Impact of image quality on reliability of the measurements of left ventricular systolic function and global longitudinal strain in 2D echocardiography

Background

Left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS) play important roles in diagnosis and management of cardiac diseases. However, the issue of the accuracy and reliability of LVEF and GLS remains to be solved. Image quality is one of the most important factors affecting measurement variability. The aim of this study was to investigate whether improved image quality could reduce observer variability.

Methods

Two sets of three apical images were acquired using relatively old- and new-generation ultrasound imaging systems (Vivid 7 and Vivid E95) in 308 subjects. Image quality was assessed by endocardial border delineation index (EBDI) using a 3-point scoring system. Three observers measured the LVEF and GLS, and these values and inter-observer variability were investigated.

Results

Image quality was significantly better with Vivid E95 (EBDI: 26.8 ± 5.9) than that with Vivid 7 (22.8 ± 6.3, P < 0.0001). Regarding the inter-observer variability of LVEF, the r-value, bias, 95% limit of agreement and intra-class correlation coefficient for Vivid 7 were comparable to those for Vivid E95. The % variabilities were significantly lower for Vivid E95 (5.3–6.5%) than those for Vivid 7 (6.5–7.5%). Regarding GLS, all observer variability parameters were better for Vivid E95 than for Vivid 7. Improvements in image quality yielded benefits to both LVEF and GLS measurement reliability. Multivariate analysis showed that image quality was indeed an important factor of observer variability in the measurement of LVEF and GLS.

Conclusions

The new-generation ultrasound imaging system offers improved image quality and reduces inter-observer variability in the measurement of LVEF and GLS.

Ultrasonic effects on electroorganic processes--Part 20. Photocatalytic oxidation of aliphatic alcohols in aqueous suspension of TiO2 powder

Ultrasonic effects in a suspension system were examined using the photocatalytic oxidation of 2-propanol to acetone and of ethanol to acetaldehyde in the aqueous suspension of TiO2 powder as a model reaction. The formation rate of acetone was significantly increased under ultrasonic irradiation. The oxidation reaction under ultrasonic irradiation was affected in a different manner from that in silence by reaction conditions such as ultrasonic power, stirring speed, amount of TiO2, concentration of 2-propanol, and pretreatment of the TiO2 powder. Furthermore, it was also observed that the particle size of the TiO2 photocatalyst powder was increased due to the particle agglomeration by ultrasonic irradiation, and consequently it was suggested that ultrasound activates the surface of the catalyst. These results are discussed on the basis of not only the activation of the photocatalyst but also ultrasonic enhancement of mass transport of 2-propanol molecules.

Prognostic value of biventricular mechanical parameters assessed using cardiac magnetic resonance feature-tracking analysis to predict future cardiac events

PURPOSE

To study and compare the prognostic value of cardiac magnetic resonance feature tracking (MR-FT) of biventricular strain parameters with a conventional method.

MATERIALS AND METHODS

We retrospectively enrolled 364 patients undergoing clinically indicated cardiac MR examinations (1.5 or 3T scanner). Standard steady-state free precession (SSFP) images were used for analysis. Left ventricular (LV) and right ventricular (RV) ejection fraction (EF) were measured using conventional disk-area summation methods. Biventricular strain parameters were measured using MR-FT. All patients were followed to record major adverse cardiac events (MACEs).

RESULTS

The correlations between LV volumes and LVEF using both methods were excellent (r = 0.87-0.98). RV strain parameters were modestly correlated with RVEF (r = 0.44-0.63). During a median follow-up of 15 months, 36 patients developed MACEs. All MR-FT-derived parameters except for RV global longitudinal strain were significantly associated with future MACEs (P < 0.05) in univariate analysis. In stepwise Cox proportional hazard models, RV global radial strain (RVGRS) provided incremental prognostic value in models adjusted for age, gender, conventional LVEF (hazard ratio 0.93; P = 0.029) or RVEF (hazard ratio 0.93; P = 0.038). LV global transverse strain (LVGTS) also offered additional value over age, gender, conventional LVEF (hazard ratio 0.94; P = 0.041), or RVEF (hazard ratio 0.94; P = 0.004). Kaplan-Meier analysis showed significant survival differences in subgroups stratified by the median value of LVGTS, RVGRS, and LVEF using MR-FT (all log-rank P < 0.05).

CONCLUSION

Deformation analysis of both ventricles using MR-FT provided significant prognostic power similar to parameters obtained using conventional methods. MR-FT is a promising alternative both for ventricular chamber quantification and for providing information of future cardiac events.

