Abstract P103: Effects of Chest Compression Pressure Field on Stroke Volume during Cardiopulmonary Resuscitation

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Joshua W Lampe ◽  
Gerrit J Noordergraaf ◽  
Abraham Noordergraaf ◽  
Lance B Becker
Keyword(s):  
Blood Flow ◽  
Stroke Volume ◽  
Chest Compression ◽  
Heart Valves ◽  
Compression Pressure ◽  
Pressure Fields ◽  
Inductive Component ◽  
Capacitive Component ◽  
Wave Forms ◽  
Rlc Circuits

Hypothesis: The way that chest compressions generate blood flow remains unclear. Additionally, different mechanical chest compression devices may create different thoracic pressure fields. We hypothesize that three thoracic pressure fields, direct ventricular massage, cardiac pump, and thoracic pump, generate blood flow through different mechanisms resulting in different stroke volumes. Methods: The Donder’s model of the human cardiovascular system models vessels as resistor-inductor-capacitor (RLC) circuits, where the resistive component describes the viscous resistance to blood flow, the inductive component describes the inertial resistance to blood flow changes, and the capacitive component describes the elastic properties of the vessel. The model can account for effects of respiration on blood flow. Cardiac output for the three pressure fields was modeled using sinusoidal compression waveforms with maximum pressures between 25 and 150 mmHg. Results: The figure shows the dependence of stroke volume on the pressure maximum for the three pressure fields. Peak stroke volumes occur near 75 mmHg for ventricular massage, 125 mmHg for thoracic pump, and 25 mmHg for cardiac pump compressions. Ventricular massage and the cardiac pump model utilize the heart valves to generate blood flow. The thoracic pump model generates blood flow by utilizing the elastic differences between veins and arteries. Conclusions: The three pressure fields have unique values for optimum compression pressure. The Donder’s model may allow for rapid investigation of many pressure fields, pressure wave forms, and compression to ventilation ratios to accelerate the optimization of CPR.

Abstract 2059: Transthoracic Application of Medium Voltage Therapy Maintains Forward Blood Flow during Cardiac Arrest

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Giuseppe Ristagno ◽  
Yongqin Li ◽  
Hao Wang ◽  
Shijie Sun ◽  
Gilman Byron ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cardiac Arrest ◽  
Cardiac Output ◽  
Ejection Fraction ◽  
Stroke Volume ◽  
Chest Compression ◽  
Entire Interval ◽  
Carotid Blood Flow ◽  
Medium Voltage ◽  
Threshold Levels

We have previously reported that transthoracic medium voltage therapy (MVT) generated coronary perfusion pressure (CPP), forward carotid blood flow (CBF) and end-tidal CO 2 (EtCO 2 ) comparable to those produced by manual chest compression. In the present study, we investigated the capability of MVT to generate and maintain forward blood flow for a longer interval, i.e. 1 min, in a porcine model of short duration cardiac arrest. MVT can maintain threshold levels of CPP, CBF and EtCO 2 , for a minute interval prior to defibrillation. In 7 domestic male pigs weighing 40 ± 1 kg, VF was electrically induced and untreated for 10 seconds. Animals were then subjected to receive MVT for one minute with the aid of a Galvani E-CPR device (Galvani Ltd, Edina, MN), after when a biphasic shock was delivered. The MVT pulsed packet was 400 msec, the pulsed packet rate was 80/min, the intra-packet pulse period was 25 ms and intra-packet pulse durations were 0.2 ms. CPP and EtCO2 were continuously measured during MVT. CBF and ejection fraction generated during MVT were measured by echo-Doppler technique, while cardiac output with stroke volume by thermodiluition method. MVT was able to maintain CPP and EtCO2 above the threshold levels for successful resuscitation for the entire interval of application (Table ). During MVT, excellent stroke volume, cardiac output and ejection fraction together with carotid blood flow were generated (Table ). MVT produced and maintained for one minute forward blood flow during cardiac arrest. This electrical therapy might represent a new approach intended to generate and/or maintain forward blood flow in lieu of or in association with chest compression in victims of cardiac arrest

scholarly journals Numerical Study of Blood Flow Through Artificial Heart Valves

2021 ◽  
Vol 1094 (1) ◽  
pp. 012120
Author(s):  
Hussein Togun ◽  
Ali Abdul Hussain ◽  
Saja Ahmed ◽  
Iman Abdul hussain ◽  
Huda Shaker
Keyword(s):  
Blood Flow ◽  
Artificial Heart ◽  
Heart Valves ◽  
Numerical Study ◽  
Artificial Heart Valves ◽  
Flow Through

