Direct measurement of respiratory pleural pressure changes in normal man

Daly, Walter J.; Bondurant, Stuart

doi:10.1152/jappl.1963.18.3.513

Cited by 47 publications

(30 citation statements)

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“…Based on analysis of esophageal pressures, which correlate closely with pleural pressures, 33 Alderman et al 3 have demonstrated that although pleural pressure varied markedly between patients, it remained relatively constant during a state of held inspiration in individual patients. Thus, acute changes in pleural pressures would not be expected to account for the displacement of ventricular pressure-volume curves in specific individuals under the standardized respiratory conditions used in our study.…”

Section: Discussionmentioning

confidence: 99%

Influence of right ventricular hemodynamics on left ventricular diastolic pressure-volume relations in man.

Ludbrook¹,

Byrne²,

McKnight³

1979

Circulation

122

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SUMMARY To clarify the mechanism of displacement of the left ventricular diastolic pressure-volume function with alteration of loading conditions, the effects of nitroglycerin on pressure-volume relations in 13 patients were compared with those of amyl nitrite in 13 other patients during cardiac catheterization. After nitroglycerin, average systemic mean arterial pressure declined by 15.1 mm Hg (17%) and left ventricular enddiastolic pressure by 9.4 mm Hg (49%); right ventricular systolic and end-diastolic pressures fell 11.6 mm Hg (36%) and 5 mm Hg (41%), respectively. In all patients diastolic pressure-volume curves were significantly displaced downward and leftward. After amyl nitrite, average systemic mean arterial pressure fell 20.1 mm Hg (22%), but left ventricular end-diastolic pressure and right ventricular systolic and end-diastolic pressures were not significantly reduced. No significant displacement of diastolic pressure-volume curves occurred. Both the rate constant of the exponentially fit diastolic pressure-volume curve, and the rate of diastolic isovolumic relaxation (T) were unchanged after each drug. Thus downward displacement of diastolic pressure-volume functions after nitroglycerin appears to be dependent more upon reduction of right ventricular filling dynamics than coronary perfusion pressures. More favorable effects upon left ventricular function may be associated with reduction of both left ventricular filling pressures and systemic impedance (reflecting both "preload" and "afterload") than of systemic arterial pressures ("afterload") alone.

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Section: Discussionmentioning

confidence: 99%

Influence of right ventricular hemodynamics on left ventricular diastolic pressure-volume relations in man.

Ludbrook¹,

Byrne²,

McKnight³

1979

Circulation

122

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“…Despite dramatic symptomatic improvement after surgery for TF, cardiovascular performance at rest2 I or during exercise'-'O may remain below normal, and major complications such as trifascicular block,"1 complete heart block'2 13 and sudden death"' 14 may occur many years after surgical treatment.…”

Section: Circulation Diastolic Pressure-volume Curves In Man/aldermanmentioning

confidence: 99%

Acute hemodynamic interventions shift the diastolic pressure-volume curve in man.

