Sanae Kaga

Background Right ventricular (RV) dysfunction is a key determinant of mortality in heart failure with reduced left ventricular ejection fraction (HFrEF). RV stroke work index (RVSWI) is an established invasive parameter of RV function; however, echocardiographic methods for estimating RVSWI have not yet been fully established. We hypothesized that the pulmonary regurgitant (PR) velocity waveform-derived early-diastolic pulmonary artery-RV pressure gradient (PRPG) would allow an accurate estimation of RVSWI because of its fidelity to the original formula. This study aimed to investigate whether non-invasive estimation of RVSWI is feasible in patients with HFrEF. Methods In this retrospective study, 120 adult patients with HFrEF who underwent right heart catheterization within 24 h of echocardiography were included. RVSWI was calculated as (mean pulmonary artery pressure – mean right atrial pressure) × stroke volume index (SVI). Based on the continuous-wave Doppler velocity measurements of PR, echocardiographic estimation of RVSWI was calculated as PRPG × pulsed-wave Doppler-derived SVI (RVSWI_PR). Results The RVSWI_PR was significantly correlated with RVSWI (ρ = 0.670, p < 0.001). Bland–Altman analysis showed no direct fixed bias. Sensitivity analysis performed in 21 patients with HFrEF and severe tricuspid regurgitation, which is a challenging subgroup for non-invasive RV function assessment, showed similar results. In the receiver operating characteristic curve analyses to detect the patients with RVSWI < 250 mmHg∙mL/m², the area under the curve was 0.954, and a cut-off value of 371 mmHg∙mL/m² showed 100% sensitivity and 82% specificity. Conclusions RVSWI_PR, based on PR velocity waveform analysis, was useful for the non-invasive assessment of RVSWI in HFrEF.

Purpose Dynamic stretching (DS), characterized by repeated movements through the joint range of motion via antagonist muscle contraction, is thought to reduce muscle stiffness through mechanisms such as reciprocal inhibition. However, whether DS effectively decreases muscle stiffness remains unclear. This study aimed to investigate the acute effects of DS on triceps surae muscle stiffness using shear wave elastography. Methods Sixteen healthy young adults performed both 120-s DS and control (no stretching) tasks. Shear wave velocities of the medial gastrocnemius (MG), lateral gastrocnemius (LG), and soleus (SOL) muscles were measured as indicators of muscle stiffness before and after DS. Results Our findings indicated that DS significantly reduced the shear wave velocity in the MG. However, no significant changes were observed in the shear wave velocities of the LG and SOL. Conclusion DS effectively decreased MG stiffness, with no observed effects in the LG or SOL. These findings highlight inter-muscular variability in response to DS and suggest that DS may be particularly beneficial for targeting stiffness in the MG of the triceps surae muscles.

Portal venous (PV) flow Doppler velocimetry assesses venous congestion in heart failure, showing PV pulsatility due to backward transmission of right atrial pressure (RAP) through the sinusoids. However, PV pulsatility has also been observed under physiological conditions. We aimed to elucidate the mechanisms and contributing factors of PV pulsatility in healthy adults. Pulsed-wave Doppler recordings of the hepatic venous (HV) and PV flow were obtained with electrocardiography. A- and V-wave velocities and their timings relative to the P- and R-waves (P-HV_A, R-HV_V) were measured from the HV waveforms. From PV waveforms, atrial and ventricular systolic descent flow velocities and their timings (P-PV_A, R-PV_V) were measured. The PV pulsatility index (VPI) was calculated. There were no differences between P-PV_A and P-HV_A, and between R-PV_V and R-HV_V, indicating similar waveforms. Seventy-nine percent of participants showed a VPI ≥ 0.3, with a higher VPI in younger vs. older participants (0.7 vs. 0.3, p < 0.01). Only age was independently associated with VPI (β = −0.56, p < 0.01). PV pulsatility was common in healthy adults, suggesting RAP transmission via the sinusoids; this physiological phenomenon was attenuated with aging. These findings highlight the importance of considering age-related physiological changes when interpreting the PV flow.

BACKGROUND: Accurate assessment of left ventricular filling pressure in patients with atrial fibrillation or flutter (AF) remains difficult. A novel 2-dimensional scoring system, visually assessing time difference between mitral valve and tricuspid valve opening (VMT) score, based on temporal analysis of early diastolic valve opening, could be applied to these patients. We aimed to determine the usefulness of the VMT score in patients with AF. METHODS: We analyzed 119 consecutive patients with AF who underwent cardiac catheterization as a derivation cohort. The diagnostic performance of the VMT score was further evaluated in an external data set containing 189 patients with AF. Elevated left ventricular filling pressure was defined as a mean pulmonary arterial wedge pressure ≥15 mm Hg. The time sequence of atrioventricular valve opening was visually assessed and scored (0, tricuspid valve first; 1, simultaneous; 2, mitral valve first). When the inferior vena cava was dilated, 1 point was added, and the VMT score was finally graded as 0 to 3. Conventional Doppler parameters to estimate left ventricular filling pressure were also measured. RESULTS: Pulmonary arterial wedge pressure was elevated with an increase in the VMT score (0: 10±3, 1: 13±5, 2: 22±7, 3: 27±6 mm Hg; P C index, 0.88 versus 0.54–0.68; P C index, 0.79–0.93; P <0.001). In the external validation cohort, VMT≥2 demonstrated acceptable accuracy of 72%. CONCLUSIONS: VMT scoring was a useful echocardiographic marker of elevated left ventricular filling pressure and had an incremental benefit over practical biomarkers in patients with AF.

