Stimulation of left-atrial protein-synthesis rates by increased left-atrial filling pressures in the perfused working rat heart in vitro.
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ABSTRACT:
SUBMITTER: Smith DM
PROVIDER: S-EPMC1152543 | biostudies-other | 1983 Dec
REPOSITORIES: biostudies-other
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Project description:AimsLeft ventricular diastolic pressure estimation is essential for characterization of heart failure (HF). Patients with normal resting left atrial (LA) pressures (LAP), but steep LAP elevation on exertion, pose a particular diagnostic challenge. Current recommendations on echocardiographic LAP estimation have limited accuracy. Our aim was to investigate whether LA mechanical alterations assessed by LA strain (LA-GS) can contribute to non-invasive LAP diagnostics.Methods and resultsSimultaneous echocardiographic and right heart catheterization (RHC) data at rest and during exercise was analyzed in 164 prospectively enrolled patients, referred for RHC due to HF symptoms. 56% had preserved ejection fraction (pEF). At rest, 97 patients displayed elevated mean pulmonary arterial wedge pressure (PAWPM); further 32 patients had normal resting, but elevated PAWPM during exercise. LA-GS demonstrated a stronger relationship with resting PAWPM (r = - 0.61, p?<?0.001) than any of the indices (E/e', LAVi, TRVmax) incorporated in the currently recommended diagnostic algorithm. The diagnostic ability of LA-GS for detecting elevated resting PAWPM (AUC: 0.80, p?<?0.001) outperformed that of the recommended algorithm (AUC: 0.69). Importantly, resting LA-GS performed even better in identifying patients with pathological PAWPM either at rest or during stress (AUC: 0.90, p?<?0.001), whereas the diagnostic potential of the current algorithm was modest and limited to pEF patients (AUC?=?0.72). Finally, among the non-invasive indices, LA-GS entailed the strongest prognostic value for death or heart transplantation (OR: 2.7; p?<?0.05).ConclusionLA-GS comprises a robust method for PAWPM assessment at rest. More importantly, it reliably discerns pathological PAWPM rise on exertion despite normal resting pressures.
| S-EPMC6529379 | biostudies-literature
Project description:Echocardiographic assessment of left ventricular (LV) filling pressures is performed using a multi-parametric algorithm. Left atrial (LA) strain was recently found to accurately classify the degree of diastolic dysfunction. We hypothesized that LA strain could be used as a stand-alone marker and sought to identify and test a cutoff, which would accurately detect elevated LV pressures. We studied 76 patients with a spectrum of LV function who underwent same-day echocardiogram and invasive left-heart catheterization. Speckle tracking was used to measure peak LA strain. The protocol involved a retrospective derivation group (N = 26) and an independent prospective validation cohort (N = 50) to derive and then test a peak LA strain cutoff which would identify pre-A-wave LV diastolic pressure > 15 mmHg. The guidelines-based assessment of filling pressures and peak LA strain were compared side-by-side against invasive hemodynamic data. In the derivation cohort, receiver-operating characteristic analysis showed area under curve of 0.76 and a peak LA strain cutoff < 20% was identified as optimal to detect elevated filling pressure. In the validation cohort, peak LA strain demonstrated better agreement with the invasive reference (81%) than the guidelines algorithm (72%). The improvement in classification using LA strain compared to the guidelines was more pronounced in subjects with normal LV function (91% versus 81%). In summary, the use of a peak LA strain to estimate elevated LV filling pressures is more accurate than the current guidelines. Incorporation of LA strain into the non-invasive assessment of LV diastolic function may improve the detection of elevated filling pressures.