LEVEL OF EVIDENCE

3 J. Magn. Reson. Imaging 2017;45:1034-1045.

Association of life habits and fermented milk intake with stool frequency, defecatory symptoms and intestinal microbiota in healthy Japanese adults

Few studies have examined the effects of smoking habit, the frequency of alcohol drinking, exercise, and fermented milk consumption on defecatory symptoms and gut microbiota composition, and particularly their interactive effects. We examined the effect of these lifestyle factors on bowel movements and gut microbiota composition in 366 healthy Japanese adults by analysis of covariance. Smoking did not affect defecatory symptoms but was negatively correlated with total bacteria and Enterococcus counts. Drinking frequency was significantly positively correlated with a feeling of incomplete evacuation and counts of the Bacteroides fragilis group and Acidaminococcus groups. Exercise frequency tended to be negatively correlated with the Bristol Stool Form Scale score and was significantly negatively correlated with the counts of Enterobacteriaceae and positively correlated with the Prevotella counts in the faeces. The frequency of fermented milk consumption was not significant but tended to be positively correlated with stool frequency. The frequency of fermented milk consumption was significantly positively correlated with the counts of the Atopobium cluster, Eubacterium cylindroides group, Acidaminococcus group, Clostridium ramosum subgroup, and Lactobacillus in the faeces. The frequency of consumption of probiotic Lactobacillus casei-containing fermented milk was significantly positively correlated with stool frequency. The counts of probiotic Lactobacillus casei in the stool was positively correlated with the counts of Bifidobacterium and total Lactobacillus. These results suggest that smoking, alcohol drinking, exercise, and consumption of fermented milk, particularly containing probiotic L. casei, differently affect bowel movements and gut microbiota composition in healthy Japanese adults.

Development of a circulatory mock loop for biventricular device testing with various heart conditions

This study aimed to evaluate a newly designed circulatory mock loop intended to model cardiac and circulatory hemodynamics for mechanical circulatory support device testing. The mock loop was built with dedicated ports suitable for attaching assist devices in various configurations. This biventricular mock loop uses two pneumatic pumps (Abiomed AB5000^™, Danvers, MA, USA) driven by a dual-output driver (Thoratec Model 2600, Pleasanton, CA, USA). The drive pressures can be individually modified to simulate a healthy heart and left and/or right heart failure conditions, and variable compliance and fluid volume allow for additional customization. The loop output for a healthy heart was tested at 4.2 L/min with left and right atrial pressures of 1 and 5 mm Hg, respectively; a mean aortic pressure of 93 mm Hg; and pulmonary artery pressure of 17 mm Hg. Under conditions of left heart failure, these values were reduced to 2.1 L/min output, left atrial pressure = 28 mm Hg, right atrial pressure = 3 mm Hg, aortic pressure = 58 mm Hg, and pulmonary artery pressure = 35 mm Hg. Right heart failure resulted in the reverse balance: left atrial pressure = 0 mm Hg, right atrial pressure = 30 mm Hg, aortic pressure = 100 mm Hg, and pulmonary artery pressure = 13 mm Hg with a flow of 3.9 L/min. For biventricular heart failure, flow was decreased to 1.6 L/min, left atrial pressure = 13 mm Hg, right atrial pressure = 13 mm Hg, aortic pressure = 52 mm Hg, and pulmonary artery pressure = 18 mm Hg. This mock loop could become a reliable bench tool to simulate a range of heart failure conditions.

An advanced universal circulatory assist device for left and right ventricular support: First report of an acute in vivo implant

Background

The Advanced ventricular assist device (Advanced VAD) is designed as a universal pump intended to prevent backflow in the event of pump stoppage, to maintain physiological pulse pressure, and to be used as both a left and right VAD. The purpose of this study was to evaluate the performance of the Advanced VAD as both a left and right VAD in an acute in vivo study in calves.

Methods

The Advanced VAD was implanted through a median sternotomy in 5 healthy calves (weight, 71.4-91.2 kg) as a left VAD (n = 3) or a right VAD (n = 2). After implantation, hemodynamic parameters, including general performance and pump stoppage, were evaluated.

Results

The Advanced VAD was successfully implanted as a left and right VAD without cardiopulmonary bypass. The speed range of the Advanced VAD was 2500 to 3500 rpm as a left VAD and 2000 to 2500 rpm as a right VAD. Up to 4.3 L/min was achieved for both left and right VAD configurations. To demonstrate the automatic shut-off feature, the pump was stopped without clamping the outflow graft. The outflow graft was then clamped, which produced no significant changes in the arterial pressure waveform. The pulse pressures under the left VAD configuration were 38 mm Hg, 17 mm Hg, 14 mm Hg, and 16 mm Hg at baseline, 2500 rpm, 3000 rpm, and 3500 rpm, respectively.

Conclusions

This acute in vivo study demonstrated the pump performance, anatomical fitting as both left VAD and right VAD, and regurgitant flow shut-off feature of the Advanced VAD.

