Cardiac Diastolic Function Research Articles

High VExUS grades are linked to cardiac function in general ICU patients.

Even though initially considered as a new standard in systemic venous congestion assessment, the semi-quantitative Doppler ultrasound-based Venous Excess Ultrasound Grading System (VExUS) showed inconsistent associations with outcomes in general intensive care unit (ICU) patients. It is unclear why VExUS is so effective in predicting outcomes in some cohorts and not in others. The determinants of higher VExUS have not been studied in a general ICU cohort. The aim of this study was to determine the factors associated with higher VExUS (≥ 2) in a general ICU cohort. We performed a post-hoc analysis of a prospective, observational cohort, including adult patients within 24 hours of ICU admission and expected ICU length of stay longer than 2 days. Collected data included patients' hemodynamic status (including ultrasound evaluation) at several points in time: ICU admission, day 1, day 2, day 5, and the last day of ICU stay. We analyzed 514 hemodynamic evaluations in 145 patients. 96/514 (18.7%) had a VExUS grade ≥ 2. The univariable followed by multivariable mixed-effects logistic regression analyses only found a statistically significant association between VExUS ≥ 2 and right ventricle S wave (OR 0.85 (0.74;0.97), p = 0.02) and left ventricle E/A ratio (OR 2.34, 95% CI (1.27;4.33), p = 0.006). The current study has elucidated that higher VExUS is primarily associated with cardiac comorbidities and ultrasound parameters of left- and right-sided cardiac systolic and/or diastolic function in general ICU patients.

Sex Differences in Response to Diet Enriched with Glutathione Precursors in the Aging Heart.

Common features of the aging heart are dysregulated metabolism, inflammation, and fibrosis. Elevated oxidative stress is another hallmark of cardiac aging that can exacerbate each of these conditions. We hypothesize that by increasing natural antioxidant levels (glutathione), we will improve cardiac function. Twenty-one-month-old mice were fed Glycine and N-Acetyl Cysteine (GlyNAC) (glutathione precursors)-supplemented or control diets for 12 weeks. Heart function was monitored longitudinally, and the exercise performance was determined at the end of the study. We found that the GlyNAC diet was beneficial for old male but not old female mice, leading to an increase of Ndufb8 expression (a subunit of the mitochondrial respiratory chain complex), and higher enzymatic activity for CPT1b and CrAT, two carnitine acyltransferases that are critical to cardiomyocyte metabolism. Although no quantifiable change of collagen turnover was detected, hearts from GlyNAC-fed old males exhibited a slight but significant enrichment in Fmod, a protein that can inhibit collagen fibril formation, possibly reducing extracellular matrix (ECM) stiffness and thus improving diastolic function. Cardiac diastolic function was modestly improved in males but not females, and surprisingly GlyNAC-fed female mice showed a decline in exercise performance. In summary, our work supports the concept that aged male and female hearts are phenotypically different. These basic differences may affect the response to pharmacological and diet interventions, including antioxidants.

Association of epicardial adipose tissue with cardiac geometry alternation and diastolic dysfunction in the early stage of diabetic cardiomyopathy

Abstract Background Diastolic dysfunction and alterations in cardiac geometry are early indicators of diabetic cardiomyopathy. However, the association between cardiac changes across the glucose continuum and the contribution of epicardial adipose tissue (EAT) to these changes has not yet been investigated. Purpose In this study, we aim to investigated the EAT on cardiac diastolic function and structural alterations along the diabetic continuum using cardiac magnetic resonance imaging (CMR). Methods We enrolled individuals who were categorized into groups based on glucose tolerance status. Left ventricular structure and diastolic function were assessed using echocardiography and CMR to determine the EAT, intramyocardial fat, and associated parameters. Multivariate logistic regression models were also used. Results In a study of 370 patients (209 normal glucose tolerance, 82 prediabetes, 79 diabetes), those with prediabetes and diabetes showed increased heart dimensions and diastolic dysfunction, including E/E' (7.9±0.51 vs. 8.5±0.64 vs. 10.0±0.93, p=0.010), left atrial volume index (28.21±14.7 vs. 33.2±12.8 vs. 37.4±8.2 mL/m2, p<0.001), and left ventricular peak filling rate (4.46±1.75 vs. 3.61±1.55 vs. 3.20±1.30 mL/s, p<0.001). EAT significantly increased in prediabetes and diabetes (26.3±1.16 vs. 31.3±1.83 vs. 33.9±1.9 gm, p=0.001), while intramyocardial fat did not differ significantly. Prediabetes altered heart geometry, but not diastolic function (OR 1.22 [1.02–1.83], p=0.012; and 1.70 [0.79–3.68], p=0.135). Diabetes significantly affected both heart structure and diastolic function (OR 1.42 [1.11–1.97], p=0.032; and 2.56 [1.03–5.40], p=0.034) after adjusting for covariates. Conclusions Elevated EAT was observed in patients with prediabetes and is associated with adverse alterations in cardiac structure and diastolic function, potentially serving as an underlying mechanism for the early onset of diabetic cardiomyopathy.