Chest compression efficacy of child resuscitators

2021 ◽  
Vol 13 (11) ◽  
pp. 448-455
Author(s):  
Tiffany Wai Shan Lau ◽  
Anthony Robert Lim ◽  
Kyra Anne Len ◽  
Loren Gene Yamamoto
Keyword(s):  
Blood Flow ◽  
Cardiopulmonary Resuscitation ◽  
Chest Compression ◽  
Minimum Weight ◽  
Success Rates ◽  
Compression Force ◽  
Chest Compressions ◽  
Traditional Methods ◽  
Video Review ◽  
Brief Training

Background: Chest compression efficacy determines blood flow in cardiopulmonary resuscitation (CPR) and relies on body mechanics, so resuscitator weight matters. Individuals of insufficient weight are incapable of generating a sufficient downward chest compression force using traditional methods. Aims: This study investigated how a resuscitator's weight affects chest compression efficacy, determined the minimum weight required to perform chest compressions and, for children and adults below this minimum weight, examine alternate means to perform chest compressions. Methods: Volunteers aged 8 years and above were enrolled to perform video-recorded, music-facilitated, compression-only CPR on an audible click-confirming manikin for 2 minutes, following brief training. Subjects who failed this proceeded to alternate modalities: chest compressions by jumping on the lower sternum; and squat-bouncing (bouncing the buttocks on the chest). These methods were assessed via video review. Findings: There were 57 subjects. The 30 subjects above 40kg were all able to complete nearly 200 compressions in 2 minutes. Success rates declined in those who weighed less than 40kg. Below 30 kg, only one subject (29.9 kg weight) out of 14 could achieve 200 effective compressions. Nearly all of the 23 subjects who could not perform conventional chest compressions were able to achieve effective chest compressions using alternate methods. Conclusion: A weight below 40kg resulted in a declining ability to perform standard chest compressions effectively. For small resuscitators, the jumping and squat-bouncing methods resulted in sufficient compressions most of the time; however, chest recoil and injuries are concerns.

Abstract 17334: The Detrimental Effect of Chest Compression Interruptions on Coronary Perfusion Pressure Dynamics

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Norman A Paradis ◽  
Karen L Moodie ◽  
Christopher L Kaufman ◽  
Joshua W Lampe
Keyword(s):  
Blood Flow ◽  
Chest Compression ◽  
Detrimental Effect ◽  
Perfusion Pressure ◽  
Vena Cava ◽  
Coronary Perfusion Pressure ◽  
Right Atrial ◽  
Coronary Perfusion ◽  
Chest Compressions ◽  
Over Time

Introduction: Guidelines for treatment of cardiac arrest recommend minimizing interruptions in chest compressions based on research indicating that interruptions compromise coronary perfusion pressure (CPP) and blood flow and reducing the likelihood of successful defibrillation. We investigated the dynamics of CPP before, during, and after compression interruptions and how they change over time. Methods: CPR was performed on domestic swine (~30 Kg) using standard physiological monitoring. Blood flow was measured in the abdominal aorta (AAo), the inferior vena cava, the right common carotid and external jugular. Ventricular fibrillation (VF) was electrically induced. Mechanical chest compressions (CC) were started after four minutes of VF. CC were delivered at a rate of 100 compressions per minute (cpm) and at a depth of 2” for a total of 12 min. CPP was calculated as the difference between aortic and right atrial pressure at end-diastole per Utstein guidelines. CPP was determined for 5 compressions prior to the interruption, every 2 seconds during the CC interruption, and for 7 compressions after the interruption. Per protocol, 12 interruptions occurred at randomized time points. Results: Across 12 minutes of CPR, averaged CPP prior to interruption was significantly greater than the averaged CPP after the interruption (22.4±1.0 vs. 15.5±0.73 mmHg). As CPR continued throughout the 12 minutes, CPP during compressions decreased (First 6 min = 24.1±1.4 vs. Last 6 min = 20.1±1.3 mmHg, p=0.05), but the effect of interruptions remained constant resulting in a 20% drop in CPP for every 2 seconds irrespective of the prior CPP. The increase (slope) of CPP after resumption of compressions was significantly reduced over time (First 6 min = 1.47±0.18 vs. Last 6 min = 0.82±0.13 mmHg/compression). Conclusions: Chest compression interruptions have a detrimental effect on coronary perfusion and blood flow. The magnitude of this effect increases over time as a resuscitation effort continues. These data confirm the importance of providing uninterrupted CPR particularly in long duration resuscitations.

