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Hamid Salehi - One of the best experts on this subject based on the ideXlab platform.

  • impaired Cardiac Reserve on dobutamine stress echocardiography predicts the development of hepatorenal syndrome
    The American Journal of Gastroenterology, 2020
    Co-Authors: A Koshy, Omar Farouque, Benjamin Cailes, Adam G Testro, Jay Ramchand, J Sajeev, Huichen Han, Piyush M Srivastava, E Jones, Hamid Salehi
    Abstract:

    OBJECTIVES Cardiac dysfunction has been implicated in the genesis of hepatorenal syndrome (HRS). It is unclear whether a low Cardiac output (CO) or attenuated contractile response to hemodynamic stress can predict its occurrence. We studied cardiovascular hemodynamics in cirrhosis and assessed whether a diminished Cardiac Reserve with stress testing predicted the development of HRS on follow-up. METHODS Consecutive patients undergoing liver transplant workup with dobutamine stress echocardiography (DSE) were included. CO was measured at baseline and during low-dose dobutamine infusion at 10 μg/kg/min. HRS was diagnosed using guideline-based criteria. RESULTS A total of 560 patients underwent DSE, of whom 488 were included after preliminary assessment. There were 64 (13.1%) patients with established HRS. The HRS cohort had a higher baseline CO (8.0 ± 2 vs 6.9 ± 2 L/min; P < 0.001) and demonstrated a blunted response to low-dose dobutamine (ΔCO 29 ± 22% vs 44 ± 32%, P < 0.001) driven primarily by inotropic incompetence. Optimal cutpoint for ΔCO in patients with HRS was determined to be <25% and was used to define a low Cardiac Reserve. Among the 424 patients without HRS initially, 94 (22.1%) developed HRS over a mean follow-up of 1.5 years. Higher proportion with a low Cardiac Reserve developed HRS (52 [55.0%] vs 56 [16.9%]; hazard ratio 4.5; 95% confidence interval 3.0-6.7; P < 0.001). In a Cox multivariable model, low Cardiac Reserve remained the strongest predictor for the development of HRS (hazard ratio 3.9; 95% confidence interval 2.2-7.0; P < 0.001). DISCUSSION Patients with HRS demonstrated a higher resting CO and an attenuated Cardiac Reserve on stress testing. On longitudinal follow-up, low Cardiac Reserve was an independent predictor for the development of HRS. Assessment of Cardiac Reserve with DSE may provide a novel noninvasive risk marker for developing HRS in patients with advanced liver disease.HRS is a life-threatening complication of liver disease. We studied whether an inability to increase Cardiac contraction in response to stress can assist in the prediction of HRS. We demonstrate that patients with liver disease who exhibit Cardiac dysfunction during stress testing had a 4-fold increased risk of developing HRS. This may improve our ability for early diagnosis and treatment of patients at a higher risk of developing HRS.

  • Impaired Cardiac Reserve on Dobutamine Stress Echocardiography Predicts the Development of Hepatorenal Syndrome.
    The American journal of gastroenterology, 2020
    Co-Authors: Anoop N. Koshy, Omar Farouque, Benjamin Cailes, Adam G Testro, Jay Ramchand, J Sajeev, Huichen Han, Piyush M Srivastava, Elizabeth F Jones, Hamid Salehi
    Abstract:

    OBJECTIVES Cardiac dysfunction has been implicated in the genesis of hepatorenal syndrome (HRS). It is unclear whether a low Cardiac output (CO) or attenuated contractile response to hemodynamic stress can predict its occurrence. We studied cardiovascular hemodynamics in cirrhosis and assessed whether a diminished Cardiac Reserve with stress testing predicted the development of HRS on follow-up. METHODS Consecutive patients undergoing liver transplant workup with dobutamine stress echocardiography (DSE) were included. CO was measured at baseline and during low-dose dobutamine infusion at 10 μg/kg/min. HRS was diagnosed using guideline-based criteria. RESULTS A total of 560 patients underwent DSE, of whom 488 were included after preliminary assessment. There were 64 (13.1%) patients with established HRS. The HRS cohort had a higher baseline CO (8.0 ± 2 vs 6.9 ± 2 L/min; P < 0.001) and demonstrated a blunted response to low-dose dobutamine (ΔCO 29 ± 22% vs 44 ± 32%, P < 0.001) driven primarily by inotropic incompetence. Optimal cutpoint for ΔCO in patients with HRS was determined to be

Shouzhong Xiao - One of the best experts on this subject based on the ideXlab platform.

