Remifentanil Induces Systemic Arterial Vasodilation in Humans with a Total Artificial Heart

2004 ◽  
Vol 100 (3) ◽  
pp. 602-607 ◽  
Author(s):  
Alexandre Ouattara ◽  
Gilles Boccara ◽  
Uwe Köckler ◽  
Patrick Lecomte ◽  
Pascal Leprince ◽  
...  
Keyword(s):  
Artificial Heart ◽  
Recovery Period ◽  
Invasive Procedure ◽  
Systemic Arterial Pressure ◽  
Early Postoperative Period ◽  
Total Artificial Heart ◽  
Right Atrial ◽  
Vascular Effects ◽  
Hemodynamic Variables ◽  
Left And Right

Background To assess intrinsic vascular effects of remifentanil, increased concentrations were infused in critically ill patients with a total artificial heart. Methods In the early postoperative period after implantation of a total artificial heart, nine ventilated patients requiring short general anesthesia were included in this study. After anesthesia was induced with 0.3 mg/kg intravenous etomidate, the artificial heart settings were modified to render cardiac output "preload-independent." While maintenance of anesthesia was ensured by a continuous infusion of etomidate, increased concentrations of remifentanil (from 0.1 to 1 microg x kg(-1) x min(-1)) were infused in steps of 5 min under hemodynamic monitoring, including left and right atrial pressures, systemic and pulmonary arterial pressures, and left and right cardiac indices. The invasive procedure was started under the highest concentration of remifentanil tolerated by the patient. Infusion of remifentanil was stopped at the end of the invasive procedure, while etomidate infusion was maintained. New hemodynamic measurements were performed at the end of the 12-min recovery period. Results Remifentanil produced a dose-dependent and significant decrease in systemic arterial pressure and vascular resistances (n = 9) from a concentration of 0.25 microg x kg(-1) x min(-1). No significant changes were observed on pulmonary vascular resistances (n = 6). Neither right (n = 9) nor left (n = 6) atrial pressures were affected by remifentanil infusion. Hemodynamic variables returned to baseline value over the 12-min recovery period. Conclusions In humans with a total artificial heart, remifentanil induces a systemic arterial vasodilation without significant effect on the capacitance vessels.

Different Stroke Volumes for the Left and Right Ventricles in the Moving-Actuator Type Total Artificial Heart

1993 ◽  
Vol 16 (1) ◽  
pp. 45-50 ◽  
Author(s):  
B. Min ◽  
I. Kim ◽  
H. Kim
Keyword(s):  
Stroke Volume ◽  
Artificial Heart ◽  
Total Artificial Heart ◽  
Right Atrial ◽  
Diastolic Filling ◽  
Imbalance Problem ◽  
Mock Circulation ◽  
Left And Right ◽  
The Right ◽  
Pressure Changes

A new electromechanical moving-actuator type total artificial heart (TAH) has been developed to solve the imbalance problem without an extra compliance chamber. A different stroke volume was achieved by the large left sac size and the asymmetry of the actuator motion referred to the center position. The left ventricle consists of a double sac with the outer sac attached to the actuator providing active diastolic filling, while the double sac of the right ventricle being free from the actuator, and having sufficient suction produced due to the rigid pump housing. The stroke volume difference between the left and right sac is compensated through the air in the interventricular space of the variable volume (VV) space. Computer simulation based on the geometrical relationships between the blood sacs and the actuator was performed to simulate the physical mechanisms of the moving-actuator type TAH. Results were then compared with the measured pressure changes in various chambers of the pump and the stroke volume differences in mock circulation test. In two acute calf experiments, the balanced left and right atrial pressures were achieved in the moving-actuator type TAH without an extra compliance chamber

PERIPHERAL VASCULAR EFFECTS OF GLUCAGON, ACETYLOCHOLINE AND DOPAMINE WITH AN IMPLANTED TOTAL ARTIFICIAL HEART (TAH)

ASAIO Journal ◽  
1977 ◽  
Vol 23 (1) ◽  
pp. 611-615 ◽  
Author(s):  
K. Kaku ◽  
I. Nagai ◽  
T. Hongo ◽  
A. K. Vakamudi ◽  
J. W. Meador ◽  
...  
Keyword(s):  
Artificial Heart ◽  
Total Artificial Heart ◽  
Peripheral Vascular ◽  
Vascular Effects

A New Automatic Cardiac Output Control Algorithm for Moving Actuator Total Artificial Heart by Motor Current Waveform Analysis

1996 ◽  
Vol 19 (3) ◽  
pp. 189-196 ◽  
Author(s):  
W.W. Choi ◽  
H.C. Kim ◽  
B.G. Min
Keyword(s):  
Cardiac Output ◽  
Artificial Heart ◽  
Control Algorithm ◽  
Total Artificial Heart ◽  
Waveform Analysis ◽  
Right Atrial ◽  
Current Waveform ◽  
Output Control ◽  
Mock Circulatory System ◽  
Motor Current

A new automatic cardiac output control algorithm for an implantable electromechanical total artificial heart (TAH) was developed based on the analysis of motor current waveform without using any transducer. The basic control requirements of an artificial heart can be described in terms of three features: preload sensitivity, afterload insensivity, and balanced ventricular output. In previous studies, transducers were used to acquire information on the hemodynamic states for automatic cardiac output control. However, such a control system has reliability problems with the sensors. We proposed a novel sensorless automatic cardiac output control algorithm (ACOCA) providing adequate cardiac output to the time-varying physiological demand without causing right atrial collapse, which is one of the critical problems in an active filling device. In vitro tests were performed on a mock circulatory system to assess the performance of the developed algorithm and the results show that the new algorithm satisfied the basic control requirements of the cardiac output response.

