Heart rate perturbation in chick embryos: a comparison of two methods

1991 ◽  
Vol 260 (6) ◽  
pp. H1864-H1869 ◽  
Author(s):  
B. Cuneo ◽  
S. Hughes ◽  
D. W. Benson
Keyword(s):  
Heart Rate ◽  
Stroke Volume ◽  
Rate Increase ◽  
Aortic Flow ◽  
Sinus Venosus ◽  
In Ovo ◽  
Cross Sectional ◽  
Intrinsic Values ◽  
Av Synchrony ◽  
Cold Probe

This report compares the effects of two methods of heart rate (HR) perturbation on stroke volume and dorsal aortic flow in the Hamburger-Hamilton stage 24 chick embryo. The sinus venosus was paced at intrinsic HR and at 150, 125, 75, and 50% of intrinsic HR (n = 23). Alternatively, a 1-mm steel probe heated to increase and cooled to decrease HR was applied to the sinus venosus (n = 15). All studies were performed in ovo at 37–38 degrees C. Aortic flow (mm3/S) and stroke volume (mm3/beat) were calculated from aortic velocity, aortic cross-sectional area, and HR. Atrioventricular (AV) inflow velocities were measured during pacing (n = 10) or probe application (n = 11) technique. Dorsal aortic flow was maximum at intrinsic HR and decreased at both increased and decreased HR. Stroke volume decreased proportionally to HR during rate increase. At decreased HR, when AV synchrony was disrupted (pacing), stroke volume was unchanged from intrinsic values. However, when AV synchrony was maintained at decreased HR (cold probe), the embryonic ventricle significantly increased stroke volume.

Heart rate perturbation in the stage 17-27 chick embryo: effect on stroke volume and aortic flow

1993 ◽  
Vol 264 (3) ◽  
pp. H755-H759 ◽  
Author(s):  
B. Cuneo ◽  
S. Hughes ◽  
D. W. Benson
Keyword(s):  
Heart Rate ◽  
Stroke Volume ◽  
Developmental Stages ◽  
Intrinsic Rate ◽  
Aortic Flow ◽  
Cross Sectional ◽  
Aortic Blood ◽  
Chick Heart ◽  
Embryonic Chick Heart ◽  
Aortic Blood Velocity

Heart rate (HR), stroke volume (SV), and aortic flow increase linearly between developmental stages 17 and 27, as the embryonic chick heart progresses from a bent tube to a rudimentary four-chambered structure and cardiac mass increases fourfold. We hypothesized that HR perturbation, expressed as percent of intrinsic HR (%HR), would have a developmentally dependent effect on flow and SV. HR was transiently perturbed to 40–250% of intrinsic rate with a 1-mm cooled or heated steel probe applied to the sinus venosus of 81 embryos. Aortic blood velocity, cross-sectional area, and HR were used to calculate flow and SV. At each stage, flow was maximal at intrinsic HR. The %HR vs. SV relationship was linear, inverse, and developmentally dependent. In spite of a tremendous change in ventricular shape, mass, and volume, HR control during development of the preinnervated heart maximizes blood flow to the developing embryo.

Exhaustion of Frank-Starling mechanism in conscious dogs with heart failure

1993 ◽  
Vol 265 (4) ◽  
pp. H1119-H1131 ◽  
Author(s):  
K. Komamura ◽  
R. P. Shannon ◽  
T. Ihara ◽  
Y. T. Shen ◽  
I. Mirsky ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Heart Failure ◽  
Heart Rate ◽  
Stroke Volume ◽  
Diastolic Pressure ◽  
Left Ventricular ◽  
Conscious Dogs ◽  
Ventricular Dilatation ◽  
Cross Sectional ◽  
Control State

The goal of this study was to elucidate the ability of the left ventricle to accommodate an increase in preload (Frank-Starling mechanism) in the presence of congestive heart failure (CHF) but in the absence of the complicating effects of hypertrophy and fibrosis. To accomplish this, the effects of volume loading were examined in eight conscious dogs during the control state and after 3 wk of right ventricular pacing (240 beats/min). CHF increased heart rate (by 16 +/- 5 from 92 +/- 5 beats/min), left ventricular (LV) end-diastolic pressure (by 17 +/- 2 from 10 +/- 1 mmHg), and LV end-diastolic volume (EDV; by 23 +/- 4 from 57 +/- 3 ml). Despite reduced LV ejection fraction (from 54 +/- 3 to 31 +/- 3%), there was no significant change in cardiac output (2.5 +/- 0.3 l/min) compared with control (2.7 +/- 0.2 l/min). Stroke volume was preserved (control 19 +/- 2 ml; CHF 18 +/- 2 ml) at a constant heart rate by a shift to the right in the relationship between LV stroke volume and EDV, indicating the importance of chronic ventricular dilatation in maintaining pump performance. In the control state, acute volume load increased LV EDV (by 17 +/- 2 ml) and stroke volume (by 11 +/- 2 ml), whereas in CHF it did not increase LV EDV or stroke volume. Scanning electron microscopy revealed areas of reduced collagen weave pattern surrounding myofibers. Myocyte cross-sectional area by transmission electron microscopy was significantly reduced, and there were multiple electron-dense expansions of the Z lines with disruption of the normal lateral sarcomere alignment. These morphological findings suggest that chronic ventricular dilatation utilized in CHF results from myocyte stretch and morphological intracellular rearrangement. Furthermore, the failing heart cannot further augment stroke volume by acutely increasing EDV in CHF, suggesting that the Frank-Starling reserve is essentially exhausted.