Left ventricular volume as a predictor of exercise capacity and functional independence in individuals with preserved ejection fraction

Abstract Background Cardiorespiratory fitness (CRF) is vital for independent living and is a powerful prognostic marker. Increased left ventricular (LV) volume has been linked with high CRF in athletes, but its utility as a diagnostic marker of low CRF across the entire health-disease continuum has yet to be tested. Methods This multi-center international cohort from Australia and Belgium examined the relationship between ventricular size on resting echocardiography and CRF (peakVO2 from cardiopulmonary exercise testing [CPET] or CPET with simultaneous echocardiography) in individuals with preserved LV ejection fraction (≥50%). LV end-diastolic volume (LVEDV) and LVEDV indexed to body surface area (LVEDVi) were tested as predictors of very low CRF (CRF associated with functional disability - peakVO2 < 1100ml or <18 ml/kg/min) and compared against other candidate measures of systolic and diastolic cardiac function that have been associated with heart disease. Thresholds for absolute and indexed LVEDV which best distinguished between lower and higher CRF status were identified. Results 2876 individuals (251 healthy non-athletes, 309 elite endurance athletes, 1969 individuals with unexplained dyspnea, 347 individuals with heart failure with preserved ejection fraction) were included. For the entire cohort, LVEDV had the strongest univariate association with peakVO2 (R2 = 0.45, standardized [std] β 0.67, p< 0.001) and, remained the strongest independent predictor of peakVO2 after adjusting for age, sex and body mass index (std β 0.44, p < 0.001). The relationship between LVEDV and VO2peak differed based on health/disease status (Figure 1). LVEDV demonstrated the greatest diagnostic capability in identifying functional disability (LVEDV AUC 0.72; LVEDVi AUC 0.71, Figure 2), outperforming ejection fraction, diastolic velocities, atrial volumes and pulmonary artery pressure estimates. The probability of achieving a peak VO2 below the threshold required for functional independence was highest for smaller ventricular volumes with LVEDV and LVEDVi of 88ml and 57 ml/m2 proving the optimal cut-points, respectively. Conclusions A small LVEDV is associated with a higher probability of poor exercise capacity, failure to achieve the peak VO2 required for functional independence and is the strongest independent echocardiographic predictor of CRF across the health-disease continuum.Figure 1.Ventricular Size and CRFFigure 2.Predictors of CRF status

ND15, subunit of the electron transport chain protein-complex I, age-dependently worsens cardiac performance in Drosophila melanogaster

Abstract Introduction In the natural aging process of the heart, aside others, mitochondrial dysfunction is an essential driver for the development of reduced cardiac performance. Previous analysis of protein expression levels in cardiomyocytes of aged mice and have found aberrancies in subunits of the mitochondrial Complexes I – IV of the electron transport chain. Especially, the complex I subunit ND15 was highly downregulated. To elucidate the functional effects of this gene on the cardiac performance, we generated cardiomyocyte specific ND15 knock-downs in Drosophila melanogaster. Methods We generated Drosophila with heart-specific (+/+; Hand4.2-GAL4/UAS-ND15; tdtK/+) (ND15-KD)knockdown of ND15 using the UAS/GAL4 system. The flies' cardiomyocytes endogenously express tdTomato, facilitating fluorescence-based live imaging of the heart by high-resolution video fluorescence microscopy. The recorded data was processed using a R-Script, resulting in Results We compared wild type (WT) flies to ND15-KD flies at age 3 weeks(young) and 7 weeks(old). Knockdown of ND15 resulted in impaired cardiac function. Most parameters deteriorated in aged flies in comparison to young flies. The heart frequency was significantly reduced (WT:6 beats/s – KD:4 beats/s – p<0.0001) in the 7 weeks old group, end-diastolic diameter of the heart tube increased significantly in 3 weeks old ND15KD flies compared to controls(WT:65µm – KD:74µm p<0,0001), resulting in a dilated heart tube Interestingly enough, this dilation in ND15-KD disappeared in 7 weeks old flies. The fractional shortening was significantly decreased in young(WT:33,5% - KD:30% p<0,01) and deteriorated in old flies (WT:35% - KD:22% p<0,0001), indicating a reduced contraction capability. For both 3 weeks and 7 weeks old groups, the heart-rate adjusted interbeat interval variance (WT:22% -KD: 40% p<0,0001) as well as the time of no cardiac action (WT: 22% - KD: 35% p<0,0001) increased and showed significant irregularities. The duration of systole and diastole combined also exhibited arrhythmic patterns (WT:15% - KD:20.5% p<0,0001). A general arrhythmia index (AI) increased significantly (WT: 0.25 – KD:0.5 p<0,0001) These arrhythmia parameters emphasize the arrhythmogenic potential of the ND15-knockdown. The relative relaxation capabilities drastically worsened with age, displaying a diastolic dysfunction in the 7 weeks old group. At half-time relaxation, the WT was at 60% relaxation, ND15KD at 46%). Conclusion This study demonstrates that heart-specific deletion of ND15 results in a marked impairment of systolic and diastolic cardiac function in Drosophila accompanied by pro-arrhythmogenic actions. We could identify ND15 as a new mitochondrial molecular target for the maintenance of regular cardiac function and rhythmicity, especially with increasing age. Further mechanistic studies and translation to mammalian organisms are ongoing.