  • Computer-assisted diagnosis for chronic heart failure by the analysis of their Cardiac Reserve and heart sound characteristics
    Computer methods and programs in biomedicine, 2015
    Co-Authors: Yineng Zheng, Xingming Guo, Jian Qin, Shouzhong Xiao
    Abstract:

    We proposed an innovative LS-SVM based system for diagnosis of CHF.Two novel features of heart sound such as fPSDmax and sub_EF were proposed.The Cardiac Reserve indexes and heart sound features were used to diagnose the CHF.The classification performances of LS-SVM, HMM and BP-ANN were compared. An innovative computer-assisted diagnosis system for chronic heart failure (CHF) was proposed in this study, based on Cardiac Reserve (CR) indexes extraction, heart sound hybrid characteristics extraction and intelligent diagnosis model definition. Firstly, the modified wavelet packet-based denoising method was applied to data pre-processing. Then, the CR indexes such as the ratio of diastolic to systolic duration (D/S) and the amplitude ratio of the first to second heart sound (S1/S2) were extracted. The feature set consisting of the heart sound characteristics such as multifractal spectrum parameters, the frequency corresponding to the maximum peak of the normalized PSD curve (fPSDmax) and adaptive sub-band energy fraction (sub_EF) were calculated based on multifractal detrended fluctuation analysis (MF-DFA), maximum entropy spectra estimation (MESE) and empirical mode decomposition (EMD). Statistical methods such as t-test and receiver operating characteristic (ROC) curve analysis were performed to analyze the difference of each parameter between the healthy and CHF patients. Finally, least square support vector machine (LS-SVM) was employed for the implementation of intelligent diagnosis. The result indicates the achieved diagnostic accuracy, sensitivity and specificity of the proposed system are 95.39%, 96.59% and 93.75% for the detection of CHF, respectively. The selected cutoff values of the diagnosis features are D/S=1.59, S1/S2=1.31, Δα=1.34 and fPSDmax=22.49, determined by ROC curve analysis. This study suggests the proposed methodology could provide a technical clue for the CHF point-of-care system design and be a supplement for CHF diagnosis.

  • Measurement of two new indicators of Cardiac Reserve in humans, rats, rabbits, and dogs
    Journal of Biomedical Science and Engineering, 2013
    Co-Authors: Yanxia Zhao, Shouzhong Xiao, Xiaobo Yan, Jianming Liu, Yong Liu, Linmei Luo, Guoxiang Xia
    Abstract:

    Background: It is difficult to observe the phenomena of Cardiac fatigue under a low or moderate workload test, and little was reported about Cardiac fatigue under a heavy workload test because of the potential risk (sudden death) of prolonged strenuous exercise. Animal experiments would be helpful to resolve this problem. The objective of this study was to obtain baseline data of two new indicators of Cardiac Reserve in rats, rabbits, and dogs. Methods: Ten New Zealand White rabbits (1. 5 to 2 kg, 4 females), 10 male Wistar rats (2 months old), and 10 Golden Retriever dogs (40 days old, 5 females) were included in this study. Phonocardiogram of each animal was recorded. The basic points concerning heart sound quantitative analysis were: 1) measuring the duration and the amplitude of relevant heart sound components; 2) calculating and analyzing relevant indicators based on the data obtained from the above measurements, including the ratio of diastolic to systolic duration (D/S) and the ratio of the amplitude of the first heart sound to the amplitude of the second heart sound (S1/S2). Results: The baseline data of D/S ratio and S1/S2 ratio in rats, rabbits, and dogs were obtained. The swimming time to exhaustion for rabbits was several to a dozen minutes, and for rats, several hours. Conclusion: D/S ratio has an important biological implication, which is a safe and easy indicator for evaluating the Cardiac health status of both animals and humans.

