scholarly journals Noninvasive Scale Measurement of Stroke Volume and Cardiac Output Compared With the Direct Fick Method: A Feasibility Study

2021 ◽  
Author(s):  
Daniel Yazdi ◽  
Suriya Sridaran ◽  
Sarah Smith ◽  
Corey Centen ◽  
Sarin Patel ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Stroke Volume ◽  
Cardiac Function ◽  
Exercise Test ◽  
Medical Center ◽  
Cardiopulmonary Exercise Test ◽  
Cardiac Monitoring ◽  
Limits Of Agreement ◽  
Cardiopulmonary Exercise ◽  
The Mean

Background Objective markers of cardiac function are limited in the outpatient setting and may be beneficial for monitoring patients with chronic cardiac conditions. We assess the accuracy of a scale, with the ability to capture ballistocardiography, electrocardiography, and impedance plethysmography signals from a patient’s feet while standing on the scale, in measuring stroke volume and cardiac output compared with the gold‐standard direct Fick method. Methods and Results Thirty‐two patients with unexplained dyspnea undergoing level 3 invasive cardiopulmonary exercise test at a tertiary medical center were included in the final analysis. We obtained scale and direct Fick measurements of stroke volume and cardiac output before and immediately after invasive cardiopulmonary exercise test. Stroke volume and cardiac output from a cardiac scale and the direct Fick method correlated with r =0.81 and r =0.85, respectively ( P <0.001 each). The mean absolute error of the scale estimated stroke volume was −1.58 mL, with a 95% limits of agreement of −21.97 to 18.81 mL. The mean error for the scale estimated cardiac output was −0.31 L/min, with a 95% limits of agreement of −2.62 to 2.00 L/min. The changes in stroke volume and cardiac output before and after exercise were 78.9% and 96.7% concordant, respectively, between the 2 measuring methods. Conclusions In a proof‐of‐concept study, this novel scale with cardiac monitoring abilities may allow for noninvasive, longitudinal measures of cardiac function. Using the widely accepted form factor of a bathroom scale, this method of monitoring can be easily integrated into a patient’s lifestyle.

scholarly journals Non-Invasive Scale Measurement of Cardiac Output Compared with the Gold-Standard Direct Fick Method: A Feasibility Study

2021 ◽  
Author(s):  
Daniel Yazdi ◽  
Sarin Patel ◽  
Suriya Sridaran ◽  
Evan Wilson ◽  
Sarah Smith ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Stroke Volume ◽  
Cardiac Function ◽  
Exercise Test ◽  
Gold Standard ◽  
Cardiopulmonary Exercise Test ◽  
Cardiac Monitoring ◽  
Non Invasive ◽  
Cardiopulmonary Exercise ◽  
The Mean

AbstractBackgroundObjective markers of cardiac function are limited in the outpatient setting and may be beneficial for monitoring patients with chronic cardiac conditions.ObjectiveWe assess the accuracy of a scale, with the ability to capture ballistocardiography, electrocardiography, and impedance plethysmography signals from a patient’s feet while standing on the scale, in measuring stroke volume and cardiac output compared to the gold-standard direct Fick method.MethodsThirty-two patients with unexplained dyspnea undergoing level 3 invasive cardiopulmonary exercise test at a tertiary medical center were included in the final analysis. We obtained scale and direct Fick measurements of stroke volume and cardiac output before and immediately after invasive cardiopulmonary exercise test.ResultsStroke volume and cardiac output from a cardiac scale and the direct Fick method correlated with r = 0.81 and r = 0.85, respectively (P < 0.001 each). The mean absolute error of the scale estimated stroke volume was -1.58 mL, with a 95% limits of agreement (LOA) of -21.97 mL to 18.81 mL. The mean error for the scale estimated cardiac output was -0.31 L/min, with a 95% LOA of -2.62 L/min to 2.00 L/min. The change in stroke volume and cardiac output before and after exercise were 78.9% and 96.7% concordant, respectively between the two measuring methods.ConclusionsThis novel scale with cardiac monitoring abilities may allow for non-invasive, longitudinal measures of cardiac function. Using the widely accepted form factor of a bathroom scale, this method of monitoring can be easily integrated into a patient’s lifestyle.

Myocardial function in rat genetic models of low and high aerobic running capacity

2002 ◽  
Vol 282 (3) ◽  
pp. R721-R726 ◽  
Author(s):  
John C. Barbato ◽  
Soon Jin Lee ◽  
Lauren Gerard Koch ◽  
George T. Cicila
Keyword(s):  
Cardiac Output ◽  
Stroke Volume ◽  
Cardiac Function ◽  
Atp Hydrolysis ◽  
Mrna Level ◽  
Inbred Strains ◽  
Left Ventricular ◽  
Genetic Models ◽  
Heart Preparation ◽  
The Mean

We recently evaluated treadmill aerobic running capacity in 11 inbred strains of rats and found that isolated working left ventricular function correlated ( r = 0.86) with aerobic running capacity. Among these 11 strains the Buffalo (BUF) hearts produced the lowest and the DA hearts the highest isolated cardiac output. The goal of this study was to investigate the components of cardiac function (i.e., coronary flow, heart rates, stroke volume, contractile dynamics, and cross-bridge cycling) to characterize further the BUF and DA inbred strains as potential models of contrasting myocardial performance. Cardiac performance was assessed using the Langendorff-Neely working heart preparation. Isolated DA hearts were superior ( P< 0.05) to the BUF hearts for cardiac output (63%), stroke volume (60%), aortic +dP/d t (47%), and aortic −dP/d t(46%). The mean α/β-myosin heavy chain (MHC) isoform ratio for DA hearts was 21-fold higher relative to BUF hearts. At the steady-state mRNA level, DA hearts had a fivefold higher α/β-ratio than the BUF hearts. The mean rate of ATP hydrolysis by MHCs was 64% greater in DA compared with BUF ventricles. These data demonstrate that the BUF and DA strains can serve as genetic models of contrasting low and high cardiac function.

