Atrial Pressure

Venous congestion is an under-recognized contributor to mortality in critically ill patients. Unfortunately, venous congestion is difficult to measure, and right heart catheterization (RHC) has been considered the most readily available means for measuring venous filling pressure. Recently, a novel "Venous Excess Ultrasound (VExUS)" score was developed to noninvasively quantify venous congestion using inferior vena cava (IVC) diameter and Doppler flow through the hepatic, portal, and renal veins. A preliminary retrospective study of post-cardiac surgery patients showed promising results, including a high positive-likelihood ratio of high VExUS grade for acute kidney injury. However, studies have not been reported in broader patient populations, and the relationship between VExUS and conventional measures of venous congestion is unknown. To address these gaps, we prospectively assessed the correlation of VExUS with right atrial pressure (RAP), with comparison to inferior vena cava (IVC) diameter. Patients undergoing RHC at Denver Health Medical Center underwent VExUS examination before their procedure. VExUS grades were assigned before RHC, blinding ultrasonographers to RHC outcomes. After controlling for age, sex, and common comorbidities, we observed a significant positive association between RAP and VExUS grade (P 2 = .68). VExUS had a favorable AUC for prediction of a RAP ≥ 12 mmHg (0.99, 95% CI 0.96-1) compared to IVC diameter (0.79, 95% CI 0.65-0.92). These results suggest a strong correlation between VExUS and RAP in a diverse patient population, and support future studies of VExUS as a tool to assess venous congestion and guide management in a spectrum of critical illnesses.

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 max) incorporated in the currently recommended diagnostic algorithm. The diagnostic ability of LA-GS for detecting elevated resting PAWPM (AUC: 0.80, p M either at rest or during stress (AUC: 0.90, p 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.

BackgroundThe 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.MethodsSixty-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.ResultsLASr 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).ConclusionsLASr 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.

Finding a potential biomarker for elevated left atrial pressure would be clinically useful as a diagnostic for pre-heart failure. Therefore, an investigation into whether the protein neuromedin U (NMU), which is significantly elevated in heart failure patients, mediates a classical diuresis that results from a sustained increase in left atrial pressure was conducted in the anaesthetized pig. Left atrial pressure was increased a little above 15 mmHg for 30 minutes in 8 chloralose anaesthetised female pigs. There was a significant increase in circulating NMU and urine flow rate, which surprisingly occurred without an accompanying natriuresis; both the serum NMU increase and the diuresis did not occur when the procedure was repeated post-vagal section. There was also a significant increase in glomerular filtration rate during the diuresis, which indicates a likely direct renal effect. The results show that NMU could be the mediator of the historic diuresis induced by an increased left atrial pressure. Future work to assess NMU levels in humans in pre-heart failure would be required to confirm NMU's potential usefulness as a diagnostic.