A personalized, 3D printed, polymeric elastic support device for the prevention of post-MI cardiac remodeling

Abstract Introduction Myocardial remodeling and dilatation following myocardial infarction (MI) initiates a vicious cycle leading to heart failure (HF). The anatomy and pathophysiology of every patient is unique. We have developed a 3D printed, biopolymer based personalized Elastic Support Device, that is 3D printed based on patient’s imaging, aiming to restore cardiac physiology. This study aimed to assess the device on rat MI model. Materials and Methods MI was induced in 24 Sprague Dawley rats by permanently ligating the mid LAD artery via midline sternotomy cut. Twelve animals underwent immediate implantation of the elastic support device that was pre-printed from animal specific 3D echocardiography. The animals were followed up with echocardiography at days -2, 7, 14, 28. The animals were sacrificed at day 28, cardiac tissue and plasma were taken for further histological and biochemical analysis. Results and discussion Mortality was similar at both groups (5 vs 4 in the device and control groups respectively). Ejection fraction reduced in both groups from a baseline of 61.9±8.9% to 47.5±12.7%. Left Ventricular End Diastolic Diameter increased from baseline to day 28 in the control (7.0±0.56mm vs 7.7±1mm) but not the device group (6.87±0.2mm vs 6.93±1.1mm, p<0.05). Parameters of diastolic function such as E/E’ were similar in both groups throughout the follow-up. Mason’s Trichrome stained cardiac sections revealed improved infarct size at the device group (7.4±1.9% vs. 10.6±2.8%) and lower overall cardiac fibrosis. Conclusion In this preliminary small animal model study, the capability to 3D print and implant an imaging based, personalized, 3D printed elastic support device. The cardiac diastolic function was not impaired, and no safety issues were noticed. Furthermore, cardiac dilatation was prevented, and infarct size was reduced.Trial design and results

Impact of microvascular resistance reserve on post-STEMI cardiac remodelling and diastolic function

Abstract Background Coronary microvascular dysfunction (CMD) is a common sequelae of ST-segment elevation myocardial infarction (STEMI), preventing adequate recovery of left ventricular (LV) perfusion. The interferences of con-commitment epicardial stenosis or hyperemic hemodynamic alterations limit traditional physiologic metrics. The microvascular resistance reserve (MRR) was developed to overcome these shortcomings. Purpose We aim to investigate the association between post-STEMI MRR, and the ensuing left ventricle (LV) diastolic dysfunction, and functional remodeling. Methods In this prospective, observational study, we enrolled STEMI patients with multivessel disease who successfully underwent primary percutaneous coronary intervention (PCI). At three months post-PCI, all patients received complete revascularization followed by coronary physiology assessment using the bolus thermodilution method to measure the fractional flow reserve (FFR), coronary flow reserve (CFR), and the index of microcirculatory resistance (IMR). MRR was calculated using the formula: MRR = (CFR/FFR) × (Pa rest/Pa hyper), where Pa rest and Pa hyper represent resting and hyperemic aortic pressure, respectively(1). CMD was defined as an MRR < 3.0 based on Boerhout et al(2). Diastolic dysfunction was defined according to the ASE 2016 guidelines. Functional LV remodelling (FLVR) was categorized according to Chimed et al(3). The relationship between CMD and the stages of FLVR and diastolic dysfunction was scrutinized over a 12-month follow-up period. Results We enrolled 210 patients, of whom 125 (59.5%) were men with a median age of 65 (IQR: 58–76). At the 3-month follow-up, the MRR was 3.46 (IQR 3.00, 3.92), with 56 (26.7%) patients having CMD (MRR<3.0). MRR is significantly correlated with the change of LVEF between primary PCI and 12 months (r=0.48, p<0.001, Fig1A). CMD patients have lower LVEF at 12 months (50.00% vs. 40.00%; p < 0.001) and demonstrated significantly less recovery in LV systolic function (-10.00% vs. 8.00%; p < 0.001, Fig 1B, 1C). CMD patients had a higher prevalence of grade 2 or 3 LV diastolic dysfunction (65.38% vs. 3.95%; p < 0.001, Fig 2A) and a higher incidence of advanced FLVR (Groups 3 and 4) compared to those without CMD (30.77% vs. vs. 10.53%; p < 0.001, Fig 2B). In multivariable logistic regression analysis, MRR was independently associated with LV diastolic dysfunction (0.17, 95%CI 0.08-0.33, p<0.001). Conclusions The novel parameter MRR is significantly related to LVEF recovery in STEMI patients and is an independent predictor for advanced LV diastolic dysfunction and FLVR. CMD patients, as diagnosed with MRR, showed a higher prevalence of advanced FLVR and diastolic dysfunction. These results suggest that MRR is a useful parameter for the identification and management of CMD in STEMI patients.

