Peak flow measurements in patients with severe aortic stenosis: a prospective comparative study between cardiovascular magnetic resonance 2D and 4D flow and transthoracic echocardiography

Background Aortic valve stenosis (AS) is the most prevalent valvular disease in the developed countries. Four-dimensional (4D) flow cardiovascular magnetic resonance (CMR) is an emerging imaging technique, which has been suggested to improve the evaluation of AS severity compared to two-dimensional (2D) flow and transthoracic echocardiography (TTE). We investigated the reliability of CMR 2D flow and 4D flow techniques in measuring aortic transvalvular peak systolic flow in patients with severe AS. Methods We prospectively recruited 90 patients referred for aortic valve replacement due to severe AS (73.3 ± 11.3 years, aortic valve area 0.7 ± 0.1 cm2, and 54/36 tricuspid/bicuspid), and 10 non-valvular disease controls. All the patients underwent echocardiography and 2D flow and 4D flow CMR. Peak flow velocity measurements were compared using Wilcoxon signed rank sum test and Bland–Altman analysis. Results 4D flow underestimated peak flow velocity in the AS group when compared with TTE (bias − 1.1 m/s, limits of agreement ± 1.4 m/s) and 2D flow (bias − 1.2 m/s, limits of agreement ± 1.6 m/s). The differences between values obtained by TTE (median 4.3 m/s, range 2.7–6.1 m/s) and 2D flow (median 4.5 m/s, range 2.9–6.5 m/s) compared to 4D flow (median 3.1 m/s, range 1.7–5.1 m/s) were significant (p < 0.001). The difference between 2D flow and TTE were insignificant (bias 0.07 m/s, limits of agreement ± 1.5 m/s). In non-valvular disease controls, peak flow velocity was measured higher by 4D flow than 2D flow (1.4 m/s, 1.1–1.7 m/s and 1.3 m/s, 1.1–1.5 m/s, respectively; bias 0.2 m/s, limits of agreement ± 0.16 m/s). Conclusions CMR 4D flow significantly underestimates systolic peak flow velocity in patients with severe AS. 2D flow, in turn, estimated the AS velocity accurately, with measured peak flow velocities comparable to TTE.

Altered left atrial appendage function associated with cardioembolic stroke in patients with rheumatic heart disease

Background: Left atrial appendage (LAA) is usually the first site for thrombus formation in rheumatic heart disease (RHD). LAA function is altered in RHD which may predispose it to thrombus formation. The aim of this study was to determine an association between function of LAA and cardioembolic stroke.Methods:Total 132 patients with RHD were studied by means of transthoracic echocardiography and/or transesophageal echocardiography and left atrial (LA) size, LAA ejection fraction (EF) and peak flow velocities were measured. These patients were followed up for 18 months with reference to development of cardioembolic stroke.Results: Seventy nine patients had atrial fibrillation (AF), of which 34 had thrombus in LAA. Out of 53 patients with sinus rhythm, 5 had LAA thrombus. Mean LAA EF was significantly lower in patients with thrombus in LAA, so was the peak flow velocity (both variables p<0.0001). Saw tooth LAA outflow velocity pattern was visible in 30 (80%) patients with LAA thrombus versus 20 (28%) patients without LAA thrombus. Total 14 patients experienced cardioembolic stroke. Patients with cardioembolic stroke had lower mean LAA EF and peak flow velocity as compared to patients without cardioembolic stroke.Conclusions:Increased LAA size, reduced LAA EF and reduced peak flow velocity are associated with increased risk of cardioembolic stroke. LAA evaluation should be mandatory in deciding treatment strategies in patients with RHD and AF.

ANOVA-Based Analysis of Early Blood Transfusions on Hemodynamics with Severely Injured Trauma Using Bedside Ultrasound Imaging

The focus of the study was to quantitatively analyze the influence of early massive blood transfusions (MBTs) on the hemodynamics and prognostic living quality of patients with severely injured trauma. 114 patients with severely injured trauma were enrolled into MBT group (67 cases) and nonmassive blood transfusions (NBT) group (47 cases) according to whether they accepted MBTs within 24 hours after the admission. All patients had bedside ultrasound technology scanning. Furthermore, the indexes were calculated for inferior vena cava (IVC), peripheral arteries, and heart. The prognostic deaths were recorded. It was found that, in the MBT group, the mortality was lower (7.55% vs. 24.23%) ( P < 0.05 ), and these indexes were higher for the IVC expansion (IVCE), the respiration variation index (RVI) of IVC (ΔIVC2), the peak flow velocity RVI of brachial artery (ΔVpeakBA), femoral artery (ΔVpeakFA), left ventricular outflow tract (ΔVpeakL), and aorta (ΔVpeakAO), as well as peak flow velocity time integral RVI of aorta (ΔVTIAO) ( P < 0.05 ). In conclusion, early MBTs can elevate survival rate and prognostic living quality and alleviate the atrophy degree of IVC, peripheral artery, and blood vessel of patients with severely injured trauma. Furthermore, bedside ultrasound scanning demonstrated superb capabilities in quantitatively displaying hemodynamics and outcomes of MBTs of patients with severely injured trauma.