Alderman¹,

Glantz²

1976

Circulation

199

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SUMMARY Frame-by-frame analysis of angiograms in 16 patients revealed that hemodynamic interventions are capable of producing substantial shifts in the diastolic pressure-volume curve. Angiotensin raises blood pressure and shifts the entire pressurevolume curve up, and nitroprusside lowers blood pressure and shifts the curve down. Indirect measurements of pleural pressure in seven patients (via esophageal pressure) showed that pleural pressure changes were too small to account for these shifts. Analyzing our results in terms of a theoretical pressure-volume equation previously validated in dog studies did not show the observed shifts to be the product of acute changes in the elasticity of the myocardium itself. This same analysis suggested that indirect changes in the external mechanical constraints acting on the left ventricle such as the right ventricular pressure, the pericardium, and perhaps viscoelastic effects related to changes in filling rate account for the pressure-volume curve shifts with intervention. The fact that one cannot in general relate a specific volume to a given pressure in the face of hemodynamic interventions calls into question the use of end-diastolic pressure interchangeably with end-iastolic fiber length when interpreting systolic events in terms of the Frank-Starling mechanism.DURING DIASTOLE the left ventricle fills passively, with its pressure and volume related by a curve which reflects both ventricular geometry and the elasticity or stiffness of cardiac muscle. One generally describes the passive elasticity of cardiac muscle by means of an exponential curve relating stress (force/area) to strain (percentage distension), with the muscle becoming stiffer as it is stretched.' The pressure-volume relationship has been assumed to be sufficiently constant over the short term to use left ventricular end-diastolic pressure interchangeably with enddiastolic circumferential fiber length in analyses of ventricular function based on the Frank-Starling mechanism. Chronic cardiac disease may cause the ventricle to dilate or hypertrophy, and these geometric changes distort its diastolic pressure-volume relationship.2 In addition, disease might change the passive elasticity of the myocardium itself, altering the pressure-volume relationship.3-6 In an acute situation, however, it is assumed that hemodynamic interventions simply move the ventricle up and down the same pressure-volume curve. This assumption is based on the fact that no agents are known to affect passive elasticity of normally oxygenated papillary muscle,' and the fact that the ventricle cannot acutely become hypertrophied.We explored this assumption of constancy of the pressure-volume relationship by measuring diastolic pressurevolume curves based on frame-by-frame analysis of angiograms in 16 patients. Acute interventions with nitroprusside and angiotensin usually noticeably shifted the diastolic pressure-volume curve. This result brings into question the assumption that the diastolic pressure-volume relationship remains constant ...

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“…This behavior has been attributed to the combined effect of (a) the "gradient" in pleural pressure down the lung and (b) the static volume-pressure relation of the lungs (4). A number of workers, using a variety of techniques, have demonstrated that there is a vertical "gradient" of pleural pressure, with the more negative values at the upper parts (5)(6)(7)(8). As a result, at resting lung volume the upper lung units are more expanded than those in the dependent zones (4).…”

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confidence: 99%

Regional distribution of pulmonary ventilation and perfusion in elderly subjects

Holland¹,

Milic–Emili²,

Macklem³

et al. 1968

J. Clin. Invest.

149

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A B S T R A C T Using radioactive xenon, we measured the regional distribution of pulmonary ventilation and blood flow in six normal men, whose ages ranged between 65 and 75 yr. The measurements were made in the standing position. The static volume-pressure relation of the lungs was also measured in five of the subjects. The results indicate that by comparison with normal young men: (a) Blood flow to the upper lung zones was increased, although it still remained predominant in the lower zones. (b) Ventilation distribution during a vital capacity inspiration was similar to that seen in young subjects. (c) In five of the six elderly subjects, however, the distribution of ventilation in the resting tidal volume range was not preferential to the lower zones as it was in young men. This was probably caused by airway closure in the lower lung zones. The elderly subjects thus exhibit during normal tidal volume breathing a ventilation distribution pattern similar to that observed in young subjects when breathing at low lung volumes, i.e., near residual volume. This difference is probably due to the combined effect of the loss in elastic recoil of the lungs observed in the elderly subjects and of a decreased resistance to collapse of the aged airways. These findings suggest that in the elderly subjects there is a significant regional ventilation-perfusion impairment during quiet breathing, which may explain in part Dr. Holland's present address is Cardio-Pulmonary Laboratory, Dalhousie University, Halifax, Canada. Address requests for reprints to Dr.

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Direct measurement of respiratory pleural pressure changes in normal man

Cited by 47 publications

References 0 publications

Influence of right ventricular hemodynamics on left ventricular diastolic pressure-volume relations in man.

Influence of right ventricular hemodynamics on left ventricular diastolic pressure-volume relations in man.

Acute hemodynamic interventions shift the diastolic pressure-volume curve in man.

Regional distribution of pulmonary ventilation and perfusion in elderly subjects

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