Fenofibrate modulates cardiac energy metabolism in moderate-severe aortic stenosis: a mechanistic double-blinded randomised controlled MR trial

Abstract Background Aortic stenosis (AS) is associated with impaired cardiac metabolism and high-energy phosphate production which can further exacerbate the progression to HF. Myocardial lipid accumulation and reduced production of high-energy phosphates have important implications for both systolic and diastolic heart function in AS. Peroxisome proliferator-activated receptor alpha (PPAR-alpha agonist, has the potential to optimise cardiac substrate metabolism, thereby, may be effective in improving cardiac dysfunction and functional capacity in AS. Methods In this prospective, randomized, double-blind, placebo-controlled study, patients with moderate-to-severe asymptomatic AS (n=72) were randomly assigned to Fenofibrate 200 mg daily or matching placebo for 6 months in 4:1 fashion. Of the total 72 participants, 59 received Fenofibrate and 13 received placebo. All subjects underwent cardiac magnetic resonance (CMR) and exercise testing at 0 and 6 months, with follow-up data available in 47 patients. The primary end point was change in myocardial triglyceride content (MTG) determined by proton magnetic resonance spectroscopy (1H-MRS). Secondary outcome measures included change in cardiac energetics (PCr/ATP) determined by phosphorus magnetic resonance spectroscopy (31P-MRS), left ventricular strain determined by myocardial tagging and exercise capacity i.e. peak VO2 assessment via cardiopulmonary exercise testing. Results Cardiac energetics (PCr/ATP) showed statistically significant improvement in the Fenofibrate group (0.14 ± 0.48; CI: - 0.03, 0.30; p=0.05) vs placebo group (0.11 ± 0.75; CI -0.42, 0.65; p=0.64). There was also significant reduction in MTG in the Fenofibrate group (mean change -0.40 ± 0.97; 95% CI -0.74, -0.06; p=0.02). MTG content also reduced in the placebo group (mean change -0.41 ± 0.26, 95% CI -1.10, 0.18, p 0.13), but the reduction was not statistically significant. Though no significant changes were seen in the systolic function parameters, there was a significant improvement in diastolic function in the fenofibrate group only (peak diastolic longitudinal strain rate 9.6, 95% CI: 1.13, 18.1; p = 0.02). Peak VO2 did not show any significant improvement in either group. Conclusions Fenofibrate works as a metabolic modulator upregulating fatty acid metabolism in pressure overload AS hearts. Such modulation is associated with an improvement in cardiac energetics and diastolic function in moderate-severe AS.Main results from baseline to 6 monthsBaseline demographic and CMR parameters

Evaluating the effects of adrenalectomy and mineralocorticoid receptor antagonist on cardiac remodeling and diastolic function in patients with aldosterone-producing adenoma.

Cardiac remodeling and diastolic dysfunction in patients with aldosterone-producing adenomas (APA) can be improved after adrenalectomy. However, the effect of mineralocorticoid receptor antagonist (MRA) treatment remains unclear. The aim of this study is to evaluate the effect of MRA on cardiac remodeling and diastolic dysfunction in patients with PA. We prospectively enrolled patients with APA from 1993 to 2023, who either received medical treatment with MRAs or underwent adrenalectomy. Biochemical characteristics and echocardiographic findings were collected at baseline and one year after treatment. Propensity score matching was conducted based on baseline biochemical characteristics, left ventricular mass index (LVMI), and diastolic function. A total of 467 APA patients were enrolled in the study. After propensity score matching, 159 patients who underwent adrenalectomy were matched with 159 patients who received MRAs. After therapy, patients who received MRAs showed significant improvement in diastolic function after one year of treatment but not LVMI. Compared to the MRA group, the adrenalectomy group had greater improvement in systolic blood pressure, plasma aldosterone concentration, plasma renin activity, aldosterone-to-renin ratio, and LVMI. In multivariable regression analysis, pretreatment echocardiographic values were significantly associated with changes in both LVMI and E/e', while the treatment strategy showed a significant association with changes in LVMI. Thus, one year after therapy, both adrenalectomy and MRA are effective in improving diastolic function in patients with APA. However, adrenalectomy is more effective than MRA treatment in reversing cardiac remodeling in patients with APA.