Paleohydrology of the Stefanina Cave (Greece)

The development of hypergene Stefanina Cave, the hydrological conditions, and the maximum discharge of the paleo-flow are studied, based on its pattern in ground-plan, the geometry of the passage, and the peak flow velocity from the dimensions of the scallops. The village of Stefanina is located East of Thessaloniki and the cave NE of the village. A study was conducted measuring the orientation of the discontinuities of the rocks inside and outside the cave, the scallops in various sites to estimate the flow velocities, and in addition, were taken photographs for the full analysis of its cross-section. The cave-in ground-plan has a pattern of branches, which is often associated with recharging through karstic depressions. The shape of the passages is both curvilinear and angular, depending on the foliage and the fractures. The symmetrical phreatic passage shape has been evolved to a vadose canyon, forming a keyhole passage in cross-section. This is indicative of a water table drop. The scallops are visible in a meandering channel, where the discharge of the paleo-flow is estimated. The estimated peak flow velocity ranges from 0.4 to 2.7 m / s, while the area-specific peak flow discharge is estimated to be 2.2 m3/s. On the one hand, the scallops represent the peak flow velocity, on the other hand, the karst springs have a limited maximum discharge, regardless of the size of the catchment, making it impossible to use the calculated paleo-discharge to estimate the respective catchment area.

Severe coarctation of the aorta without a severely elevated echocardiographic pressure gradient: a case highlighting the importance of aortic Doppler flow profile

An asymptomatic 5-year-old male was diagnosed with severe coarctation of the aorta despite normal peak flow velocity with pathology identified on the basis of Doppler flow profile.

P1512 Combination of mitral annular peak systolic and early diastolic velocities with early transmitral peak flow velocity: a new prognostic echo index in patients with acute coronary syndrome

Background One of the novel echocardiographic indices reflecting left ventricular (LV) diastolic filling is the combination of mitral annular peak systolic (s’) and early diastolic velocities (e’) with early transmitral peak flow velocity (E); E/(e’ x s’). This index is reported to be useful to predict a prognosis of heart failure patients regardless of their LV ejection fraction (LVEF).Purpose: The aim of this study was to examine whether or not E/(e’ x s’) could predict cardiac events in patients with acute coronary syndrome (ACS).Methods: We studies consecutive ACS patients hospitalized in our institution between December 2009 and February 2012. They underwent echo examination within 7 days after admission. By use of Doppler tissue imaging, e’ and s’ were respectively calculated by averaging the peak velocities measured at both septal and lateral mitral annulus in 4-chamber view. The exclusion criteria were as follows: atrial fibrillation, significant valvular diseases and inadequate echo images. Cardiac events were defined as re-hospitalization due to recurrent ACS and/or heart failure, and cardiac mortality.Results: In total, 168 patients were eligible for this study (mean age 67 ± 11 years, mean LVEF 51.7 ± 10.3 %). Median follow-up period was 22.5 months. During the follow-up, cardiac events occurred in 27 patients (16.1%). Between the patients with cardiac events and those without, there were significant differences in LV end-systolic volume (44.2 ± 29.1 vs 33.2 ± 13.6 ml, p &lt; 0.05), LV mass index (122.4 ± 38.9 vs 107.5 ± 26.4 g/m², p &lt; 0.05), left atrial volume index (31.7 ± 9.2 vs 27.6 ± 9.4 ml/m², p &lt; 0.05), LVEF (45.7 ± 13.5 vs 52.9 ± 9.2 %, p &lt; 0.05), s’ (5.1 ± 1.6 vs 7.1 ± 1.7 cm/sec, p &lt; 0.001), e’ (4.8 ± 1.3 vs 6.0 ± 1.9 cm/sec, p &lt; 0.05), E/e’ (16.4 ± 6.6 vs 12.5 ± 4.9, p &lt; 0.05), E/(e’ x s’) (3.78 ± 2.52 vs 1.94 ± 1.08, p &lt; 0.001), and serum B-type natriuretic peptide (334.7 ± 420.1 vs 113.8 ± 177.2 pg/ml, p &lt; 0.05). While Cox proportional hazard multivariate analysis detected that E/(e’ x s’) and E/e’ were independent predictors of cardiac events, E/(e’ x s’) was more powerful than E/e’ (p = 0.0002 vs p = 0.0072). ROC analysis revealed that 2.35 of E/(e’ x s’) was the optimal cutoff values to predict cardiac events in ACS patients (AUC 0.79). Patients with E/(e’ x s’) &lt;2.35 had significantly better prognosis than the rest (p &lt; 0.0001, Log-rank; Figure)Conclusion: E/(e’ x s’) could be a useful echo marker to predict cardiac events in ACS patients. Abstract P1512 Figure.

