Circulation and Blood Pressure in the Great Vessels and Heart of the Turtle (Chelydra serpentina)

1957 ◽  
Vol 190 (2) ◽  
pp. 320-326 ◽  
Author(s):  
F. R. Steggerda ◽  
Hiram E. Essex
Keyword(s):  
Blood Pressure ◽  
Pulmonary Artery ◽  
Diastolic Pressure ◽  
Chelydra Serpentina ◽  
Venous Resection ◽  
Septal Defects ◽  
Great Vessels ◽  
The Right ◽  
Blood Pressure Patterns ◽  
Turtle Heart

Circulation through the heart of the turtle ( Chelydra serpentina) was studied by means of simultaneous recordings of oxygen saturation, blood-saturation dye curves and pressure measurements in the cardiac chambers and arteries leaving the heart. The saturation levels of the blood leaving the heart via the right and left aortas are the same while pulmonary artery blood is distinctly more venous. Resection of the septal mechanism resulted in oxygen saturations of similar value in all vessels leaving the heart. The dye curves showed that less than 10% of the blood of the turtle may pass from right to left but a much larger volume of blood passes from left to right. The findings in the turtle heart resemble those found in human patients with congenital ventricular septal defects. Blood pressure patterns in the carotid, subclavian arteries and the two aortas are very similar. Systolic pressures in the aortas and pulmonary artery are the same, but diastolic pressure in the pulmonary artery is distinctly lower than in the aortas.

scholarly journals Importance of Preserved Tricuspid Valve Function for Effective Soft Robotic Augmentation of the Right Ventricle in Cases of Elevated Pulmonary Artery Pressure

2021 ◽  
Author(s):  
Isaac Wamala ◽  
Christopher J. Payne ◽  
Mossab Y. Saeed ◽  
Daniel Bautista-Salinas ◽  
David Van Story ◽  
...  
Keyword(s):  
Pulmonary Artery ◽  
Right Ventricle ◽  
Tricuspid Regurgitation ◽  
Diastolic Pressure ◽  
Right Heart Failure ◽  
Lower Grade ◽  
Ventricular Assist ◽  
Valve Function ◽  
Right Ventricular Assist Device ◽  
The Right

Abstract Purpose In clinical practice, many patients with right heart failure (RHF) have elevated pulmonary artery pressures and increased afterload on the right ventricle (RV). In this study, we evaluated the feasibility of RV augmentation using a soft robotic right ventricular assist device (SRVAD), in cases of increased RV afterload. Methods In nine Yorkshire swine of 65–80 kg, a pulmonary artery band was placed to cause RHF and maintained in place to simulate an ongoing elevated afterload on the RV. The SRVAD was actuated in synchrony with the ventricle to augment native RV output for up to one hour. Hemodynamic parameters during SRVAD actuation were compared to baseline and RHF levels. Results Median RV cardiac index (CI) was 1.43 (IQR, 1.37–1.80) L/min/m2 and 1.26 (IQR 1.05–1.57) L/min/m2 at first and second baseline. Upon PA banding RV CI fell to a median of 0.79 (IQR 0.63–1.04) L/min/m2. Device actuation improved RV CI to a median of 0.87 (IQR 0.78–1.01), 0.85 (IQR 0.64–1.59) and 1.11 (IQR 0.67–1.48) L/min/m2 at 5 min (p = 0.114), 30 min (p = 0.013) and 60 (p = 0.033) minutes respectively. Statistical GEE analysis showed that lower grade of tricuspid regurgitation at time of RHF (p = 0.046), a lower diastolic pressure at RHF (p = 0.019) and lower mean arterial pressure at RHF (p = 0.024) were significantly associated with higher SRVAD effectiveness. Conclusions Short-term augmentation of RV function using SRVAD is feasible even in cases of elevated RV afterload. Moderate or severe tricuspid regurgitation were associated with reduced device effectiveness.

scholarly journals Novel Neuromodulation Approach to Improve Left Ventricular Contractility in Heart Failure