Cardiac Fatigue in Male Athletes with Exercise-Induced Pulmonary Impairments After a Very Long-Distance Triathlon.

Prolonged strenuous exercise can transiently decrease cardiac function. Other studies have identified three major exercise-induced pulmonary changes: bronchoconstriction, dynamic hyperinflation and pulmonary oedema with reduced alveolar-capillary membrane diffusing capacity. This study investigated whether athletes with one of these pulmonary dysfunctions following a very long-distance triathlon exhibit similar cardiac alterations as those without dysfunctions. Sixty trained male triathletes (age 39 ± 9years) underwent baseline and post-race assessments, including echocardiography (with standard, 2D-strain and myocardial work assessments), spirometry and double-diffusion technique to evaluate alveolar-capillary membrane diffusing capacity for carbon monoxide (DMCO). Cardiac function in athletes with exercise-induced bronchoconstriction (> 10% decrease FEV1), dynamic hyperinflation (> 10% decrease inspiratory capacity) or impaired diffusion capacity (> 20% decrease DMCO/alveolar volume) were compared with those without these dysfunctions. The race lasted 14h 20min ± 1h 26min. Both systolic and diastolic cardiac functions declined post-race. Post-race, 18% of athletes had bronchoconstriction, 58% dynamic hyperinflation and 40% impaired diffusing capacity. Right and left ventricular standard and 2D-strain parameters were similar before the race in all subgroups and changed similarly post-race, except E/E', which decreased in the bronchoconstriction subgroup and increased in those with diffusion impairment. Global constructive work decreased by ~ 19% post-race (2302 ± 226 versus 1869 ± 328mmHg%, P < 0.001), more pronounced in athletes with diffusion impairment compared with others (- 26 ± 13 versus - 15 ± 9%, P = 0.001) and positively correlated with DMCO/alveolar volume reduction. After a very long-distance triathlon, bronchoconstriction and hyperinflation were not associated with significant cardiac changes, whereas impaired alveolar-capillary membrane diffusing capacity was associated with a more significant decline in myocardial function. These findings highlight the complex relationship between pulmonary gas exchange abnormalities and cardiac fatigue following prolonged strenuous exercise.

Assessment of fetal cardiac function in pregnant women with anemia: prospective case-control study.

To compare fetal cardiac function in pregnant women with iron deficiency anemia (IDA) vs healthy pregnant controls. This was a single-center, prospective, case-control study conducted in a tertiary hospital between November 2022 and September 2023. Women diagnosed with IDA who attended as outpatients at the pregnancy follow-up clinic at 30-34 weeks' gestation or who were hospitalized for intravenous iron treatment owing to profound anemia were included. The control group consisted of randomly selected gestational-age-matched pregnant women with no obstetric complications or comorbidities and who did not have anemia. Patients underwent two-dimensional imaging, followed by pulsed-wave Doppler and M-mode and tissue Doppler imaging (TDI) to evaluate fetal cardiac function. A fetal cardiac score was calculated using systolic, diastolic and global hemodynamic function parameters, and was compared between patients with IDA and those without. The fetal cardiac score was also assessed according to the severity of anemia in the IDA group. A total of 150 patients, comprising 50 patients with IDA and 100 healthy pregnant women at 30-34 weeks' gestation, were included in the study. Of the patients with IDA, 20 had mild, 18 had moderate and 12 had severe anemia. The fetal myocardial performance index and isovolumetric relaxation time were significantly higher in the IDA group compared with the control group (P < 0.0001 for both), while isovolumetric contraction time was similar. Among the fetal tricuspid and mitral valve diastolic parameters, the E, A and E/A values were significantly lower in the IDA group (P < 0.05 for all). Mitral (MAPSE) and tricuspid (TAPSE) annular plane systolic excursions were significantly lower in the IDA group (P < 0.05 for both). The IDA group also had significantly lower values for the TDI parameters mitral and tricuspid E', A', S' and E'/A' ratio and a significantly higher E/E' ratio (P < 0.05 for all). Among the IDA subgroups, a significant decrease was observed in the tricuspid and mitral A, E and E/A ratio in fetuses whose mothers had severe anemia (P = 0.001). M-mode Doppler analysis revealed significantly lower fetal TAPSE and MAPSE in the patient group with severe maternal anemia (P = 0.001 for both). According to the subgroup comparison of TDI findings, the fetuses of mothers with severe anemia had significantly lower tricuspid and mitral E', A', S' and E'/A' ratio values and a significantly higher E/E' ratio (P < 0.05 for all). The fetal cardiac score was significantly higher in the maternal IDA group compared with the control group (P < 0.001). A significant negative correlation was found between maternal hemoglobin level and fetal cardiac score (P < 0.001). We observed differences in fetal systolic and diastolic cardiac function in pregnancies with maternal IDA. Fetal cardiac function was affected more among patients with severe anemia. This study found an increased E/E' ratio in the fetuses of pregnant women with IDA, suggesting decreased fetal heart maturation. Prenatal fetal cardiac evaluation, especially in women with severe anemia, can facilitate a more seamless transition to the postnatal period for these newborns. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Assessing and interpreting diastolic function in animal models of heart disease

