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Physiological Reports Jul 2022Volume responsiveness can be evaluated by tilting maneuvers such as head-down tilt (HDT) and passive leg raising (PLR), but the two procedures use different references... (Randomized Controlled Trial)
Randomized Controlled Trial
Volume responsiveness can be evaluated by tilting maneuvers such as head-down tilt (HDT) and passive leg raising (PLR), but the two procedures use different references (HDT the supine position; PLR the semi-recumbent position). We tested whether the two procedures identify "normovolemia" by evaluating the stroke volume (SV) and cardiac output (CO) responses and whether the peripheral perfusion index (PPI) derived from pulse oximetry provides similar information. In randomized order, 10 healthy men were exposed to both HDT and PLR, and evaluations were made also when the subjects fasted. Central cardiovascular variables were derived by pulse contour analysis and changes in central blood volume assessed by thoracic electrical admittance (TEA). During HDT, SV remained stable (fasted 110 ± 16 vs. 109 ± 16 ml; control 113 ± 16 vs. 111 ± 16 ml, p > 0.05) with no change in CO, TEA, PPI, or SV variation (SVV). In contrast during PLR, SV increased (fasted 108 ± 17 vs. 117 ± 17 ml; control 108 ± 18 vs. 117 ± 18 ml, p < 0.05) followed by an increase in TEA (p < 0.05) and CO increased when subjects fasted (6.7 ± 1.5 vs. 7.1 ± 1.5, p = 0.007) with no change in PPI or SVV. In conclusion, SV has a maximal value for rest in supine men, while PLR restores SV as CBV is reduced in a semi-recumbent position and the procedure thereby makes healthy volunteers seem fluid responsive.
Topics: Blood Volume; Cardiac Output; Head-Down Tilt; Hemodynamics; Humans; Leg; Male; Stroke Volume
PubMed: 35854636
DOI: 10.14814/phy2.15216 -
Journal of Cardiology Jan 2017In a given individual, a consistent relationship exists between oxygen uptake (V˙O) and heart rate (HR) during exercise. The quotient of V˙O and HR (V˙O/HR) is called...
BACKGROUND
In a given individual, a consistent relationship exists between oxygen uptake (V˙O) and heart rate (HR) during exercise. The quotient of V˙O and HR (V˙O/HR) is called the oxygen pulse (O pulse), and its value is dependent on stroke volume (SV). However, it is difficult to believe that the O pulse would indicate the SV when HR has been modified as with the use of beta-adrenergic receptor blockers (BB). Until now, the effect of BB on peak O pulse has not been precisely studied. We tried to clarify the effect of BB on the relationship between O pulse and SV.
METHODS
Of 699 consecutive heart disease subjects who performed cardiopulmonary exercise tests (CPX) from 2012 to 2014, we enrolled 430 subjects who had sinus rhythm and could perform CPX until exhaustion. One hundred and fifty-seven subjects were taking BB. SV was evaluated during CPX using impedance cardiography, and we compared the peak O pulse with peak SV between patients without BB (Group A) and with BB (Group B).
RESULTS
The HRs at rest and peak exercise in Group A were greater than those in Group B (74.4±13.0/min vs. 71.8±11.3/min, p<0.01, 134.9±21.7/min vs. 124.9±23.6/min, p<0.01, respectively). The regression line of the peak O pulse against the peak SV was steeper in Group B than in Group A. When we divided the patients into two groups according to the average values of the peak SV and peak V˙O, O pulse/SV ratio in Group B above the average was greater than that in Group A, whereas it was similar in the two groups that were below average.
CONCLUSION
We found that the increase in the O pulse was disproportionately greater than the SV that was measured by impedance cardiography when a BB was used in patients with preserved SV and exercise tolerance.
Topics: Adrenergic beta-Antagonists; Aged; Cardiography, Impedance; Exercise Test; Exercise Tolerance; Female; Heart Diseases; Heart Rate; Humans; Male; Middle Aged; Oxygen Consumption; Rest; Stroke Volume
PubMed: 27021429
DOI: 10.1016/j.jjcc.2016.02.017 -
Anesthesiology May 2019
Review
Topics: Fasting; Fluid Therapy; Hemodynamics; Humans; Perioperative Care; Stroke Volume
PubMed: 30789364
DOI: 10.1097/ALN.0000000000002603 -
Journal of Cardiac Failure Sep 2022The role of blood volume (BV) expansion vs a change in vascular compliance in worsening heart failure (HF) remains under debate. We aimed to assess the relationship...
BACKGROUND
The role of blood volume (BV) expansion vs a change in vascular compliance in worsening heart failure (HF) remains under debate. We aimed to assess the relationship between BV and resting and stress hemodynamics in worsening HF and to further elucidate the significance of BV in cardiac decompensation.
