Relationship of radius to pressure along the aorta in living dogs

Patel, Dali J.; Freitas, Flavio M. De; Greenfield, Joseph C.; Fry, Donald L.

doi:10.1152/jappl.1963.18.6.1111

Cited by 144 publications

(53 citation statements)

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“…As expected, AR direct and RP derived increased more gradually in comparison with aortic BP in this study. Although others have suggested that a strict linear relationship exists between aortic BP and dimensions, 21 our findings lend credence to more recent literature that describes a hysteretic (loop) relationship between aortic BP and dimensions. [22][23][24] Physiologically, this makes sense because there must be a delay in the volumetric increase (relative to pressure), while the aorta fills with blood ( Figure 4D-4I).…”

Section: Aortic Reservoir and Excess Pressure: A Physiological Paradigmsupporting

confidence: 88%

Aortic Reservoir Pressure Corresponds to Cyclic Changes in Aortic Volume

Schultz

Davies

Hardikar

et al. 2014

ATVB

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C entral (aortic) blood pressure (BP) waveform indices independently predict cardiovascular events and all-cause mortality, 1 but the physiological mechanisms to explain the waveform morphology remain disputed. The well-established wave reflection theory ascribes transmission of discrete forward and backward (incident and reflected) waves as the principal contributory factor underlying the shape of the central BP waveform.2 However, while providing a plausible description of central BP morphology, recent studies have concluded that the influence of discrete reflected waves on central BP may be less than originally conceived, and this is probably because of wave dispersion along the aorta and entrapment of reflected waves in the periphery. 3,4 Indeed, augmentation of central BP may be largely attributable to forward wave propagation (as a result of left ventricular [LV] ejection) and proximal aortic reservoir function. [5][6][7][8][9] Importantly, wave separation theory obscures the pressure buffering role of the highly elastic proximal aorta (ie, the aortic reservoir), and a failure to consider this function may lead to incorrect interpretations of the physiology underlying central BP waveform morphology.The reservoir-excess pressure concept is an alternate method proposed to explain the underlying physiology of the aortic BP waveform. This method has been used invasively to study changes in aortic BP associated with both aging and exercise. 6,8 Moreover, indices derived from this model were recently shown to predict cardiovascular events (fatal and nonfatal) and procedures independent from brachial BP and other conventional cardiovascular risk parameters (eg, age, sex, cholesterol, smoking, diabetes mellitus), including Framingham risk score, in an analysis of the Conduit Artery Function Evaluation study. 10 In accounting for the reservoir function of the aorta, 7,11 the reservoir-excess pressure model is founded on the basis that aortic BP can be separated into © 2014 American Heart Association, Inc.

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Section: Aortic Reservoir and Excess Pressure: A Physiological Paradigmsupporting

confidence: 88%

Aortic Reservoir Pressure Corresponds to Cyclic Changes in Aortic Volume

Schultz

Davies

Hardikar

et al. 2014

ATVB

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“…The wide variation noted in the values of compliance listed in Table 1 are somewhat surprising, but are similar to the range of values obtained in studying the in vivo dynamic vessel mechanics in other arteries (7). At least a part of the differences may be explained by variations in vessel tone at the time of study, but it is our belief that these findings are indicative of a wide range of coronary artery compliance which is present in vivo.…”