Cardiac Output Changes in Newborns With Hyperbilirubinemia Treated With Phototherapy

PEDIATRICS ◽  
1985 ◽  
Vol 76 (6) ◽  
pp. 918-921
Author(s):  
Frans J. Walther ◽  
Paul Y. K. Wu ◽  
Bijan Siassi
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Stroke Volume ◽  
Skin Blood Flow ◽  
Peripheral Blood ◽  
Cardiovascular Effects ◽  
Tissue Perfusion ◽  
Peripheral Blood Flow ◽  
Limb Blood Flow ◽  
Term Infants

Phototherapy is known to increase peripheral blood flow in neonates, but information on the associated cardiovascular effects is not available. Using pulsed Doppler echocardiography we evaluated cardiac output and stroke volume in 12 preterm and 13 term neonates during and after phototherapy. We concomitantly measured arterial limb blood flow by strain gauge plethysmography and skin blood flow by photoplethysmography. Cardiac output decreased by 6% due to reduced stroke volume during phototherapy, whereas total limb blood flow and skin blood flow increased by 38% and 41%, respectively. Peripheral blood flow increments tended to be higher in the preterm than in the term infants. The reduced stroke volume during phototherapy may be an expression of reduced activity of the newborn during phototherapy. For healthy neonates the reduction in cardiac output is minimal, but for sick infants with reduced cardiac output, this reduction may further aggravate the decrease in tissue perfusion.

Abstract 439: Using the Time Interval Between R-Wave Detection and Maximum Compression Pressure to Target and Validate Delivery of Synchronized Chest Compressions During Pseudo Electro-Mechanical Dissociation

Circulation ◽  
2019 ◽  
Vol 140 (Suppl_2) ◽  
Author(s):  
Joshua W Lampe ◽  
Jeff R Gould ◽  
Karen L Moodie ◽  
Zachary P Soucy ◽  
Peter S Burrage ◽  
...  
Keyword(s):  
Blood Flow ◽  
Time Interval ◽  
Hemodynamic Parameters ◽  
Chest Compressions ◽  
Compression Pressure ◽  
Carotid Blood Flow ◽  
Maximum Compression ◽  
Local Maxima ◽  
Blood Flows ◽  
Mechanical Dissociation

Introduction: The treatment of pseudo electro-mechanical dissociation (P-EMD) with standard chest compressions leads to some compressions that interfere with blood flow created by ventricular contraction and others that are synergistic. We have previously reported that the hemodynamics generated by standard chest compressions (StdCPR) depended on the time interval between the R-wave and the maximum compression pressure (t_int). Our goal was to use the t_int to identify the optimal timing for compression synchronization and to validate the delivery of synchronized chest compressions. Methods: Eight animals underwent surgical preparation and were exposed to hypoxia to induce P-EMD. The treatment period was divided into eight 45 sec epochs during which the P-EMD was left untreated or was treated with StdCPR or chest compressions synchronized to the R-wave in the ECG (SyncCPR). For each heart beat t_int was calculated as t peak AOP - t Rwave , blood pressures were averaged, and blood flows were integrated. 1,598 chest compressions were analyzed. The location of local extrema in hemodynamic parameters as a function of positive t_int values were identified recursively by dividing the range of t_int values into increasing numbers of bins and determining which bin had the highest mean value. Results: Blood flows and pressures exhibited a non-linear dependence on t_int. The maximum CPP occurred at t_int = 90 ±2.3 ms. The maximum aortic pressure occurred at t_int = 70 ±2.3 ms. The minimum right atrial pressure occurred at t_int = 280 ±2.3 ms. The maximum carotid blood flow occurred at t_int = 100 ±2.3 ms. The maximum jugular blood flow occurred at t_int = 400 ±2.3 ms. Unsynchronized chest compressions resulted in a t_int of -21 ± 170 ms. Synchronized chest compressions resulted in a t_int of 119 ± 13 ms. Conclusions: Local maxima and minima during StdCPR were identified in several hemodynamic parameters, but the extrema were not perfectly co-located. It appears that a t_int of 90-100 ms could be optimal. SyncCPR were delivered at 119 ms, which is not far from the local maxima observed for CPP and carotid blood flow.

scholarly journals Development of a Simple ImageJ-Based Method for Dynamic Blood Flow Tracking in Zebrafish Embryos and Its Application in Drug Toxicity Evaluation

