Acute, reversible tricuspid insufficiency: creation in canine model

1991 ◽  
Vol 260 (2) ◽  
pp. H638-H641 ◽  
Author(s):  
T. E. Kinney ◽  
G. N. Olinger ◽  
K. B. Sagar ◽  
L. E. Boerboom
Keyword(s):  
Right Atrium ◽  
Color Doppler ◽  
Canine Model ◽  
Atrial Pressure ◽  
Right Atrial ◽  
Right Atrial Pressure ◽  
Atrioventricular Canal ◽  
Control Value ◽  
Tricuspid Insufficiency ◽  
The Right

Relatively few methods have been described for the creation of valvular insufficiency in an animal model. Those presented involve limitations such as permanent destruction of the valves or lack of control over the degree of regurgitation produced. We describe a method of acute reversible tricuspid insufficiency that can be easily created and controlled in anesthetized dogs. The model employs a wire spiral that is advanced through the atrioventricular canal from the right atrium. The spiral causes regurgitation by preventing complete apposition of the valve leaflets while permitting retrograde flow to occur through the spiral lumen. The degree of regurgitation can be controlled by the use of spirals of different sizes. Creation of tricuspid insufficiency is demonstrated by the onset of right atrial pressure V waves, a "ballooning" of the right atrium during ventricular systole, palpation of an atrial thrill, or by color Doppler echocardiography. In 14 dogs, right atrial pressure increased from a control value of 9 +/- 3 (mean +/- SD) mmHg to 10 +/- 3 and 12 +/- 3 mmHg, respectively, with spirals of 1.5 and 2.2 cm in diameter (both P less than 0.05). With the 2.2-cm spiral, aortic blood pressure decreased from a control value of 104 +/- 20 to 83 +/- 17 mmHg (P less than 0.05), and cardiac output decreased from 73 +/- 26 to 59 +/- 19 ml.min-1.kg-1 (P less than 0.05). This model is reversible, allows repeated trials of various grades of regurgitation, does not require ventriculotomy, and is relatively nonarrhythmogenic.

Pressure-flow and volume-flow relationships of the systemic circulation of the dog

1975 ◽  
Vol 229 (3) ◽  
pp. 761-769 ◽  
Author(s):  
JF Green
Keyword(s):  
Volume Flow ◽  
Back Pressure ◽  
Atrial Pressure ◽  
Right Atrial ◽  
Right Atrial Pressure ◽  
Sodium Pentobarbital ◽  
Pressure Flow ◽  
Group I ◽  
Group Ii ◽  
The Right

Mean systemic pressure-flow (Ps-Q) and volume-flow (V-Q) relationships of the systemic vascular bed were determined in two groups of dogs anesthetized with sodium pentobarbital (group I) and with methoxyflurane (group II). All blood returning to the heart (Q) was removed from the right atrial appendage and passed through a Starling resistor, a pump, a flowmeter , and then returned directly into the pulmonary artery. Ps was estimated from plateau values of right atrial pressure obtained during stop-flow procedures. Both the Ps-Q and V-Q relationships were nonlinear. This nonlinearity may be attributed to a redistribution of blood flow between systemic vascular compartments of unequal time constants. With group II, the Ps-Q and V-Q curves were shifted markedly to the right along the Ps and V axes, respectively. Evidence is presented which suggests that this shift was due to an effective back pressure other than right atrial pressure produced by a hepatic waterfall. The beta-adrenergic antagonist practolol increased the effective back pressure and augmented the shift in the Ps-Q and V-Q curves.

Effect of canine cardiac nerves on heart rate, rhythm, and pacemaker location

1986 ◽  
Vol 250 (4) ◽  
pp. H630-H644 ◽  
Author(s):  
R. B. Schuessler ◽  
J. P. Boineau ◽  
A. C. Wylds ◽  
D. A. Hill ◽  
C. B. Miller ◽  
...  
Keyword(s):  
Heart Rate ◽  
Right Atrium ◽  
General Trend ◽  
Canine Model ◽  
Right Atrial ◽  
Sympathetic Stimulation ◽  
Open Chest ◽  
Left Posterior ◽  
The Right ◽  
Cardiac Nerves

In open-chest dogs, right- and left-sided cardiac nerves were stimulated to determine their effect on heart rate, rhythm, and pacemaker location. The majority of the nerves produced chronotropic changes; 72% of the induced rhythms originated from within the atrial pacemaker complex. Ten percent of the stimulations produced an atrio-ventricular (AV) nodal rhythm; most of the time this was induced by the left posterior and anterior ansae and ventrolateral nerves. The dominance of a lateral right atrial pacemaker was observed in 8% of the stimulations; the dorsal cardiac and innominate nerves induced this rhythm the majority of the time. The general trend was for a cranial shift in the location of the pacemaker within the pacemaker complex with sympathetic stimulation and a caudal shift with parasympathetic stimulation. Exceptions to the pattern may be explained by the preferential effect of the nerves on the pacemakers in the right atrium. The study demonstrates, in the canine model, that in addition to the sinus and AV nodes, there is a system of pacemakers controlled by the cardiac nerves.