Increasing interest in identifying the causes of and treatments for heart failure with preserved ejection fraction and cardiac fibrosis has spawned a focus on measures of cardiac diastolic function. The methods, their underlying principals and mechanics, and caveats to their measurement were largely worked out decades ago, but some of this seems a bit forgotten as scientists working in the field now have backgrounds more in molecular and cellular biology. This perspective was spawned by seeing the growing number of studies where diastolic function analysis is a key parameter used to justify a given pre-clinical model or to show the consequences of a particular genetic or pharmacological therapy. The goals are to discuss what comprises and influences diastolic function, how it is measured, what the parameters mean and what their limitations are, and what comprises evidence for pathophysiologically meaningful diastolic dysfunction.

MMP-8 causes leftward shift in end-diastolic pressure-volume relationship and may explain the development of diastolic dysfunction in septic cardiomyopathy.

Septic cardiomyopathy (SCM) with diastolic dysfunction carries a poor prognosis, and the mechanisms underlying the development of diastolic dysfunction remain unclear. Matrix metalloproteinase-8 (MMP-8) is released from neutrophils and degrades collagen I. MMP-8 levels correlate with SCM severity. We scrutinized, for the first time, the direct impact of MMP-8 on cardiac systolic and diastolic functions. Isolated rat hearts were perfused with Krebs-Henseleit solution in a Langendorff setup with computer-controlled filling pressures of both ventricles in an isovolumetric regime. The end-diastolic pressure (EDP) varied periodically between 3 and 20 mmHg. After baseline recordings, MMP-8 (100 µg/mL) was added to the perfusion. Short-axis views of both ventricles were continuously acquired by echocardiography. MMP-8 perfusion resulted in a progressive decline in peak systolic pressures (Psys) in both ventricles, but without significant changes in their end-systolic pressure-area relationships (ESPARs). Counterintuitively, conspicuous leftward shifts of the end-diastolic pressure-area relationships (EDPARs) were observed in both ventricles. The left ventricle (LV) end-diastolic area (EDA) decreased by 32.8 ± 5.7% (P = 0.008) at an EDP of 10.5 ± 0.4 mmHg, when LV Psys dropped by 20%. The decline of Psys was primarily due to the decrease in EDA, and restoring the baseline EDA by increasing EDP recovered 81.33 ± 5.87% of the pressure drop. Collagen I generates tensile (eccentric) stress, and its degradation by MMP-8 causes end-diastolic pressure-volume relationship (EDPVR) leftward shift, resulting in diastolic and systolic dysfunctions. The diastolic dysfunction explains the clinically observed fluid unresponsiveness, whereas the decrease in end-diastolic volume (EDV) diminishes the systolic functions. MMP-8 can explain the development of SCM with diastolic dysfunction.NEW & NOTEWORTHY MMP-8, released from activated neutrophils and macrophages, is markedly elevated in sepsis, correlating with sepsis severity and mortality. MMP-8 targets collagen I of the cardiac ECM and induces diastolic dysfunction with fluid unresponsiveness, associated with decreased EDV, reduced sarcomere length, and diminished systolic function. Unlike other MMPs that predominantly cleave collagen-III and contribute to cardiac dilatation, thereby increasing sarcomere length, MMP-8 leads to a leftward shift in the EDPVR, resulting in diastolic and systolic dysfunctions.

NT-proBNP and Cardiac Troponin I, but Not Cardiac Troponin T, Are Associated With 7-Year Changes in Cardiac Structure and Function in Older Adults: The ARIC Study.