Left and Right Pump Output Control in One-Piece Electromechanical Total Artificial Heart

2008 ◽  
Vol 17 (3) ◽  
pp. 176-184 ◽  
Author(s):  
Setsuo Takatani ◽  
Motomi Shiono ◽  
Tatsuya Sasaki ◽  
Yukihiko Orime ◽  
Ichiro Sakuma ◽  
...  
Keyword(s):  
Artificial Heart ◽  
Total Artificial Heart ◽  
Output Control ◽  
Pump Output ◽  
Left And Right

scholarly journals Mutual information discloses relationship between hemodynamic variables in artificial heart-implanted dogs

1998 ◽  
Vol 275 (4) ◽  
pp. H1419-H1433 ◽  
Author(s):  
Motohisa Osaka ◽  
Tomoyuki Yambe ◽  
Hirokazu Saitoh ◽  
Makoto Yoshizawa ◽  
Takashi Itoh ◽  
...  
Keyword(s):  
Time Delay ◽  
Mutual Information ◽  
Sympathetic Nerve ◽  
Artificial Heart ◽  
Total Artificial Heart ◽  
Ventricular Assist Devices ◽  
Renal Sympathetic Nerve ◽  
Hemodynamic Variables ◽  
Arterial Blood ◽  
Renal Sympathetic

A mutual information (MI) method for assessment of the relationship between hemodynamic variables was proposed and applied to the analysis of heart rate (HR), arterial blood pressure (BP), and renal sympathetic nerve activity (RSNA) in artificial heart-implanted dogs to quantify correlation between these parameters. MI measures the nonlinear as well as linear dependence of two variables. Simulation studies revealed that this MI technique furnishes mathematical features well suited to the investigation of nonlinear dynamics such as the cardiovascular system and can quantify a relationship between two parameters. To constitute a model free of the natural heart, two pneumatically actuated ventricular assist devices were implanted as biventricular bypasses in acute canine experiments. RSNA was detected with the use of bipolar electrodes attached to the renal sympathetic nerve. Analysis of data during control revealed that correlation between HR and RSNA was higher than that between HR and BP and that between RSNA and BP ( P < 0.05). Although RSNA seemed to fluctuate noncorrelatedly with BP in higher pacing rates, the MI values between them disclosed their strong correlation. Surprisingly, correlation between RSNA and BP was stronger during a pacing rate of 60 beats/min than during higher pacing rates and control ( P < 0.05). It is suggested that the baroreflex system may be susceptible to pacing rates during the total artificial heart state. We calculated the time delay between HR and RSNA, between RSNA and BP, and between HR and BP by regarding a time delay at which the maximum MI value between each pair of parameters was given as a physiological delay. Our results indicate that RSNA leads BP, BP leads HR, and RSNA leads HR during control ( P < 0.05). We conclude that this method could provide a powerful means for measuring correlation of physiological variables.

Flow Balance Between the Left and Right Cardiac Output of an Eccentric Roller Type Total Artificial Heart

1999 ◽  
Vol 23 (8) ◽  
pp. 741-746 ◽  
Author(s):  
Hideichi Wada ◽  
Shintaro Fukunaga ◽  
Masanobu Watari ◽  
Hiroshi Sakai ◽  
Yuji Sugawara ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Artificial Heart ◽  
Total Artificial Heart ◽  
Flow Balance ◽  
Left And Right

Native Right Atrial Tamponade with the Jarvik Total Artificial Heart

CHEST Journal ◽  
1991 ◽  
Vol 99 (6) ◽  
pp. 1523-1525 ◽  
Author(s):  
Peter Linden ◽  
Keith Stein ◽  
John Pristas ◽  
Robert L. Kormos ◽  
Bartley P Griffith
Keyword(s):  
Artificial Heart ◽  
Total Artificial Heart ◽  
Right Atrial

Calves Chronically Implanted with a Total Artificial Heart as a Pharmacological Model

1991 ◽  
Vol 14 (12) ◽  
pp. 775-780 ◽  
Author(s):  
S.D. Everett ◽  
G.M. Pantalos ◽  
I.F. Goldenberg ◽  
J.W. Long ◽  
P.D. Robison ◽  
...  
Keyword(s):  
Vascular Resistance ◽  
Artificial Heart ◽  
Left Ventricular ◽  
Pharmacological Therapy ◽  
Total Artificial Heart ◽  
Vascular Effects ◽  
Vascular Effect ◽  
New Agents ◽  
Left Ventricular Preload ◽  
Pharmacological Model

Pharmacological therapy for congestive heart failure includes drugs that have both inotropic and vasoactive effects, although it is sometimes difficult to differentiate between the two effects. An animal with an implanted total artificial heart (TAH) allows the investigation of the vascular effect of these drugs in the absence of the effect on the myocardium. An advantage of the TAH model is its sensitivity to changes in right and left ventricular preload and afterload. Four instrumented TAH calves were given vasoactive drugs and the response was compared to control. Epinephrine, dopamine, isoproterenol, and nitroprusside were selected because of the predictability of their responses. Epinephrine caused a significant increase in systemic vascular resistance (SVR), and dopamine caused a significant increase in Pulmonary vascular resistance (PVR) and Isoproterenol caused a significant decrease in PVR. TAH implanted calves can thus serve as a pharmacological model to study the vascular response, which may be useful in investigation of new agents with inotropic and vascular effects.

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