Left atrial assist device function at various heart rates using a mock circulation loop

We are developing a new left atrial assist device (LAAD) for patients who have heart failure with preserved ejection fraction (HFpEF). This study aimed to assess the hemodynamic effects of the LAAD under both normal heart conditions and various diastolic heart failure (DHF) conditions using a mock circulatory loop. A continuous-flow pump that simulates LAAD, was placed between the left atrial (LA) reservoir and a pneumatic ventricle that simulated a native left ventricle on a pulsatile mock loop. Normal heart (NH) and mild, moderate, and severe DHF conditions were simulated by adjusting the diastolic drive pressures of the pneumatic ventricle. With the LAAD running at 3200 rpm, data were collected at 60, 80, and 120 bpm of the pneumatic ventricle. Cardiac output (CO), mean aortic pressure (AoP), and mean LA pressure (LAP) were compared to evaluate the LAAD performance. With LAAD support, the CO and AoP rose to a sufficient level at all heart rates and DHF conditions (CO; 3.4-3.8 L/min, AoP; 90-105 mm Hg). Each difference in the CO and the AoP among various heart rates was minuscule compared with non-pump support. The LAP decreased from 21-23 to 17-19 mm Hg in all DHF conditions (difference not significant). Furthermore, hemodynamic parameters improved for all DHF conditions, independent of heart rate. The LAAD can provide adequate flow to maintain the circulation status at various heart rates in an in vitro mock circulatory loop.

Thyroid-stimulating antibody in a patient with euthyroid Graves' disease

We report an 11-year-old girl with euthyroid Graves' disease. She was referred to our clinic because of left exophthalmos without other symptoms suggestive of hyperthyroidism. Her serum concentration of free thyroxine (FT4) and free triiodothyronine (FT3) were normal, but thyroid-stimulating hormone (TSH) was below normal and impaired TSH response to TSH releasing hormone (TRH) was found. Although the sera were positive for anti-TSH receptor antibody (TRAb) and thyroid-stimulating antibody (TSAb), both titers were not as high as usually observed in Graves' disease. Three months later, she developed hyperthyroidism and was treated with propylthiouracil. Within 2 weeks of the initiation of therapy, all symptoms except exophthalmos disappeared, and after 2 months of treatment TRAb was negative though TSAb remained positive. TSAb is therefore a good indicator to use in the diagnosis and follow-up of euthyroid Graves' disease and should be measured in patients with exophthalmos of unknown origin, even in children.

Ultrasonic effects on electroorganic processes. Part 14. Indirect electroreduction of benzyl chlorides with anthracene redox-mediatory system

Ultrasonic effects were observed in the indirect electroreduction of benzyl chlorides with a radical anion mediator electrogenerated from anthracene. Both the current efficiency for the toluenes formed and the current density (reaction rate) at a working electrode were significantly increased in potential-controlled electrolysis under ultrasonic irradiation (20 kHz). These effects are important from a practical aspect and are rationalized as being due to mass transport promotion caused by ultrasonic cavitation. Although the efficiency could be also increased in the direct electroreduction in the absence of the mediator under irradiation, the current density was only slightly increased.

First In Vivo Experience With Biventricular Circulatory Assistance Using a Single Continuous Flow Pump

Biventricular assist device (BVAD) implantation is the treatment of choice in patients with severe biventricular heart failure and cardiogenic shock. Our team has developed a miniaturized continuous flow, double-ended centrifugal pump intended for total artificial heart implant (CFTAH). The purpose of this initial in vivo study was to demonstrate that the scaled-down CFTAH (P-CFTAH) can be appropriate for BVAD support. The P-CFTAH was implanted in 4 acute lambs (average weight, 41.5 ± 2.8 kg) through a median sternotomy. The cannulation was performed through the left and right atria, and cannulae length adjustment was performed for atrial and ventricular cannulation. The BVAD system was tested at 3 pump speeds (3000, 4500, and 6000 rpm). The BVAD performed very well for both atrial and ventricular cannulation within the 3000-6000 rpm range. Stable hemodynamics were maintained after implantation of the P-CFTAH. The self-regulating performance of the system in vivo was demonstrated by the left (LAP) and right (RAP) pressure difference (LAP-RAP) falling predominantly within the range of -5 to 10 mm Hg with variation, in addition to in vitro assessment of left and right heart failure conditions. Left and right pump flows and total flow increased as the BVAD speed was increased. This initial in vivo testing of the BVAD system demonstrated satisfactory device performance and self-regulation for biventricular heart failure support over a wide range of conditions. The BVAD system keeps the atrial pressure difference within bounds and maintains acceptable cardiac output over a wide range of hemodynamic conditions.