Higher circulating concentrations of NT-proBNP (N-terminal pro-B-type natriuretic peptide) and high-sensitivity cardiac troponin T (hs-cTnT) and I (hs-cTnI) are associated with left ventricular remodeling and with incident heart failure. The associations of these cardiac biomarkers with changes in cardiac structure and function over time are uncharacterized. Among 2006 participants in the ARIC prospective cohort study (Atherosclerosis Risk in Communities) who were free of overt cardiovascular disease and underwent echocardiography at study visits 5 (2011- 2013) and 7 (2018-2019), we assessed the associations of NT-proBNP, hs-cTnT, and hs-cTnI concentrations at visit 5 with changes in left ventricular structure and function between visits 5 and 7 (≈7-year change) using multivariable linear regression with the biomarkers modeled as restricted cubic splines. Models were adjusted for age, sex, race, body mass index, smoking, diabetes, hypertension, and renal function at visit 5; blood pressure and heart rate at both visits; and the baseline value of the echocardiographic parameter of interest. Mean±SD age was 74±4 years at visit 5; 61% were women; and 23% were Black adults. Median (25th-75th percentile) concentrations at visit 5 of NT-proBNP, hs-cTnT, and hs-cTnI were 87 ng/L (50-157 ng/L), 9 ng/L (6-12 ng/L), and 2.6 ng/L (1.9-3.9 ng/L). In adjusted models, elevated baseline concentrations of NT-proBNP and hs-cTnI were significantly associated with 7-year decline in left ventricular systolic function (ejection fraction, longitudinal and circumferential strain) and worsening diastolic indices. In contrast, elevated baseline concentrations of hs-cTnT were not significantly associated with 7-year changes in cardiac structure, systolic function, or diastolic function (all P>0.05). Higher concentrations of NT-proBNP and hs-cTnI, but not hs-cTnT, were associated with greater declines in left ventricular function over ≈7 years in late life independently of traditional cardiovascular risk factors.AQ.

Clinical utility of electrocardiographic voltage parameters for the diagnosis of hypertrophic cardiomyopathy.

While electrocardiographic parameters of hypertensive left ventricular hypertrophy (H-LVH) are well known, limited data are available regarding hypertrophic cardiomyopathy (HCM). This study was to assess the diagnostic value of electrocardiographic voltage parameters in HCM. Included patients with HCM treated between March 2015 and May 2023. Voltage parameters (S-L, Cornell, Cornell product, Lewis, Peguero, and modified Cornell voltages) and echocardiography were evaluated. Receiver operating characteristic (ROC) curves were used to assess the diagnostic value of electrocardiogram in HCM. The multiple linear regression was conducted to analyze the correlation between electrocardiogram indicators and cardiac diastolic function. The highest sensitivity for HCM was Peguero voltage (70.4%; 88.6% specificity). The Peguero voltage had high sensitivity in male (63.8%) and female patients (84.9%), those aged <65 years (71.6%) and ≥65 years (68.3%), with non-apical HCM (AHCM) (76.7%), obstructive HCM (82.1%), and non-obstructive HCM (66.9%). The sensitivity of the S-L voltage was high in AHCM (72.2%). The sensitivity for HCM reached 88.7% when the S-L and Peguero voltages were combined. The modified Cornell index had the highest area under the curve (0.88, 95% CI: 0.84-0.91), and its optimal cutoff value was 2.05 mV in males (77.6% sensitivity and 74% specificity) and 1.935 mV in females (90.6% sensitivity and 91.4% specificity). Peguero voltage (beta = 0.154, P = 0.034) and SD (beta = 0.223 P = 0.004) were independently correlated with E/e', an index of left ventricular diastolic function. The Peguero voltage had high sensitivity and specificity for detecting the presence of HCM. It was positively correlated with E/e' in patients with HCM. For AHCM, the S-L voltage was more advantageous. Combining the S-L voltage with the Peguero voltage further improves the sensitivity for HCM and thus could be used to improve the screening of HCM in clinical practice. The SD and modified Cornell voltage also had good diagnostic performance, especially in females.

Subclinical Left Ventricular Dysfunction over Seven-Year Follow-Up in Type 2 Diabetes Patients without Cardiovascular Diseases.

Subclinical left ventricular dysfunction (LVD) is common in asymptomatic patients with type 2 diabetes (T2D). This study aimed to define long-term structural and functional disorders of the left ventricle (LV) myocardium over a 7-year follow-up in patients with T2D without cardiovascular diseases (CVD). Of the 120 patients with and without T2D of both sexes aged from 45 to 75 years (57.11 ± 7.9 years), included in the study in 2012-2013, 57 responded to the follow-up study. They were divided into two groups: one with T2D (n = 29), the other without it, the control (n = 28). All patients underwent transthoracic two-dimensional echocardiography with an assessment of standard indicators of systolic and diastolic cardiac function, global longitudinal strain (GLS), laboratory diagnostics of carbohydrate metabolism disorders markers, NT-proBNP, and CRP. The median follow-up duration was 7.2 [7.0-7.8] years. During the follow-up, a statistically significant increase in the incidence of diastolic dysfunction (DD) from 53% to 61% (p = 0.004) was found in the T2D group; no significant dynamics were noted in the control group (p = 0.48). The proportion of patients with reduced GLS (<-18%) increased in the T2D group (p = 0.036). A significant difference in the frequency of decreased GLS depending on presence of T2D was demonstrated. In conclusion, T2D is an independent risk factor for the worsening of subclinical left ventricular dysfunction in asymptomatic patients with T2D without CVD over 7-year follow-up.

