Left Ventricular Ejection Time Research Articles

Comprehensive echocardiographic and biomarker assessment of patients with diabetic ketoacidosis

BackgroundSystemic stress, inflammation, and hydroelectrolytic and acid‒base abnormalities observed during diabetic ketoacidosis (DKA) can cause changes in the heart and even induce cardiovascular damage. We aimed to evaluate the structure and function of the heart during and after a DKA episode via echocardiography and biomarker assessment.MethodsWe performed a transthoracic echocardiogram (TTE) in subjects with an episode of DKA in the first 4–6 h of treatment. We evaluated left ventricular wall thickness, diameters and volumes, as well as systolic and diastolic function using tissue Doppler imaging, pulsed wave Doppler and left ventricular ejection fraction (LVEF). Left ventricular function was also assessed with global longitudinal strain (GLS). We obtained cardiac troponin levels in the first 24 h after admission. A second TTE was performed following the same protocol 6–12 h after the resolution of the DKA episode.ResultsWe included a total of 20 subjects. The mean age was 33 ± 13.6 years; 70% were female, and 70% had type 1 DM. 75% of the patients experienced severe episodes, and the rest experienced moderate episodes. Left ventricular isovolumetric contraction and ejection time were significantly shorter during DKA and prolonged after the resolution of the episodes (47.6 ± 9.9 vs. 62.2 ± 14.1, p = < 0.001) and (218.6 ± 37.9 vs. 265.06 ± 34.7). The isovolumetric relaxation time was also shorter during DKA, (41.72 ± 8.29 vs. 59.32 ± 17.98, p = < 0.001). Volumes and diameters of the left ventricle increased significantly after DKA resolution. We found no difference between LVEF or GLS during and after DKA resolution. 20% of the participants had troponin elevations, half of whom had moderate episodes and half of whom had severe episodes. 35% had LV dysfunction, 28.5% both in GLS and LVEF. 28.5% occurred after DKA resolution, with alterations in GLS.ConclusionsDiabetic ketoacidosis induces changes in the structure and function of the heart, which are mostly transient, reflect the presence of a hyperdynamic state and resolve after the resolution of the episode. Some subjects present with evidence of myocardial injury with elevated cardiac troponin and left ventricular dysfunction.Graphical abstractIcons in the graphical abstract are made by Freepik from www.flaticon.com.

Long term outcomes of patients with decompensated aortic stenosis undergoing urgent transcatheter aortic valve implantation: a TAVI-NOR subs-study

Abstract Background Aortic stenosis (AS) is a progressive disease, which untreated leads to irreversible myocardial damage and potentially death. Patients with AS may present with acute decompensation (ADAS) even during active surveillance. Purpose In this TAVI-NOR sub-study, we investigate the clinical profile, risk factors, epidemiology and long-term outcomes of patients treated with TAVI after presenting with ADAS compared to stable patients who underwent elective TAVI (no ADAS). Method A total of 600 patients with severe AS consecutively treated with TAVI between January 2012 and July 2019 were enrolled in TAVI-NOR study. Predictors and long-term clinical outcomes were explored in binary logistic and Cox regression models. Results A total of 68 patients (11.3%) received urgent TAVI due to acute hospitalization with ADAS. Age (80±8.0 years vs 81±6.0 years, p=0.662), gender (56% males vs 50% males, p=0.361) and other comorbidities at baseline such as cardiovascular disease, chronic lung disease and atrial fibrillation (AF) were comparable in patients with ADAS and no ADAS (n=532) (p&amp;gt;0.05 for all). However, patients with ADAS had greater symptom burden (NYHA III-IV 81% vs 51%, p&amp;lt;0.001), lower blood pressure, higher heart rate and lower estimated glomeruli filtration rate (52.0±10.8 vs 54.6±9.8 mL/min/1.73m2, p&amp;lt;0.045). They had also higher prevalence of ECG left ventricular (LV) hypertrophy (40% vs 27%, p=0.027), more often reduced LV ejection fraction (&amp;lt;50%) (41% vs 16%, p&amp;lt;0.001), lower stroke volume (39±11 ml/m2 vs 42±11 ml/m2 vs, p=0.030) a trend of abnormal ECG (p=0.055) and longer hospital stay (11.5 ±8.7 days 6.6± 4.9 days, p&amp;lt;0.001). Patients with ADAS were comparable with no ADAS in terms of early short-term (&amp;lt;30 days) all-cause mortality (p&amp;gt;0.05). Although 1-year mortality was comparable (1.5% in ADAS vs 2.1% in no ADAS, p&amp;gt;0.99), mid- to late-term mortality rates were significantly higher in patient with ADAS receiving urgent TAVI, with 3-, 5- and 7 years mortality of 22% vs 11%, p=0.008; 46% vs 29%, p=0.005; 53% vs 39%, p=0.033, respectively. In a Kaplan-Meier analysis, event-free survival was significantly reduced for patients with ADAS undergoing urgent TAVI compared with stable patients undergoing elective TAVI HR 1.63, 95% CI 1.15-2.31, p=0.006), confirmed by a multivariable-adjusted model (HR 1.54; 95% CI 1.05-2.25, p=0.026) independent of age, gender, AF, LV ejection fraction and time from diagnosis to TAVI (Fig). Conclusion Patients with AS presenting with acute decompensation and treated with urgent TAVI had excellent short-term survival. This was irrespective of increased symptom burden, adversely remodeled and functionally reduced LV at baseline. These findings might explain the observed higher mid- and long-term mortality compared with stable patients undergoing elective TAVI. It is essential to identify patients at risk of acute decompensation and treat them timely before irreversible myocardial damage occur.