2020 ◽  
Vol 13 (11) ◽  
Author(s):  
Vivek Y. Reddy ◽  
Jan Petrů ◽  
Filip Málek ◽  
Lee Stylos ◽  
Steve Goedeke ◽  
...  
Keyword(s):  
Heart Failure ◽  
Pulmonary Artery ◽  
Diastolic Pressure ◽  
Acute Decompensated Heart Failure ◽  
Systolic Pressure ◽  
Decompensated Heart Failure ◽  
Left Ventricular ◽  
Ventricular Contractility ◽  
Right Pulmonary Artery ◽  
The Right

Background: Morbidity and mortality outcomes for patients admitted for acute decompensated heart failure are poor and have not significantly changed in decades. Current therapies are focused on symptom relief by addressing signs and symptoms of congestion. The objective of this study was to test a novel neuromodulation therapy of stimulation of epicardial cardiac nerves passing along the posterior surface of the right pulmonary artery. Methods: Fifteen subjects admitted for defibrillator implantation and ejection fraction ≤35% on standard heart failure medications were enrolled. Through femoral arterial access, high fidelity pressure catheters were placed in the left ventricle and aortic root. After electro anatomic rendering of the pulmonary artery and branches, either a circular or basket electrophysiology catheter was placed in the right pulmonary artery to allow electrical intravascular stimulation at 20 Hz, 4 ms pulse width, and ≤20 mA. Changes in maximum positive dP/dt (dP/dt Max ) indicated changes in ventricular contractility. Results: Of 15 enrolled subjects, 5 were not studied due to equipment failure or abnormal pulmonary arterial anatomy. In the remaining subjects, dP/dt Max increased significantly by 22.6%. There was also a significant increase in maximum negative dP/dt (dP/dt Min ), mean arterial pressure, systolic pressure, diastolic pressure, and left ventricular systolic pressure. There was no significant change in heart rate or left ventricular diastolic pressure. Conclusions: In this first-in-human study, we demonstrated that in humans with stable heart failure, left ventricular contractility could be accentuated without an increase in heart rate or left ventricular filling pressures. This benign increase in contractility may benefit patients admitted for acute decompensated heart failure.

scholarly journals Giant Dilatation of the Right Coronary Aortic Bulb with Compression of the Right Ventricular Outflow Tract Mimicking a Ventricular Septal Defect: Diagnostic workup Using Echocardiography, Heart Catheterization, and Cardiac Computed Tomography

2012 ◽  
Vol 2012 ◽  
pp. 1-4
Author(s):  
Nina P. Hofmann ◽  
Hassan Abdel-Aty ◽  
Stefan Siebert ◽  
Hugo A. Katus ◽  
Grigorios Korosoglou
Keyword(s):  
Computed Tomography ◽  
Blood Pressure ◽  
Ventricular Septal Defect ◽  
Pulmonary Artery ◽  
Right Ventricular ◽  
Septal Defect ◽  
Cardiac Computed Tomography ◽  
Outflow Tract ◽  
Annuloaortic Ectasia ◽  
The Right

Annuloaortic ectasia is a relatively rare diagnosis. Herein, we report an unusual case of an annuloaortic ectasia with asymmetric dilatation of the right coronary bulb mimicking a membranous ventricular septal defect (VSD) with Eisenmenger reaction by transthoracic echocardiography. Aortic angiography showed a dilated aortic root and moderate aortic regurgitation. Right cardiac catheterization, on the other hand, exhibited normal pulmonary artery blood pressure and normal pulmonary resistance, whereas normal venous gas values were measured throughout the caval vein and the right atrium, excluding relevant left-right shunting. Further diagnostic workup by cardiac computed tomography angiography (CCTA) unambiguously illustrated the asymmetric geometry of the ectatic aortic cusp and root causing compression of the right heart and of the right ventricular (RV) outflow tract. After review of echocardiographic acquisitions, the blood flow detected between the left and right ventricles (mimicking VSD) was interpreted as turbulent inflow from the left ventricle into the ectatic right coronary cusp. Furthermore, elevated pulmonary artery blood pressure measured by echocardiography was attributed to “functional pulmonary stenosis” due to compression of the RV outflow tract by the aorta, as demonstrated by CCTA.