Potential Mechanisms of Epicardial Adipose Tissue Influencing Heart Failure with Preserved Ejection Fraction.

Heart failure (HF) is the predominant terminal stage and the leading cause of mortality in cardiac disease. Heart failure with preserved ejection fraction (HFpEF) affects roughly 50% of HF patients globally. Due to the global aging population, the prevalence, morbidity, and mortality of HFpEF have gradually increased. Epicardial adipose tissue (EAT), as a key visceral adipose tissue around the heart, affects cardiac diastolic function and exercise reserve capacity. EAT closely adheres to the myocardium and can produce inflammatory factors, neurotransmitters, and other factors through autocrine or paracrine mechanisms, affecting the heart function by inflammatory response, cardiac metabolism and energy supply, cardiomyocyte structure and electrical activity, and pericardial vascular function. Currently, research on the mechanism and treatment methods of HFpEF is constantly improving. EAT may play a multi-level impact on the occurrence and development of HFpEF. This review also summarizes the potential impact of EAT on the heart in HFpEF combined with other metabolism-related diseases such as obesity or diabetes over other obesity-related measures, such as body mass index (BMI) or other adipose tissue. Above all, this review comprehensively summarizes the potential mechanisms by which EAT may affect HFpEF. The objective is to enhance our comprehension and management of HFpEF. Future research should delve into the mechanistic relationship between EAT and HFpEF, and investigate interventions aimed at EAT to improve the prognosis of patients with HFpEF.

Cardiac Diastolic Function by Echocardiography in Normotensive Pregnancies vs Pregnancies Complicated by Hypertensive Disorders

Cardiac Diastolic Function by Echocardiography in Normotensive Pregnancies vs Pregnancies Complicated by Hypertensive Disorders

Effects of voluntarily consumed sweetened alcohol and naringin on cardiac function in male and female Sprague-Dawley rats.

This study assessed the impact of sweetened alcohol and naringin on cardiac function in Sprague-Dawley rats. Male (n = 40) and female (n = 40) rats were allocated to control, sweetened alcohol (SOH), naringin (NA), and sweetened alcohol with naringin (SOH + NA) groups. SOH and SOH + NA rats received 10% alcohol + 20% fructose in gelatine; SOH + NA and NA rats received 50 mg/kg naringin in gelatine daily for 10 weeks. Echocardiography was performed to assess left ventricular (LV) function. LV cardiomyocyte diameters and collagen area fraction were determined by H&E and picrosirius-red staining, respectively. In males, sweetened alcohol and naringin did not affect cardiac function. Female SOH rats had increased LV end-diastolic posterior wall (p = 0.04), relative wall thicknesses (p = 0.01), and LV cardiomyocyte diameters (p = 0.005) compared with control. Female SOH and SOH + NA had reduced lateral e' and e'/a' and increased E/e' (p < 0.0001). Female SOH (p = 0.01) and SOH + NA (p = 0.04) rats had increased LV collagen area fraction compared with controls. In males, neither sweetened alcohol nor naringin affected cardiac geometry or diastolic function. In females, sweetened alcohol induced concentric remodelling, impaired LV relaxation, and elevated filling pressures. Naringin may have the potential to improve the sweetened alcohol-induced concentric remodelling; however, it did not ameliorate diastolic dysfunction in females.

ICG signal denoising based on ICEEMDAN and PSO-VMD methods.

Impedance cardiography (ICG) plays a crucial role in clinically evaluating cardiac systolic and diastolic functions, along with various other cardiac parameters. However, its accuracy heavily depends on precisely identifying feature points reflecting cardiac function. Moreover, traditional signal processing techniques used to mitigate random noise and breathing artifacts may inadvertently distort the amplitude and temporal characteristics of ICG signals. To address this issue, this study investigates a noise and artifact elimination method based on Improved Complete Ensemble Empirical Mode Decomposition with Adaptive Noise (ICEEMDAN) and Particle Swarm Optimization-based Variational Mode Decomposition Algorithm (PSO-VMD). The goal is to preserve the amplitude and temporal features of ICG signals to ensure accurate feature point extraction and computation of associated cardiac parameters. Comparative analysis with signal processing methods employing various wavelet families and Ensemble Empirical Mode Decomposition (EEMD) in ICG signal processing applications reveals that the proposed method achieves superior signal-to-noise ratio (SNR) and lower root-mean-square error (RMSE), while demonstrating enhanced correlation and waveform consistency with the original signal.