healthy participants (65% men; mean age, 47.4±9.9 years) were eligible for speckle tracking analysis. Peak atrial longitudinal systolic strain and strain rate (SR) at systolic (SRs), early diastolic (SRe), and late diastolic atrial contraction phases (SRa) were analyzed by dedicated software (EchoPAC, GE) and compared in terms of age, sex, and blood pressure. Overall, women demonstrated higher peak atrial longitudinal systolic strain (39.34±7.99% versus 37.95±7.96%; P<0.001) and showed age-dependent more pronounced peak atrial longitudinal systolic strain functional decay than those of men (P value for interaction, <0.05), with men showing higher SRs and SRa, although lower SRe (all P<0.001). Both increasing age and higher blood pressure were independently associated with deteriorated peak atrial longitudinal systolic strain, SRs, and SRe, although augmented LA SRa, even after accounting for baseline clinical covariates in multivariable models that incorporated LA volume, NT-proBNP (N-terminal pro-B-type natriuretic peptide), or left ventricular E/e' (all P<0.001). Our findings suggest LA mechanical functional decays in association with increasing age and higher blood pressure, which seem to be compensated for by augmentation of atrial pump function. We have also provided age- and sex-stratified reference values for strain and SR based on a large-scale Asian population.

Improvements in Regional Left Ventricular Function Following Late Percutaneous Coronary Intervention for Anterior Myocardial Infarction.

Background:Late revascularization following a myocardial infarction has questionable clinical benefit.Methods:We studied 13 patients with anterior wall myocardial infarction who underwent percutaneous coronary intervention within 2 weeks of the primary event, by quantitative analysis of 2-dimensional echocardiographic images. Endocardial segmentations of the left ventricular (LV) endocardium from the 4-chamber views were studied over time to establish cumulative wall displacements (CWDs) throughout the cardiac cycle.Results:Left ventricular end-systolic volume decreased to 42 ± 8 mL/body surface area (P = .034) and LV ejection fraction improved to 52% ± 7% (P = .04). Analysis of LV endocardial CWD demonstrated significant improvements in mid-systolic to late-systolic phases in the apical LV segments, from 3.5 ± 0.32 to 5.89 ± 0.43 mm (P = .019). Improvements in CWD were also observed in the late-diastolic phase of the cardiac cycle, from 1.50 ± 0.42 to 1.76 ± 0.52 mm (P = .04).Conclusions:In our pilot patient cohort, following late establishment of infarct-related artery patency following an anterior wall myocardial infarction, regional improvements were noted in the LV apical segments during systole and late diastole.

The assessment of diastolic blood flow field related energy loss of left ventricle in patients with right heart dual-chamber pacing using ultrasonic vector flow mapping

Objective To assess the changes of diastolic blood flow field and energy loss of left intra-ventricular flow in patients with heart dual-chamber pacing using ultrasonic vector flow mapping(VFM), and to explore the clinical value of VFM technology for the assessment of left ventricular diastolic function in patients with cardiac pacing. Methods After routine echocardiographic exam for 51 patients with dual-chamber pacing as pacemaker group and 73 volunteers as control group, the color Doppler flow imagings from standard dynamic apical two, three and four-chamber views for 3 completed cardiac cycles were acquired in VFM mode, and were imported to DAS-RSI workstation subsequently. The off-line measurement of diastolic left intra-ventricular flow for prescription parameter, such as energy loss, vortex area and vortex intensity, was performed. The left intra-ventricular parameters of two groups were compared for difference, and the correlationship between parameters at isovolumetric, early, mid and late diastolic phases was analyzed with SPSS 17.0 statistical software. Results 1) The energy losses of pacemaker group compared with the those of control group were significantly higher at isovolumetric, early, and late diastolic phases(Z=-6.689, -5.683, -3.014, -4.418, P<0.001), and at mild-diastole, energy loss was reduced mildly(Z=-3.014, P<0.05). 2) Vortical intensity of pacemaker group was significantly greater than that of the control group in isovolumic, early and late diastolic phases (t=2.388, 2.988, 3.153, P<0.05) separately, there was not statistically vertical intensity differences in mid-diastole between the two groups and no significant vortical area difference between the two groups. 3) There was no correlationship in the two groups for all the phases between energy loss and vertical area or intensity. For each phases, vortical area of the control group was correlated with vortical intensity(r=0.396-0.809, P=0.003-0.000). Only isovolumic vortical area was correlated with the vortex intensity in pacemaker group (r=0.807, P=0.000). Conclusions The dual-chamber pacing of right ventricle and right atrium could induce a significant energy loss of left intra-ventricular fluid and obvious abnormal distribution of eddies during diastole. The disappearence of correlationship between vertical area and intensity in cardiac pacemaker group during left diastole might lead to more turbulance flow and energy loss of left ventricle during right dual chamber pacing. Key words: Echocardiography; Ventricular function, left; Cardiac pacing, artificial; Vector flow mapping

Intra-left ventricular flow dynamics in patients with preserved and impaired left ventricular function: Analysis with 3D cine phase contrast MRI (4D-Flow).

To examine how left ventricular (LV) volume and function affect flow dynamics by analyzing 3D intra-LV vortex features using 4D-Flow. Twenty-one patients with preserved (LVEF > 60%) and 14 with impaired LV function (LVEF < 40%) underwent 4D-Flow (at 3T). In patients with preserved LV function, the intra-LV vortices developed in both the early and late diastolic phases. The shift of inflow vectors at the basal LV toward the posterior-lateral side of the LV and the mid-ventricular turn of inflow vectors toward the LV outflow could explain clearer vortex formation in the late diastolic phase. In patients with impaired LV function, the intra-LV vortices during the diastolic phase located at the more apical LV were larger and more spherically shaped. Both the distance to the vortex core and the vortex area correlated significantly with LV end-diastolic volume (r = 0.66 and 0.73), LVEF (r = -0.74 and -0.68), LV sphericity index (r = -0.60 and -0.65), and peak filling rate (r = -0.61 and -0.64), respectively (P < 0.01). The intra-LV vortices developed during the systolic phase in 10 cases. In those, some of the particles at the apical LV rotated within the LV, whereas in patients with preserved LV function, all of the particles were directed straight to the ascending aorta with accelerated flow velocity (256.8 ± 120.2 cm/s vs. 414.3 ± 88.2 cm/s, P < 0.01). Vortex formation during the diastolic phase may be critical for both LV filling and ejection. 4D-Flow showed the 3D alterations of intra-LV flow dynamics by LV dilatation and dysfunction in a noninvasive and comprehensive manner. J. Magn. Reson. Imaging 2016;44:1493-1503.