scholarly journals Mechanical support of the pressure overloaded right ventricle: an acute feasibility study comparing low and high flow support

2015 ◽  
Vol 309 (4) ◽  
pp. H615-H624 ◽  
Author(s):  
Tom Verbelen ◽  
Jelle Verhoeven ◽  
Motohiko Goda ◽  
Daniel Burkhoff ◽  
Marion Delcroix ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Pulmonary Artery ◽  
Right Ventricle ◽  
Right Ventricular ◽  
High Flow ◽  
Low Flow ◽  
Mechanical Support ◽  
Arterial Blood ◽  
The Right

The objectives of this study were to assess the feasibility of low flow right ventricular support and to describe the hemodynamic effects of low versus high flow support in an animal model of acute right ventricular pressure overload. A Synergy Pocket Micro-pump (HeartWare International, Framingham, MA) was implanted in seven sheep. Blood was withdrawn from the right atrium to the pulmonary artery. Hemodynamics and pressure-volume loops were recorded in baseline conditions, after banding the pulmonary artery, and after ligating the right coronary artery in these banded sheep. End-organ perfusion (reflected by total cardiac output and arterial blood pressure) improved in all conditions. Intrinsic right ventricular contractility was not significantly impacted by support. Diastolic unloading of the pressure overloaded right ventricle (reflected by decreases in central venous pressure, end-diastolic pressure and volume, and ventricular capacitance) was successful, but with a concomitant and flow-dependent increase of the systolic afterload. This unloading diminished with right ventricular ischemia. Right ventricular mechanical support improves arterial blood pressure and cardiac output. It provides diastolic unloading of the right ventricle, but with a concomitant and right ventricular assist device flow-dependent increase of systolic afterload. These effects are most distinct in the pressure overloaded right ventricle without profound ischemic damage. We advocate the low flow strategy, which is potentially beneficial for the afterload sensitive right ventricle and has the advantage of avoiding excessive increases in pulmonary artery pressure when pulmonary hypertension exists. This might protect against the development of pulmonary edema and hemorrhage.

Effect of increased pulmonary vascular resistance on right ventricular systolic performance in dogs

1984 ◽  
Vol 246 (3) ◽  
pp. H339-H343 ◽  
Author(s):  
M. Ghignone ◽  
L. Girling ◽  
R. M. Prewitt
Keyword(s):  
Pulmonary Artery ◽  
Right Ventricular ◽  
Pulmonary Vascular Resistance ◽  
Vascular Resistance ◽  
Diastolic Pressure ◽  
Systolic Pressure ◽  
Glass Beads ◽  
Ventricular Systolic Pressure ◽  
Bead Injection ◽  
The Right

We tested the possibility that for a given contractile state and right ventricular systolic pressure (RVSP), rate and extent of ventricular shortening would be reduced as resistance to ejection increased. In eight anesthetized, ventilated dogs, we measured RV and pulmonary artery pressure (Ppa), blood pressure, heart rate, cardiac output (CO), and RV dP/dt before (condition 1) and after (condition 2) pulmonary vascular resistance (PVR) was increased by injection of small (80 micron) glass beads. Glass beads caused a large increase (P less than 0.001) in Ppa and in RVSP and, despite increased RV end-diastolic pressure (EDP), CO and stroke volume (SV) were reduced. A third set of measurements was obtained following a further increase in resistance (condition 3). A comparison of condition 2 with condition 3, despite constant RVSP, constant mean Ppa, and increased EDP, showed a marked fall in CO and SV (P less than 0.001) when glass bead injection increased calculated resistance from 21 (condition 2) to 34 (condition 3) mmHg X 1(-1) X min. RV contractility, as assessed by Vmax and peak dP/dt was similar in both conditions. In five additional dogs, we measured the same parameters as before plus instantaneous pulmonary artery flow in all conditions. In a comparison of conditions 2 and 3, despite constant RVSP and increased EDP, peak and total flow (P less than 0.05) were reduced as resistance to RV ejection increased. We conclude that the right ventricle shortens more slowly and to a smaller extent against the same systolic pressure when its resistive afterload increases.

