Heart function after injection of small air bubbles in coronary artery of pigs

1993 ◽  
Vol 75 (3) ◽  
pp. 1201-1207 ◽  
Author(s):  
J. H. Van Blankenstein ◽  
C. J. Slager ◽  
J. C. Schuurbiers ◽  
S. Strikwerda ◽  
P. D. Verdouw
Keyword(s):  
Coronary Artery ◽  
Heart Function ◽  
Left Ventricular Pressure ◽  
Relative Increase ◽  
Left Ventricular ◽  
Ventricular Pressure ◽  
Relative Reduction ◽  
Air Bubbles ◽  
First Derivative ◽  
A Minor

By its nature, vaporization of atherosclerotic plaques by laser irradiation or spark erosion may produce a substantial amount of gas. To evaluate the effect of gas embolism possibly caused by vaporization techniques, air bubbles with diameters of 75, 150, or 300 microns, each in a volume of 2 microliters/kg, were selectively injected subproximal in the left anterior descending coronary artery of seven anesthetized pigs (28 +/- 3 kg). Systemic hemodynamics such as heart rate, left ventricular pressure and its peak positive first derivative, and mean arterial pressure did not change after air injection, whereas there was a minor change in peak negative first derivative of left ventricular pressure. After injection of air bubbles there was a maximal relative reduction of systolic segment shortening (SS) in the myocardium supplied by the left anterior descending coronary artery of 27, 45, and 58% for 75-, 150-, and 300-microns bubbles, respectively, and a relative increase of postsystolic SS (PSS) of 148, 200, and 257% for 75-, 150-, and 300-microns bubbles, respectively. Recovery of SS and PSS started after 2 min and was completed after 10 min. A difference in SS and PSS changes between different bubble size injections could be demonstrated. From this study it is clear that depression of regional myocardial function after injection of air bubbles could pass unnoticed on the basis of global hemodynamic measurements.

Impairment of contraction increases sensitivity of epicardial lymph pressure for left ventricular pressure

1998 ◽  
Vol 274 (1) ◽  
pp. H187-H192 ◽  
Author(s):  
Jurgen W. G. E. Vanteeffelen ◽  
Daphne Merkus ◽  
Luc J. Bos ◽  
Isabelle Vergroesen ◽  
Jos A. E. Spaan
Keyword(s):  
Time Derivative ◽  
Left Ventricular Pressure ◽  
Relative Increase ◽  
Left Ventricular ◽  
Cardiac Contraction ◽  
Ventricular Pressure ◽  
Local Contraction ◽  
Lymphatic Vasculature ◽  
Anesthetized Dogs ◽  
Lidocaine Administration

In the present study, cardiac contraction was regionally impaired to investigate the relationship between contractility [maximum first time derivative of left ventricular pressure (dPLV/d tmax)] and PLVon epicardial lymph pressure (Plymph) generation. Measurements were performed in open-chest anesthetized dogs under control conditions and while local contraction was abolished by intracoronary administration of lidocaine. Lidocaine significantly lowered dPLV/d tmaxand PLVpulse to 77 ± 9 (SD; n = 5) and 82 ± 5% of control, respectively, whereas Plymphpulse increased to 186 ± 101%. The relative increase of maximum Plymphto PLVrelated inversely to the change in dPLV/d tmaxafter lidocaine administration. Additional data were obtained when PLVwas transiently increased by constriction of the descending aorta. The ratio of pulse Plymphto PLVduring aortic clamping increased after lidocaine administration, from 0.063 ± 0.03 to 0.15 ± 0.09. The results suggest that transmission of PLVto the cardiac lymphatic vasculature is enhanced when regional contraction is impaired. These findings imply that during normal, unimpaired contraction lymph vessels are shielded from high systolic PLVby the myocardium itself.

Image-Based Modeling of Blood Flow in Human Coronary Arteries With and Without Bypass Grafts During Rest and Simulated Exercise

2008 ◽  
Author(s):  
Jessica Shih ◽  
Hyun Jin Kim ◽  
Charles A. Taylor
Keyword(s):  
Coronary Artery ◽  
Coronary Bypass ◽  
Left Ventricular Pressure ◽  
Left Ventricular ◽  
Ventricular Pressure ◽  
Bypass Grafts ◽  
Heart Model ◽  
Intramyocardial Pressure ◽  
Image Based Modeling ◽  
Lumped Parameter

The number of patients with coronary artery disease continues to rise, with approximately 469,000 coronary bypass procedures in 2005 alone [1]. A priori knowledge of the flow features within the coronary vascular system could prove useful in predicting flow changes due to coronary bypass surgery. Image-based modeling and 3-D computational simulations could be used to compute flow and pressure in a patient-specific manner. However, modeling coronary flow requires knowledge of the intramyocardial pressure that compresses coronary vessels, resulting in decreased flow in systole and increased flow in diastole. Left ventricular pressure can provide an estimate to intramyocardial pressure, but the aortic pressure and left ventricular pressure must be coupled in systole when the aortic valve is open. Previously, we have developed a method to couple a lumped-parameter heart model to the inlet of a 3-D model to compute aortic and ventricular pressure [2]. In this study, we use the lumped-parameter heart model and computational fluid dynamics to calculate flow dynamics in a patient model with coronary artery bypass grafts.

scholarly journals Analysis of left ventricular pressure during isovolumic relaxation in coronary artery disease.