Control of right atrial pressure at constant cardiac output suppresses volume natriuresis in anesthetized rats

1984 ◽  
Vol 62 (7) ◽  
pp. 798-801 ◽  
Author(s):  
U. Ackermann ◽  
J. R. Rudolph
Keyword(s):  
Blood Volume ◽  
Volume Expansion ◽  
Atrial Pressure ◽  
Right Atrial ◽  
Right Atrial Pressure ◽  
Control Value ◽  
Volume Load ◽  
Arterial Blood ◽  
Anesthetized Rats ◽  
Blood Volume Expansion

The blood volume of anesthetized rats was expanded acutely by 33% with donor blood while a caval snare was gradually tightened so that right atrial pressure (RAP) was prevented from rising (n = 6). In control experiments (n = 5) an aortic snare was used to hold mean arterial blood pressure near the values found in the experimental series. However, RAP was allowed to change freely and increased by 1.6 ± 0.4 mmHg (1 mmHg = 133.322 Pa) during volume expansion. When the two groups were compared, there were no significant differences between their mean arterial blood pressures (near 110 mmHg) or in their cardiac outputs (near 0.25 mL∙min−1∙g body weight−1). There were, however, significant differences between their renal responses to the volume load. When RAP was free to change, the rate of volume excretion [Formula: see text] increased to 30 ± 15 (SEM) μL∙min−1∙g kidney weight−1 (KW) from its control value of 3.49 ± 0.31 and the rate of sodium excretion [Formula: see text] increased to 3.59 ± 0.20 μequiv.∙min−1∙g KW−1 from its preinfusion value of 0.42 ± 0.10. When RAP was not allowed to increase during volume loading, [Formula: see text] and [Formula: see text] did not change from their respective preinfusion values (2.99 ± 0.46 μL∙min−1∙g KW−1 and 0.35 ± 0.10 μequiv.∙min−1∙g KW−1). The results imply that during acute blood volume expansion increased central vascular pressure is a prerequisite for the homeostasis of body water and salt.

Bovine atrial natriuretic peptide in heart failure

1990 ◽  
Vol 124 (3) ◽  
pp. 463-467 ◽  
Author(s):  
N. Takemura ◽  
H. Koyama ◽  
T. Sako ◽  
K. Ando ◽  
S. Motoyoshi ◽  
...  
Keyword(s):  
Heart Failure ◽  
Plasma Concentration ◽  
Atrial Natriuretic Peptide ◽  
Natriuretic Peptide ◽  
Right Atrium ◽  
Left Ventricular ◽  
Atrial Pressure ◽  
Right Atrial ◽  
The Right ◽  
Atrial Natriuretic

ABSTRACT The present study describes the concentration and molecular form of atrial natriuretic peptide (ANP) in Holstein dairy cattle with mild (bacterial endocarditis; BEC) or severe (dilated cardiomyopathy; DCM) heart failure. Significant increases in plasma concentration of ANP were observed in cattle with DCM (73·3 ± 16·02 pmol/l, n=4, P<0·01) and BEC (20·6± 3·45 pmol/l, n=7, P<0·05), when compared with those in control cattle (14·5± 1·84 pmol/l, n= 12). The concentration of ANP in cattle with DCM was significantly (P<0·01) higher compared with that in cattle with BEC. Plasma concentration of ANP correlated significantly with right atrial pressure (r =0·95, P<0·01) and left ventricular end-diastolic pressure (r= 0·84, P<0·01). Gel-permeation chromatography of ANP in plasma and the right atrium from control and cattle with BEC revealed a single peak corresponding to the elution position of authentic human ANP(99–126) in plasma, and two peaks corresponding to those of authentic human ANP(99–126) and pro-ANP in the atrial extract. In cattle with DCM, however, peaks corresponding to the elution positions of authentic human β-ANP and/or pro-ANP were detected in addition to the peak corresponding to ANP(99–126). The content of ANP in the right atrium of cattle with DCM was significantly (P<0·05) increased compared with that in control cattle and those with BEC. The present study therefore suggests that the synthesis and secretion of ANP might be stimulated by atrial distention induced by increased atrial pressure. This suggestion is supported by the fact that the middle molecular weight form of ANP, possibly corresponding to human β-ANP, was detected in both the plasma and atria of the cattle with severe heart failure. Journal of Endocrinology (1990) 124, 463–467

scholarly journals The Impact of Deep Y Descent on Hemodynamics in Patients With Heart Failure and Preserved Left Ventricular Systolic Function