Association between Left Ventricular Geometry, Systolic Ejection Time, and Estimated Glomerular Filtration Rate in Ambulatory Patients with Preserved Left Ventricular Ejection Fraction

Plain Language SummaryCardiac function is important to quantify for risk stratification. Although left ventricular ejection fraction is commonly used, and identifies patients with poor systolic function, other easily acquired measures of cardiac function are needed. In this retrospective cohort study of 375 patients with increased left ventricular relative wall thickness, an easily derived measure from standard transthoracic echocardiography was independently associated with a surrogate of subclinical systolic dysfunction, left ventricular ejection time, and chronic kidney disease. Left ventricular geometry identifies clinically relevant subclinical systolic dysfunction and patients with worse kidney function.

Adaptive morphological modeling and optimal estimation for dynamic LVET measurement from seismocardiographic signals

The dynamic left ventricular ejection time (LVET) represents a crucial cardiovascular health indicator. Seismocardiography (SCG) offers substantial advantages over conventional techniques, however, it is susceptible to motion artifacts and exhibits complex morphologies, posing challenges for accurate dynamic LVET measurement. This study proposes a synergistic approach that integrates adaptive morphological modeling with an optimal estimation technique to accurately measure dynamic LVET from SCG signals. Firstly, an active feature recognition method was proposed to automatically identify 10 morphological features, followed by modeling them using 10 Gaussian functions. Subsequently, the model results were fused with measured SCG through optimal estimation, involving adaptive updating of the measurement noise matrix. When evaluated against state-of-the-art algorithms on the open-source CEBS dataset (82997 heartbeats) and the experimental dataset (34181 heartbeats), the proposed algorithm exhibits outstanding performance, with a goodness of fit (R2) of 0.9272 and root-mean-square error (RMSE) of 13.808 ms, convincingly demonstrating its effectiveness and advancement.

The role of cardiac acoustic biomarkers in monitoring patients with heart failure: A systematic literature review.

Heart failure (HF) creates a considerable clinical, humanistic and economic burden on patients and caregivers as well as on healthcare systems. To attenuate the significant burden of HF, there is a need for enhanced management of patients with HF. The use of digital tools for remote non-invasive monitoring of heart parameters is gaining traction, and cardiac acoustic biomarkers (CABs) have been proposed as a complementary set of measures to assess heart function alongside traditional methods such as electrocardiogram and echocardiography. We conducted a systematic literature review to evaluate associations between CABs and HF outcomes. Embase and MEDLINE databases were searched for recent studies published between 2013 and 2023 that evaluated CABs in patients with HF. Additional grey literature (i.e., conference, congress and pre-print publications from January 2021 to May 2023) searches were included. Two reviewers independently examined all articles; a third resolved conflicts. Data were extracted from articles meeting inclusion criteria. Extracted studies underwent quality and bias assessments using the Joanna Briggs Institute (JBI) critical appraisal tools. In total, 3074 records were screened, 73 full-text articles were assessed for eligibility and 27 publications were included. Third heart sound (S3) and electromechanical activation time (EMAT) were the CABs most often reported in the literature for monitoring HF. Fifteen publications discussed changes in S3 characteristics and its role in HF detection or outcomes: six studies highlighted S3 assessment among various groups of patients with HF; four studies evaluated the strength or amplitude of S3 with clinical outcomes; five studies assessed the relationship between S3 presence and clinical outcomes; and one study assessed both S3 presence and amplitude in relation to HF clinical outcomes. Eleven publications reported on EMAT and its derivatives: five studies on the relationship between EMAT and HF and six studies on the association of EMAT and HF clinical outcomes. Studies reporting the first and fourth heart sound, left ventricular ejection time and systolic dysfunction index were limited. Published literature supported S3 and EMAT as robust CAB measures in HF that may have value in remote clinical monitoring and management of patients with HF. Additional studies designed to test the predictive power of these CABs, and others less well-characterized, are needed. This work was funded by Astellas Pharma Inc.