Section: Discussionsupporting

confidence: 75%

Epicardial Coronary Artery Compliance in the Dog

Douglas

Greenfield

1970

Circulation Research

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The dynamic compliance of 21 coronary arteries from 17 dogs was determined in situ. Intramyocardial portion* were occluded with a mixture of 200(1 glass beads and liquid silicone. To simulate in vivo pressure-volume conditions, 0.1 ml of saline was injected in 150 to 240 msec at a rate of 30 pulses/min. Silicone casts of the vessels, made at 100 mm Hg distending pressure, were used as a reference volume. The results indicate that the dynamic compliance decreases as the initial distending pressure rises. The change in volume for a 50 mm Hg pressure increment (initial distending pressure of 100 mm Hg) was 3.7 ± 0.6% (mean±SE). In four dogs, phasic flow in the left circumflex coronary artery was measured. The volume of systolic flow per beat during the control state was of the same order of magnitude as the compliance of the vessels; however, during reactive hyperemia, systolic coronary flow markedly exceeded the dynamic compliance of the coronary vessels. In six dogs the static compliance of a segment of coronary artery was obtained radiographically. A 30.1 ± 1. 4% change in volume occurred when the intravascular pressure was increased from 70 to 120 mm Hg.ADDITIONAL KEY WORDS coronary artery coronary artery elasticity pressure-radius relation• The pressure-volume relationships of the epicardial coronary arterial tree have not been previously described. These data are necessary to formulate any realistic dynamic model of the coronary circulation. For example, to determine the degree to which the myocardium is perfused during systole, the compliance of the epicardial coronary vessels must be known (1). Accordingly, this study was designed to determine the dynamic pressure-volume relationships, of the in situ epicardial coronary arteries in the dog and to relate these measurements to volumes of these vessels obtained from casts. These data were com- This work was supported by U. S. Public Health Service Research Grant HE-09711 and by Training Grant HE-05736, from the National Heart and Lung Institute.Received June 29, 1970; accepted for publication October 2, 1970. pared to values of phasic coronary artery blood flow obtained in vivo. In addition, static pressure-volume measurements of an epicardial segment of the left coronary artery were obtained radiographically. MethodsSeventeen mongrel dogs weighing 12 to 30 kg were killed rapidly with pentobarbital. The left circumflex coronary artery and aortic blood flows in four of these dogs had previously been measured as described below. The hearts were excised and placed in a pan of saline at room temperature. The aortic and pulmonary arteries were cut away within 1 cm of the semilunar valves and the hearts weighed. The left coronary artery was dissected from its origin for 3 mm. A 5-cm segment of high pressure, noncompliant catheter having a flame-flanged distal tip was inserted into the coronary ostia and secured with a ligature. Care was taken not to disturb the remainder of the coronary vascular bed. This technique was used to cannulate the main left coro...

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“…Many studies using dogs have demonstrated that arterial pressure waveforms and diameter-change waveforms are similar [1,30]. We reported the similarity between carotid arterial pressure waveforms measured with a catheter-tipped micromanometer and carotid arterial diameter-change waveforms measured by echo tracking in humans [34].…”

Section: Measurements Of Pressure Waveformsmentioning

confidence: 58%

Clinical usefulness of wave intensity analysis

Sugawara

Niki

Ohte

et al. 2008

Med Biol Eng Comput

105

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Wave intensity (WI) is a hemodynamic index, which can evaluate the working condition of the heart interacting with the arterial system. It can be defined at any site in the circulatory system and provides a great deal of information. However, we need simultaneous measurements of blood pressure and velocity to obtain wave intensity, which has limited the clinical application of wave intensity, in spite of its potential. To expand the application of wave intensity in the clinical setting, we developed a real-time non-invasive measurement system for wave intensity based on a combined color Doppler and echo-tracking system. We measured carotid arterial WI in normal subjects and patients with various cardiovascular diseases. In the coronary artery disease group, the magnitude of the first peak of carotid arterial WI (W 1 ) increased with LV max. dP/dt (r = 0.74, P \ 0.001), and the amplitude of the second peak (W 2 ) decreased with an increase in the time constant of LV pressure decay (r = -0.77, P \ 0.001). In the dilated cardiomyopathy group, the values of W 1 were much lower than those in the normal group (P \ 0.0001). In the hypertrophic cardiomyopathy group, the values of W 2 were much smaller than those in the normal group (P \ 0.0001). In mitral regurgitation before surgery, W 2 decreased or disappeared, but after surgery W 2 appeared clearly. In the hypertension group, the magnitude of reflection from the head was considerably greater than that in the normal group (P \ 0.0001). We also evaluated hemodynamic effects of sublingual nitroglycerin in normal subjects. Nitroglycerin increased W 1 significantly (P \ 0.001). WI can be obtained non-invasively using an echo-Doppler system in the clinical setting. This method will increase the clinical usefulness of wave intensity.

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Relationship of radius to pressure along the aorta in living dogs

Cited by 144 publications

References 0 publications

Aortic Reservoir Pressure Corresponds to Cyclic Changes in Aortic Volume

Aortic Reservoir Pressure Corresponds to Cyclic Changes in Aortic Volume

Epicardial Coronary Artery Compliance in the Dog

Clinical usefulness of wave intensity analysis

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