Inventions ◽  
2019 ◽  
Vol 4 (4) ◽  
pp. 65 ◽  
Author(s):  
Fiorency Santoso ◽  
Bonifasius Putera Sampurna ◽  
Yu-Heng Lai ◽  
Sung-Tzu Liang ◽  
Erwei Hao ◽  
...  
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Cardiac Output ◽  
Blood Cell ◽  
Stroke Volume ◽  
Flow Velocity ◽  
Blood Flow Velocity ◽  
Video Recording ◽  
Cardiovascular Function ◽  
Zebrafish Embryos

This study aimed to develop a simple and cost-effective method to measure blood flow in zebrafish by using an image-based approach. Three days post fertilization (dpf) zebrafish embryos were mounted with methylcellulose and subjected to video recording for tracking blood flow under an inverted microscope equipped with a high-speed CCD camera. In addition, Hoffman lens was used to enhance the blood cell contrast. The red blood cell movement was tracked by using the TrackMate plug-in in the ImageJ image processing program. Moreover, Stack Difference and Time Series Analyzer plug-in were used to detect dynamic pixel changes over time to calculate the blood flow rate. In addition to blood flow velocity and heart rate, the effect of drug treatments on other cardiovascular function parameters, such as stroke volume and cardiac output remains to be explored. Therefore, by using this method, the potential side effects on the cardiovascular performance of ethyl 3-aminobenzoate methanesulfonate (MS222) and 3-isobutyl-1-methylxanthine (IBMX) were evaluated. MS222 is a common anesthetic, while IBMX is a naturally occurring methylxanthine. Compared to normal embryos, MS222- and IBMX-treated embryos had a reduced blood flow velocity by approximately 72% and 58%, respectively. This study showed that MS222 significantly decreased the heart rate, whereas IBMX increased the heart rate. Moreover, it also demonstrated that MS222 treatment reduced 50% of the stroke volume and cardiac output. While IBMX decreased the stroke volume only. The results are in line with previous studies that used expensive instruments and complicated software analysis to assess cardiovascular function. In conclusion, a simple and low-cost method can be used to study blood flow in zebrafish embryos for compound screening. Furthermore, it could provide a precise measurement of clinically relevant cardiac functions, specifically heart rate, stroke volume, and cardiac output.

scholarly journals Intracranial hemodynamic relationships in patients with cerebral small vessel disease

Neurology ◽  
2020 ◽  
Vol 94 (21) ◽  
pp. e2258-e2269 ◽  
Author(s):  
Gordon W. Blair ◽  
Michael J. Thrippleton ◽  
Yulu Shi ◽  
Iona Hamilton ◽  
Michael Stringer ◽  
...  
Keyword(s):  
Blood Flow ◽  
Ischemic Stroke ◽  
White Matter ◽  
Basal Ganglia ◽  
Stroke Volume ◽  
Small Vessel Disease ◽  
Foramen Magnum ◽  
Cerebral Small Vessel Disease ◽  
Vessel Disease ◽  
Minor Ischemic Stroke

ObjectiveTo investigate cerebrovascular reactivity (CVR), blood flow, vascular and CSF pulsatility, and their independent relationship with cerebral small vessel disease (SVD) features in patients with minor ischemic stroke and MRI evidence of SVD.MethodsWe recruited patients with minor ischemic stroke and assessed CVR using blood oxygen level–dependent MRI during a hypercapnic challenge, cerebral blood flow (CBF), vascular and CSF pulsatility using phase-contrast MRI, and structural magnetic resonance brain imaging to quantify white matter hyperintensities (WMHs) and perivascular spaces (PVSs). We used multiple regression to identify parameters associated with SVD features, controlling for patient characteristics.ResultsFifty-three of 60 patients completed the study with a full data set (age 68.0% ± 8.8 years, 74% male, 75% hypertensive). After controlling for age, sex, and systolic blood pressure, lower white matter CVR was associated with higher WMH volume (−0.01%/mm Hg per log10 increase in WMH volume, p = 0.02), basal ganglia PVS (−0.01%/mm Hg per point increase in the PVS score, p = 0.02), and higher venous pulsatility (superior sagittal sinus −0.03%/mm Hg, p = 0.02, per unit increase in the pulsatility index) but not with CBF (p = 0.58). Lower foramen magnum CSF stroke volume was associated with worse white matter CVR (0.04%/mm Hg per mL increase in stroke volume, p = 0.04) and more severe basal ganglia PVS (p = 0.09).ConclusionsLower CVR, higher venous pulsatility, and lower foramen magnum CSF stroke volume indicate that dynamic vascular dysfunctions underpin PVS dysfunction and WMH development. Further exploration of microvascular dysfunction and CSF dynamics may uncover new mechanisms and intervention targets to reduce SVD lesion development, cognitive decline, and stroke.

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