scholarly journals An Evaluation of Blood Pressure Measurement

1981 ◽  
Vol 9 (4) ◽  
pp. 314-325 ◽  
Author(s):  
W. B. Runciman ◽  
A. J. Rutten ◽  
A. H. Ilsley
Keyword(s):  
Blood Pressure ◽  
Pulmonary Artery ◽  
Nursing Staff ◽  
Diastolic Pressure ◽  
Pressure Measurements ◽  
Central Venous ◽  
Indirect Measurements ◽  
Arterial Blood ◽  
Pulmonary Capillary ◽  
Significant Difference

The accuracy of routine measurements by nursing staff of systemic arterial, central venous, pulmonary artery and pulmonary capillary wedge pressures was determined. There was a significant difference between direct mean arterial blood pressure measurements and routine indirect measurements by the nursing staff in the pressure range of 50-100 mmHg, whereas there was no significant difference between direct and indirect measurements when indirect measurements were made by specially trained hypertension clinic personnel. However, there was a good correlation between direct and indirect measurements in each instance, indicating that changes in blood pressure could be adequately followed by both groups. Systems commonly used to measure blood pressure directly were tested. Limits in frequency response preclude the routine direct measurement of systolic or diastolic blood pressures. If direct systolic and diastolic pressure measurements are required, it is necessary to check the performance of the amplifier and recording system, attach the transducer to the patient, and determine and adjust, if necessary, the natural frequency and damping coefficient of each system before each measurement. However, it is suggested that a knowledge of systolic and diastolic pressure measurements seldom improves patient management, and if mean pressures are accepted, reliable routine measurements may be obtained by the nursing staff. The digital display of the systems tested may be accepted for mean arterial pressure, but for accurate mean central venous and pulmonary capillary wedge pressure measurements, it is necessary to interpret the trace on a chart recorder; pulmonary artery pressure can often only be estimated.

Reflex changes in heart rate and ventilation induced by central blood pressure changes

1965 ◽  
Vol 208 (6) ◽  
pp. 1222-1230 ◽  
Author(s):  
G. L. Kinnison ◽  
C. J. Breeden ◽  
R. M. Carmack ◽  
B. M. Ballard ◽  
P. J. Mel ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Pulmonary Artery ◽  
Respiration Rate ◽  
Vena Cava ◽  
Distribution Patterns ◽  
Right Atrial ◽  
Quantitative Evidence ◽  
The Right ◽  
Pressure Changes

To determine the existence and assess the importance of reflex mechanoreceptor areas other than carotid and aortic baroreceptor sites in dogs, balloon and monitoring catheters were placed in the pulmonary artery proximal to the bifurcation, in the inferior vena cava, and in the thoracic aorta above the diaphragm. Inflation of these balloons made it possible to produce a variety of pressure distribution patterns in the circulation. Pressures were recorded from the bifurcation of the pulmonary artery, right and left atria, aortic arch, and intrathoracic esophagus to obtain evidence for the existence of blood pressure reflexes originating above the diaphragm. The results contain quantitative evidence for the following reflexes in dogs anesthetized with chloralose, and breathing normally with closed chest: 1) the Bainbridge "effect;" 2) the well-known barostatic reflexes, except that respiration rate was found to be independent of arterial pressure; 3) a previously unreported reflex: when the pulmonary artery pressure is lowered (the right atrial and aortic pressures being maintained constant) there results an immediate increase in respiration rate and depth without a concomitant change in heart rate.

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