Roadmap of Photoplethysmography Technology in Advanced Cardiovascular Assessment

This review explores the trajectory of photoplethysmography (PPG) technology from its inception in 1934 to its integration into smart devices in 2013. While PPG has proven effective in estimating left ventricular ejection time (LVET) and distinguishing between hypertensive and normotensive patients, challenges persist. The need for a robust mathematical model to explain physiological behaviors, address calibration protocols, and handle waveform variability is emphasized. Despite limitations, PPG is on the cusp of achieving clinical-grade confidence, particularly in estimating blood pressure and tracking vasomotor states. Integration into wearable devices is a prominent trend, with major companies exploring applications for improved health monitoring. Open-source databases and the availability of physiological data aim to enhance understanding, paving the way for universally accepted protocols. As PPG advances, it holds promise for personalized healthcare, revolutionizing treatment evaluations and preventive measures. However, potential disagreements over protocols may impede progress. Nevertheless, the technology's potential to remotely monitor cardiovascular markers could reduce physicians' workload for routine tasks. PPG stands as a beacon for the future of noninvasive cardiovascular assessment.

Long-term myocardial effects of noninvasive ventilation in patients with obesity hypoventilation syndrome

IntroductionChronic effects of noninvasive ventilation on myocardial function in patients with obesity hypoventilation syndrome (OHS) are scarcely understood. The aim of the present study was to evaluate the long-term effects of volume-targeted bilevel positive airway pressure ventilation (BiPAP) on cardiac parameters and myocardial biomarkers in patients with OHS. MethodsClinically stable patients with OHS referred to the tertiary center for the initiation of long-term BiPAP therapy were consecutively enrolled. At baseline, all participants underwent overnight cardiorespiratory polygraphy. BiPAP therapy using volume-targeted spontaneous/timed mode delivered via an oro-nasal mask was initiated. Beat-to-beat noninvasive monitoring by impedance cardiography was used to assess heart function at baseline and after 3 and 12 months of BiPAP use. Serum troponin 1, N-Terminal Pro-B-Type Natriuretic Peptide (NT-ProBNP), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6) were monitored. ResultsThirteen patients (10 men; mean age, 55.8 ± 9.8 years; mean body mass index of 47.8 ± 5.9 kg/m2) were recruited. From baseline to 3, and to 12 months of BiPAP use, left ventricular stroke volume (SV), ejection time (LVET), and ejection time index significantly increased (P = 0.030; P < 0.001; P = 0.003, respectively), while heart rate and systolic time ratio significantly decreased (P = 0.004; P = 0.034, respectively). Reductions in serum NT-proBNP, IL-6 and TNF-α were observed (P = 0.045; P = 0.018; P = 0.003, respectively). No significant changes in serum troponin were detected throughout the study. ConclusionsThe present findings of increased SV, in association with lengthening of LVET, reductions of NT-proBNP and reductions in circulatory inflammatory markers in patients with stable OHS and chronic moderate-to-severe daytime hypercapnia treated with BiPAP over 1 year support the role of this therapeutic mode in such patients.

Вплив реваскуляризації коронарних артерій на механічну дисинхронію міокарду лівого шлуночка у хворих з коронарною хворобою серця

Introduction. Defining a treatment strategy for patients with stable coronary heart disease will require the development of personalized criteria, among which the assessment of myocardial dyssynchrony is considered promising. The aim of the study was to evaluate the effect of revascularization of coronary arteries on indicators of mechanical myocardial dyssynchrony in patients with stable coronary heart disease. Materials and methods. The study included 121 patients with coronary heart disease, who were assessed for mechanical myocardial dyssynchrony before and 2 weeks after revascularization. The main group included 48 patients with myocardial dyssynchrony, and the comparison group included 73 patients without myocardial dyssynchrony. Complete occlusion and lesions of 3 coronary arteries were found more often in the group with myocardial dyssynchrony, and the main group also had a higher SYNTAX SCORE. The results. Mechanical dyssynchrony of the myocardium was found in 39% of patients with coronary heart disease. Before revascularization, a signifiant increase in SPWMD, APEI, IVMD, and a decrease in LVFT and LVET were found in the group of patients with myocardial dyssynchrony. After revascularization in the main group, in 9 patients out of 48 (18.7%), indicators of myocardial dyssynchrony returned to normal values. LVFT in the group of patients with myocardial dyssynchrony significantly increased, as well as left ventricular ejection time (LVET) (from 318.5±9.6 ms to 344.9±23.2 ms, p&lt;0.01). Conclusions. After revascularization, the number of patients with myocardial dyssynchrony significantly decreased due to the improvement of interventricular and intraventricular dyssynchrony indicators. Key words: myocardial dyssynchrony, coronary heart disease, revascularization, coronary angiography, SYNTAX SCORE.