  • A clinical study of Cardiac Reserve mobilizing condition for pregnant women
    Sheng wu yi xue gong cheng xue za zhi = Journal of biomedical engineering = Shengwu yixue gongchengxue zazhi, 2010
    Co-Authors: Ying-hong Zhang, Yong Shao, Shouzhong Xiao, Xingming Guo
    Abstract:

    This study was conducted on the basis of informed consent of subjects and was approved by the ethical review committee concerned. 527 pregnant women voluntarily participated in this project for the investigation of Cardiac Reserve mobilizing condition. Using the digital technique of heart sound signal processing, we measured the heart rate (HR), the ratio of the first heart sound to the second heart sound (S1/S2)and the ratio of diastolic to systolic duration (D/S) during pregnancy. There was significant difference of HR and S1/S2 between the group of non-pregnant (G1), the group of 28-36 pregnant weeks (G2), and the group of 37-42 pregnant weeks (G3) (HR, S1/S2: G1 vs G2, G1 vs G3: P or = 1.30; 64.33% of pregnant women were found to have 1.00 < D/S < 1.30, whereas 3.05% of pregnant women were found to have D/S < 1.00. These data revealed that the heart burden of the pregnant woman increased with the increase of pregnant weeks and the mobilization of Cardiac Reserve.

  • Clinical analysis of Cardiac Reserve function and outcome of preeclampsia.
    Zhonghua fu chan ke za zhi, 2009
    Co-Authors: Yong Shao, Shouzhong Xiao, Ying-hong Zhang, Xingming Guo
    Abstract:

    Objective To investigate Cardiac Reserve function and pregnant results of preeclampsia.Methods Pregnant women chosen by randomized table and hospitalized in the department of obstetrics of the first affiliated hospital of Chongqing MedicaI University were involved in this study from January to December,2008.Sixty-nine cases of normal pregnant women were divided into 3 groups:normal group 1(20cases),normal group 2(26 cases)and normal group 3(23 cases).The normal group number 1 to number 3 were paired to gestational hypertension(20 cases),mild preeclampsia(26 cases)and severe preeclampsia (23 cases),respectively.The digital technique of heart sound signal processing WaS used to measure Cardiac Reserve function parameters including the heart rate(HR),the ratio of the amplitude of the first heart sound to the second heart sound(S1/S2)and the ratio of diastolic to systolic duration(D/S)of pregnant women.The pregnant results were also recorded.Results (1)The ratio of S1/S2 in the group of severe preeclampsia 4.5±3.2 was significantly bigher than the group of gestational hypertension 2.2±1.1 and normal group 32.2±1.1(P＜0.01).The ratio of D/S of the group of severe preeclampsia 1.1±0.3 Was significantly lower than the group of gestational hypertension 1.4±0.3 and normal group 31.4±0.2(P＜0.01).(2)All cases of the normal group number 1 to number 3 and the group of gestational hypertension were found the ratio of D/S≥1.00,whereas 1 case(1/26,4%)of the group of mild preeclampsia and 4 cases(4/23.17%)of the group of severe preeclampsia were found the ratio of D/S＜1.00.(3)The two cases of the pregnant wornen(including one woman died of Cardiac arrest)with S1/S2＞5.00 and D/S＜1.00,who were in the group of severe preeclampsia,were sent to Intensive Care Unit after delivery.There were 4 cases(4/26,15%)and 6 cages(6/23,26%)of 1 minute Apgar score less than 7,7 cases(7/26,27%)and 6 cases(6/23,26%)sent to neonatal Intensive Care Unit,2 cases(2/26,8%)and 4 cases(4/23,17%)of neonatal death in the group of mild preeclampsia and in the group of severe preeclampsia,respectively.All newborns in the normal group number 1 to number 3 and the group of gestational hypertension were normal.Conclusions The Cardiac Reserve function of a pregnant woman with preeelampsia is decreased with the severity of preeclampsia and the parturient and neonatal results get worse.The distal technique of heart sound signal processing is a safe,harmless,simple and effective tool to measure Cardiac Reserve funotion of preeclampsia,and is worthy of widely used clinically. Key words: Pre-eclampsia; Pregnancy complications,cardiovascular; Stroke volume; Pregnancy outcome

  • A relative value method for measuring and evaluating Cardiac Reserve.
    Biomedical engineering online, 2002
    Co-Authors: Shouzhong Xiao, Xingming Guo, Xiaobo Sun, Zifu Xiao
    Abstract:

    Background Although a very close relationship between the amplitude of the first heart sound (S1) and the Cardiac contractility have been proven by previous studies, the absolute value of S1 can not be applied for evaluating Cardiac contractility. However, we were able to devise some indicators with relative values for evaluating Cardiac function.

