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.www.nature.com/scientificreports www.nature.com/scientificreports/ vorticity and EL. A stepwise method was used for selection of the variables, choosing the variables which minimized Akaike's information criterion. ResultsStudy population. The number of cases was 58. The mean weight was 8.65 (1.3-42.3, SD 6.93) kg. The length of the left ventricle was 34.0 (21.9-49.0, SD 7.3) mm on average. The mean heart rate was 117.6 (66.0-Characteristics of the canine heart with various size. The mean value of the short axis inner diameter of the left ventricle (LVIDd) was SD 7.36) mm. The sphericity index (SI) of the left ventricle was 0.75 (0.51-1.0, SD 0.12). The relationship between short and long axis diameter was shown in Fig. 1. LVL was linearly correlated with LVIDd (R = 0.78, p < 0.01). Statistical correlation was not found between LVL and SI.Conventional indexes of diastolic property (E vel, e′, E/A, E/e′) were not statistically correlated with LVL.Scientific RepoRtS | (2020) 10:1106 | https://doi.

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Restrictions on the conventional evaluation of diastolic function have been recognized, especially under various loading conditions. Recently, new noninvasive ventricular vortex indexes have been introduced and are expected to reflect the cardiac function. Physiologically, there is a hypothesis that the intraventricular pressure difference (IVPD) is related to the formation of vortexes. IVPD and vortex indexes were simultaneously measured, and the relationship between the two was investigated. To verify the possibility of diastolic vorticity as an index of diastolic relaxation, a correlation between diastolic vorticity and the load dependency of vorticity [time constant (τ)] was examined. Six healthy dogs were studied using transthoracic echocardiography, pressure, and a conductance catheter. Vorticity was analyzed using vector flow mapping (VFM). IVPD was determined using Euler’s equation with color M-mode Doppler images. Data were obtained at baseline, at balloon dilatation in the thoracic aorta to alter afterload, at hydroxyethyl starch infusion to alter preload, and at milrinone administration to alter ventricular relaxation. Peak vorticity at early diastole (E-Vor) and IVPD of the midventricle (MIVPD) decreased under pressure loading, were unchanged under volume loading, and increased during milrinone administration. In multivariate analysis, the independent predictors of τ were global longitudinal strain, strain rate at early diastole, and E-Vor. MIVPD was strongly correlated with E-Vor ( r = 0.84). VFM-derived peak E vorticity was strongly related to IVPD, especially MIVPD, under various loading conditions. Both of these novel indexes are promising as reliable indexes of ventricular relaxation, independent from preload. NEW & NOTEWORTHY We showed the close relationship of vortex and intraventricular pressure difference and showed that both of them can become new markers of the left ventricular relaxation property. Our present study creates a paradigm for future studies in the field of intraventircular flow physiology and clinical diastology.

Background Subclinical diastolic dysfunction in patients with Type 1 diabetes mellitus (T1DM) caused by myocardial injury due to diabetic cardiomyopathy leads to a high risk of death and heart failure. This myocardial injury extends not only to the left ventricle (LV) but also to the left atrium (LA). However, LA function in children and young adults with T1DM has not been extensively studied. Objective Therefore, the aim of this study was to assess LA dysfunction in pediatric and adult patients with T1DM using LA strain analysis with echocardiography. Subjects Fifty‐three patients (median age: 23 [range: 5–41] years) with T1DM. Methods We divided the patients into three age groups (D1: 5–14 years, D2: 15–24 years, D3: 25–41 years); 53 age‐ and sex‐matched controls were divided into three corresponding groups (C1, C2, and C3). LA and LV functions were evaluated using echocardiography. Results LA reservoir strain was lower in the D2 and D3 groups than in the C2 and C3 groups (P = 0.001, P = 0.004, respectively). LA conduit strain was lower in the D2 group than in the C2 group (P = 0.002). LA stiffness was significantly greater in the D3 group than in the C3 group (P < 0.001). Conclusions In patients with T1DM, LA phasic function decreased in adolescents and young adults, and LA stiffness increased in adult patients aged >30 years. LA phasic function and LA stiffness can be potentially used as early markers for diastolic dysfunction.

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.