Right ventricular (RV) diastolic stiffness is an independent predictor of survival and is strongly associated with disease severity in patients with precapillary pulmonary hypertension (PH). Therefore, a fully validated echocardiographic method for assessing RV diastolic stiffness needs to be established. This study aimed to compare echocardiography-derived RV diastolic stiffness and invasively measured pressure-volume loop-derived RV diastolic stiffness in patients with precapillary PH. We studied 50 consecutive patients with suspected or confirmed precapillary PH who underwent cardiac catheterization, magnetic resonance imaging, and echocardiography within a 1-week interval. Single-beat RV pressure-volume analysis was performed to determine the gold standard for RV diastolic stiffness. Elevated RV end-diastolic pressure (RVEDP) was defined as RVEDP ≥ 8 mmHg. Using continuous-wave Doppler and M-mode echocardiography, an echocardiographic index of RV diastolic stiffness was calculated as the ratio of the atrial-systolic descent of the pulmonary artery-RV pressure gradient derived from pulmonary regurgitant velocity (PRPGD_AC) to the tricuspid annular plane movement during atrial contraction (TAPM_AC). PRPGD_AC/TAPM_AC showed significant correlation with β (r = 0.54, p < 0.001) and RVEDP (r = 0.61, p < 0.001). A cut-off value of 0.74 mmHg/mm for PRPGD_AC/TAPM_AC showed 83% sensitivity and 93% specificity for identifying elevated RVEDP. Multivariate analyses indicated that PRPGD_AC/TAPM_AC was independently associated with disease severity in patients with precapillary PH, including substantial PH symptoms, stroke volume index, right atrial size, and pressure. PRPGD_AC/TAPM_AC, based on pulmonary regurgitation velocity waveform analysis, is useful for the noninvasive assessment of RV diastolic stiffness and is associated with prognostic risk factors in precapillary PH.

Background: Heat application before peripheral intravenous catheterization is recommended for venous dilation. Hot pack application enlarges the venous diameter in healthy adults; however, hot towels (moist and dry heat) are used often in some medical cases. However, it is unclear whether hot towel application promotes venous dilation better than hot pack application. This study compared the venous dilation effect of using a hot towel (moist and dry heat) to a hot pack before applying the tourniquet at an access site for peripheral intravenous catheterization. Methods: Eighty-eight healthy females aged 18–29 years were recruited for this quasi-experimental study. They underwent three types of heat applications (hot pack, moist hot towel, and dry hot towel [moist hot towel wrapped in a dry plastic bag], all of which were warmed to 40 ± 2 °C and performed for 7 min) to their forearm and tourniquet application for 30 s after each heating. Venous diameter and depth were measured using ultrasonography, and venous palpability and visibility (venous assessment score) was observed as venous dilatation effects. In addition, the skin temperature, stratum corneum hydration, and subjective evaluation of the warmth were measured. Results: There were no significant differences in venous diameter and assessment scores after intervention between the dry hot towel and the hot pack groups, and the effect size was negligible (Cohen’s d < 0.20). However, these measurements were significantly lower for the moist hot towel than for the other two heat applications (P < .001). Although there was no significant difference in skin temperature and warmth rating score between the dry hot towel and the hot pack, these were significantly lower for the moist hot towel than for the other two heat applications (P < .001). The amount of change in stratum corneum hydration of the dry hot towel was not significantly different from that of the hot pack; however, that of the moist hot towel was significantly larger than that of the other two heat applications (P < . 001.) Conclusions: A method in which a towel warmed in hot water is wrapped in a dry barrier may be an alternative to a hot pack. Trial registration: This study was registered with University Hospital Medical Information Network in Japan (Registration No.: UMIN000048308. Registered on July 7, 2022).

Background: Accurate detection of significant pulmonary regurgitation (PR) is critical in management of patients after right ventricular (RV) outflow reconstruction in Tetralogy of Fallot (TOF) patients, because of its influence on adverse outcomes. Although pressure half time (PHT) of PR velocity is one of the widely used echocardiographic markers of the severity, shortened PHT is suggested to be seen in conditions with increased RV stiffness with mild PR. However, little has been reported about the exact characteristics of patients showing discrepancy between PHT and PR volume in this population. Methods: Echocardiography and cardiac magnetic resonance imaging (MRI) were performed in 74 TOF patients after right ventricular outflow tract (RVOT) reconstruction [32 ± 10 years old]. PHT was measured from the continuous Doppler PR flow velocity profile and PHT < 100 ms was used as a sign of significant PR. Presence of end-diastolic RVOT forward flow was defined as RV restrictive physiology. By using phase-contrast MRI, forward and regurgitant volumes through the RVOT were measured and regurgitation fraction was calculated. Significant PR was defined as regurgitant fraction ≥ 25%. Results: Significant PR was observed in 54 of 74 patients. While PHT < 100 ms well predicted significant PR with sensitivity of 96%, specificity of 52%, and c-index of 0.72, 10 patients showed shortened PHT despite regurgitant fraction < 25% (discordant group). Tricuspid annular plane systolic excursion and left ventricular (LV) ejection fraction were comparable between discordant group and patients showing PHT < 100 ms and regurgitant fraction ≥ 25% (concordant group). However, discordant group showed significantly smaller mid RV diameter (30.7 ± 4.5 vs. 39.2 ± 7.3 mm, P < 0.001) and higher prevalence of restrictive physiology (100% vs. 42%, P < 0.01) than concordant group. When mid RV diameter ≥ 32 mm and presence of restrictive physiology were added to PHT, the predictive value was significantly improved (sensitivity: 81%, specificity: 90%, and c-index: 0.89, P < 0.001 vs. PHT alone by multivariable logistic regression model). Conclusion: Patients with increased RV stiffness and non-enlarged right ventricle showed short PHT despite mild PR. Although it has been expected, this was the first study to demonstrate the exact characteristics of patients showing discrepancy between PHT and PR volume in TOF patients after RVOT reconstruction.