Circulation ◽  
1982 ◽  
Vol 65 (4) ◽  
pp. 690-697 ◽  
Author(s):  
D S Thompson ◽  
C B Waldron ◽  
S M Juul ◽  
N Naqvi ◽  
R H Swanton ◽  
...  
Keyword(s):  
Coronary Artery Disease ◽  
Coronary Artery ◽  
Left Ventricular Pressure ◽  
Left Ventricular ◽  
Ventricular Pressure ◽  
Artery Disease ◽  
Isovolumic Relaxation

Physical criteria for measurement of left ventricular pressure and its first derivative

1971 ◽  
Vol 5 (1) ◽  
pp. 32-40 ◽  
Author(s):  
B. J. Gersh ◽  
C. E. W. Hahn ◽  
C. Prys-Roberts ◽  
J. Cashion
Keyword(s):  
Left Ventricular Pressure ◽  
Left Ventricular ◽  
Ventricular Pressure ◽  
First Derivative

Influence of nonuniformity on rate of left ventricular pressure fall in the dog

1989 ◽  
Vol 256 (1) ◽  
pp. H222-H232 ◽  
Author(s):  
W. Y. Lew ◽  
C. M. Rasmussen
Keyword(s):  
Coronary Artery ◽  
Left Ventricle ◽  
Ventricular Function ◽  
Anterior Segment ◽  
Left Ventricular Pressure ◽  
Left Ventricular ◽  
Ventricular Pressure ◽  
Low Flow ◽  
High Dose ◽  
Pressure Fall

We examined the influence of nonuniformity in regional ventricular function on the rate of left ventricular pressure fall in 10 anesthetized dogs. Ultrasonic segment gauges were implanted in the midwall of the anterior, lateral, and posterior left ventricle. In seven dogs, nonuniformity was produced by infusing isoproterenol (0.4 microgram/ml) into the mid-left anterior descending coronary artery at low flow (0.5 +/- 0.7 ml/min) and high flow (1.5 +/- 1.2 ml/min) rates, for total doses of 0.1 +/- 0.1 and 0.3 +/- 0.2 micrograms, respectively. This produced a dose-dependent increase in anterior segment shortening so that shortening was completed earlier and marked segment lengthening occurred during isovolumic relaxation. Lateral and posterior segments were not directly stimulated. The heart rate, left ventricular end-diastolic pressure, and peak systolic pressure remained constant. However, tau, the time constant of left ventricular pressure fall, increased from 32 +/- 8 to 37 +/- 10 ms with the low dose, and from 35 +/- 6 to 49 +/- 12 ms with the high dose of isoproterenol. Similar results occurred in two dogs when isoproterenol was infused into the proximal, mid, or distal left anterior descending and in three dogs with infusions in the left circumflex coronary artery. We conclude that nonuniformity of regional left ventricular function is an important and independent factor regulating the rate of pressure fall in the intact ejecting left ventricle.

Functional evaluation of the rat heart in situ

1975 ◽  
Vol 39 (6) ◽  
pp. 1043-1047 ◽  
Author(s):  
R. T. Dowell ◽  
A. F. Cutilletta ◽  
P. C. Sodt
Keyword(s):  
Rat Heart ◽  
Function Analysis ◽  
Heart Function ◽  
Left Ventricular Pressure ◽  
Left Ventricular ◽  
Aortic Flow ◽  
Ventricular Pressure ◽  
Functional Evaluation ◽  
Flow Measurements

We have developed methods for evaluating muscle function in the intact rat heart in situ using a contractility index (dP/dt)P-1, calculated from left ventricular pressure derivative-left ventricular pressure loop plots. Aortic flow measurements were also taken to further characterize in situ rat heart function. The preparation remained functionally stable and was within physiological blood gas and pH limits for at least 30 min following surgical procedures. The contractility index was not influenced by increased afterload, decreased preload or increased heart rate; however, appropriate changes were observed following isoproterenol and propranolol administration. Appropriate changes in aortic flow measurements were observed also with the above interventions. These studies demonstrate that the in situ rat heart is a stable physiological experimental preparation. It should be useful for evaluating heart function since a contractility index derived from pressure-velocity relationships and measurements necessary for pump function analysis can be obtained simultaneously.

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