Aaron L Baggish - One of the best experts on this subject based on the ideXlab platform.

  • post exercise oxygen uptake recovery delay a novel index of impaired Cardiac Reserve capacity in heart failure
    Jacc-Heart Failure, 2018
    Co-Authors: Cole S Bailey, Luke Wooster, Mary D Buswell, Sarvagna Patel, Paul P Pappagianopoulos, Kristian Bakken, Casey White, Melissa Tanguay, Jasmine B Blodgett, Aaron L Baggish
    Abstract:

    Abstract Objectives This study sought to characterize the functional and prognostic significance of oxygen uptake (VO2) kinetics following peak exercise in individuals with heart failure (HF). Background It is unknown to what extent patterns of VO2 recovery following exercise reflect circulatory response during exercise in HF with pReserved ejection fraction (HFpEF) and HF with reduced ejection fraction (HFrEF). Methods We investigated patients (30 HFpEF, 20 HFrEF, and 22 control subjects) who underwent cardiopulmonary exercise testing with invasive hemodynamic monitoring and a second distinct HF cohort (n = 106) who underwent noninvasive cardiopulmonary exercise testing with assessment of long-term outcomes. Fick Cardiac output (CO) and Cardiac filling pressures were measured at rest and throughout exercise in the initial cohort. A novel metric, VO2 recovery delay (VO2RD), defined as time until post-exercise VO2 falls permanently below peak VO2, was measured to characterize VO2 recovery kinetics. Results VO2RD in patients with HFpEF (median 25 s [interquartile range (IQR): 9 to 39 s]) and HFrEF (28 s [IQR: 2 to 52 s]) was in excess of control subjects (5 s [IQR: 0 to 7 s]; p  Conclusions Post-exercise VO2RD is an easily recognizable, noninvasively derived pattern that signals impaired Cardiac output augmentation during exercise and predicts outcomes in HF. The presence and duration of VO2RD may complement established exercise measurements for assessment of Cardiac Reserve capacity.

  • post exercise oxygen uptake recovery delay a novel index of impaired Cardiac Reserve capacity in heart failure
    Jacc-Heart Failure, 2018
    Co-Authors: Cole S Bailey, Luke Wooster, Mary D Buswell, Sarvagna Patel, Paul P Pappagianopoulos, Kristian Bakken, Casey White, Melissa Tanguay, Jasmine B Blodgett, Aaron L Baggish
    Abstract:

    Abstract Objectives This study sought to characterize the functional and prognostic significance of oxygen uptake (VO 2 ) kinetics following peak exercise in individuals with heart failure (HF). Background It is unknown to what extent patterns of VO 2 recovery following exercise reflect circulatory response during exercise in HF with pReserved ejection fraction (HFpEF) and HF with reduced ejection fraction (HFrEF). Methods We investigated patients (30 HFpEF, 20 HFrEF, and 22 control subjects) who underwent cardiopulmonary exercise testing with invasive hemodynamic monitoring and a second distinct HF cohort (n = 106) who underwent noninvasive cardiopulmonary exercise testing with assessment of long-term outcomes. Fick Cardiac output (CO) and Cardiac filling pressures were measured at rest and throughout exercise in the initial cohort. A novel metric, VO 2 recovery delay (VO 2 RD), defined as time until post-exercise VO 2 falls permanently below peak VO 2 , was measured to characterize VO 2 recovery kinetics. Results VO 2 RD in patients with HFpEF (median 25 s [interquartile range (IQR): 9 to 39 s]) and HFrEF (28 s [IQR: 2 to 52 s]) was in excess of control subjects (5 s [IQR: 0 to 7 s]; p  2 RD was inversely related to Cardiac output augmentation during exercise in HFpEF (ρ = −0.70) and HFrEF (ρ = −0.73, both p  2 RD predicted transplant-free survival in univariate and multivariable Cox regression analysis (Cox hazard ratios: 1.49 and 1.37 per 10-s increase in VO 2 RD, respectively; both p  Conclusions Post-exercise VO 2 RD is an easily recognizable, noninvasively derived pattern that signals impaired Cardiac output augmentation during exercise and predicts outcomes in HF. The presence and duration of VO 2 RD may complement established exercise measurements for assessment of Cardiac Reserve capacity.