METHODS AND RESULTS
Patients with worsening HF underwent radiolabeled indicator-dilution BV analysis and cardiac catheterization. Intravascular volumes and resting/stress hemodynamics were recorded. Provocative stress maneuvers included change in systolic blood pressure (ΔSBP) from lying to standing and Valsalva and intracardiac pressure changes with leg raise. Correlation between BV and invasive hemodynamics were assessed by linear regression. Of 27 patients with worsening HF, patients' characteristics included mean age 61 ± 12 years, 70% male, 19% Black, and mean ejection fraction 29% ± 15%. Of the patients, 13 (48%) had hypervolemia as measured by total BV, which weakly correlated with ΔSBP by position (R = 0.009) and Valsalva (R = 0.003) and with right atrial (R = 0.049) and pulmonary capillary wedge (R = 0.047) pressure changes during leg raise.
CONCLUSIONS
In patients with worsening HF, BV mildly correlated with intracardiac pressures at rest. Provocative maneuvers intended to test vascular compliance did not correlate with BV, indicating that compliance may serve as a stand-alone metric in HF.
Topics: Aged; Blood Volume; Female; Heart Failure; Hemodynamics; Humans; Male; Middle Aged; Pulmonary Wedge Pressure; Stroke Volume
PubMed: 35483537
DOI: 10.1016/j.cardfail.2022.04.004 -
BMC Anesthesiology Apr 2023Left ventricular end-diastolic volume (EDV) is a major determinant of cardiac preload. However, its use in fluid management is limited by the lack of a simple means to... (Observational Study)
Observational Study
A method for calculating left ventricular end-diastolic volume as an index of left ventricular preload from the pre-ejection period, ejection time, blood pressure, and stroke volume: a prospective, observational study.
BACKGROUND
Left ventricular end-diastolic volume (EDV) is a major determinant of cardiac preload. However, its use in fluid management is limited by the lack of a simple means to measure it noninvasively. This study presents a new noninvasive method that was validated against simultaneously measured EDV by transthoracic echocardiography (TTE). The goal of this study was to develop and validate a method to estimate EDV in humans non-invasively from left ventricular arterial coupling (Ees/Ea) and stroke volume (SV).
METHODS
Ees/Ea can be calculated non-invasively from the four parameters of end-systolic arterial pressure (Pes), diastolic arterial pressure (DBP), pre-ejection period (PEP), and ejection time (ET), using the approximation formula. In addition, if SV can be assessed, EDV can be calculated. Therefore, using a vascular screening system (VaSera 1000/1500, Fukuda Denshi Co., Ltd., Tokyo, Japan), blood pressure, PEP, and ET were measured noninvasively, the SV value was obtained using an ultrasound diagnostic device, EDV was calculated (EDV calc), and it was compared with EDV obtained using the ultrasound diagnostic device (EDV echo). The results are shown as mean ± standard deviation values.
RESULTS
There were 48 healthy subjects (40 men, 8 women), with a mean age of 24 ± 4 years, mean height of 169 ± 7 cm, and mean weight of 65 ± 12 kg. EDV echo was 91 ± 16 ml, and EDV calc was 102 ± 21 ml. There was a significant correlation between EDV echo and EDV calc (R = 0.81, p < 0.01). A Bland-Altman plot between EDV echo and EDV calc showed that the bias and limits of agreement were -11.2 ml (-36.6, + 14.2 ml).
CONCLUSIONS
The results suggest that EDV can be measured non-invasively from Ees/Ea and SV. This suggests that continuous measurements may potentially work, using equipment available in the intraoperative setting.
Topics: Male; Humans; Female; Young Adult; Adult; Stroke Volume; Blood Pressure; Prospective Studies; Heart Ventricles; Heart
PubMed: 37118667
DOI: 10.1186/s12871-023-02103-2 -
Journal of the American College of... Feb 2016
Topics: Exercise Tolerance; Female; Heart Failure; Humans; Male; Stroke Volume; Ventricular Function, Left
PubMed: 26868692
DOI: 10.1016/j.jacc.2015.11.045 -
JACC. Heart Failure Oct 2023Among patients with heart failure with preserved ejection fraction (HFpEF), a distinct hemodynamic phenotype has been recently described, ie, latent pulmonary vascular...
BACKGROUND
Among patients with heart failure with preserved ejection fraction (HFpEF), a distinct hemodynamic phenotype has been recently described, ie, latent pulmonary vascular disease (HFpEF-latentPVD), defined by exercise pulmonary vascular resistance (PVR) >1.74 WU.
OBJECTIVES
This study aims to explore the pathophysiological significance of HFpEF-latentPVD.
METHODS
The authors analyzed a cohort of patients who had undergone supine exercise right heart catheterization with cardiac output (CO) measured by direct Fick method, between 2016 and 2021. HFpEF-latentPVD patients were compared with HFpEF control patients.