Impact of changes in heart rate and stroke volume on the cross sectional flow velocity distribution of diastolic mitral blood flow

1992 ◽  
Vol 8 (2) ◽  
pp. 75-83 ◽  
Author(s):  
Stein O. Samstad ◽  
Joern Bathen ◽  
Ole Rossvoll ◽  
Hans G. Torp ◽  
Terje Skjaerpe ◽  
...  
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Stroke Volume ◽  
Velocity Distribution ◽  
Flow Velocity ◽  
Cross Sectional ◽  
The Cross

scholarly journals Effect of Heart Rate Increase on Dorsal Aortic Flow before and after Volume Loading in the Stage 24 Chick Embryo

1989 ◽  
Vol 26 (5) ◽  
pp. 438-441 ◽  
Author(s):  
D Woodrow Benson ◽  
Sharon F Hughes ◽  
Norman Hu ◽  
Edward B Clark
Keyword(s):  
Heart Rate ◽  
Chick Embryo ◽  
Rate Increase ◽  
Aortic Flow ◽  
Heart Rate Increase ◽  
Volume Loading ◽  
Before And After

scholarly journals Effect of Heart Rate Increase on Dorsal Aortic Flow in the Stage 24 Chick Embryo

1987 ◽  
Vol 22 (4) ◽  
pp. 442-444 ◽  
Author(s):  
Ann Dunnigan ◽  
Norman Hu ◽  
D Woodrow Benson ◽  
Edward B Clark
Keyword(s):  
Heart Rate ◽  
Chick Embryo ◽  
Rate Increase ◽  
Aortic Flow ◽  
Heart Rate Increase

scholarly journals Evaluation of Stroke Volume Variation Obtained by the FloTrac™/Vigileo™ System to Guide Preoperative Fluid Therapy in Patients Undergoing Brain Surgery

2012 ◽  
Vol 40 (3) ◽  
pp. 1175-1181 ◽  
Author(s):  
J Li ◽  
Fh Ji ◽  
Jp Yang
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Stroke Volume ◽  
Stroke Volume Variation ◽  
Brain Surgery ◽  
Fluid Loading ◽  
Volume Loading ◽  
Fluid Infusion ◽  
Volume Variation ◽  
Ringer’S Lactate

OBJECTIVE: The accuracy of stroke volume variation (SVV) obtained by the FloTrac™/Vigileo™ system in otherwise healthy patients undergoing brain surgery was assessed. METHODS: Anaesthesia was induced in 48 patients with minimal fluid infusion. Before surgery, fluid volume loading was performed by infusion with Ringer's lactate solution in 200 ml steps over 3 min, repeated successively if the patient responded with an increase in stroke volume of ≥ 10%, until the increase was < 10% (nonresponsive). RESULTS: A total of 157 volume loading steps were performed in the 48 patients. Responsive and nonresponsive steps differed significantly in baseline values of blood pressure, heart rate and SVV. Significant correlations were found between the change in stroke volume after fluid loading and values of blood pressure, heart rate and SVV before fluid loading, with SVV the most sensitive variable. CONCLUSION: Stroke volume variation obtained using the FloTrac™/Vigileo™ system is a sensitive predictor of fluid responsiveness in healthy patients before brain surgery.

scholarly journals Heart Rate Variability and Long Chain n-3 Polyunsaturated Fatty Acids in Chronic Kidney Disease Patients on Haemodialysis: A Cross-Sectional Pilot Study

Nutrients ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 2453
Author(s):  
Ana M Pinto ◽  
Helen L MacLaughlin ◽  
Wendy L Hall
Keyword(s):  
Chronic Kidney Disease ◽  
Fatty Acids ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Kidney Disease ◽  
Polyunsaturated Fatty Acids ◽  
Cardiac Death ◽  
Cross Sectional ◽  
Ckd Stage ◽  
Long Chain

