Left atrial dysfunction and stiffness in pediatric and adult patients with Type 1 diabetes mellitus assessed with speckle tracking echocardiography.

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.

Deep insight into cardiac dysfunction in children and young adults with Wolff-Parkinson-White syndrome using speckle tracking imaging.

Although ventricular pre-excitation via accessory pathways (APs) causes cardiac dysfunction in children and young adults with Wolff-Parkinson-White (WPW) syndrome, the underlying cardiac dysfunction mechanisms are unclear. This study aimed to characterize cardiac dysfunction and clarify sensitive cardiac dysfunction indicators in WPW syndrome patients classified by the APs location with a layer-specific strain analysis. Twenty-four patients with WPW syndrome with a mean age of 14.1 years (6.9-21.6 years) (11 cases: type A with a left-sided AP [WA group], 13 cases: type B with a right-sided AP [WB group]), and 37 age-matched normal controls (N group) were examined. We measured the left ventricle (LV), base-, mid-, and apical-level of circumferential strain (CS), and longitudinal strain (LS) using a layer-specific strain with speckle tracking imaging. Dyssynchrony was also measured based on the timing of the radial strain at each segment. Peak endomyocardial base- and mid-level of CS was lower in both the WA and WB groups compared to the N group. Peak mid-myocardial and epimyocardial base-level of CS and peak mid-myocardial mid-level of CS were lower only in the WB group compared to the N group. Peak LS in all three layers was lower only in the WB group compared to the N group. There was a significant difference between the patient and normal groups for the dyssynchrony index only at the base-level, and there was no significant difference between the groups for LV ejection fraction (EF). Layer-specific strain decreased in more sites in the WB group despite the normal EF value. Layer-specific strains are sensitive indicators for the detection of the early stages of cardiac dysfunction.

Exercise echocardiography demonstrates potential myocardial damage in patients with repaired tetralogy of Fallot using layer-specific strain analysis.

INTRODUCTION: Exercise stress echocardiography and layer-specific strains are emerging as important tools for cardiac assessment. This study was aimed to evaluate layer-specific strains and torsion parameters during exercise in order to investigate the characteristics of cardiac dysfunction in patients with repaired tetralogy of Fallot and to detect subclinical left ventricular dysfunction. MATERIALS AND METHODS: Thirteen patients with repaired tetralogy of Fallot (median age, 17.3 [interquartile range, 14.5-22.9] years; 6 males) and 13 controls (median age, 28.5 [interquartile range, 27.6-31.6] years; 13 males) underwent echocardiography at rest and during supine exercise. Layer-specific longitudinal strain and circumferential strain of three myocardial layers (endocardium, midmyocardium, and epicardium), torsion, and untwisting rate were measured using two-dimensional speckle-tracking echocardiography. RESULTS: Peak endocardial papillary circumferential strain (-21.1 ± 2.6% vs. -25.8 ± 3.8%, p = 0.007), midmyocardial apical circumferential strain (-11.1 ± 4.0% vs. -15.6 ± 3.2%, p = 0.001), epicardial apical circumferential strain (-11.1 ± 4.0% vs. -15.6 ± 3.2%, p = 0.021), and torsion (8.9 ± 6.0 vs. 14.9 ± 4.8 degree, p = 0.021) were significantly lower in the repaired tetralogy of Fallot group than in the control group during exercise, though no significant difference was found between patients and controls at rest. CONCLUSIONS: Analysis of layer-specific strains and torsion parameters during exercise could detect subclinical left ventricular dysfunction in patients with repaired tetralogy of Fallot, which might reflect potential myocardial damage, at a stage where these parameters have normal values at rest. This finding provides new insight into the mechanisms of cardiac dysfunction in patients with repaired tetralogy of Fallot.

Left ventricular vortex and intraventricular pressure difference in dogs under various loading conditions.

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.

In-Depth Insight Into the Mechanisms of Cardiac Dysfunction in Patients With Type 1 Diabetes Mellitus Using Layer-Specific Strain Analysis.

BACKGROUND: Although the subclinical left ventricular (LV) dysfunction caused by diabetes mellitus (DM) results in a high risk of death and heart failure, the details of cardiac dysfunction across a wide age range remain unclear. The aim of this study was to assess LV dysfunction in patients with type 1 DM (T1DM) using layer-specific strain analysis by echocardiography.Methods and Results:The 52 patients (median age: 23 [range: 5-40] years) with T1DM were divided into 3 age groups (D1: 5-14 years, D2: 15-24 years, D3: 25-40 years); 78 age- and sex-similar controls were divided into 3 corresponding groups (C1, C2, and C3). Layer-specific longitudinal strain (LS) and circumferential strain (CS) of the 3 myocardial layers (endocardium, midmyocardium, and epicardium) were determined using echocardiography. Strains did not decrease in D1. Epicardial and midmyocardial CS at the basal level and LS in all layers were decreased in D2 compared with C2. CS at the basal level and LS in all layers were lower in D3 than in C3. The strains correlated with the duration of T1DM and LV wall thickness. CONCLUSIONS: In patients with T1DM, longitudinal deformation in all layers and epicardial and midmyocardial circumferential deformation at the basal level decreased from the late teens, which correlated with the duration of the disease and LV hypertrophy.

In-Depth Insight Into the Mechanisms of Cardiac Dysfunction in Patients With Childhood Cancer After Anthracycline Treatment Using Layer-Specific Strain Analysis.