Nico A. Blom - One of the best experts on this subject based on the ideXlab platform.

  • Effect of age on exercise capacity and Cardiac Reserve in patients with pulmonary atresia with intact ventricular septum after biventricular repair.
    Journal of Cardiovascular Magnetic Resonance, 2012
    Co-Authors: Soha Romeih, Maarten Groenink, Mart N. Van Der Plas, Barbara J.m. Mulder, Nico A. Blom, Anje M. Spijkerboer
    Abstract:

    OBJECTIVESIn patients with pulmonary atresia with intact ventricular septum (PAIVS), biventricular repair is considered to be the optimal treatment option in the absence of significant right ventricular (RV) hypoplasia. However, long-term clinical outcome studies are limited. We evaluated exercise capacity and Cardiac function during pharmacological stress in children and young adults with PAIVS after biventricular repair.METHODSTen PAIVS patients after biventricular repair, with a median age of 12 years (range 9-42 years), underwent a cardiopulmonary exercise test, dobutamine stress magnetic resonance imaging (DS-MRI) and delayed contrast enhancement (DCE) MRI.RESULTSThe patients' ages negatively correlated with exercise capacity (r = -0.72, P = 0.01) as well as left (LV) and RV stroke volume (SV) response to pharmacological stress (r = -0.72, P = 0.02; and r = -0.64, P = 0.04; respectively), Furthermore, older age was associated with decreased RV E/A volume ratio and increased pulmonary late diastolic forward flow percentage (r = 0-0.65, P = 0.04, r = 0.66, P = 0.03, respectively). RV E/A volume ratio positively correlated with RV-SV response to DS-MRI (r = 0.77, P = 0.009). and O(2)-pulse during physical stress correlated with biventricular SV response to DS-MRI. No RV or LV ventricular myocardial fibrosis was detected.CONCLUSIONSIn PAIVS patients after biventricular repair exercise capacity and Cardiac Reserve decrease with age. These findings appear to be related to impaired diastolic RV function and decreased RV filling, indicating that the function of the relatively small RV deteriorates with time

  • Exercise capacity and Cardiac Reserve in children and adolescents with corrected pulmonary atresia with intact ventricular septum after univentricular palliation and biventricular repair
    The Journal of thoracic and cardiovascular surgery, 2011
    Co-Authors: Soha Romeih, Maarten Groenink, Arno A.w. Roest, Mart N. Van Der Plas, Mark G. Hazekamp, Barbara J.m. Mulder, Nico A. Blom
    Abstract:

    Objective Management of pulmonary atresia with intact ventricular septum is challenging and depends on the severity of right ventricular hypoplasia. Clinical outcomes of biventricular repair seem favorable to univentricular palliation, but data on superiority of biventricular repair regarding exercise capacity are conflicting. We investigated the response to physical and pharmacologic stress in patients with surgically corrected pulmonary atresia with intact ventricular septum. Methods Sixteen patients (7 patients after univentricular palliation, age 11.8 ± 2.6 years; 7 patients after biventricular repair, age 12.9 ± 2.7 years; and 2 patients after 1.5 ventricular repair, age 12 and 19 years) underwent cardiopulmonary exercise test, dobutamine stress magnetic resonance imaging, and delayed contrast-enhanced magnetic resonance imaging. Results The univentricular group showed impaired exercise capacity in contrast with normal exercise capacity in the biventricular group. Left ventricular ejection fraction increased in both groups. With dobutamine, left ventricular stroke volume increased only in the biventricular group (+11.3 ± 5.0 mL, P P  = .9). Heart rate increase was inadequate in the univentricular group. Maximum oxygen consumption and oxygen pulse were strongly correlated with left ventricular stroke volume during stress but not at rest. The results of the 2 patients after 1.5 ventricular repair were comparable to those of the univentricular group. No myocardial fibrosis was detected. Conclusions Impaired exercise capacity in children and adolescents with pulmonary atresia with intact ventricular septum after univentricular palliation is related to decreased Cardiac Reserve and inadequate chronotropic response. Young patients with pulmonary atresia with intact ventricular septum after biventricular repair show normal exercise capacity and Cardiac Reserve.