An algorithm to detect dicrotic notch in arterial blood pressure and photoplethysmography waveforms using the iterative envelope mean method

Background and objectiveDetection of the dicrotic notch (DN) within a cardiac cycle is essential for assessment of cardiac output, calculation of pulse wave velocity, estimation of left ventricular ejection time, and supporting feature-based machine learning models for noninvasive blood pressure estimation, and hypotension, or hypertension prediction. In this study, we present a new algorithm based on the iterative envelope mean (IEM) method to detect automatically the DN in arterial blood pressure (ABP) and photoplethysmography (PPG) waveforms. MethodsThe algorithm was evaluated on both ABP and PPG waveforms from a large perioperative dataset (MLORD dataset) comprising 17,327 patients. The analysis involved a total of 1,171,288 cardiac cycles for ABP waveforms and 3,424,975 cardiac cycles for PPG waveforms. To evaluate the algorithm's performance, the systolic phase duration (SPD) was employed, which represents the duration from the onset of the systolic phase to the DN in the cardiac cycle. Correlation plots and regression analysis were used to compare the algorithm against marked DN detection, while box plots and Bland-Altman plots were used to compare its performance with both marked DN detection and an established DN detection technique (second derivative). The marking of the DN temporal location was carried out by an experienced researcher using the help of the 'find_peaks' function from the scipy Python package, serving as a reference for the evaluation. The marking was visually validated by both an engineer and an anesthesiologist. The robustness of the algorithm was evaluated as the DN was made less visually distinct across signal-to-noise ratios (SNRs) ranging from -30 dB to -5 dB in both ABP and PPG waveforms. ResultsThe correlation between SPD estimated by the algorithm and that marked by the researcher is strong for both ABP (R2(87,343) =0.99, p<.001) and PPG (R2(86,764) =0.98, p<.001) waveforms. The algorithm had a lower mean error of DN detection (s): 0.0047 (0.0029) for ABP waveforms and 0.0046 (0.0029) for PPG waveforms, compared to 0.0693 (0.0770) for ABP and 0.0968 (0.0909) for PPG waveforms for the established 2nd derivative method. The algorithm has high rate of detectability of DN detection for SNR of >= -9 dB for ABP waveforms and >= -12 dB for PPG waveforms indicating robust performance in detecting the DN when it is less visibly distinct. ConclusionOur proposed IEM- based algorithm can detect DN in both ABP and PPG waveforms with low computational cost, even in cases where it is not distinctly defined within a cardiac cycle of the waveform (‘DN-less signals’). The algorithm can potentially serve as a valuable, fast, and reliable tool for extracting features from ABP and PPG waveforms. It can be especially beneficial in medical applications where DN-based features, such as SPD, diastolic phase duration, and DN amplitude, play a significant role.

Chronic Cervical Midline Contusion in Rats Disrupts Multiple Facets of Cardiovascular Function

Cardiovascular dysfunction is the leading cause of morbidity and mortality following spinal cord injury (SCI). There are a limited number of studies assessing cardiovascular deficits after cervical SCI. This study aimed to assess disrupted cardiovascular function following a chronic severe incomplete C8 SCI in rats, via damaging descending sympathetic projections to the spinal sympathetic preganglionic neurons. Rats were first trained on the isometric pull task before receiving a C8 midline contusion (Infinite Horizon Impact Device; 250 kilodynes; 0 s dwell time) or laminectomy and were tested one day per week from weeks 7-13 following surgery. Isometric forelimb strength and correlates of muscle endurance were monitored during pull task sessions. Cardiovascular function was evaluated 16 weeks post-surgery. Tilt table testing was used to induce an orthostatic challenge by tilting rats 90 degrees head-up from a supine position and 90 degrees head-down from supine position as a control. Following tilt table testing, dobutamine (DOB; 2 μg/kg/min and 10 μg/kg/min) and norepinephrine (NE; 1 μg/kg/min and 4 μg/kg/min) were infused into the femoral vein separately to assess cardiovascular responses to a pharmacological challenge. We monitored cardiovascular physiology during all terminal testing. A blood pressure catheter was inserted into the left common carotid artery and advanced to the aortic arch to monitor interatrial blood pressure, 2 pairs of impedance cardiography (ICG) electrodes were placed on the left side of the thorax to evaluate inotropic correlates of cardiac function, and 2 photoplethysmography (PPG) sensors were affxed over the forelimbs flexor muscles to examine peripheral hemodynamics. To verify the accuracy of ICG-derived cardiac function, rats were examined by echocardiography at week 15. Spinal cords were collected for lesion analysis and were also stained for tyrosine hydroxylase. Our preliminary results demonstrate that chronic severe incomplete C8 SCI resulted in a significant and sustained hypotension during the 3-minute period of 90 degrees head-up tilting (systolic blood pressure = ~ -22 mmHg; diastolic blood pressure = ~ -19 mmHg) compared to laminectomy. There were also significant differences in left ventricular ejection time, heart rate, and stroke volume across groups, whereas forelimb hemodynamics did not differ across groups. Additionally, correlates of forelimb muscle endurance significantly decreased in SCI rats, despite similar isometric forelimb strength across groups. Intravenous infusion of DOB and NE demonstrated significant and dose-dependent effects on cardiovascular parameters. Overall, our data demonstrate that chronic severe C8 SCI in rats leads to orthostatic hypotension and also impairs multiple additional aspects of function. This study was supported by: NIH (R01 NS131493) and Florida Department of Health (COPBC). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Artificial Intelligence Applied to Electrical and Non-Invasive Hemodynamic Markers in Elderly Decompensated Chronic Heart Failure Patients.