2021 ◽  
Vol 8 ◽  
Author(s):  
Daisuke Harada ◽  
Hidetsugu Asanoi ◽  
Takahisa Noto ◽  
Junya Takagawa
Keyword(s):  
Heart Rate ◽  
Systolic Function ◽  
Left Ventricular Systolic Function ◽  
Left Ventricular ◽  
Atrial Pressure ◽  
Right Atrial ◽  
Right Atrial Pressure ◽  
Pressure Waveform ◽  
Ventricular Systolic Function ◽  
The Right

Background: Influence of right ventricular diastolic function on the hemodynamics of heart failure (HF). We aimed to clarify the hemodynamic features of deep Y descent in the right atrial pressure waveform in patients with HF and preserved left ventricular systolic function.Methods: In total, 114 consecutive inpatients with HF who had preserved left ventricular systolic function (left ventricular ejection fraction ≥ 50%) and right heart catheterization were retrospectively enrolled in this study. The patients were divided into two groups according to right atrial pressure waveform, and those with Y descent deeper than X descent in the right atrial pressure waveform were assigned to the deep Y descent group. We enrolled another seven patients (two men, five women; mean age, 87 ± 6) with HF and preserved ejection fraction, and implanted a pacemaker to validate the results of this study.Results: The patients with deep Y descent had a higher rate of atrial fibrillation, higher right atrial pressure and mean pulmonary arterial pressure, and lower stroke volume and cardiac index than those with normal Y descent (76 vs. 7% p &lt; 0.001, median 8 vs. 5 mmHg p = 0.001, median 24 vs. 21 mmHg p = 0.036, median 33 vs. 43 ml/m2p &lt; 0.001, median 2.2 vs. 2.7 L/m2, p &lt; 0.001). Multiple linear regression revealed a negative correlation between stroke volume index and pulmonary vascular resistance index (wood unit*m2) only in the patients with deep Y descent (estimated regression coefficient: −1.281, p = 0.022). A positive correlation was also observed between cardiac index and heart rate in this group (r = 0.321, p = 0.038). In the other seven patients, increasing the heart rate (from median 60 to 80/min, p = 0.001) significantly reduced the level of BNP (from median 419 to 335 pg/ml, p = 0.005).Conclusions: The hemodynamics of patients with HF with deep Y descent and preserved left ventricular systolic function resembled right ventricular restrictive physiology. Optimizing the heart rate may improve hemodynamics in these patients.

Right Ventricular Assistance by Continuous Flow Device

2007 ◽  
Vol 46 (05) ◽  
pp. 530-537 ◽  
Author(s):  
G. Ferrari ◽  
C. De Lazzari
Keyword(s):  
Right Ventricular ◽  
Rotational Speed ◽  
Continuous Flow ◽  
Mean Value ◽  
Atrial Pressure ◽  
Right Atrial ◽  
Right Atrial Pressure ◽  
Total Flow ◽  
Pump Speed ◽  
The Right

Summary Objectives·. This work is another step in the development of the circulatory model CARDIOSIM® and of its model library. Continuous flow assistance is often used to support the right ventricular failure. Computer simulation is one of the methods to study the effect of this assistance on the failing ventricle. The purpose of this study was to evaluate the effect of this support on some hemodynamic variables, when different right ventricular end-systolic elastance and pump speed values were applied. Methods: The rotary blood pump model was included into the software package CARDIOSIM®, which reproduces the cardiovascular system. Lumped parameters models were used to reproduce the circulatory phenomena. Variable elastance models reproduced the Starling’s law of the heartfor both ventricles. In the study right ventricular end-systolic elastance (EmaxraT) and the rotational speed of the pumptookthree different values. All the other parameters of the model were constants. Results: The rotational speed of the pump had a significant influence on right ventricular end-diastolic and end-systolic volumes, right atrial pressure (Pra), right ventricular (Qro) and pump flows. The effects on pulmonary arterial pressure (Pap) were more evident when the right ventricular end-systolic elastance was low. When the speed of the device increased the mean value of Pra decreased for each value of EmaxMT. The total flow (Qro + pump flow) increased when the speed of the pump increased. Conclusions: Our simulation (in good agreement with the results presented in literature) showed that Hemo-pump produces a rise in total flow, a drop in blood flow pumped out by the right ventricle and a drop in right atrial pressure.

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