| S-EPMC6353699 | biostudies-literature
Project description:AimThe aim of this study was to assess PCWP with passive leg-lifting (PLL) and exercise, in two groups of patients presenting with normal left ventricular ejection fraction (LVEF); one group with elevated NT-proBNP (eBNP), and one with normal NT-proBNP (nBNP) plasma concentration.Methods and resultsFifty-one patients with eBNP (NT-proBNP ≥ 125 ng/l) and LVEF > 50%, were investigated and compared with 34 patients with nBNP (NT-proBNP < 125 ng/l) and LVEF > 50%. Both groups underwent right heart catheterization (RHC) at rest, PLL and exercise. From RHC, mean pulmonary arterial pressure (mPAP), cardiac output (CO), and PCWP were measured. All nBNP patients had PCWP < 15 mmHg at rest, and a PCWP of < 25 mmHg with PLL and during exercise. Patients with eBNP had higher (p < 0.01) resting mPAP, PCWP, and mPAP/CO. These values increased with exercise; however, CO increased less in comparison with nBNP patients (p = 0.001). 20% of patients with eBNP had a PCWP > 15 mmHg at rest, this percentage increased to 47% with PLL and 41% had a PCWP > 25 mmHg during exercise. Of those with PCWP > 25 mmHg during exercise, 91% had a PCWP > 15 mmHg with PLL. A PCWP > 15 mmHg on PLL had a 91% sensitivity and 92% specificity in predicting exercise-induced PCWP of > 25 mmHg.ConclusionIn patients presenting with eBNP, PLL can predict which patients will develop elevated PCWP with exercise. These findings highlight the role of stress assessment.
| S-EPMC7098926 | biostudies-literature
Project description:Echocardiographic assessment of diastolic dysfunction depends on surrogate parameters. In recent years, guideline committees attempted to combine these parameters to diagnostic flowcharts allowing for correct classification of left ventricular filling pressures (LVFP). The value of these diagnostic tools is limited if the applied surrogate parameters are elevated due to other reasons as is the case with maximal tricuspid regurgitation velocity. We aimed to compare the accuracy of the 2009 and the 2016 guideline recommendations in patients with pulmonary hypertension (PH). We included 101 consecutive patients who underwent right heart catheterization and transthoracic echocardiography for suspicion of PH. For the final analysis, only patients with PH were considered. The 2009 and 2016 recommendations for the assessment of diastolic function by echocardiography were applied on each patient. A total of 63 PH patients were included in the final analysis, 43% had elevated LVFP. By using the 2009 recommendations, sensitivity for correct classification of diastolic dysfunction was 67%, specificity was 82%, area under the curve (AUC) was 0.74. By using the 2016 recommendations, sensitivity for correct classification of diastolic dysfunction was 84%, specificity was 80%, AUC was 0.82. In ROC comparison, the AUC for the 2016 recommendations with 0.82 was significantly better compared to the AUC of 0.74 for the 2009 recommendations (p = 0.04). Our study demonstrates that the 2016 recommendations for echocardiographic evaluation of diastolic function are superior to the 2009 recommendations in estimating left ventricular filling pressures in patients with PH.
| S-EPMC6486531 | biostudies-literature
Project description:Recent findings suggest that left atrial (LA) function is more strongly related to adverse prognosis than LA volumes. We aimed to evaluate the associations between LA volumes and Doppler filling indices with LA function. Echocardiographic LA volumes (LAVs), mitral valve early (MV-E) and late (MV-A) peak flow velocities, and mitral atrioventricular plane tissue-Doppler early (TD-e') and late (TD-a') peak velocities were obtained in 320 patients with acute myocardial infarction (AMI) free from atrial fibrillation and more than moderate valvular disease. LA function was estimated as the LA emptying fraction (LAEF), that is 100× (LAVmax-LAVmin)/LAVmax. LA reservoir volume was calculated as LAVmax-LAVmin and LA transit volume as LV stroke volume-reservoir volume. In restricted cubic spline regression analyses with multivariable adjustment, a reduced LAEF was strongly associated with smaller reservoir volume, larger transit volume, LAVmax, LAVpreA and especially LAVmin. MV-E linearly increased with a lower LAEF, whereas MV-A decreased but only below LAEF levels of approximately 45%. The resulting E/A ratio showed a sudden increase in LAEF levels below ~45%. Lower TD-a' was linearly associated with a lower LAEF. In conclusion, a reduced atrial function was associated with smaller LA reservoir volume, larger LA transit volume, lower TD-a', a non-linear decrease in MV-A and a non-linear increase in E/A. Our findings are likely a reflection of the adaptation to sustain LV filling volume and counteracting a rise in pulmonary venous pressure in face of an enhanced LV end-diastolic pressure.