The first aim of this study was to assess the predictive power of Tend interval (Te) and non-invasive hemodynamic markers, based on bioimpedance in decompensated chronic heart failure (CHF). The second one was to verify the possible differences in repolarization and hemodynamic data between CHF patients grouped by level of left ventricular ejection fraction (LVEF). Finally, we wanted to check if repolarization and hemodynamic data changed with clinical improvement or worsening in CHF patients. Two hundred and forty-three decompensated CHF patients were studied by 5 min ECG recordings to determine the mean and standard deviation (TeSD) of Te (first study). In a subgroup of 129 patients (second study), non-invasive hemodynamic and repolarization data were recorded for further evaluation. Total in-hospital and cardiovascular mortality rates were respectively 19 and 9%. Te was higher in the deceased than in surviving subjects (Te: 120 ± 28 vs. 100 ± 25 ms) and multivariable logistic regression analysis reported that Te was related to an increase of total (χ2: 35.45, odds ratio: 1.03, 95% confidence limit: 1.02-1.05, p < 0.001) and cardiovascular mortality (χ2: 32.58, odds ratio: 1.04, 95% confidence limit: 1.02-1.06, p < 0.001). Subjects with heart failure with reduced ejection fraction (HFrEF) reported higher levels of repolarization and lower non-invasive systolic hemodynamic data in comparison to those with preserved ejection fraction (HFpEF). In the subgroup, patients with the NT-proBNP reduction after therapy showed a lower rate of Te, heart rate, blood pressures, contractility index, and left ventricular ejection time in comparison with the patients without NT-proBNP reduction. Electrical signals from ECG and bioimpedance were capable of monitoring the patients with advanced decompensated CHF. These simple, inexpensive, non-invasive, easily repeatable, and transmissible markers could represent a tool to remotely monitor and to intercept the possible worsening of these patients early by machine learning and artificial intelligence tools.

Detecting aortic valve stenosis based on the non-invasive blood pressure waveform—a proof of concept study

The incidence of aortic valve stenosis (AoS) increases with age, and once diagnosed, symptomatic severe AoS has a yearly mortality rate of 25%. AoS is diagnosed with transthoracic echocardiography (TTE), however, this gold standard is time consuming and operator and acoustic window dependent. As AoS affects the arterial blood pressure waveform, AoS-specific waveform features might serve as a diagnostic tool. Aim of the present study was to develop a novel, non-invasive, AoS detection model based on blood pressures waveforms. This cross-sectional study included patients with AoS undergoing elective transcatheter or surgical aortic valve replacement. AoS was determined using TTE, and patients with no or mild AoS were labelled as patients without AoS, while patients with moderate or severe AoS were labelled as patients with AoS. Non-invasive blood pressure measurements were performed in awake patients. Ten minutes of consecutive data was collected. Several blood pressure-based features were derived, and the median, interquartile range, variance, and the 1st and 9th decile of the change of these features were calculated. The primary outcome was the development of a machine-learning model for AoS detection, investigating multiple classifiers and training on the area under the receiver-operating curve (AUROC). In total, 101 patients with AoS and 48 patients without AoS were included. Patients with AoS showed an increase in left ventricular ejection time (0.02 s, p = 0.001), a delayed maximum upstroke in the systolic phase (0.015 s, p < 0.001), and a delayed maximal systolic pressure (0.03 s, p < 0.001) compared to patients without AoS. With the logistic regression model, a sensitivity of 0.81, specificity of 0.67, and AUROC of 0.79 were found. The majority of the population without AoS was male (85%), whereas in the population with AoS this was evenly distributed (54% males). Age was significantly (5 years, p < 0.001) higher in the population with AoS. In the present study, we developed a novel model able to distinguish no to mild AoS from moderate to severe AoS, based on blood pressure features with high accuracy. Clinical registration number: The study entailing patients with TAVR treatment was registered at ClinicalTrials.gov (NCT03088787, https://clinicaltrials.gov/ct2/show/NCT03088787). The study with elective cardiac surgery patients was registered with the Netherland Trial Register (NL7810, https://trialsearch.who.int/Trial2.aspx?TrialID=NL7810).