The Application of Computational Fluid Dynamics in the Evaluation of Laryngotracheal Pathology

Objectives: Laryngotracheal stenosis and obstruction can be challenging to manage. Traditional assessment tools are limited in clinical correlation. Three-dimensional computational fluid dynamics (CFD) modeling is a novel technique used to analyze airflow dynamics. The objective of this study was to apply CFD to the human upper airway to explore its utility. Methods: CFD models were constructed on an adult patient with an obstructive tracheal lesion before and after intervention and on an adult with normal airway anatomy, using computed tomographic imaging obtained retrospectively. Key airflow metrics were calculated. Results: CFD provided detailed airway geometry. The normal airway had a peak flow velocity of 3.12 m/s, wall shear stress of 0.30 Pa, and resistance of 0.02 Pa/mL/s. The pathologic patient showed an elevated peak flow velocity of 12.25 m/s, wall shear stress of 3.90 Pa, and resistance of 0.22 Pa/mL/s. This was reflected clinically with dyspnea, stridor, and obstructive impairment via pulmonary function testing. Following treatment, peak flow velocity corrected to 3.95 m/s, wall shear stress to 0.72Pa, and resistance to 0.01 Pa/mL/s. Cross-sectional area improved to 190 mm2 from a minimum of 53 mm2 at the same segment. Stridor and dyspnea resolved. Conclusions: CFD metrics were calculated on the normal, diseased, and posttreatment upper airway. Variations were reflected in clinical symptoms. These methods could model surgical outcomes and anticipate disease severity.

Pathophysiological and Clinical Approach to Cirrhotic Cardiomyopathy

Hyperdynamic circulation, systolic and diastolic left ventricular dysfunction and certain electrophysiological abnormalities have been associated with cirrhosis and known for a long time. These clinical features have been introduced as cirrhotic cardiomyopathy (CCM), which is characterized by blunted myocardial contractile responsiveness to physical, physiological and pharmacological stress. Importantly, cardiac dysfunction can be reversible and can improve due to effective medical treatment and also after liver transplantation. Echocardiography and electrocardiography are essential tools for recognizing the characteristic changes in the myocardial function and also the alterations in the electrophysiological properties of the heart. Laboratory markers are auxiliary modalities further aiding the establishment of the correct diagnosis. In this review, we aimed to collect the pathophysiological background and clinical characteristics of CCM with the intention of summarizing the current possibilities for the diagnosis establishment and treatment of this cardio-hepatic disorder.Abbreviations: A: late diastolic transmitral peak flow velocity; ACE: angiotensin converting enzyme; ANP: atrial natriuretic peptide; ARB: angiotensin receptor blocker; BNP: brain natriuretic peptide; cAMP: cyclic adenosine monophosphate; CCM: cirrhotic cardiomyopathy; CGRP: calcitonin gene-related peptide; CO: carbon monoxide; DD: diastolic dysfunction; DT: deceleration time; E: early diastolic transmitral peak flow velocity; Ea: early diastolic velocity of the septal mitral annulus; EF: ejection fraction; MUGA: Multi Gated Acquisition Scan; NO: nitric oxide; NSBB: non-selective beta-blocker; pro-BNP: pro-brain natriuretic peptide; QTc: corrected QT interval; RAAS: renin-angiotensin aldosterone system; RALES: Randomized Aldactone Evaluation Study; suPAR: urokinase-type plasminogen activator receptor; TDI: Tissue Doppler Imaging; TIPS: transjugular intrahepatic portosystemic shunt; TNF-alpha: tumor necrosis factor-alpha.