| S-EPMC7379494 | biostudies-literature
Project description:BACKGROUND:The 2016 guidelines for left ventricular diastolic dysfunction diagnosis has been simplified from previous versions; however, multiparametric diagnosis approach still exists indeterminate left ventricular diastolic dysfunction category. Left atrial (LA) strain was recently found useful to predict elevated left ventricular (LV) filling pressures noninvasively. This study aimed to (1) analyze the diagnostic value of LA strain for noninvasive assessment of LV filling pressures in patients with stable coronary artery disease (CAD) with preserved LV ejection fraction (LVEF), using invasive hemodynamic assessment as the gold standard, and (2) explore whether LA strain combined with conventional diastolic parameters could detect elevated LV filling pressures alone. METHODS:Sixty-four patients with stable CAD having LVEF >?50% and 30 healthy controls were enrolled. Two-dimensional speckle-tracking echocardiography was used to measure LA strain during the reservoir (LASr), conduit, and contraction phases. LV end-diastolic pressure (LVEDP), as a surrogate for LV filling pressures, was invasively obtained by left heart catheterization. Logistic regression was used to calculate the odds ratio to predict LV filling pressures. Pearson's correlation was used to analyze associations between echocardiographic parameters and LVEDP. The area under the receiver-operating characteristic curve was calculated to determine the capability of the echocardiographic parameters to detect elevated LVEDP. Inter-technique agreement was analyzed by contingency tables and tested by kappa statistics. RESULTS:LASr and the ratio of early-diastolic transmitral flow velocity (E) to tissue Doppler early-diastolic septal mitral annular velocity (E/E'septal) significantly predicted elevated LV filling pressures. LASr was combined with E/E'septal to generate a novel parameter (LASr/E/E'septal). LASr/E/E'septal had the best predictive ability of elevated LV filling pressures. LVEDP was negatively correlated with LASr and LASr/E/E'septal but positively correlated with E/E'septal. The area under the receiver-operating characteristic curve of LASr/E/E'septal was higher than that of LASr alone (0.83 vs. 0.75), better than all conventional LV diastolic parameters. Inter-technique agreement analysis showed that LASr/E/E'septal had good agreement with the invasive LVEDP measurement, better than the 2016 guideline (kappa?=?0.63 vs. 0.25). CONCLUSIONS:LASr provided additive diagnostic value for the noninvasive assessment of LV filling pressures. LASr/E/E'septal had the potential to be a better single noninvasive index to predict elevated LV filling pressures in patients with stable CAD and preserved LVEF.
| S-EPMC7183713 | biostudies-literature
Project description:AimsThe aim of this study is to investigate determinants of left atrial (LA) reservoir and pump strain and if these parameters may serve as non-invasive markers of left ventricular (LV) filling pressure.Methods and resultsIn a multicentre study of 322 patients with cardiovascular disease of different aetiologies, LA strain and other echocardiographic parameters were compared with invasively measured LV filling pressure. The strongest determinants of LA reservoir and pump strain were LV global longitudinal strain (GLS) (r-values 0.64 and 0.51, respectively) and LV filling pressure (r-values -0.52 and -0.57, respectively). Left atrial volume was another independent, but weaker determinant of both LA strains. For both LA strains, association with LV filling pressure was strongest in patients with reduced LV ejection fraction. Left atrial reservoir strain <18% and LA pump strain <8% predicted elevated LV filling pressure better (P < 0.05) than LA volume and conventional Doppler parameters. Accuracy to identify elevated LV filling pressure was 75% for LA reservoir strain alone and 72% for pump strain alone. When combined with conventional parameters, accuracy was 82% for both LA strains. In patients with normal LV systolic function by GLS, LA pump strain >14% identified normal LV filling pressure with 92% accuracy.ConclusionLeft atrial reservoir and pump strain are determined predominantly by LV GLS and filling pressure. Accuracy of LA strains to identify elevated LV filling pressure was best in patients with reduced LV systolic function. High values of LA pump strain, however, identified normal LV filling pressure with good accuracy in patients with normal systolic function.
| S-EPMC8685600 | biostudies-literature
Project description:The synthesis rates of total heart protein and of sarcoplasmic and myofibrillar protein fractions have been determined by perfusion of isolated rat hearts with [(14)C]tyrosine at constant specific radioactivity. In hearts perfused without insulin, both myofibrillar and sarcoplasmic proteins were synthesized at a fractional rate of 10-11% per day. This corresponds to a half-life for synthesis of about 7 days. The effect of added insulin was to increase the rate of heart-protein synthesis to a half-life of 3-4 days. With hearts perfused via the left atrium and performing external work, there was a rise in the specific radioactivity of intracellular free tyrosine, and the half-life for synthesis of proteins was 3-4 days. The extent of labelling of individual myofibrillar proteins was estimated after polyacrylamide-gel electrophoresis of solubilized myofibrils in the presence of sodium dodecyl sulphate. No particular protein showed an unusually high or low specific radioactivity after labelling in perfusion. Insulin caused a general increase in labelling of all the proteins analysed.