Is the Corrected Carotid Flow Time a Clinically Acceptable Surrogate Hemodynamic Parameter for the Left Ventricular Ejection Time?

ObjectiveThe corrected left ventricular ejection time (cLVET) comprises the phase from aortic valve opening to aortic valve closure corrected for heart rate. As a surrogate measure for cLVET, the corrected carotid flow time (ccFT) has been proposed in previous research. The aim of this study was to assess the clinical agreement between cLVET and ccFT in a dynamic clinical setting. MethodsTwenty-five patients with severe aortic valve stenosis (AS) were selected for transcatheter aortic valve replacement (TAVR). The cLVET and ccFT were derived from the left ventricular outflow tract (LVOT) and the common carotid artery (CCA) respectively, using pulsed wave Doppler ultrasound. Bazett's (B) and Wodey's (W) equation were used to calculate cLVET and ccFT. Measurements were performed directly before (T1), and after (T2) TAVR. Correlation, Bland-Altman, and concordance analyses were performed. ResultsThe cLVET decreased from T1 to T2 (p<0.001), with a relative reduction of 11% (B) and 9% (W). The ccFT decreased (p<0.001) with a relative reduction of 12% (B) and 10% (W). The correlation between cLVET and ccFT was strong for B (ρ=0.74, p<0.001), and W (ρ=0.81, p<0.001). The bias was -39 ms (B) and -37 ms (W), and the upper and lower level of agreement were 19 ms and -98 ms (B) and 5 ms and -78 ms (W), respectively. The trending ability between cLVET and ccFT was good (concordance 96%) for both B and W. ConclusionIn TAVR patients, the clinical agreement between cLVET and ccFT was acceptable, indicating that ccFT could serve as a surrogate measure for cLVET.

Assessing Passive Leg Raise Test in Pediatric Shock Using Electrical Cardiometry

AbstractPassive leg raise (PLR) is widely used to incite an autobolus to assess fluid responsiveness in adults; however, there is a paucity of studies exploring its utility in children. Our study aimed to analyze the efficacy of PLR in determining fluid responsiveness in children presenting with shock using electrical cardiometry. Patients in the age group of 0 to 20 years who presented in shock to our children's hospital emergency department were evaluated. Multiple hemodynamic metrics including, heart rate, systolic/diastolic blood pressure, cardiac output (CO), stroke index, stroke volume (SV), flow time corrected (FTC), and left ventricular ejection time (LVET) were recorded using the noninvasive ICON device and compared at baseline and post-PLR. A total of 68 patients had pre- and post-PLR data available for review between June and July 2022. Median age was 7 years (54% male); most common etiology was hypovolemic (67.6%) shock. Following PLR, there was no significant change in most hemodynamic parameters, including SV and CO; however, there was a significant difference in FTC (301 [pre-PLR] vs. 307 [post-PLR], p = 0.016) (ms) and LVET (232 [pre-PLR] vs. 234 [post-PLR], p = 0.014) (ms). A significantly higher proportion of children diagnosed with septic shock demonstrated fluid responsiveness (ΔSV ≥ 10% from baseline) compared with those with hypovolemic shock (p = 0.036). This study demonstrated no identifiable fluid responsiveness (ΔSV ≥ 10% from baseline) following PLR; however, a significantly higher proportion of children suffering from septic shock demonstrated fluid responsiveness compared with those with hypovolemic shock. Larger studies are needed to further assess the utility of PLR, as well as other modalities, in determining fluid responsiveness in children.

Mechanocardiography detects improvement of systolic function caused by resynchronization pacing.

