Published ahead of print on May 11, 2006, doi:10.1164/rccm.200510-1634OC
Am. J. Respir. Crit. Care Med., Volume 174, Number 3, August 2006, 245-253
A more recent version of this article appeared on August 1, 2006
Submitted on October 18, 2005
Accepted on May 11, 2006
Regional Pulmonary Perfusion, Inflation and Ventilation Defects in Bronchoconstricted Asthmatics
R. Scott Harris1*, Tilo Winkler2, Nora Tgavalekos3, Guido Musch2, Marcos F Vidal Melo2, Tobias Schroeder2, Yuchiao Chang1, and Jose G Venegas2
1 Department of Medicine (Pulmonary and Critical Care Unit and General Medicine Unit), Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA,
2 Department of Anesthesia and Critical Care, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA,
3 Department of Anesthesia and Critical Care, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA; Department of Biomedical Engineering, Boston University, Boston, MA, USA
* To whom correspondence should be addressed. E-mail: rharris{at}partners.org.
Rationale: Bronchoconstriction in asthma leads to heterogeneous ventilation and the formation of large and contiguous ventilation defects in the lungs. However, the regional adaptations of pulmonary perfusion (Q) to such ventilation defects have not been well studied. Methods: We used positron emission tomography to assess the intrapulmonary kinetics of intravenously infused tracer Nitrogen-13 (13NN), and measured the regional distributions of ventilation and perfusion in 11 mild asthmatics. For each subject, the regional washout kinetics of 13NN before and during methacholine-induced bronchoconstriction were analyzed. Two regions of interest (ROI's) were defined: one over a spatially contiguous area of high tracer retention (TR) during bronchoconstriction and a second one, covering an area of similar size, showing minimal tracer retention (NR). Results: Both ROI's demonstrated heterogeneous washout kinetics, which could be described by a two-compartment model with fast and slow washout rates. We found a systematic reduction in regional Q to the TR ROI during bronchoconstriction and a variable and non-significant change in relative Q for NR regions. The reduction in regional Q was associated with an increase in regional gas content of the TR ROI, but its magnitude was greater than that anticipated solely by the change in regional lung inflation. Conclusion: During methacholine-induced bronchoconstriction, perfusion to ventilation defects is systematically reduced by a relative increase in regional pulmonary vascular resistance.
Key words: vasoconstriction, ventilation-perfusion ratio, pulmonary gas exchange, vascular resistance, emission-computed tomography
This article has been cited by other articles:
|
|
|
|
 
R. S. Harris, T. Winkler, G. Musch, M. F. Vidal Melo, T. Schroeder, N. Tgavalekos, and J. G. Venegas
The prone position results in smaller ventilation defects during bronchoconstriction in asthma
J Appl Physiol,
July 1, 2009;
107(1):
266 - 274.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
P. A. Munoz, F. P. Gomez, H. A. Manrique, J. Roca, J. A. Barbera, I. H. Young, S. D. Anderson, and R. Rodriguez-Roisin
Pulmonary gas exchange response to exercise- and mannitol-induced bronchoconstriction in mild asthma
J Appl Physiol,
November 1, 2008;
105(5):
1477 - 1485.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
D. C. M. Simoes, T. Vassilakopoulos, D. Toumpanakis, K. Petrochilou, C. Roussos, and A. Papapetropoulos
Angiopoietin-1 Protects against Airway Inflammation and Hyperreactivity in Asthma
Am. J. Respir. Crit. Care Med.,
June 15, 2008;
177(12):
1314 - 1321.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
R. H. Brown, D. W. Kaczka, K. Fallano, S. Chen, and W. Mitzner
Temporal variability in the responses of individual canine airways to methacholine
J Appl Physiol,
May 1, 2008;
104(5):
1381 - 1386.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. Haller, D. Hyde, N. Deliolanis, R. de Kleine, M. Niedre, and V. Ntziachristos
Visualization of pulmonary inflammation using noninvasive fluorescence molecular imaging
J Appl Physiol,
March 1, 2008;
104(3):
795 - 802.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. B. Dolovich and D. P. Schuster
Positron Emission Tomography and Computed Tomography versus Positron Emission Tomography Computed Tomography: Tools for Imaging the Lung
Proceedings of the ATS,
August 1, 2007;
4(4):
328 - 333.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. Venegas
Linking ventilation heterogeneity and airway hyperresponsiveness in asthma
Thorax,
August 1, 2007;
62(8):
653 - 654.
[Full Text]
[PDF]
|
|
|
|
|
|
|
N. T. Tgavalekos, G. Musch, R. S. Harris, M. F. Vidal Melo, T. Winkler, T. Schroeder, R. Callahan, K. R. Lutchen, and J. G. Venegas
Relationship between airway narrowing, patchy ventilation and lung mechanics in asthmatics
Eur. Respir. J.,
June 1, 2007;
29(6):
1174 - 1181.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
L. K. A. Lundblad, J. Thompson-Figueroa, G. B. Allen, L. Rinaldi, R. J. Norton, C. G. Irvin, and J. H. T. Bates
Airway Hyperresponsiveness in Allergically Inflamed Mice: The Role of Airway Closure
Am. J. Respir. Crit. Care Med.,
April 15, 2007;
175(8):
768 - 774.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
W. C. Moore and S. P. Peters
Update in Asthma 2006
Am. J. Respir. Crit. Care Med.,
April 1, 2007;
175(7):
649 - 654.
[Full Text]
[PDF]
|
|
|
|
|
|
|
R. S. Harris and D. P. Schuster
Visualizing lung function with positron emission tomography
J Appl Physiol,
January 1, 2007;
102(1):
448 - 458.
[Abstract]
[Full Text]
[PDF]
|
|
|
Copyright © 2006 American Thoracic Society
|
|
|