RESULTS
Out of 86 HFpEF patients, 21% qualified as having HFpEF-latentPVD, 78% of whom had PVR >2 WU at rest. Patients with HFpEF-latentPVD were older, with a higher pretest probability of HFpEF, and more frequently experienced atrial fibrillation and at least moderate tricuspid regurgitation (P < 0.05). PVR trajectories differed between HFpEF-latentPVD patients and HFpEF control patients (P = 0.008), slightly increasing in the former and reducing in the latter. HFpEF-latentPVD patients displayed more frequent hemodynamically significant tricuspid regurgitation during exercise (P = 0.002) and had more impaired CO and stroke volume reserve (P < 0.05). Exercise PVR was correlated with mixed venous O tension (R = 0.33) and stroke volume (R = 0.31) in HFpEF-latentPVD patients. The HFpEF-latentPVD patients had had higher dead space ventilation during exercise and higher PaCO (P < 0.05), which correlated with resting PVR (R = 0.21). Event-free survival was reduced in HFpEF-latentPVD patients (P < 0.05).
CONCLUSIONS
The results suggest that when CO is measured by direct Fick, few HFpEF patients have isolated latent PVD (ie, normal PVR at rest, becoming abnormal during exercise). HFpEF-latentPVD patients present with CO limitation to exercise, associated with dynamic tricuspid regurgitation, altered ventilatory control, and pulmonary vascular hyperreactivity, portending a poor prognosis.
Topics: Humans; Stroke Volume; Heart Failure; Tricuspid Valve Insufficiency; Cardiac Output; Vascular Diseases; Exercise Test
PubMed: 37115127
DOI: 10.1016/j.jchf.2023.03.003 -
Clinical Medicine (London, England) Apr 2018Heart failure with preserved ejection fraction (HFpEF) represents a heterogeneous collection of conditions that are unified by the presence of a left ventricular... (Review)
Review
Heart failure with preserved ejection fraction (HFpEF) represents a heterogeneous collection of conditions that are unified by the presence of a left ventricular ejection fraction ≥50%, evidence of impaired diastolic function and elevated natriuretic peptide levels, all within the context of typical heart failure signs and symptoms. However, while HFpEF is steadily becoming the predominant form of heart failure, disease-modifying treatment options for this population remain sparse. This review provides an overview of the diagnosis, management and prevention of HFpEF for general physicians.
Topics: Heart Failure; Humans; Stroke Volume; Ventricular Dysfunction, Left
PubMed: 29700089
DOI: 10.7861/clinmedicine.18-2-s24 -
The Journal of the American Osteopathic... Jul 2015Heart failure with preserved ejection fraction (HFpEF) is a complex clinical condition. Initially called diastolic heart failure, it soon became clear that this... (Review)
Review
Heart failure with preserved ejection fraction (HFpEF) is a complex clinical condition. Initially called diastolic heart failure, it soon became clear that this condition is more than the opposite side of systolic heart failure. It is increasingly prevalent and lethal. Currently, HFpEF represents more than 50% of heart failure cases and shares a 90-day mortality and readmission rate similar to heart failure with reduced ejection fraction. Heart failure with preserved ejection fraction is best considered to be a systemic disease. From a cardiovascular standpoint, it is not just a stiff ventricle. A stiff ventricle combined with a stiff arterial and venous system account for the clinical manifestations of flash pulmonary edema and the marked changes in renal function or systemic blood pressure with minor changes in fluid volume status. No effective pharmacologic treatments are available for patients with HFpEF, but an approach to the musculoskeletal system has merit: the functional limitations and exercise intolerance that patients experience are largely due to abnormalities of peripheral vascular function and skeletal muscle dysfunction. Regular exercise training has strong objective evidence to support its use to improve quality of life and functional capacity for patients with HFpEF. This clinical review summarizes the current evidence on the pathophysiologic aspects, diagnosis, and management of HFpEF.
Topics: Heart Failure; Humans; Severity of Illness Index; Stroke Volume; Ventricular Function, Left
PubMed: 26111131
DOI: 10.7556/jaoa.2015.089 -
Experimental Physiology Jul 2005In this paper we review recent developments in the methodology of non-invasive finger arterial pressure measurement and the information about arterial flow that can be... (Review)
Review
In this paper we review recent developments in the methodology of non-invasive finger arterial pressure measurement and the information about arterial flow that can be obtained from it. Continuous measurement of finger pressure based on the volume-clamp method was introduced in the early 1980s both for research purposes and for clinical medicine. Finger pressure tracks intra-arterial pressure but the pressure waves may differ systematically both in shape and magnitude. Such bias can, at least partly, be circumvented by reconstruction of brachial pressure from finger pressure by using a general inverse anti-resonance model correcting for the difference in pressure waveforms and an individual forearm cuff calibration. The Modelflow method as implemented in the Finometer computes an aortic flow waveform from peripheral arterial pressure by simulating a non-linear three-element model of the aortic input impedance. The methodology tracks fast changes in stroke volume (SV) during various experimental protocols including postural stress and exercise. If absolute values are required, calibration against a gold standard is needed. Otherwise, Modelflow-measured SV is expressed as change from control with the same precision in tracking. Beat-to-beat information on arterial flow offers important and clinically relevant information on the circulation beyond what can be detected by arterial pressure.
Topics: Arteries; Blood Pressure; Electrophysiology; Fingers; Humans; Patch-Clamp Techniques; Stroke Volume
PubMed: 15802289
DOI: 10.1113/expphysiol.2005.030262