Objective.Cardiac resynchronization therapy (CRT) is commonly used to manage heart failure with dyssynchronous ventricular contraction. CRT pacing resynchronizes the ventricular contraction, while AAI (single-chamber atrial) pacing does not affect the dyssynchronous function. This study compared waveform characteristics during CRT and AAI pacing at similar pacing rates using seismocardiogram (SCG) and gyrocardiogram (GCG), collectively known as mechanocardiogram (MCG).Approach.We included 10 patients with heart failure with reduced ejection fraction and previously implanted CRT pacemakers. ECG and MCG recordings were taken during AAI and CRT pacing at a heart rate of 80 bpm. Waveform characteristics, including energy, vertical range (amplitude) during systole and early diastole, electromechanical systole (QS2) and left ventricular ejection time (LVET), were derived by considering 6 MCG axes and 3 MCG vectors across frequency ranges of >1 Hz, 20-90 Hz, 6-90 Hz and 1-20 Hz.Main results.Significant differences were observed between CRT and AAI pacing. CRT pacing consistently exhibited higher energy and vertical range during systole compared to AAI pacing (p< 0.05). However, QS2, LVET and waveform characteristics around aortic valve closure did not differ between the pacing modes. Optimal differences were observed in SCG-Y, GCG-X, and GCG-Y axes within the frequency range of 6-90 Hz.Significance.The results demonstrate significant differences in MCG waveforms, reflecting improved mechanical cardiac function during CRT. This information has potential implications for predicting the clinical response to CRT. Further research is needed to explore the differences in signal characteristics between responders and non-responders to CRT.

Cardiac Autonomic Balance Is Altered during the Acute Stress Response in Adolescent Major Depression-Effect of Sex.

Autonomic nervous system (ANS) abnormalities are associated with major depressive disorder (MDD) already at adolescent age. The majority of studies so far evaluated parasympathetic and sympathetic branches of ANS individually, although composite indices including cardiac autonomic balance (CAB) and cardiac autonomic regulation (CAR) seem to measure ANS functioning more comprehensively and thus could provide better psychopathologies' predictors. We aimed to study CAB and CAR derived from high-frequency bands of heart rate variability and left ventricular ejection time during complex stress response (rest-Go/NoGo task-recovery) in MDD adolescents with respect to sex. We examined 85 MDD adolescents (52 girls, age: 15.7 ± 0.14 yrs.) and 80 age- and sex-matched controls. The MDD group showed significantly reduced CAB compared to controls at rest, in response to the Go/NoGo task, and in the recovery phase. Moreover, while depressed boys showed significantly lower CAB at rest and in response to the Go/NoGo task compared to control boys, depressed girls showed no significant differences in evaluated parameters compared to control girls. This study for the first time evaluated CAB and CAR indices in drug-naïve first-episode diagnosed MDD adolescents during complex stress responses, indicating an altered cardiac autonomic pattern (i.e., reciprocal sympathetic dominance associated with parasympathetic underactivity), which was predominant for depressed boys.

Short versus long-term anticoagulation for left ventricular thrombosis resolution during vitamin k antagonist therapy

Abstract Background The optimal duration of anticoagulant therapy to achieve thrombus resolution and prevent cardioembolic events in left ventricular thrombosis (LVT) has not yet been established. Purpose The purpose of our study is to evaluate the incidence of LVT resolution at 3 versus 12 months of vitamin K antagonists (VKAs) therapy. Methods Consecutive patients diagnosed with LVT and treated with VKAs for at least 12 months at 5 anticoagulant outpatient clinics in Italy were retrospectively included. The primary effectiveness outcome was on-treatment thrombus resolution while the secondary was objectively documented on-treatment acute ischemic stroke, peripheral embolism, and myocardial infarction at 12-months follow-up. Safety outcomes were on-treatment major and clinically relevant non-major bleedings at 12-months follow-up as defined by the ISTH criteria. Cumulative incidences of thrombus resolution with 95% confidence intervals (CIs) were calculated while other outcomes were descriptively reported. Multivariable Cox hazards models were calculated using age, sex, reduced left ventricular ejection fraction (EF &amp;lt; 35%), VKAs monotherapy, and time in therapeutic range (TTR) below 60% as covariates for thrombus persistence at 12-months of follow-up. Results Out of 95 patients, 87 were finally included (Table) and 8 excluded due to the lack of relevant data. Median age was 67 years and 75.9% were men. A total of 64.4% of patients had acute myocardial infarction as risk factor for LVT development while 21.8% and 5.7% of patients had dilated and primary hypertrophic cardiomyopathy, respectively. A reduced EF and atrial fibrillation were present in 77.0% and 19.5% of patients, respectively. All but one patient received warfarin with a median TTR of 54%, and 35.5% of patients did not receive concomitant antiplatelet therapy. All included patients received VKAs for at least 12-months. The 3 and 12 month cumulative incidences (Figure) of thrombus resolution were 34.5% (95% CI, 24.7%-44.5%) and 68.3% (95% CI, 57.2%-77.1%), respectively. At multivariable Cox regression analysis, the presence of a reduced EF appeared to be associated with a higher risk of thrombus persistence at 12-months follow-up (Hazard Ratio 3.09; 95% CI 1.27-7.55; p=0.013). During 12-months follow-up, two patients (2.3%) had acute ischemic stroke at 4 and 7 months from the start of VKAs therapy. Three patients (3.4%) had a major and 5 (5.7%) a clinically relevant non-major bleeding that occurred within the first three months of VKAs. Conclusions A 12-month course of anticoagulant therapy with VKA appeared to be effective and safe in patients with LVT and appeared to be associated with a higher cumulative incidence of LVT resolution than a 3-month course. A reduced left ventricular EF was associated with a higher risk of LVT persistence. Whether anticoagulant agents with improved ease-of-use and safety profile are effective in this setting remains undefined.Baseline patients' characteristicsCumulative incidences of LVT resolution