Do rebreathing manoeuvres for non-invasive measurement of cardiac output during maximum exercise test alter the main cardiopulmonary parameters?

2019 ◽  
Vol 26 (15) ◽  
pp. 1616-1622 ◽  
Author(s):  
Carlo Vignati ◽  
Marco Morosin ◽  
Laura Fusini ◽  
Beatrice Pezzuto ◽  
Emanuele Spadafora ◽  
...  
Keyword(s):  
New York ◽  
Cardiac Output ◽  
Oxygen Uptake ◽  
Anaerobic Threshold ◽  
Exercise Testing ◽  
Exercise Test ◽  
Cardiopulmonary Exercise Testing ◽  
Heart Association ◽  
Cardiopulmonary Exercise Test ◽  
Cardiopulmonary Exercise

Background Inert gas rebreathing has been recently described as an emergent reliable non-invasive method for cardiac output determination during exercise, allowing a relevant improvement of cardiopulmonary exercise test clinical relevance. For cardiac output measurements by inert gas rebreathing, specific respiratory manoeuvres are needed which might affect pivotal cardiopulmonary exercise test parameters, such as exercise tolerance, oxygen uptake and ventilation vs carbon dioxide output (VE/VCO2) relationship slope. Method We retrospectively analysed cardiopulmonary exercise testing of 181 heart failure patients who underwent both cardiopulmonary exercise testing and cardiopulmonary exercise test+cardiac output within two months (average 16 ± 15 days). All patients were in stable clinical conditions (New York Heart Association I–III) and on optimal medical therapy. Results The majority of patients were in New York Heart Association Class I and II (78.8%), with a mean left ventricular ejection fraction of 31 ± 10%. No difference was found between the two tests in oxygen uptake at peak exercise (1101 (interquartile range 870–1418) ml/min at cardiopulmonary exercise test vs 1103 (844–1389) at cardiopulmonary exercise test-cardiac output) and at anaerobic threshold. However, anaerobic threshold and peak heart rate, peak workload (75 (58–101) watts and 64 (42–90), p < 0.01) and carbon dioxide output were significantly higher at cardiopulmonary exercise testing than at cardiopulmonary exercise test+cardiac output, whereas VE/VCO2 slope was higher at cardiopulmonary exercise test+cardiac output (30 (27–35) vs 33 (28–37), p < 0.01). Conclusion The similar anaerobic threshold and peak oxygen uptake in the two tests with a lower peak workload and higher VE/VCO2 slope at cardiopulmonary exercise test+cardiac output suggest a higher respiratory work and consequent demand for respiratory muscle blood flow secondary to the ventilatory manoeuvres. Accordingly, VE/VCO2 slope and peak workload must be evaluated with caution during cardiopulmonary exercise test+cardiac output.

Novel rehabilitation program after left ventricular assist device (LVAD) implantation improves functional tests and reduces levels of prognostic heart failure biomarkers

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
T Chwyczko ◽  
L Zalucka ◽  
E Smolis-Bak ◽  
I Kowalik ◽  
E Noszczak ◽  
...  
Keyword(s):  
Heart Failure ◽  
Exercise Test ◽  
Cardiopulmonary Exercise Test ◽  
Rehabilitation Program ◽  
Left Ventricular ◽  
Prognostic Biomarkers ◽  
Funding Source ◽  
Walking Test ◽  
Cardiopulmonary Exercise ◽  
Galectin 3

Abstract Background Rehabilitation after LVAD implantation is increasingly used. We developed the novel method of comprehensive rehabilitation starting directly after LVAD implantation. Study group 21 recent LVAD (15 Heart Mate III, 6 HeartWare) recipients (56.2±11.7 yrs, 100% men) were included to 5-week rehabilitation program, which included supervised endurance training on cycloergometer (5 times per week), resistance training, general fitness exercises with elements of equivalent and coordination exercises (every day). 6-minute walking test (6MWT), cardiopulmonary exercise test (CPET) and prognostic biomarkers: NT-proBNP, Galectin-3 and ST2 were investigated at the beginning and at the end of rehabilitation program. Results See Table 1. At the end of rehabilitation program, significant increase in 6MWT distance, maximum workload, peak VO2 and upward shift of anaerobic threshold in CPET were observed in all patients. Significant reductions of NTproBNP, ST2 and galectin-3 levels were observed. There were no major adverse events during rehabilitaton. Conclusions Comprehensive novel rehabilitation in LVAD recipients is safe and results in significant improvement of 6-minutes walking test distance and cardiopulmonary exercise test results. Moreover, this novel rehabilitation program reduces levels of prognostic biomarkers of heart failure: NT-proBNP, Galectin-3 and ST2. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): National Center for Research and Development - STRATEGMED II project

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