Use of a Virtual Mock Loop model to evaluate a new left ventricular assist device for transapical insertion

We are developing a novel type of miniaturized left ventricular assist device that is configured for transapical insertion. The aim of this study was to assess the performance and function of a new pump by using a Virtual Mock Loop system for device characterization and mapping. The results, such as pressure-flow performance curves, from pump testing in a physical mock circulatory loop were used to analyze its function as a left ventricular assist device. The Virtual Mock Loop system was programmed to mimic the normal heart condition, systolic heart failure, diastolic heart failure, and both systolic and diastolic heart failure, and to provide hemodynamic pressure values before and after the activation of several left ventricular assist device pump speeds (12,000, 14,000, and 16,000 r/min). With pump support, systemic flow and mean aortic pressure increased, and mean left atrial pressure and pulmonary artery pressure decreased for all heart conditions. Regarding high pump-speed support, the systemic flow, aortic pressure, left atrial pressure, and pulmonary artery pressure returned to the level of the normal heart condition. Based on the test results from the Virtual Mock Loop system, the new left ventricular assist device for transapical insertion may be able to ease the symptoms of patients with various types of heart failure. The Virtual Mock Loop system could be helpful to assess pump performance before in vitro bench testing.

Left Atrial Remodeling in Segmental vs. Global Mitral Valve Prolapse - Three-Dimensional Echocardiography

BACKGROUND

Segmental and global mitral valve prolapse (MVP) comprise 2 representative phenotypes in this syndrome. While mitral regurgitation (MR) severity is a major factor causing left atrial (LA) remodeling in MVP, prominent mitral valve (MV) annulus dilatation in global MVP may specifically cause inferiorly predominant LA remodeling. We compared MV annulus and LA geometry in patients with segmental and global MVP.

METHODS AND RESULTS

LA volume as well as inferior, middle, and superior LA cross-sectional areas (CSA) were measured on 3-D echocardiography in 20 controls, in 40 patients with segmental MVP, and in 18 with global MVP. On multivariate analysis, MR severity was primarily associated with LA dilatation in segmental MVP (P<0.001), while MV annular dilatation was primarily associated with LA dilatation in global MVP (P<0.001). Although there was no regional predominance in LA dilatation in segmental MVP, inferior predominance of LA dilatation was significant in global MVP (increase in inferior, middle, and superior LA-CSA relative to mean of the controls: +220±70% vs. +171±55% vs. +137±37%, P<0.001).

CONCLUSIONS

LA remodeling in segmental and global MVP is considerably different regarding its association with MR volume or MV annular dilatation and its regional predominance. While MR volume may mainly contribute to LA remodeling in segmental MVP, MV annular dilatation seems to have an important role in LA remodeling in global MVP. (Circ J 2016; 80: 2533-2540).

Effects of blood pump orientation on performance: In vitro assessment of universal advanced ventricular assist device

An advanced ventricular assist device (VAD), which is under development in our institution, has specific features that allow changes in the axial rotor position and pump performance by intrapump pressure difference. However, performance could be influenced by the pump orientation because of the effect of gravity on the rotor position. The purpose of this study was to evaluate the effects of pump orientation on the pump performance, including pulse pressure and regurgitant flow through the pump when the pump was stopped. Bench testing of the VAD was performed on a static or pulsatile mock loop with a pneumatic device to simulate the native ventricle. The pump performance, including pressure-flow curve, pulsatility, and regurgitant flow, was evaluated at several angles, ranging from -90° (inlet pointed upward) to +90° (inlet pointed downward) at pump speeds of 2000, 2500, 3000, and 3500 rpm. The pump performance was slightly lower at +90° at all rotational speeds, compared with -90°. The pulse pressure on the pulsatile mock loop (80 bpm) was 50 mm Hg without pump support, remained at 50 mm Hg during pump support, and was not changed by orientation (-90°, 0°, and +90°). When the pump was stopped, the regurgitant flow was near 0 L/min at all angles. Pump orientation had a minor effect on pump performance, with no effect on pulse pressure or regurgitant flow when the pump was stopped. This indicates that the effect of gravity on the rotor assembly is insignificant.

Protective effects of neutral amino acids against amphipathic drug-induced hemolysis

Some neutral amino acids were compared for their anti-hemolytic effects with sugars which are well-known colloid-osmotic protectants. The kinetic studies in isotonic suspensions of erythrocytes indicated that the hemolysis induced by the amphipathic drug chlorpromazine (CPZ) or flufenamic acid (FA) was retarded by addition of sugars, and the degree of the anti-hemolytic effect increased with increases in molecular size. Phenylalanine (Phe), the largest among the amino acids tested, showed the greatest inhibitory effect on CPZ-induced hemolysis, but not on FA-induced hemolysis. This demonstrated that the anti-hemolytic effects of amino acids were not the result of colloid-osmotic protection. Hemolytic actions of amino acids were also examined to determine their interaction with the erythrocyte membrane, and the mechanism of their inhibitory effects against amphipathic drug-induced hemolysis was discussed.