Low heart rate variability (HRV) is independently associated with increased risk of sudden cardiac death (SCD) and all cardiac death in haemodialysis patients. Long chain n-3 polyunsaturated fatty acids (LC n-3 PUFA) may exert anti-arrhythmic effects. This study aimed to investigate relationships between dialysis, sleep and 24 h HRV and LC n-3 PUFA status in patients who have recently commenced haemodialysis. A cross-sectional study was conducted in adults aged 40–80 with chronic kidney disease (CKD) stage 5 (n = 45, mean age 58, SD 9, 20 females and 25 males, 39% with type 2 diabetes). Pre-dialysis blood samples were taken to measure erythrocyte and plasma fatty acid composition (wt % fatty acids). Mean erythrocyte omega-3 index was not associated with HRV following adjustment for age, BMI and use of β-blocker medication. Higher ratios of erythrocyte eicosapentaenoic acid (EPA) to docosahexaenoic acid (DHA) were associated with lower 24 h vagally-mediated beat-to-beat HRV parameters. Higher plasma EPA and docosapentaenoic acid (DPAn-3) were also associated with lower sleep-time and 24 h beat-to-beat variability. In contrast, higher plasma EPA was significantly related to higher overall and longer phase components of 24 h HRV. Further investigation is required to investigate whether patients commencing haemodialysis may have compromised conversion of EPA to DHA, which may impair vagally-mediated regulation of cardiac autonomic function, increasing risk of SCD.

scholarly journals Cardiovascular health indicators in soccer exercise during adolescence: systematic review

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Heloyse Elaine Gimenes Nunes ◽  
Evelinn Amarilha Faria ◽  
Paula Felippe Martinez ◽  
Silvio Assis de Oliveira-Júnior
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Waist Circumference ◽  
Methodological Quality ◽  
Cardiovascular Health ◽  
Longitudinal Design ◽  
Health Indicators ◽  
Soccer Players ◽  
Cross Sectional ◽  
Blood Institute

Abstract This review analyzed the studies that evaluated cardiovascular health indicators (blood pressure, waist circumference, heart rate, glucose index and lipid blood) in recreational soccer players during adolescence, and identify possible associated factors. The search was performed in the electronic databases (PubMED, SciELO, LILACS, Scopus, SPORTDiscus and Web of Science). Inclusion criteria were: population composed of children and/or adolescents (10–19 years or average age up to 19 years); studies adolescents engaged in recreational soccer regularly and observational studies with cross-sectional or longitudinal design. The process of analysis of studies involved reading titles, abstracts and full texts. After these phases, seven articles were eligible. Regarding the design, all studies were cross-sectional. Of the total studies included, five presented moderate methodological quality values and two presented low methodological quality values, according to National Heart, Lung, and Blood Institute instrument. The most cardiovascular health indicators used in recreational soccer players during adolescence was waist circumference; three studies analyzed heart rate, two evaluated blood pressure, one analyzed insulin resistance and none of the included studies analyzed lipid profile. Factors associated were analyzed in four studies, being that sedentary time and body mass index (BMI) present association with at least one indicator of cardiovascular health.

scholarly journals Heart Rate Variability Monitoring during Interferential Current Application in the Lower Back Area: A Cross-Sectional Study

2021 ◽  
Vol 18 (7) ◽  
pp. 3394
Author(s):  
Blanca De-la-Cruz-Torres ◽  
Eva Martínez-Jiménez ◽  
Emmanuel Navarro-Flores ◽  
Patricia Palomo-López ◽  
Vanesa Abuín-Porras ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Placebo Group ◽  
Intervention Group ◽  
Lumbar Pain ◽  
Poincaré Plot ◽  
Current Application ◽  
Cross Sectional ◽  
Vasovagal Reactions ◽  
Interferential Current

Vasovagal reactions may occur occasionally during electrical stimulation using interferential current (IFC). The purpose of this study was to examine variations in autonomic activity during the application of IFC in asymptomatic participants by analysis of their heart rate variability (HRV). Seventy-three male volunteers were randomly assigned to a placebo group (n = 36; HRV was documented for 10 min, both at rest and during a placebo intervention) and an intervention group (n = 37; HRV was documented for 10 min in two conditions labelled as (1) rest and (2) application of IFC technique on the lumbar segment). The diameters of the Poincaré plot (SD1, SD2), stress score (SS), and the ratio between sympathetic and parasympathetic activity (S/PS) were measured. After interventions, differences amongst the placebo group and the IFC group were found in SD2 (p < 0.001), SS (p = 0.01) and S/PS ratio (p = 0.003). The IFC technique was associated with increased parasympathetic modulation, which could induce a vasovagal reaction. Monitorization of adverse reactions should be implemented during the application of IFC technique. HRV indicators might have a part in prevention of vasovagal reactions. Further studies in patients with lumbar pain are needed to explore possible differences in HRV responses due to the presence of chronic pain.

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