Barry A. Borlaug - One of the best experts on this subject based on the ideXlab platform.

  • Myocardial Injury and Cardiac Reserve in Patients With Heart Failure and PReserved Ejection Fraction
    Journal of the American College of Cardiology, 2018
    Co-Authors: Masaru Obokata, Yogesh N.v. Reddy, Vojtech Melenovsky, Garvan C. Kane, Thomas P. Olson, Petr Jarolim, Barry A. Borlaug
    Abstract:

    Abstract Background Cardiac Reserve is depressed in patients with heart failure and pReserved ejection fraction (HFpEF). The mechanisms causing this are poorly understood. Objectives The authors hypothesized that myocardial injury might contribute to the hemodynamic derangements and Cardiac Reserve limitations that are present in HFpEF. Markers of cardiomyocyte injury, central hemodynamics, ventricular function, and determinants of Cardiac oxygen supply–demand balance were measured. Methods Subjects with HFpEF (n = 38) and control subjects without heart failure (n = 20) underwent Cardiac catheterization, echocardiography, and expired gas analysis at rest and during exercise. Central venous blood was sampled to measure plasma high-sensitivity troponin T levels as an index of cardiomyocyte injury. Results Compared with control subjects, troponins were more than 2-fold higher in subjects with HFpEF at rest and during exercise (p  −1  × l × dl −1 vs. 30 ± 9 mm Hg × s × min −1  × l × dl −1 ; p  Conclusions Limitations in LV functional Reserve and the hemodynamic derangements that develop secondary to these limitations during exercise in HFpEF are correlated with the severity of Cardiac injury, assessed by plasma levels of troponin T. Further study is warranted to determine the mechanisms causing myocyte injury in HFpEF and the potential role of ischemia, and to identify and test novel interventions targeted to these mechanisms. (EXEC [Study of Exercise and Heart Function in Patients With Heart Failure and Pulmonary Vascular Disease]; NCT01418248)

  • Myocardial Injury and Cardiac Reserve Limitation in Heart Failure with PReserved Ejection Fraction
    Journal of Cardiac Failure, 2018
    Co-Authors: Masaru Obokata, Yogesh N.v. Reddy, Vojtech Melenovsky, Garvan C. Kane, Thomas P. Olson, Petr Jarolim, Barry A. Borlaug
    Abstract:

    Background Cardiac Reserve is depressed in patients with heart failure and pReserved ejection fraction (HFpEF). The mechanisms causing this are poorly understood. We tested the hypotheses that myocardial injury might contribute to the hemodynamic derangements and Cardiac Reserve limitations that are present in HFpEF. Methods Subjects with HFpEF (n=38) and controls without HF (n=20) underwent Cardiac catheterization, echocardiography, and expired gas analysis at rest and during exercise. Markers of cardiomyocyte injury (high sensitivity troponin T), central hemodynamics, ventricular function, and determinants of Cardiac oxygen supply-demand balance were measured. Results Compared to controls, troponins were more than two-fold higher in subjects with HFpEF at rest and during exercise (p Conclusions Limitations in left ventricular functional Reserve and the hemodynamic derangements that develop secondary to these limitations during exercise in HFpEF are correlated with the severity of Cardiac injury, assessed by plasma levels of troponin T. Further study is warranted to determine the mechanisms causing myocyte injury in HFpEF, the potential role of ischemia, and to identify and test novel interventions targeted to these mechanisms.

  • Reply: Nitrites/Nitrates in Heart Failure With PReserved Ejection Fraction.
    Journal of the American College of Cardiology, 2016
    Co-Authors: Barry A. Borlaug, Katlyn E. Koepp, Vojtech Melenovsky
    Abstract:

    We thank Dr. Weber and colleagues for their interest and thoughtful comments regarding our recent trial [(1)][1] demonstrating improvement in exercise hemodynamics and Cardiac Reserve following acute infusion of sodium nitrite in patients with heart failure and pReserved ejection fraction (HFpEF