Left Ventricular Ejection Time Estimation from Blood Pressure and Photoplethysmography Signals Based on Tidal Wave

Left ventricular ejection time (LVET) is an important parameter for assessing cardiovascular disorders. In a medical office, it is typically measured using the Tissue Doppler Imaging technique, but new wearable devices have led to a growing interest in integrating this parameter into them, increasing accessibility to personalized healthcare for users and patients. In the cardiovascular domain, photoplethysmography (PPG) is a promising technology that shares two distinctive features with invasive arterial blood pressure (ABP) tracing: the tidal wave (TDW) and the dicrotic wave (DCW). In the early years of cardiovascular research, the duration of the dicrotic point was initially linked to the ending phase of left ventricular ejection. Subsequent studies reported deviations from the initial association, suggesting that the ejection period is related to the tidal wave feature. In this current study, we measured left ventricular ejection time in both ABP and PPG waveforms, considering recent research results. A total of 27,000 cardiac cycles were analyzed for both afore-mentioned signals. The reference value for ejection time was computed based on the T-wave segment duration from the electrocardiogram waveform. In lower blood pressure, which is associated with decreased heart contractility, the results indicated an underestimation of −29 ± 19 ms in ABP and an overestimation of 18 ± 31 ms in PPG. On the other side of the spectrum, during increased contractility, the minimum errors were −3 ± 18 ms and 4 ± 33 ms, respectively. Since the tidal wave feature is strongly affected by arterial tree compliance, the population evaluation results indicate a Pearson’s correlation factor of 0.58 in the ABP case, and 0.53 in PPG. These findings highlight the need for advanced compensation techniques, in particular for PPG assessment, to achieve clinical-grade accuracy.

Artificial intelligence technology applied to an unoccluded catheter for recognition of hemodynamic changes

This study seeks to provide a reliable means for physicians to diagnose hemorrhagic complications associated with patent ductus arteriosus (PDA) in extremely low birth weight (ELBW) infants. We employ the YOLOv4 algorithm to analyze cardiac parameters from the echocardiography device's ultrasonic wave, such as left ventricular ejection time (LVET), left ventricular internal dimension-diastole (LVIDd), left ventricular internal dimension-systole (LVIDs), posterior wall thickness at end-systole (HES), and RR interval. The proposed model has achieved an impressive average detection accuracy of 89.4% for these five parameters. Additionally, the further evaluation of cardiac function can be done by deriving the end-systolic wall stress (ESWS) and left ventricle rate-corrected mean velocity of circumferential fiber shortening (mVcFc) values from these parameters. As a result, it indicates that the accuracy of ESWS and mVcFc values is 88.7% and 90.3%, respectively. With this deep learning-based approach, physicians can confidently evaluate the cardiac function of ELBW infants and diagnose PDA-related hemorrhagic complications.

Impact of bimonthly repeated total sleep deprivation and recovery sleep on cardiovascular indices.

Since short sleep duration adversely affects cardiovascular (CV) health, we investigated the effects of exposures to total sleep deprivation (TSD), and baseline (BL) and recovery (REC) sleep on CV measures. We conducted a 5-day experiment at months 2 and 4 in two separate studies (N = 11 healthy adults; 5 females). During these repeated experiments, CV measures [stroke volume (SV), cardiac index (CI), systemic vascular resistance index (SVRI), left ventricular ejection time, heart rate (HR), systolic and diastolic blood pressure (SBP and DBP) and mean arterial pressure (MAP)] were collected at three assessment time points after: (1) two BL 8 h time-in-bed (TIB) sleep opportunity nights; (2) a TSD night; and (3) two REC 8-10 h TIB nights. CV measures were also collected pre-study. TSD significantly increased SV and CI, and decreased SVRI, with large effect sizes, which importantly were reversed with recovery, indicating these measures are possible novel biomarkers for assessing the adverse consequences of TSD. Pre-study SV, CI, SVRI, HR, SBP, and MAP measures also significantly associated with TSD CV responses at months 2 and 4 [Pearson's r: 0.615-0.862; r2 : 0.378-0.743], indicating they are robust correlates of future TSD CV responses. Our novel findings highlight the critical impact of sleep on CV health across time.