| S-EPMC1177625 | biostudies-other
Project description:Background Despite correction of the atrial septal defect (ASD), patients experience atrial fibrillation frequently and have increased morbidity and mortality. We examined physical capacity, cardiac performance, and invasive hemodynamics in patients with corrected ASD. Methods and Results Thirty-eight corrected patients with isolated secundum ASD and 19 age-matched healthy controls underwent right heart catheterization at rest and during exercise with simultaneous expired gas assessment and echocardiography. Maximum oxygen uptake was comparable between groups (ASD 32.7±7.7 mL O2/kg per minute, controls 35.2±7.5 mL O2/kg per minute, P=0.3), as was cardiac index at both rest and peak exercise. In contrast, pulmonary artery wedge v wave pressures were increased at rest and peak exercise (rest: ASD 14±4 mm Hg, controls 10±5 mm Hg, P=0.01; peak: ASD 25±9 mm Hg, controls 14±9 mm Hg, P=0.0001). The right atrial v wave pressures were increased at rest but not at peak exercise. The transmural filling pressure gradient (TMFP) was higher at peak exercise among patients with ASD (10±6 mm Hg, controls 7±3 mm Hg, P=0.03). One third of patients with ASD demonstrated an abnormal hemodynamic exercise response defined as mean pulmonary artery wedge pressure ≥25 mm Hg and/or mean pulmonary artery pressure ≥35 mm Hg at peak exercise. These patients had significantly elevated peak right and left atrial a wave pressures, right atrial v wave pressures, pulmonary artery wedge v wave pressures, and transmural filling pressure compared with both controls and patients with ASD with a normal exercise response. Conclusions Patients with corrected ASD present with elevated right and in particular left atrial pressures at rest and during exercise despite preserved peak exercise capacity. Abnormal atrial compliance and systolic atrial function could predispose to the increased long-term risk of atrial fibrillation. Registration Information clinicaltrials.gov. Identifier: NCT03565471.
| S-EPMC8483478 | biostudies-literature
Project description:BackgroundDiastolic dysfunction is associated with morbidity and mortality in multiple pediatric disease processes. Cardiovascular magnetic resonance (CMR) provides a non-invasive method of studying left ventricular (LV) diastolic dysfunction through the assessment of LV filling curves and left atrial (LA) volume and function. However, there are no normative data for LV filling curves and the standard method is time-intensive. This study aims to compare an alternate, more rapid method of obtaining LV filling curves to standard methodology and report normative CMR diastolic function data for LV filling curves and LA volumes and function.MethodsNinety-six healthy pediatric subjects (14.3 ± 3.4 years) with normal CMR defined by normal biventricular size and systolic function without late gadolinium enhancement were included. LV filling curves were generated by removing basal slices without myocardium present throughout the cardiac cycle and apical slices with poor endocardial delineation (compressed method), then re-generated including every phase of myocardium from apex to base (standard method). Indices of diastolic function included peak filling rate and time to peak filling. Systolic metrics included peak ejection rate and time to peak ejection. Both peak ejection and peak filling rates were indexed to end-diastolic volume. LA maximum, minimum and pre-contraction volumes were calculated using a biplane method. Inter-and intra-observer variability were assessed with intraclass correlation coefficient. Multivariable linear regression was used to assess the effects of body surface area (BSA), gender and age on metrics of diastolic function.ResultsBSA had the largest effect on LV filling curves. Normal LV filling data are reported for both compressed and standard methods. The time to perform the compressed method was significantly shorter than the standard method (median 6.1 min vs. 12.5 min, p < 0.001). Both methods had strong to moderate correlation for all metrics. Intra-observer reproducibility was moderate to high for all LV filling and LA metrics except for time to peak ejection and peak filling.ConclusionsWe report reference values for LV filling metrics and LA volumes. The compressed method is more rapid and produces similar results to standard methodology, which may facilitate the use of LV filling in clinical CMR reporting.
| S-EPMC10258747 | biostudies-literature