BACKGROUND: Anthracycline cardiotoxicity affects clinical outcomes, and its early detection using methods that rely on conventional echocardiography, such as left ventricular ejection fraction (LVEF) is difficult. This study aimed to evaluate the characteristics and the differences in cardiac dysfunction among childhood cancer survivors in 3 age groups using layer-specific strain analysis in a wide age range.Methods and Results:The 56 patients (median age: 15 [range: 6.8-40.2] years) who had been treated with anthracycline for childhood cancer were divided into 3 age groups (C1: 6-12 years, C2: 13-19 years, C3: 20-40 years) after anthracycline treatment, and 72 controls of similar ages were divided into 3 corresponding groups (N1, N2, and N3). Layer-specific longitudinal strain (LS) and circumferential strain (CS) of 3 myocardial layers (endocardium, midmyocardium, and epicardium) were determined using echocardiography. Myocardial damage had not occurred yet in C1. Endocardial CS at the basal level was less in C2 than in N2. Endocardial CS at all levels and midmyocardial CS at the basal and papillary levels were lower in C3 than in N3. LVEF and LS were not significantly different between patients and controls. CONCLUSIONS: Among survivors of childhood cancer, impaired myocardial deformation starts in adolescence and extends from the endocardium towards the epicardium and from the base towards the apex with age. These findings are a novel insight into the time course of anthracycline cardiotoxicity.

Novel Findings of Early Cardiac Dysfunction in Patients With Childhood-Onset Inflammatory Bowel Disease Using Layer-Specific Strain Analysis.

BACKGROUND: Patients with inflammatory bowel disease (IBD) are at a higher risk of developing cardiovascular diseases than healthy individuals, owing to persistent chronic inflammation and treatment effects. This study aimed to assess left ventricular function in patients with childhood-onset IBD using layer-specific strain analysis and to identify early indicators of cardiac dysfunction in them. METHODS: A total of 47 patients with childhood-onset ulcerative colitis (UC), 20 patients with Crohn's disease (CD), and 75 age- and sex-matched healthy control subjects were included in this study. Conventional echocardiographic measurements of layer-specific (ie, endocardium, midmyocardium, and epicardium) global longitudinal strain and global circumferential strain (GCS) were evaluated in these participants. RESULTS: Layer-specific strain analysis showed that global longitudinal strain was lower in all layers for the UC (P < .001) and CD (P < .001) groups, regardless of the age at onset, but that GCS was only lower in the midmyocardial (P = .032) and epicardial (P = .018) layers in the CD group than in the control group. Although the mean left ventricular wall thickness was not significantly different among the groups, it was significantly correlated with the GCS of the endocardial layer in the CD group (ρ= -0.615; P = .004), suggesting that thickening of the left ventricular wall occurred as a compensatory mechanism to maintain the endocardial strain in the CD group layer. CONCLUSIONS: Children and young adults with childhood-onset IBD displayed decreased midmyocardial deformation. Layer-specific strain could also be useful to identify indicators of cardiac dysfunction in patients with IBD.

Patients with inflammatory bowel disease are at a higher risk of developing cardiovascular disease than healthy individuals. Our study revealed that children and young adults with childhood-onset inflammatory bowel disease already have reduced myocardial deformability.

The Utility of Intraventricular Pressure Gradient for Early Detection of Chemotherapy-Induced Subclinical Cardiac Dysfunction in Dogs.

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.

Changes in left ventricular blood flow during diastole due to differences in chamber size in healthy dogs.

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.

Cardiac Function in Infants Born to Mothers With Gestational Diabetes　- Estimation of Early Diastolic Intraventricular Pressure Differences.

Background: This study compared the myocardial performance of infants born to mothers with gestational diabetes mellitus (IGDM) and without GDM (controls) under the new GDM definitions. Methods and Results: The subjects consisted of 36 IGDM and 39 control infants. GDM diagnosis was based on oral glucose tolerance test during pregnancy or the presence of diabetes prior to the current pregnancy. Between-group infant cardiac function was determined and compared using 2-D speckle tracking analysis, intraventricular pressure difference (IVPD) and IVP gradient (IVPG), using color M-mode Doppler imaging. IVPD and IVPG were higher in IGDM than in the controls, particularly the mid-apical IVPG. The global circumferential strain (GCS) and endocardial GCS were higher in IGDM than in controls. Increased maternal glycated hemoglobin was correlated with reduced transmural and epicardial GCS in the IGDM. Maternal maximum fasting blood sugar had a mild, positive correlation with IVPD and IVPG. Conclusions: Ventricular sucking force, measured as the IVPD, IVPG, and endocardial GCS, were higher in IGDM than in the controls. A hyperglycemic environment during pregnancy leads to impaired cardiac performance in IGDM, compared with control infants. IGDM might have favorable systolic and diastolic cardiac performance due to cardiac metabolic adaptations occurring before poor glucose control causes impaired cardiac performance.

Occurrence of type 3 sodium channel peptide toxins in two species of sea anemones (Dofleinia armata and Entacmaea ramsayi).

From two species of sea anemones, Dofleinia armata and Entacmaea ramsayi, three peptide toxins (two from the former and one from the latter) with crab toxicity were purified and completely sequenced. The three toxins (30-32 residues) are highly homologous to each other and also to PaTX from Entacmaea actinostoloides, a type 3 sea anemone sodium channel toxin. This study reveals that there is a family of PaTX-like toxins in sea anemones.